bims-cagime Biomed News
on Cancer, aging and metabolism
Issue of 2022‒01‒30
forty-four papers selected by
Kıvanç Görgülü
Technical University of Munich
  1. Degradation of nuclear components via different autophagy pathways.
  2. De novo expression of gastrokines in pancreatic precursor lesions impede the development of pancreatic cancer.
  3. Senescence induction dictates response to chemo- and immunotherapy in preclinical models of ovarian cancer.
  4. Understanding metabolic alterations and heterogeneity in cancer progression through validated immunodetection of key molecular components: a case of carbonic anhydrase IX.
  5. Metabolic regulation of ferroptosis in the tumor microenvironment.
  6. Time-dependent changes in autophagy, mitophagy and lysosomes in skeletal muscle during denervation-induced disuse.
  7. Bile acid- and ethanol-mediated activation of Orai1 damages pancreatic ductal secretion in acute pancreatitis.
  8. Cytosolic adaptation to mitochondria-induced proteostatic stress causes progressive muscle wasting.
  9. A systematic review examining the relationship between cytokines and cachexia in incurable cancer.
  10. Targeting the translational machinery to overcome apoptosis resistance in pancreatic cancer.
  11. Colon stroma mediates an inflammation-driven fibroblastic response controlling matrix remodeling and healing.
  12. scDART-seq reveals distinct m6A signatures and mRNA methylation heterogeneity in single cells.
  13. Targeting pancreatic cancer by TAK-981: a SUMOylation inhibitor that activates the immune system and blocks cancer cell cycle progression in a preclinical model.
  14. Disruption of pancreatic stellate cell myofibroblast phenotype promotes pancreatic tumor invasion.
  15. Metabolic signatures of regulation by phosphorylation and acetylation.
  16. Sex- and strain-specific effects of mitochondrial uncoupling on age-related metabolic diseases in high-fat diet-fed mice.
  17. A low amino acid environment promotes cell macropinocytosis through the YY1-FGD6 axis in Ras-mutant pancreatic ductal adenocarcinoma.
  18. Neoadjuvant Chemoradiotherapy Versus Upfront Surgery for Resectable and Borderline Resectable Pancreatic Cancer: Long-Term Results of the Dutch Randomized PREOPANC Trial.
  19. Volume growth in animal cells is cell cycle dependent and shows additive fluctuations.
  20. Targeting Wnt/Tenascin C-Mediated Cross Talk between Pancreatic Cancer Cells and Stellate Cells via activation of the Metastasis Suppressor NDRG1.
  21. Rethinking the bioavailability and cellular transport properties of S-adenosylmethionine.
  22. Targeting Extracellular Matrix Glycation to Attenuate Fibroblast Activation.
  23. Compartmentalization of telomeres through DNA-scaffolded phase separation.
  24. Sensory representation and detection mechanisms of gut osmolality change.
  25. Exercise medicine for cancer cachexia: targeted exercise to counteract mechanisms and treatment side effects.
  26. Whole-body and adipose tissue metabolic phenotype in cancer patients.
  27. Collective durotaxis of cohesive cell clusters on a stiffness gradient.
  28. Liquid biopsy reveals collateral tissue damage in cancer.
  29. Smad3 methylation by EZH2 promotes its activation and tumor metastasis.
  30. A computational modeling of invadopodia protrusion into an extracellular matrix fiber network.
  31. Regulation of reverse electron transfer at mitochondrial complex I by unconventional Notch action in cancer stem cells.
  32. Safety and efficacy of combination chemotherapy regimens in older adults with pancreatic ductal adenocarcinoma: a systematic review.
  33. Eukaryotic lipid droplets: metabolic hubs, and immune first responders.
  34. Weight Tracking as a Novel Prognostic Marker After Pancreatectomy.
  35. Multi-omic analysis reveals divergent molecular events in scarring and regenerative wound healing.
  36. Atg8-PE protein-based in vitro biochemical approaches to autophagy studies.
  37. Predicting pancreatic cancer in the UK Biobank cohort using polygenic risk scores and diabetes mellitus.
  38. The protein level of the tumor-promoting factor SET is regulated by cell density.
  39. A critique on the theory of homeostasis.
  40. Durable clinical benefit from PARP inhibition in a platinum-sensitive, BRCA2-mutated pancreatic cancer patient after earlier progression on placebo treatment on the POLO trial: a case report.
  41. Current challenges in metastasis research and future innovation for clinical translation.
  42. Lipid Droplets Embedded in a Model Cell Membrane Create a Phospholipid Diffusion Barrier.
  43. Targeting the Mitochondrial Permeability Transition Pore for Drug Discovery: Challenges and Opportunities.
  44. Nucleus segmentation: towards automated solutions.
  1. Trends Cell Biol. 2022 Jan 20. pii: S0962-8924(21)00267-1. [Epub ahead of print]
    Degradation of nuclear components via different autophagy pathways.
    Ziyang Li, Hitoshi Nakatogawa.
      Eukaryotic cells have evolved different modes of autophagy, including macroautophagy and microautophagy, to deliver their own components to lysosomes or vacuoles for degradation. While an increasing body of research has established that autophagy plays pivotal roles for the maintenance and regulation of various cellular constituents, recent studies have begun to reveal that parts of the nucleus, for example, nucleus-derived vesicles and nuclear proteins, also become targets of autophagic degradation in different physiological or pathological contexts, including nutrient deprivation, defective nuclear pore complex (NPC) assembly, DNA damage, cellular senescence, and oncogenic insults. Here, we overview our current knowledge on the mechanisms and physiological roles of these 'nucleophagy' pathways and discuss their possible interplays and remaining issues.
    Keywords:  autophagy; intracellular degradation; lysosomes; nuclear pore complexes; nucleus; vacuoles
    DOI:  https://doi.org/10.1016/j.tcb.2021.12.008
  2. Oncogene. 2022 Jan 26.
    De novo expression of gastrokines in pancreatic precursor lesions impede the development of pancreatic cancer.
    Sabrina Steiner, Gitta M Seleznik, Theresia Reding, Matea Stopic, Daniela Lenggenhager, Emiel Ten Buren, Dilmurodjon Eshmuminov, Katharina Endhardt, Catherine Hagedorn, Anna M Heidenblut, Anna Bratus-Neuenschwander, Jonas Grossmann, Christian Trachsel, Karolina S Jabbar, Stephan A Hahn, Johannes Vom Berg, Rolf Graf, Anurag Gupta.
      Molecular events occurring in stepwise progression from pre-malignant lesions (pancreatic intraepithelial neoplasia; PanIN) to the development of pancreatic ductal adenocarcinoma (PDAC) are poorly understood. Thus, characterization of early PanIN lesions may reveal markers that can help in diagnosing PDAC at an early stage and allow understanding the pathology of the disease. We performed the molecular and histological assessment of patient-derived PanINs, tumor tissues and pancreas from mouse models with PDAC (KC mice that harbor K-RAS mutation in pancreatic tissue), where we noted marked upregulation of gastrokine (GKN) proteins. To further understand the role of gastrokine proteins in PDAC development, GKN-deficient KC mice were developed by intercrossing gastrokine-deficient mice with KC mice. Panc-02 (pancreatic cancer cells of mouse origin) were genetically modified to express GKN1 for further in vitro and in vivo analysis. Our results show that gastrokine proteins were absent in healthy pancreas and invasive cancer, while its expression was prominent in low-grade PanINs. We could detect these proteins in pancreatic juice and serum of KC mice. Furthermore, accelerated PanIN and tumor development were noted in gastrokine deficient KC mice. Loss of gastrokine 1 protein delayed apoptosis during carcinogenesis leading to the development of desmoplastic stroma while loss of gastrokine 2 increased the proliferation rate in precursor lesions. In summary, we identified gastrokine proteins in early pancreatic precursor lesions, where gastrokine proteins delay pancreatic carcinogenesis.
    DOI:  https://doi.org/10.1038/s41388-022-02182-4
  3. Proc Natl Acad Sci U S A. 2022 Feb 01. pii: e2117754119. [Epub ahead of print]119(5):
    Senescence induction dictates response to chemo- and immunotherapy in preclinical models of ovarian cancer.
    Stella V Paffenholz, Camilla Salvagno, Yu-Jui Ho, Matthew Limjoco, Timour Baslan, Sha Tian, Amanda Kulick, Elisa de Stanchina, John E Wilkinson, Francisco M Barriga, Dmitriy Zamarin, Juan R Cubillos-Ruiz, Josef Leibold, Scott W Lowe.
      High-grade serous ovarian carcinoma (HGSOC) is a cancer with dismal prognosis due to the limited effectiveness of existing chemo- and immunotherapies. To elucidate mechanisms mediating sensitivity or resistance to these therapies, we developed a fast and flexible autochthonous mouse model based on somatic introduction of HGSOC-associated genetic alterations into the ovary of immunocompetent mice using tissue electroporation. Tumors arising in these mice recapitulate the metastatic patterns and histological, molecular, and treatment response features of the human disease. By leveraging these models, we show that the ability to undergo senescence underlies the clinically observed increase in sensitivity of homologous recombination (HR)-deficient HGSOC tumors to platinum-based chemotherapy. Further, cGas/STING-mediated activation of a restricted senescence-associated secretory phenotype (SASP) was sufficient to induce immune infiltration and sensitize HR-deficient tumors to immune checkpoint blockade. In sum, our study identifies senescence propensity as a predictor of therapy response and defines a limited SASP profile that appears sufficient to confer added vulnerability to concurrent immunotherapy and, more broadly, provides a blueprint for the implementation of electroporation-based mouse models to reveal mechanisms of oncogenesis and therapy response in HGSOC.
    Keywords:  cancer immunotherapy; mouse models; ovarian cancer; senescence
    DOI:  https://doi.org/10.1073/pnas.2117754119
  4. Cancer Metastasis Rev. 2022 Jan 26.
    Understanding metabolic alterations and heterogeneity in cancer progression through validated immunodetection of key molecular components: a case of carbonic anhydrase IX.
    Martina Takacova, Ivana Kajanova, Maria Kolarcikova, Jana Lapinova, Miriam Zatovicova, Silvia Pastorekova.
      Cancer metabolic heterogeneity develops in response to both intrinsic factors (mutations leading to activation of oncogenic pathways) and extrinsic factors (physiological and molecular signals from the extracellular milieu). Here we review causes and consequences of metabolic alterations in cancer cells with focus on hypoxia and acidosis, and with particular attention to carbonic anhydrase IX (CA IX). CA IX is a cancer-associated enzyme induced and activated by hypoxia in a broad range of tumor types, where it participates in pH regulation as well as in molecular mechanisms supporting cancer cells' invasion and metastasis. CA IX catalyzes reversible conversion of carbon dioxide to bicarbonate ion plus proton and cooperates with a spectrum of molecules transporting ions or metabolites across the plasma membrane. Thereby CA IX contributes to extracellular acidosis as well as to buffering intracellular pH, which is essential for cell survival, metabolic performance, and proliferation of cancer cells. Since CA IX expression pattern reflects gradients of oxygen, pH, and other intratumoral factors, we use it as a paradigm to discuss an impact of antibody quality and research material on investigating metabolic reprogramming of tumor tissue. Based on the validation, we propose the most reliable CA IX-specific antibodies and suggest conditions for faithful immunohistochemical analysis of molecules contributing to heterogeneity in cancer progression.
    Keywords:  Acidosis; Antibody validation; Carbonic anhydrase IX; Heterogeneity; Hypoxia; Metabolism
    DOI:  https://doi.org/10.1007/s10555-021-10011-5
  5. J Biol Chem. 2022 Jan 20. pii: S0021-9258(22)00057-6. [Epub ahead of print] 101617
    Metabolic regulation of ferroptosis in the tumor microenvironment.
    Nneka E Mbah, Costas A Lyssiotis.
      Ferroptosis is an iron-dependent, non-apoptotic form of regulated cell death triggered by impaired redox and antioxidant machinery and propagated by the accumulation of toxic lipid peroxides. A compendium of experimental studies suggest that ferroptosis is tumor-suppressive. Sensitivity or resistance to ferroptosis can be regulated by cell-autonomous and non-cell-autonomous metabolic mechanisms. This includes a role for ferroptosis that extends beyond the tumor cells themselves, mediated by components of the tumor microenvironment, including T cells and other immune cells. Herein, we review the intrinsic and extrinsic factors that promote the sensitivity of cancer cells to ferroptosis and conclude by describing approaches to harness the full utility of ferroptotic agents as therapeutic options for cancer therapy.
    Keywords:  cancer; ferroptosis; metabolism; tumor immunity; tumor microenvironment
    DOI:  https://doi.org/10.1016/j.jbc.2022.101617
  6. J Physiol. 2022 Jan 24.
    Time-dependent changes in autophagy, mitophagy and lysosomes in skeletal muscle during denervation-induced disuse.
    Matthew Triolo, Mikhaela Slavin, Neushaw Moradi, David A Hood.
      KEY POINTS: Denervation is an experimental model of peripheral neuropathies as well as muscle disuse, and it helps us understand some aspects of the sarcopenia of aging. Muscle disuse is associated with reduced mitochondrial content and function, leading to metabolic impairments within the tissue. Although the processes that regulate mitochondrial biogenesis are understood, those that govern mitochondrial breakdown (i.e., mitophagy) are not well characterized in this context. Autophagy and mitophagy flux, measured up to the point of the lysosome (pre-lysosomal flux rates), were increased in the early stages of denervation, along with mitochondrial dysfunction, but were reduced at later time points when the degree of muscle atrophy was highest. Denervation led to progressive increases in lysosomal proteins to accommodate mitophagy flux, yet evidence for lysosomal impairment at later stages may limit the removal of dysfunctional mitochondria, stimulate reactive oxygen species signaling, and reduce muscle health as denervation time progresses.ABSTRACT: Deficits in skeletal muscle mitochondrial content and quality are observed following denervation-atrophy. This is due to alterations in the biogenesis of new mitochondria as well as their degradation via mitophagy. The regulation of autophagy and mitophagy over the course of denervation (Den) remains unknown. Further, the time-dependent changes in lysosome content, the end-stage organelle for mitophagy, remains unexplored. Here, we studied autophagic as well as mitophagic pre-lysosomal flux in subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria from rat muscle subjected to Den for 1, 3, or 7 days. We also assessed flux at 1-day post-denervation in transgenic mt-keima mice. Markers of mitochondrial content were reduced at 7 days following Den, and Den further resulted in rapid decrements in mitochondrial respiration, along with increased ROS emission. Pre-lysosomal autophagy flux was upregulated at 1- and 3-days post-Den but was reduced compared to time-matched sham-operated controls at 7-days post-Den. Similarly, pre-lysosomal mitophagy flux was enhanced in SS mitochondria as early as 1- and 3-days of Den but decreased in both SS and IMF subfractions following 7 days of Den. Lysosome protein content and transcriptional regulators TFEB and TFE3 were progressively enhanced with Den, an adaptation designed to enhance autophagic capacity. However, evidence for lysosome dysfunction was apparent by 7 days, which may limit degradation capacity. This may contribute to an inability to clear dysfunctional mitochondria and increased ROS signaling, thereby accelerating muscle atrophy. Thus, therapeutic targeting of lysosome function may help to maintain autophagy and muscle health during conditions of muscle disuse or denervation. Abstract figure legend This study investigates the temporal regulation of the autophagy-lysosome system in rat skeletal muscle following neuromuscular denervation (Den) with a focus on mitochondrial decay through mitophagy. We show that mitochondrial dysfunction is time-dependant, with elevations at 3-days post-Den and further at 7 days, preceding decrements in mitochondrial protein content. Deficits in mitochondrial content may be explained by prior elevations in mitophagy as early as 1- and 3-days post-Den, but these elevations were bi-phasic, returning to lower values by 7-days post-Den. To meet the demands of increased autophagy, lysosome protein content was progressively upregulated with 3- and 7-day of Den, but evidence of lysosome dysfunction was evident, and this could impede the removal of poor-quality mitochondria. Overall, these changes in the autophagy-lysosome system following neuromuscular denervation and provide insight into the processes that contribute to Den-induced muscle atrophy. Representative graphs are Den/Sham, with the dotted line representing sham-operated control values. This article is protected by copyright. All rights reserved.
    Keywords:  TFEB; atrophy; lysosome dysfunction; mitochondrial dysfunction; reactive oxygen species
    DOI:  https://doi.org/10.1113/JP282173
  7. J Physiol. 2022 Jan 26.
    Bile acid- and ethanol-mediated activation of Orai1 damages pancreatic ductal secretion in acute pancreatitis.
    Petra Pallagi, Marietta Görög, Noémi Papp, Tamara Madácsy, Árpád Varga, Tim Crul, Viktória Szabó, Melinda Molnár, Krisztina Dudás, Anna Grassalkovich, Edit Szederkényi, György Lázár, Viktória Venglovecz, Péter Hegyi, József Maléth.
      KEY POINTS: Sustained intracellular Ca2+ overload in pancreatic acinar and ductal cells is a hallmark of biliary and alcohol-induced acute pancreatitis, which leads to impaired ductal ion and fluid secretion. Orai1 is a plasma membrane Ca2+ channel that mediates extracellular Ca2+ influx upon endoplasmic reticulum Ca2+ depletion. Our results showed that Orai1 is expressed on the luminal plasma membrane of the ductal cells and selective Orai1 inhibition impaired Stim1-dependent extracellular Ca2+ influx evoked by bile acids or ethanol combined with non-oxidative ethanol metabolites. The prevention of sustained extracellular Ca2+ influx protected ductal cell secretory functions in in vitro models and maintained exocrine pancreatic secretion in in vivo AP models. Orai1 inhibition prevents the bile acid-, and alcohol-induced damage of the pancreatic ductal secretion and holds the potential of improving the outcome of acute pancreatitis.ABSTRACT: Regardless of its etiology, sustained intracellular Ca2+ overload is a well-known hallmark of acute pancreatitis (AP). Toxic Ca2+ elevation induces pancreatic ductal cell damage characterized by impaired ion- and fluid secretion -essential to wash out the protein-rich fluid secreted by acinar cells while maintaining the alkaline intra-ductal pH under physiological conditions- and mitochondrial dysfunction. While prevention of ductal cell injury decreases the severity of AP, no specific drug target has yet been identified in the ductal cells. Although Orai1 -a store operated Ca2+ influx channel- is known to contribute to sustained Ca2+ overload in acinar cells, details concerning its expression and function in ductal cells are currently lacking. In this study, we demonstrate that functionally active Orai1 channels reside dominantly in the apical plasma membrane of pancreatic ductal cells. Selective CM5480-mediated Orai1 inhibition impairs Stim1-dependent extracellular Ca2+ influx evoked by bile acids or ethanol combined with non-oxidative ethanol metabolites. Furthermore, prevention of sustained extracellular Ca2+ influx protects ductal cell secretory function in vitro and decrease pancreatic ductal cell death. Finally, Orai1-inhibition partially restores and maintains proper exocrine pancreatic secretion in in vivo AP models. In conclusion, our results indicate that Orai1 inhibition prevents AP-related ductal cell function impairment and holds the potential of improving disease outcome. Abstract figure legend  This article is protected by copyright. All rights reserved.
    Keywords:  Ca2+ signaling; Orai1 channel; acute pancreatitis; bile acid; epithelial ion transport; ethanol
    DOI:  https://doi.org/10.1113/JP282203
  8. iScience. 2022 Jan 21. 25(1): 103715
    Cytosolic adaptation to mitochondria-induced proteostatic stress causes progressive muscle wasting.
    Xiaowen Wang, Frank A Middleton, Rabi Tawil, Xin Jie Chen.
      Mitochondrial dysfunction causes muscle wasting in many diseases and probably also during aging. The underlying mechanism is poorly understood. We generated transgenic mice with unbalanced mitochondrial protein loading and import, by moderately overexpressing the nuclear-encoded adenine nucleotide translocase, Ant1. We found that these mice progressively lose skeletal muscle. Ant1-overloading reduces mitochondrial respiration. Interestingly, it also induces small heat shock proteins and aggresome-like structures in the cytosol, suggesting increased proteostatic burden due to accumulation of unimported mitochondrial preproteins. The transcriptome of Ant1-transgenic muscles is drastically remodeled to counteract proteostatic stress, by repressing protein synthesis and promoting proteasomal function, autophagy, and lysosomal amplification. These proteostatic adaptations collectively reduce protein content thereby reducing myofiber size and muscle mass. Thus, muscle wasting can occur as a trade-off of adaptation to mitochondria-induced proteostatic stress. This finding could have implications for understanding the mechanism of muscle wasting, especially in diseases associated with Ant1 overexpression, including facioscapulohumeral dystrophy.
    Keywords:  Biological sciences; Cell biology; Cellular physiology; Functional aspects of cell biology
    DOI:  https://doi.org/10.1016/j.isci.2021.103715
  9. J Cachexia Sarcopenia Muscle. 2022 Jan 25.
    A systematic review examining the relationship between cytokines and cachexia in incurable cancer.
    Caledonian Cachexia Collaborative
      Cancer cachexia is an unmet clinical need that affects more than 50% of patients with cancer. The systemic inflammatory response, which is mediated by a network of cytokines, has an established role in the genesis and maintenance of cancer as well as in cachexia; yet, the specific role of the cytokine milieu in cachexia requires elucidation. This systematic review aims to examine the relationship between cytokines and the cachexia syndrome in patients with incurable cancer. The databases MEDLINE, EMBASE, CINAHL, CENTRAL, PsycINFO, and Web of Science were searched for studies published between 01/01/2004 and 06/01/2020. Included studies measured cytokines and their relationship with cachexia and related symptoms/signs in adults with incurable cancer. After title screening (n = 5202), the abstracts (n = 1264) and the full-text studies (n = 322) were reviewed independently by two authors. The quality assessment of the selected papers was conducted using the modified Downs and Black checklist. Overall, 1277 patients with incurable cancer and 155 healthy controls were analysed in the 17 eligible studies. The mean age of the patients was 64 ± 15 (mean ± standard deviation). Only 34% of included participants were female. The included studies were assessed as moderate-quality to high-quality evidence (mean quality score: 7.8; range: 5-10). A total of 31 cytokines were examined in this review, of which interleukin-6 (IL-6, 14 studies) and tumour necrosis factor-α (TNF-α, 12 studies) were the most common. The definitions of cachexia and the weight-loss thresholds were highly variable across studies. Although the data could not be meta-analysed due to the high degree of methodological heterogeneity, the findings were discussed in a systematic manner. IL-6, TNF-α, and IL-8 were greater in cachectic patients compared with healthy individuals. Also, IL-6 levels were higher in cachectic participants as opposed to non-cachectic patients. Leptin, interferon-γ, IL-1β, IL-10, adiponectin, and ghrelin did not demonstrate any significant difference between groups when individuals with cancer cachexia were compared against non-cachectic patients or healthy participants. These findings suggest that a network of cytokines, commonly IL-6, TNF-α, and IL-8, are associated with the development of cachexia. Yet, this relationship is not proven to be causative and future studies should opt for longitudinal designs with consistent methodological approaches, as well as adequate techniques for analysing and reporting the results.
    Keywords:  Cachexia; Cancer; Cytokines; Weight loss
    DOI:  https://doi.org/10.1002/jcsm.12912
  10. Transl Oncol. 2022 Jan 22. pii: S1936-5233(22)00005-5. [Epub ahead of print]17 101343
    Targeting the translational machinery to overcome apoptosis resistance in pancreatic cancer.
    Matthias Wirth.
      
    Keywords:  Apoptosis; MCL1; MYC; Pancreatic cancer; Resistance
    DOI:  https://doi.org/10.1016/j.tranon.2022.101343
  11. PLoS Biol. 2022 Jan 27. 20(1): e3001532
    Colon stroma mediates an inflammation-driven fibroblastic response controlling matrix remodeling and healing.
    Guadalupe J Jasso, Alok Jaiswal, Mukund Varma, Tyler Laszewski, Angelo Grauel, Abdifatah Omar, Nilsa Silva, Glenn Dranoff, Jeffrey A Porter, Keith Mansfield, Viviana Cremasco, Aviv Regev, Ramnik J Xavier, Daniel B Graham.
      Chronic inflammation is often associated with the development of tissue fibrosis, but how mesenchymal cell responses dictate pathological fibrosis versus resolution and healing remains unclear. Defining stromal heterogeneity and identifying molecular circuits driving extracellular matrix deposition and remodeling stands to illuminate the relationship between inflammation, fibrosis, and healing. We performed single-cell RNA-sequencing of colon-derived stromal cells and identified distinct classes of fibroblasts with gene signatures that are differentially regulated by chronic inflammation, including IL-11-producing inflammatory fibroblasts. We further identify a transcriptional program associated with trans-differentiation of mucosa-associated fibroblasts and define a functional gene signature associated with matrix deposition and remodeling in the inflamed colon. Our analysis supports a critical role for the metalloprotease Adamdec1 at the interface between tissue remodeling and healing during colitis, demonstrating its requirement for colon epithelial integrity. These findings provide mechanistic insight into how inflammation perturbs stromal cell behaviors to drive fibroblastic responses controlling mucosal matrix remodeling and healing.
    DOI:  https://doi.org/10.1371/journal.pbio.3001532
  12. Mol Cell. 2022 Jan 17. pii: S1097-2765(21)01143-6. [Epub ahead of print]
    scDART-seq reveals distinct m6A signatures and mRNA methylation heterogeneity in single cells.
    Matthew Tegowski, Mathieu N Flamand, Kate D Meyer.
      N6-methyladenosine (m6A) is an abundant RNA modification that plays critical roles in RNA regulation and cellular function. Global m6A profiling has revealed important aspects of m6A distribution and function, but to date such studies have been restricted to large populations of cells. Here, we develop a method to identify m6A sites transcriptome-wide in single cells. We uncover surprising heterogeneity in the presence and abundance of m6A sites across individual cells and identify differentially methylated mRNAs across the cell cycle. Additionally, we show that cellular subpopulations can be distinguished based on their RNA methylation signatures, independent from gene expression. These studies reveal fundamental features of m6A that have been missed by m6A profiling of bulk cells and suggest the presence of cell-intrinsic mechanisms for m6A deposition.
    DOI:  https://doi.org/10.1016/j.molcel.2021.12.038
  13. Gut. 2022 Jan 24. pii: gutjnl-2021-324834. [Epub ahead of print]
    Targeting pancreatic cancer by TAK-981: a SUMOylation inhibitor that activates the immune system and blocks cancer cell cycle progression in a preclinical model.
    Sumit Kumar, Mark J A Schoonderwoerd, Jessie S Kroonen, Ilona J de Graaf, Marjolein Sluijter, Dina Ruano, Román González-Prieto, Matty Verlaan-de Vries, Jasper Rip, Ramon Arens, Noel F C C de Miranda, Lukas J A C Hawinkels, Thorbald van Hall, Alfred C O Vertegaal.
      OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) has the characteristics of high-density desmoplastic stroma, a distinctive immunosuppressive microenvironment and is profoundly resistant to all forms of chemotherapy and immunotherapy, leading to a 5-year survival rate of 9%. Our study aims to add novel small molecule therapeutics for the treatment of PDAC.DESIGN: We have studied whether TAK-981, a novel highly selective and potent small molecule inhibitor of the small ubiquitin like modifier (SUMO) activating enzyme E1 could be used to treat a preclinical syngeneic PDAC mouse model and we have studied the mode of action of TAK-981.
    RESULTS: We found that SUMOylation, a reversible post-translational modification required for cell cycle progression, is increased in PDAC patient samples compared with normal pancreatic tissue. TAK-981 decreased SUMOylation in PDAC cells at the nanomolar range, thereby causing a G2/M cell cycle arrest, mitotic failure and chromosomal segregation defects. TAK-981 efficiently limited tumour burden in the KPC3 syngeneic mouse model without evidence of systemic toxicity. In vivo treatment with TAK-981 enhanced the proportions of activated CD8 T cells and natural killer (NK) cells but transiently decreased B cell numbers in tumour, peripheral blood, spleen and lymph nodes. Single cell RNA sequencing revealed activation of the interferon response on TAK-981 treatment in lymphocytes including T, B and NK cells. TAK-981 treatment of CD8 T cells ex vivo induced activation of STAT1 and interferon target genes.
    CONCLUSION: Our findings indicate that pharmacological inhibition of the SUMO pathway represents a potential strategy to target PDAC via a dual mechanism: inhibiting cancer cell cycle progression and activating anti-tumour immunity by inducing interferon signalling.
    Keywords:  T lymphocytes; immune response; interferon; pancreatic cancer; signal transduction
    DOI:  https://doi.org/10.1136/gutjnl-2021-324834
  14. Cell Rep. 2022 Jan 25. pii: S2211-1247(21)01731-9. [Epub ahead of print]38(4): 110227
    Disruption of pancreatic stellate cell myofibroblast phenotype promotes pancreatic tumor invasion.
    Elizabeth R Murray, Shinelle Menezes, Jack C Henry, Josie L Williams, Lorena Alba-Castellón, Priththivika Baskaran, Ivan Quétier, Ami Desai, Jacqueline J T Marshall, Ian Rosewell, Marianthi Tatari, Vinothini Rajeeve, Faraz Khan, Jun Wang, Panoraia Kotantaki, Eleanor J Tyler, Namrata Singh, Claire S Reader, Edward P Carter, Kairbaan Hodivala-Dilke, Richard P Grose, Hemant M Kocher, Nuria Gavara, Oliver Pearce, Pedro Cutillas, John F Marshall, Angus J M Cameron.
      In pancreatic ductal adenocarcinoma (PDAC), differentiation of pancreatic stellate cells (PSCs) into myofibroblast-like cancer-associated fibroblasts (CAFs) can both promote and suppress tumor progression. Here, we show that the Rho effector protein kinase N2 (PKN2) is critical for PSC myofibroblast differentiation. Loss of PKN2 is associated with reduced PSC proliferation, contractility, and alpha-smooth muscle actin (α-SMA) stress fibers. In spheroid co-cultures with PDAC cells, loss of PKN2 prevents PSC invasion but, counter-intuitively, promotes invasive cancer cell outgrowth. PKN2 deletion induces a myofibroblast to inflammatory CAF switch in the PSC matrisome signature both in vitro and in vivo. Further, deletion of PKN2 in the pancreatic stroma induces more locally invasive, orthotopic pancreatic tumors. Finally, we demonstrate that a PKN2KO matrisome signature predicts poor outcome in pancreatic and other solid human cancers. Our data indicate that suppressing PSC myofibroblast function can limit important stromal tumor-suppressive mechanisms, while promoting a switch to a cancer-supporting CAF phenotype.
    Keywords:  CAF; PKN2; Rho GTPases; cancer-associated fibroblasts; matrisome; pancreatic cancer; protein kinase N2; tumour microenvironment
    DOI:  https://doi.org/10.1016/j.celrep.2021.110227
  15. iScience. 2022 Jan 21. 25(1): 103730
    Metabolic signatures of regulation by phosphorylation and acetylation.
    Kirk Smith, Fangzhou Shen, Ho Joon Lee, Sriram Chandrasekaran.
      Acetylation and phosphorylation are highly conserved posttranslational modifications (PTMs) that regulate cellular metabolism, yet how metabolic control is shared between these PTMs is unknown. Here we analyze transcriptome, proteome, acetylome, and phosphoproteome datasets in E. coli, S. cerevisiae, and mammalian cells across diverse conditions using CAROM, a new approach that uses genome-scale metabolic networks and machine learning to classify targets of PTMs. We built a single machine learning model that predicted targets of each PTM in a condition across all three organisms based on reaction attributes (AUC>0.8). Our model predicted phosphorylated enzymes during a mammalian cell-cycle, which we validate using phosphoproteomics. Interpreting the machine learning model using game theory uncovered enzyme properties including network connectivity, essentiality, and condition-specific factors such as maximum flux that differentiate targets of phosphorylation from acetylation. The conserved and predictable partitioning of metabolic regulation identified here between these PTMs may enable rational rewiring of regulatory circuits.
    Keywords:  Metabolic flux analysis; Omics; Systems biology
    DOI:  https://doi.org/10.1016/j.isci.2021.103730
  16. Aging Cell. 2022 Jan 28. e13539
    Sex- and strain-specific effects of mitochondrial uncoupling on age-related metabolic diseases in high-fat diet-fed mice.
    Leigh Goedeke, Kelsey N Murt, Andrea Di Francesco, João Paulo Camporez, Ali R Nasiri, Yongliang Wang, Xian-Man Zhang, Gary W Cline, Rafael de Cabo, Gerald I Shulman.
      Mild uncoupling of oxidative phosphorylation is an intrinsic property of all mitochondria and may have evolved to protect cells against the production of damaging reactive oxygen species. Therefore, compounds that enhance mitochondrial uncoupling are potentially attractive anti-aging therapies; however, chronic ingestion is associated with a number of unwanted side effects. We have previously developed a controlled-release mitochondrial protonophore (CRMP) that is functionally liver-directed and promotes oxidation of hepatic triglycerides by causing a subtle sustained increase in hepatic mitochondrial inefficiency. Here, we sought to leverage the higher therapeutic index of CRMP to test whether mild mitochondrial uncoupling in a liver-directed fashion could reduce oxidative damage and improve age-related metabolic disease and lifespan in diet-induced obese mice. Oral administration of CRMP (20 mg/[kg-day] × 4 weeks) reduced hepatic lipid content, protein kinase C epsilon activation, and hepatic insulin resistance in aged (74-week-old) high-fat diet (HFD)-fed C57BL/6J male mice, independently of changes in body weight, whole-body energy expenditure, food intake, or markers of hepatic mitochondrial biogenesis. CRMP treatment was also associated with a significant reduction in hepatic lipid peroxidation, protein carbonylation, and inflammation. Importantly, long-term (49 weeks) hepatic mitochondrial uncoupling initiated late in life (94-104 weeks), in conjugation with HFD feeding, protected mice against neoplastic disorders, including hepatocellular carcinoma (HCC), in a strain and sex-specific manner. Taken together, these studies illustrate the complex variation of aging and provide important proof-of-concept data to support further studies investigating the use of liver-directed mitochondrial uncouplers to promote healthy aging in humans.
    Keywords:  2,4-dinitrophenol; anti-aging; hepatic steatosis; insulin sensitivity; longevity; mitochondrial uncoupling
    DOI:  https://doi.org/10.1111/acel.13539
  17. Oncogene. 2022 Jan 27.
    A low amino acid environment promotes cell macropinocytosis through the YY1-FGD6 axis in Ras-mutant pancreatic ductal adenocarcinoma.
    Yi-Fan Zhang, Qing Li, Pei-Qi Huang, Tong Su, Shu-Heng Jiang, Li-Peng Hu, Xue-Li Zhang, Yue Sun, Hong Pan, Xiao-Mei Yang, Jun Li, Yan-Zhi Gai, Lei Zhu, Lin-Li Yao, Dong-Xue Li, Yong-Wei Sun, Zhi-Gang Zhang, De-Jun Liu, Yan-Li Zhang, Hui-Zhen Nie.
      Pancreatic ductal adenocarcinoma (PDAC), cancer with a high mortality rate and the highest rate of KRAS mutation, reportedly internalizes proteins via macropinocytosis to adapt to low amino acid levels in the tumor microenvironment. Here, we aimed to identify a key regulator of macropinocytosis for the survival of tumor cells in a low amino acid environment in PDAC. FYVE, RhoGEF, and PH domain-containing protein 6 (FGD6) were identified as key regulators of macropinocytosis. FGD6 promoted PDAC cell proliferation, macropinocytosis, and tumor growth both in vitro and in vivo. The macropinocytosis level was decreased with FGD6 knockdown in PDAC cell lines. Moreover, FGD6 promoted macropinocytosis by participating in the trans-Golgi network and enhancing the membrane localization of growth factor receptors, especially the TGF-beta receptor. TGF-beta enhanced macropinocytosis in PDAC cells. Additionally, YAP nuclear translocation induced by a low amino acid tumor environment initiated FGD6 expression by coactivation with YY1. Clinical data analysis based on TCGA and GEO datasets showed that FGD6 expression was upregulated in PDAC tissue, and high FGD6 expression was correlated with poor prognosis in patients with PDAC. In tumor tissue from KrasG12D/+/Trp53R172H/-/Pdx1-Cre (KPC) mice, FGD6 expression escalated during PDAC development. Our results uncover a previously unappreciated mechanism of macropinocytosis in PDAC. Strategies to target FGD6 and growth factors membrane localization might be developed for the treatment of PDAC.
    DOI:  https://doi.org/10.1038/s41388-021-02159-9
  18. J Clin Oncol. 2022 Jan 27. JCO2102233
    Neoadjuvant Chemoradiotherapy Versus Upfront Surgery for Resectable and Borderline Resectable Pancreatic Cancer: Long-Term Results of the Dutch Randomized PREOPANC Trial.
    Dutch Pancreatic Cancer Group
      PURPOSE: The benefit of neoadjuvant chemoradiotherapy in resectable and borderline resectable pancreatic cancer remains controversial. Initial results of the PREOPANC trial failed to demonstrate a statistically significant overall survival (OS) benefit. The long-term results are reported.METHODS: In this multicenter, phase III trial, patients with resectable and borderline resectable pancreatic cancer were randomly assigned (1:1) to neoadjuvant chemoradiotherapy or upfront surgery in 16 Dutch centers. Neoadjuvant chemoradiotherapy consisted of three cycles of gemcitabine combined with 36 Gy radiotherapy in 15 fractions during the second cycle. After restaging, patients underwent surgery followed by four cycles of adjuvant gemcitabine. Patients in the upfront surgery group underwent surgery followed by six cycles of adjuvant gemcitabine. The primary outcome was OS by intention-to-treat. No safety data were collected beyond the initial report of the trial.
    RESULTS: Between April 24, 2013, and July 25, 2017, 246 eligible patients were randomly assigned to neoadjuvant chemoradiotherapy (n = 119) and upfront surgery (n = 127). At a median follow-up of 59 months, the OS was better in the neoadjuvant chemoradiotherapy group than in the upfront surgery group (hazard ratio, 0.73; 95% CI, 0.56 to 0.96; P = .025). Although the difference in median survival was only 1.4 months (15.7 months v 14.3 months), the 5-year OS rate was 20.5% (95% CI, 14.2 to 29.8) with neoadjuvant chemoradiotherapy and 6.5% (95% CI, 3.1 to 13.7) with upfront surgery. The effect of neoadjuvant chemoradiotherapy was consistent across the prespecified subgroups, including resectable and borderline resectable pancreatic cancer.
    CONCLUSION: Neoadjuvant gemcitabine-based chemoradiotherapy followed by surgery and adjuvant gemcitabine improves OS compared with upfront surgery and adjuvant gemcitabine in resectable and borderline resectable pancreatic cancer.
    DOI:  https://doi.org/10.1200/JCO.21.02233
  19. Elife. 2022 Jan 28. pii: e70816. [Epub ahead of print]11
    Volume growth in animal cells is cell cycle dependent and shows additive fluctuations.
    Clotilde Cadart, Larisa Venkova, Matthieu Piel, Marco Cosentino Lagomarsino.
      The way proliferating animal cells coordinate the growth of their mass, volume, and other relevant size parameters is a long-standing question in biology. Studies focusing on cell mass have identified patterns of mass growth as a function of time and cell cycle phase, but little is known about volume growth. To address this question, we improved our fluorescence exclusion method of volume measurement (FXm) and obtained 1700 single-cell volume growth trajectories of HeLa cells. We find that, during most of the cell cycle, volume growth is close to exponential and proceeds at a higher rate in S-G2 than in G1. Comparing the data with a mathematical model, we establish that the cell-to-cell variability in volume growth arises from constant-amplitude fluctuations in volume steps rather than fluctuations of the underlying specific growth rate. We hypothesize that such 'additive noise' could emerge from the processes that regulate volume adaptation to biophysical cues, such as tension or osmotic pressure.
    Keywords:  cell biology; cell cycle; cell growth; human; noise; physics of living systems; volume
    DOI:  https://doi.org/10.7554/eLife.70816
  20. J Biol Chem. 2022 Jan 19. pii: S0021-9258(22)00048-5. [Epub ahead of print] 101608
    Targeting Wnt/Tenascin C-Mediated Cross Talk between Pancreatic Cancer Cells and Stellate Cells via activation of the Metastasis Suppressor NDRG1.
    Bekesho Geleta, Faten S Tout, Syer Choon Lim, Sumit Sahni, Patric J Jansson, Minoti V Apte, Des R Richardson, Žaklina Kovačević.
      A major barrier to successful pancreatic cancer (PC) treatment is the surrounding stroma, which secretes growth factors/cytokines that promote PC progression. Wnt and tenascin C (TnC) are key ligands secreted by stromal pancreatic stellate cells (PSCs) that then act on PC cells in a paracrine manner to activate the oncogenic β-catenin and YAP/TAZ signaling pathways. Therefore, therapies targeting oncogenic Wnt/TnC cross talk between PC cells and PSCs constitute a promising new therapeutic approach for PC treatment. The metastasis suppressor N-myc downstream-regulated gene 1 (NDRG1) inhibits tumor progression and metastasis in numerous cancers, including PC. We demonstrate herein that targeting NDRG1 using the clinically trialed anti-cancer agent di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) inhibited Wnt/TnC-mediated interactions between PC cells and the surrounding PSCs. Mechanistically, NDRG1 and DpC markedly inhibit secretion of Wnt3a and TnC by PSCs, while also attenuating Wnt/β-catenin and YAP/TAZ activation and downstream signaling in PC cells. This anti-oncogenic activity was mediated by direct inhibition of β-catenin and YAP/TAZ nuclear localization and by increasing the Wnt inhibitor, DKK1. Expression of NDRG1 also inhibited transforming growth factor (TGF)-β secretion by PC cells, a key mechanism by which PC cells activate PSCs. Using an in vivo orthotopic PC mouse model, we show DpC downregulated β-catenin, TnC, and YAP/TAZ, while potently increasing NDRG1 expression in PC tumors. We conclude NDRG1 and DpC inhibit Wnt/TnC-mediated interactions between PC cells and PSCs. These results further illuminate the anti-oncogenic mechanism of NDRG1 and the potential of targeting this metastasis suppressor to overcome the oncogenic effects of the PC-PSC interaction.
    Keywords:  NDRG1; Pancreatic cancer; TnC; Wnt; tumor microenvironment
    DOI:  https://doi.org/10.1016/j.jbc.2022.101608
  21. Cell Stress. 2022 Jan;6(1): 1-5
    Rethinking the bioavailability and cellular transport properties of S-adenosylmethionine.
    Yudong Sun, Jason W Locasale.
      S-adenosylmethionine (SAM) is a versatile metabolite that participates in a wide range of reactions such as methylation and transsulfuration. These capabilities allow SAM to influence cellular processes such as gene expression and redox balancing. The importance of SAM is highlighted by its widespread usage as an over-the-counter nutrient supplement and as an experimental reagent in molecular biology. The bioavailability and cellular transport properties of SAM, however, are often overlooked under these contexts, putting limits on SAM's therapeutic potential and complicating the interpretation of experimental results. In this article, we examined the chemical stability and cellular permeability of SAM, proposed a schematic for indirect SAM transport across the mammalian plasma membrane, and lastly discussed the implications arising from such transport schematic.
    Keywords:  S-adenosyl-methionine; SAM; metabolism; methionine
    DOI:  https://doi.org/10.15698/cst2022.01.261
  22. Acta Biomater. 2022 Jan 23. pii: S1742-7061(22)00049-6. [Epub ahead of print]
    Targeting Extracellular Matrix Glycation to Attenuate Fibroblast Activation.
    Minjeong Jang, Seung Won Oh, Yunji Lee, Jin Young Kim, Eun Sun Ji, Pilnam Kim.
      The extracellular matrix (ECM) of the tumor microenvironment undergoes constant remodeling that alters its biochemical and mechano-physical properties. Non-enzymatic glycation can induce the formation of advanced glycation end-products (AGEs), which may cause abnormal ECM turnover with excessively cross-linked collagen fibers. However, the subsequent effects of AGE-mediated matrix remodeling on the characteristics of stromal cells in tumor microenvironments remain unclear. Here, we demonstrate that AGEs accumulated in the ECM alter the fibroblast phenotype within a three-dimensional collagen matrix. Both the AGE interaction with its receptor (RAGE) and integrin-mediated mechanotransduction signaling were up-regulated in glycated collagen matrix, leading to fibroblast activation to acquire a cancer-associated fibroblast (CAF)-like phenotype. These effects were blocked with neutralizing antibodies against RAGE or the inhibition of focal adhesion (FA) signaling. An AGE cross-link breaker, phenyl-4,5-dimethylthiazolium bromide (ALT 711), also reduced the transformation of fibroblasts into the CAF-like phenotype because of its dual inhibitory role in the AGE-modified matrix. Apart from targeting the AGE-RAGE interaction directly, the decreased matrix stiffness attenuated fibroblast activation by inhibiting the downstream cellular response to matrix stiffness. Our results suggest that indirect/direct targeting of accumulated AGEs in the ECM has potential for targeting the tumor stroma to improve cancer therapy. STATEMENT OF SIGNIFICANCE: : Advanced glycated end-products (AGEs)-modified extracellular matrix (ECM) is closely associated with pathological states and is recognized as a critical factor that precedes tumorigenesis. While increased matrix stiffness is known to induce fibroblast activation, less is known about how both biochemical and mechano-physical changes in AGE-mediated matrix-remodeling cooperate to produce a myofibroblastic cancer-associated fibroblast (CAF)-like phenotype. For the first time, we found that both the AGE interaction with its receptor (RAGE) and integrin-mediated mechanotransduction were up-regulated in glycated collagen matrix, leading to fibroblast activation. We further demonstrated that an AGE cross-link breaker, ALT-711, reduced the CAF-like transformation because of its dual inhibitory role in the AGE-modified matrix. Our findings offer promising extracellular-reversion strategies targeting the non-enzymatic ECM glycation, to regulate fibroblast activation.
    Keywords:  Advanced Glycation End-products (AGEs); ECM-targeting; Extracellular matrix (ECM); Fibroblast Activation
    DOI:  https://doi.org/10.1016/j.actbio.2022.01.040
  23. Dev Cell. 2022 Jan 24. pii: S1534-5807(21)01037-6. [Epub ahead of print]57(2): 277-290.e9
    Compartmentalization of telomeres through DNA-scaffolded phase separation.
    Amanda Jack, Yoonji Kim, Amy R Strom, Daniel S W Lee, Byron Williams, Jeffrey M Schaub, Elizabeth H Kellogg, Ilya J Finkelstein, Luke S Ferro, Ahmet Yildiz, Clifford P Brangwynne.
      Telomeres form unique nuclear compartments that prevent degradation and fusion of chromosome ends by recruiting shelterin proteins and regulating access of DNA damage repair factors. To understand how these dynamic components protect chromosome ends, we combine in vivo biophysical interrogation and in vitro reconstitution of human shelterin. We show that shelterin components form multicomponent liquid condensates with selective biomolecular partitioning on telomeric DNA. Tethering and anomalous diffusion prevent multiple telomeres from coalescing into a single condensate in mammalian cells. However, telomeres coalesce when brought into contact via an optogenetic approach. TRF1 and TRF2 subunits of shelterin drive phase separation, and their N-terminal domains specify interactions with telomeric DNA in vitro. Telomeric condensates selectively recruit telomere-associated factors and regulate access of DNA damage repair factors. We propose that shelterin mediates phase separation of telomeric chromatin, which underlies the dynamic yet persistent nature of the end-protection mechanism.
    Keywords:  DNA repair; chromatin organization; phase separation; shelterin; telomeres
    DOI:  https://doi.org/10.1016/j.devcel.2021.12.017
  24. Nature. 2022 Jan 26.
    Sensory representation and detection mechanisms of gut osmolality change.
    Takako Ichiki, Tongtong Wang, Ann Kennedy, Allan-Hermann Pool, Haruka Ebisu, David J Anderson, Yuki Oka.
      Ingested food and water stimulate sensory systems in the oropharyngeal and gastrointestinal areas before absorption1,2. These sensory signals modulate brain appetite circuits in a feed-forward manner3-5. Emerging evidence suggests that osmolality sensing in the gut rapidly inhibits thirst neurons upon water intake. Nevertheless, it remains unclear how peripheral sensory neurons detect visceral osmolality changes, and how they modulate thirst. Here we use optical and electrical recording combined with genetic approaches to visualize osmolality responses from sensory ganglion neurons. Gut hypotonic stimuli activate a dedicated vagal population distinct from mechanical-, hypertonic- or nutrient-sensitive neurons. We demonstrate that hypotonic responses are mediated by vagal afferents innervating the hepatic portal area (HPA), through which most water and nutrients are absorbed. Eliminating sensory inputs from this area selectively abolished hypotonic but not mechanical responses in vagal neurons. Recording from forebrain thirst neurons and behavioural analyses show that HPA-derived osmolality signals are required for feed-forward thirst satiation and drinking termination. Notably, HPA-innervating vagal afferents do not sense osmolality itself. Instead, these responses are mediated partly by vasoactive intestinal peptide secreted after water ingestion. Together, our results reveal visceral hypoosmolality as an important vagal sensory modality, and that intestinal osmolality change is translated into hormonal signals to regulate thirst circuit activity through the HPA pathway.
    DOI:  https://doi.org/10.1038/s41586-021-04359-5
  25. J Cancer Res Clin Oncol. 2022 Jan 27.
    Exercise medicine for cancer cachexia: targeted exercise to counteract mechanisms and treatment side effects.
    Georgios Mavropalias, Marc Sim, Dennis R Taaffe, Daniel A Galvão, Nigel Spry, William J Kraemer, Keijo Häkkinen, Robert U Newton.
      PURPOSE: Cancer-induced muscle wasting (i.e., cancer cachexia, CC) is a common and devastating syndrome that results in the death of more than 1 in 5 patients. Although primarily a result of elevated inflammation, there are multiple mechanisms that complement and amplify one another. Research on the use of exercise to manage CC is still limited, while exercise for CC management has been recently discouraged. Moreover, there is a lack of understanding that exercise is not a single medicine, but mode, type, dosage, and timing (exercise prescription) have distinct health outcomes. The purpose of this review was to examine the effects of these modes and subtypes to identify the most optimal form and dosage of exercise therapy specific to each underlying mechanism of CC.METHODS: The relevant literatures from MEDLINE and Scopus databases were examined.
    RESULTS: Exercise can counteract the most prominent mechanisms and signs of CC including muscle wasting, increased protein turnover, systemic inflammation, reduced appetite and anorexia, increased energy expenditure and fat wasting, insulin resistance, metabolic dysregulation, gut dysbiosis, hypogonadism, impaired oxidative capacity, mitochondrial dysfunction, and cancer treatments side-effects. There are different modes of exercise, and each mode has different sub-types that induce vastly diverse changes when performed over multiple sessions. Choosing suboptimal exercise modes, types, or dosages can be counterproductive and could further contribute to the mechanisms of CC without impacting muscle growth.
    CONCLUSION: Available evidence shows that patients with CC can safely undertake higher-intensity resistance exercise programs, and benefit from increases in body mass and muscle mass.
    Keywords:  Cancer cachexia; Exercise; Inflammation; Muscle atrophy; Muscle wasting; Tumor
    DOI:  https://doi.org/10.1007/s00432-022-03927-0
  26. J Cachexia Sarcopenia Muscle. 2022 Jan 28.
    Whole-body and adipose tissue metabolic phenotype in cancer patients.
    Lindsey J Anderson, Jonathan Lee, Barbara Anderson, Benjamin Lee, Dorota Migula, Adam Sauer, Nicole Chong, Haiming Liu, Peter C Wu, Atreya Dash, Yi-Ping Li, Jose M Garcia.
      BACKGROUND: Altered adipose tissue (AT) metabolism in cancer-associated weight loss via inflammation, lipolysis, and white adipose tissue (WAT) browning is primarily implicated from rodent models; their contribution to AT wasting in cancer patients is unclear.METHODS: Energy expenditure (EE), plasma, and abdominal subcutaneous WAT were obtained from men (aged 65 ± 8 years) with cancer, with (CWL, n = 27) or without (CWS, n = 47) weight loss, and weight-stable non-cancer patients (CON, n = 26). Clinical images were assessed for adipose and muscle area while plasma and WAT were assessed for inflammatory, lipolytic, and browning markers.
    RESULTS: CWL displayed smaller subcutaneous AT (SAT; P = 0.05) and visceral AT (VAT; P = 0.034) than CWS, and displayed higher circulating interleukin (IL)-6 (P = 0.01) and WAT transcript levels of IL-6 (P = 0.029), IL-1β (P = 0.042), adipose triglyceride lipase (P = 0.026), and browning markers (Dio2, P = 0.03; PGC-1a, P = 0.016) than CWS and CON. There was no difference across groups in absolute REE (P = 0.061), %predicted REE (P = 0.18), circulating free fatty acids (FFA, P = 0.13) or parathyroid hormone-related peptide (PTHrP; P = 0.88), or WAT protein expression of inflammation (IL-6, P = 0.51; IL-1β, P = 0.29; monocyte chemoattractant protein-1, P = 0.23) or WAT protein or gene expression of browning (uncoupling protein-1, UCP-1; P = 0.13, UCP-1, P = 0.14). In patients with cancer, FFA was moderately correlated with WAT hormone-sensitive lipase transcript (r = 0.38, P = 0.018, n = 39); circulating cytokines were not correlated with expression of WAT inflammatory markers and circulating PTHrP was not correlated with expression of WAT browning markers. In multivariate regression using cancer patients only, body mass index (BMI) directly predicted SAT (N = 25, R2  = 0.72, P < 0.001), VAT (N = 28, R2  = 0.64, P < 0.001), and absolute REE (N = 22, R2  = 0.43, P = 0.001), while BMI and WAT UCP-1 protein were indirectly associated with %predicted REE (N = 22, R2  = 0.45, P = 0.02), and FFA was indirectly associated with RQ (N = 22, R2  = 0.52, P < 0.001).
    CONCLUSIONS: Cancer-related weight loss was associated with elevated circulating IL-6 and elevations in some WAT inflammatory, lipolytic and browning marker transcripts. BMI, not weight loss, was associated with increased energy expenditure. The contribution of inflammation and lipolysis, and lack thereof for WAT browning, will need to be clarified in other tumour types to increase generalizability. Future studies should consider variability in fat mass when exploring the relationship between cancer and adipose metabolism and should observe the trajectory of lipolysis and energy expenditure over time to establish the clinical significance of these associations and to inform more mechanistic interpretation of causation.
    Keywords:  Adipose browning; Energy expenditure; Inflammation; Lipolysis; White adipose tissue
    DOI:  https://doi.org/10.1002/jcsm.12918
  27. Eur Phys J E Soft Matter. 2022 Jan 24. 45(1): 7
    Collective durotaxis of cohesive cell clusters on a stiffness gradient.
    Irina Pi-Jaumà, Ricard Alert, Jaume Casademunt.
      Many types of motile cells perform durotaxis, namely directed migration following gradients of substrate stiffness. Recent experiments have revealed that cell monolayers can migrate toward stiffer regions even when individual cells do not-a phenomenon known as collective durotaxis. Here, we address the spontaneous motion of finite cohesive cell monolayers on a stiffness gradient. We theoretically analyze a continuum active polar fluid model that has been tested in recent wetting assays of epithelial tissues and includes two types of active forces (cell-substrate traction and cell-cell contractility). The competition between the two active forces determines whether a cell monolayer spreads or contracts. Here, we show that this model generically predicts collective durotaxis, and that it features a variety of dynamical regimes as a result of the interplay between the spreading state and the global propagation, including sequential contraction and spreading of the monolayer as it moves toward higher stiffness. We solve the model exactly in some relevant cases, which provides both physical insights into the mechanisms of tissue durotaxis and spreading as well as a variety of predictions that could guide the design of future experiments.
    DOI:  https://doi.org/10.1140/epje/s10189-021-00150-6
  28. JCI Insight. 2022 Jan 25. pii: e153559. [Epub ahead of print]7(2):
    Liquid biopsy reveals collateral tissue damage in cancer.
    Asael Lubotzky, Hai Zemmour, Daniel Neiman, Marc Gotkine, Netanel Loyfer, Sheina Piyanzin, Bracha-Lea Ochana, Roni Lehmann-Werman, Daniel Cohen, Joshua Moss, Judith Magenheim, Maureen F Loftus, Lauren Brais, Kimmie Ng, Raul Mostoslavsky, Brian M Wolpin, Aviad Zick, Myriam Maoz, Albert Grinshpun, Anatoli Kustanovich, Chen Makranz, Jonathan E Cohen, Tamar Peretz, Ayala Hubert, Mark Temper, Azzam Salah, Shani Avniel-Polak, Simona Grozinsky-Glasberg, Kirsty L Spalding, Ariel Rokach, Tommy Kaplan, Benjamin Glaser, Ruth Shemer, Yuval Dor.
      Cancer inflicts damage to surrounding normal tissues, which can culminate in fatal organ failure. Here, we demonstrate that cell death in organs affected by cancer can be detected by tissue-specific methylation patterns of circulating cell-free DNA (cfDNA). We detected elevated levels of hepatocyte-derived cfDNA in the plasma of patients with liver metastases originating from different primary tumors, compared with cancer patients without liver metastases. In addition, patients with localized pancreatic or colon cancer showed elevated hepatocyte cfDNA, suggesting liver damage inflicted by micrometastatic disease, by primary pancreatic tumor pressing the bile duct, or by a systemic response to the primary tumor. We also identified elevated neuron-, oligodendrocyte-, and astrocyte-derived cfDNA in a subpopulation of patients with brain metastases compared with cancer patients without brain metastasis. Cell type-specific cfDNA methylation markers enabled the identification of collateral tissue damage in cancer, revealing the presence of metastases in specific locations and potentially assisting in early cancer detection.
    Keywords:  Cell Biology; Epigenetics; Molecular diagnosis; Oncology
    DOI:  https://doi.org/10.1172/jci.insight.153559
  29. J Clin Invest. 2022 Jan 27. pii: e152394. [Epub ahead of print]
    Smad3 methylation by EZH2 promotes its activation and tumor metastasis.
    Changsheng Huang, Fuqing Hu, Da Song, Xuling Sun, Anyi Liu, Qi Wu, Xiaowei She, Yaqi Chen, Lisheng Chen, Fayong Hu, Feng Xu, Xuelai Luo, Yongdong Feng, Xiangping Yang, Junbo Hu, Guihua Wang.
      SMAD3 plays a central role in cancer metastasis, and its hyperactivation is linked to poor cancer outcomes. Thus, it is critical to understand the upstream signaling pathways that govern SMAD3 activation. Here, we report that SMAD3 undergoes methylation at K53 and K333 by EZH2, a process crucial for cell membrane recruitment, phosphorylation, and activation of SMAD3 upon TGFB1 stimulation. Mechanistically, EZH2-triggered SMAD3 methylation facilitates SMAD3 interaction with its cellular membrane localization molecule (SARA), which in turn sustains SMAD3 phosphorylation by the TGFB receptor. Pathologically, EZH2 expression increasing results in the accumulation of SMAD3 methylation to facilitate SMAD3 activation. EZH2-mediated SMAD3 K53/K333 methylation is upregulated and correlated with SMAD3 hyperactivation in breast cancer, promotes tumor metastasis, and is predictive of poor survival outcome. We used two TAT-peptides to abrogate SMAD3 methylation and therapeutically inhibit cancer metastasis. Collectively, these findings reveal the complicated layers in regulation of SMAD3 activation coordinated by EZH2-mediated SMAD3 K53/K333 methylation to drive cancer metastasis.
    Keywords:  Cancer; Molecular biology; Oncology
    DOI:  https://doi.org/10.1172/JCI152394
  30. Sci Rep. 2022 Jan 24. 12(1): 1231
    A computational modeling of invadopodia protrusion into an extracellular matrix fiber network.
    Min-Cheol Kim, Ran Li, Rohan Abeyaratne, Roger D Kamm, H Harry Asada.
      Invadopodia are dynamic actin-rich membrane protrusions that have been implicated in cancer cell invasion and metastasis. In addition, invasiveness of cancer cells is strongly correlated with invadopodia formation, which are observed during extravasation and colonization of metastatic cancer cells at secondary sites. However, quantitative understanding of the interaction of invadopodia with extracellular matrix (ECM) is lacking, and how invadopodia protrusion speed is associated with the frequency of protrusion-retraction cycles remains unknown. Here, we present a computational framework for the characterization of invadopodia protrusions which allows two way interactions between intracellular branched actin network and ECM fibers network. We have applied this approach to predicting the invasiveness of cancer cells by computationally knocking out actin-crosslinking molecules, such as α-actinin, filamin and fascin. The resulting simulations reveal distinct invadopodia dynamics with cycles of protrusion and retraction. Specifically, we found that (1) increasing accumulation of MT1-MMP at tips of invadopodia as the duration of protrusive phase is increased, and (2) the movement of nucleus toward the leading edge of the cell becomes unstable as duration of the retractile phase (or myosin turnover time) is longer than 1 min.
    DOI:  https://doi.org/10.1038/s41598-022-05224-9
  31. Dev Cell. 2022 Jan 24. pii: S1534-5807(21)01040-6. [Epub ahead of print]57(2): 260-276.e9
    Regulation of reverse electron transfer at mitochondrial complex I by unconventional Notch action in cancer stem cells.
    Rani Ojha, Ishaq Tantray, Suman Rimal, Siddhartha Mitra, Sam Cheshier, Bingwei Lu.
      Metabolic flexibility is a hallmark of many cancers where mitochondrial respiration is critically involved, but the molecular underpinning of mitochondrial control of cancer metabolic reprogramming is poorly understood. Here, we show that reverse electron transfer (RET) through respiratory chain complex I (RC-I) is particularly active in brain cancer stem cells (CSCs). Although RET generates ROS, NAD+/NADH ratio turns out to be key in mediating RET effect on CSC proliferation, in part through the NAD+-dependent Sirtuin. Mechanistically, Notch acts in an unconventional manner to regulate RET by interacting with specific RC-I proteins containing electron-transporting Fe-S clusters and NAD(H)-binding sites. Genetic and pharmacological interference of Notch-mediated RET inhibited CSC growth in Drosophila brain tumor and mouse glioblastoma multiforme (GBM) models. Our results identify Notch as a regulator of RET and RET-induced NAD+/NADH balance, a critical mechanism of metabolic reprogramming and a metabolic vulnerability of cancer that may be exploited for therapeutic purposes.
    Keywords:  NAD(+)/NADH; Sirtuin; Warburg effect; glioblastoma multiforme; inflammation; metabolic reprogramming; mitochondrial complex I; non-canonical Notch signaling; reactive oxygen species; reverse electron transport
    DOI:  https://doi.org/10.1016/j.devcel.2021.12.020
  32. J Gastrointest Oncol. 2021 Dec;12(6): 2591-2599
    Safety and efficacy of combination chemotherapy regimens in older adults with pancreatic ductal adenocarcinoma: a systematic review.
    Patricia Saade-Lemus, Leah Biller, Andrea Bullock.
      Background: Pancreatic ductal adenocarcinoma (PDA) is often diagnosed in older adults. However, most published studies investigating chemotherapy for PDA include a predominantly younger population, and the standard of care for the older adult population is not defined. It is our goal to review the literature available about the safety and efficacy of combination chemotherapy for locally advanced or metastatic PDA in older adults ≥65 years.Methods: We conducted a systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting checklist. We searched PubMed, EMBASE and MEDLINE databases to identify retrospective and prospective studies published until October 2018 that assessed the survival outcomes and adverse events in patients 65 years and older diagnosed with PDA and treated with combination chemotherapy.
    Results: A total of 1,479 studies were screened. Twenty-four full-text studies were assessed for eligibility. Nineteen were excluded due to wrong study design (n=4) or abstract only with no further publication (n=15). A total of 5 full text studies met eligibility and were included in the present review. Combination chemotherapy is associated with similar survival to that reported in younger populations with advanced PDA. The most common toxicities across studies included: sensory neuropathy and neutropenia. Two studies each reported one death related to treatment-associated sepsis.
    Discussion: Papers examined in this systematic review concluded that the use of combination chemotherapy regimens is safe and effective for older adults with minimal comorbidities and adequate performance status. Prospective data is needed to confirm these findings, provided that the most significant limitation of these studies was a small sample size.
    Keywords:  Pancreatic neoplasms; aged; antineoplastic agents; antineoplastic combined chemotherapy protocols; elderly
    DOI:  https://doi.org/10.21037/jgo-21-87
  33. Trends Endocrinol Metab. 2022 Jan 19. pii: S1043-2760(21)00301-5. [Epub ahead of print]
    Eukaryotic lipid droplets: metabolic hubs, and immune first responders.
    Marta Bosch, Albert Pol.
      As major eukaryotic lipid storage organelles, lipid droplets (LDs) are metabolic hubs coordinating energy flux and building block distribution. Infectious pathogens often promote accumulation and physically interact with LDs. The most accepted view is that host LDs are hijacked by invaders to draw on nutrients for host colonisation. However, unique traits such as biogenesis plasticity, dynamic proteome, signalling capacity, and ability to interact with other organelles endow LDs with competencies to face complex biological challenges. Here, we focus on published data suggesting that LDs are not usurped organelles but innate immunity first responders. By comparison with analogous mechanisms activated on LDs in nutrient-poor environments, our review supports the hypothesis that host LDs actively participate in immunometabolism, immune signalling, and microbial killing.
    Keywords:  infection; innate immunity; lipid droplet; metabolism
    DOI:  https://doi.org/10.1016/j.tem.2021.12.006
  34. Ann Surg Oncol. 2022 Jan 23.
    Weight Tracking as a Novel Prognostic Marker After Pancreatectomy.
    Jonathan J Hue, Lee M Ocuin, Ravi K Kyasaram, John Shanahan, Goutham Rao, Luke D Rothermel, John B Ammori, Jeffrey M Hardacre, Jordan M Winter, Sarah C Markt.
      BACKGROUND: Objective measures of post-pancreatectomy weight change for pancreatic ductal adenocarcinoma (PDAC) have not been extensively studied for long-term outcomes. We used weight measurements in our institutional medical record to analyze trends in post-pancreatectomy weight and determine the association with disease status.METHODS: Pancreatectomies for PDAC (n = 315) and benign indications (n = 111) were identified. Preoperative baseline, minimum postoperative (Min #1), and subsequent postoperative maximum (Max) weights were abstracted. Multivariable Cox hazards regression was conducted to analyze the association between weight change and survival.
    RESULTS: Median weight loss postoperatively in each group was > 20 lbs. PDAC patients gained 10 lbs after Min #1 compared to 15 lbs in the benign cohort (p < 0.001). Few patients returned to their preoperative weight (29.8% PDAC vs. 40.5% benign, p = 0.04). Patients with early PDAC recurrence (< 13 months) lost more weight (18.0% vs. 13.3% vs. 10.9%, p < 0.001) and gained less weight (2.1% vs. 12.0% vs. 7.9%, p < 0.001) compared with those with late cancer recurrence (≥ 13 months) or no evidence of active disease, respectively. PDAC patients lost 11.2 lbs in the year preceding recurrence diagnosis. Weight loss was not associated with survival; however, weight gain was associated with improved survival.
    CONCLUSIONS: Resections for PDAC are complicated by a similar degree of weight loss as patients with benign disease, and there is no association with survival. However, failure to gain weight is especially ominous. Weight loss after weight recovery foreshadows disease recurrence. These data suggest that rigorous weight tracking is an untapped surveillance strategy in patients with PDAC.
    DOI:  https://doi.org/10.1245/s10434-022-11325-6
  35. Cell Stem Cell. 2022 Jan 19. pii: S1934-5909(21)00525-7. [Epub ahead of print]
    Multi-omic analysis reveals divergent molecular events in scarring and regenerative wound healing.
    Shamik Mascharak, Heather E Talbott, Michael Januszyk, Michelle Griffin, Kellen Chen, Michael F Davitt, Janos Demeter, Dominic Henn, Clark A Bonham, Deshka S Foster, Nancie Mooney, Ran Cheng, Peter K Jackson, Derrick C Wan, Geoffrey C Gurtner, Michael T Longaker.
      Regeneration is the holy grail of tissue repair, but skin injury typically yields fibrotic, non-functional scars. Developing pro-regenerative therapies requires rigorous understanding of the molecular progression from injury to fibrosis or regeneration. Here, we report the divergent molecular events driving skin wound cells toward scarring or regenerative fates. We profile scarring versus YAP-inhibition-induced wound regeneration at the transcriptional (single-cell RNA sequencing), protein (timsTOF proteomics), and tissue (extracellular matrix ultrastructural analysis) levels. Using cell-surface barcoding, we integrate these data to reveal fibrotic and regenerative "molecular trajectories" of healing. We show that disrupting YAP mechanotransduction yields regenerative repair by fibroblasts with activated Trps1 and Wnt signaling. Finally, via in vivo gene knockdown and overexpression in wounds, we identify Trps1 as a key regulatory gene that is necessary and partially sufficient for wound regeneration. Our findings serve as a multi-omic map of wound regeneration and could have therapeutic implications for pathologic fibroses.
    Keywords:  fibroblast heterogeneity; fibrosis; mechanotransduction signaling; regeneration; wound healing
    DOI:  https://doi.org/10.1016/j.stem.2021.12.011
  36. Autophagy. 2022 Jan 24. 1-16
    Atg8-PE protein-based in vitro biochemical approaches to autophagy studies.
    Xue Huang, Jia Yao, Lu Liu, Yu Luo, Aimin Yang.
      Macroautophagy/autophagy is an evolutionarily conserved intracellular degradation pathway that maintains cellular homeostasis. Over the past two decades, a series of scientific breakthroughs have helped explain autophagy-related molecular mechanisms and physiological functions. This tremendous progress continues to depend largely on powerful research methods, specifically, various autophagy marker Atg8-PE protein-based methods for studying membrane dynamics and monitoring autophagic activity. Recently, several biochemical approaches have been successfully developed to produce the lipidated protein Atg8-PE or its mimics in vitro, including enzyme-mediated reconstitution systems, chemically defined reconstitution systems, cell-free lipidation systems and protein chemical synthesis. These approaches have contributed important insights into the mechanisms underlying Atg8-mediated membrane dynamics and protein-protein interactions, creating a new perspective in autophagy studies. In this review, we comprehensively summarize Atg8-PE protein-based in vitro biochemical approaches and recent advances to facilitate a better understanding of autophagy mechanisms. In addition, we highlight the advantages and disadvantages of various Atg8-PE protein-based approaches to provide general guidance for their use in studying autophagy.
    Keywords:  Atg8–PE; LC3–PE; autophagy; biochemical approaches; cell-free lipidation system; chemically defined reconstitution systems; enzyme-mediated reconstitution system; protein chemical synthesis
    DOI:  https://doi.org/10.1080/15548627.2022.2025572
  37. Gastroenterology. 2022 Jan 20. pii: S0016-5085(22)00032-4. [Epub ahead of print]
    Predicting pancreatic cancer in the UK Biobank cohort using polygenic risk scores and diabetes mellitus.
    Shreya Sharma, William J Tapper, Andrew Collins, Zaed Z R Hamady.
      BACKGROUND AND AIMS: Diabetes mellitus (DM) is known to be associated with Pancreatic ductal adenocarcinoma (PDAC), particularly, new-onset DM (NODM). Others have developed polygenic risk scores (PRS) associated with PDAC risk. We aimed to compare the performance of these PRS in an independent cohort to determine if they can discriminate between NODM and long standing DM (LSDM) patients with PDAC.METHODS: Cases (1,042) and matched cancer free controls (10,420) were drawn from the UK Biobank. Five PRS models were calculated using single nucleotide polymorphisms (SNPs) from previous studies (Nakatochi, Galeotti, Molina, Jia and Rashkin) and a combination of these. Regression models were used to assess the association between PDAC and PRS adjusted for ancestry, smoking, DM, waist circumference, and a family history of digestive cancer. Receiver operator characteristic (ROC) curves and the area under the curve metrics (AUC) were used to assess the performance of each PRS for classifying PDAC risk.
    RESULTS: The combined PRS model achieved the highest AUC (0.605), and significantly improved a clinical risk model in this cohort (AUC=0.83, P =0.0002). Individuals within the 5th quintile have a 2.74-fold increased risk of developing PDAC versus those in the 1st quintile (P <0.001), and have a 3.05-fold increased risk of developing PDAC if they have DM versus those without DM (P <0.001). The positive predictive value (PPV) was 11.9% in participants without DM, 23.9% with LSDM and 86.7% with NODM.
    CONCLUSIONS: The PDAC related common genetic variants are more strongly associated with DM. This PRS has the potential for targeting individuals with NODM for PDAC secondary screening measures.
    Keywords:  Early detection; Genetic risk score; Pancreatic Adenocarcinoma
    DOI:  https://doi.org/10.1053/j.gastro.2022.01.016
  38. J Biochem. 2022 Jan 25. pii: mvab125. [Epub ahead of print]
    The protein level of the tumor-promoting factor SET is regulated by cell density.
    Naoki Kohyanagi, Nao Kitamura, Keiko Tanaka, Takuya Mizuno, Nobuyuki Fujiwara, Takashi Ohama, Koichi Sato.
      SET/I2PP2A is a multifunctional protein that acts as an intrinsic inhibitor of the tumor suppressor protein phosphatase 2A and as a histone chaperone. Increased SET levels have been observed in various cancers; however, the underlying molecular mechanisms remain unclear. In this study, we found that SET protein accumulates with the increasing density of cultured cells. This phenomenon was observed not only in cancer cell lines but also in non-cancer cell lines. The mRNA levels of SET were not affected by the cell density. Proteasome inhibition decreased SET levels, whereas autophagy inhibition led to SET accumulation, indicating the involvement of autophagy. The mRNA and protein expression of SETBP1, which stabilizes the SET protein, increased with cell density. The decrease in SET level due to the loss of SETBP1 was more pronounced in wild-type cells than that in autophagy-deficient cells. These results have revealed a mechanism underlying the regulation of SET level, wherein increased cell density induces SETBP1 expression and protects SET from autophagy.
    Keywords:  PP2A; SET/I2PP2A; SETBP1; cell density
    DOI:  https://doi.org/10.1093/jb/mvab125
  39. Physiol Behav. 2022 Jan 20. pii: S0031-9384(22)00019-1. [Epub ahead of print] 113712
    A critique on the theory of homeostasis.
    Laurival A De Luca.
      The objective of this critique is to demonstrate that the theory of "internal environment" (TIE) does not support the theory of "homeostasis" (TOH). We review and conclude that remains valid the concept of "internal environment", which corresponds anatomically to the extracellular fluid (ECF) that bathes tissue cells. The Claude Bernard's classification of "life", a corollary of the TIE under a strict "reactive" paradigm, we then interpret as a classification of how animals behave in response to environmental changes. According to such interpretation, the two theories agree that, when facing changes in the external environment, animals with "free" behavior regulate essential metabolism factors present in the ECF. These are "internalized environmental factors" or IEF (temperature, O2, water, and basic organic and inorganic "nutrients"), a marine legacy of the evolution of the body fluid compartments. However, we show that have empirical and logical shortcomings key inferences derived from the TIE. Such inferences representing traditional premises of TOH we summarize here in two axioms: "if free behavior then regulated IEF" and "all behavioral mechanisms regulate the IEF". In addition, whereas "stability" means "free behavior versus dormancy" in TIE, it means "tissue cells that resist destruction" in TOH. This leads to inevitable contradictions, here discussed at length, that reduce the scope of TOH. We might be in need of a theory that considers not only where TIE and TOH are superficially valid, but also where they crucially diverge, in order to explain "stability" as applied to physiology and behavior.
    Keywords:  behavior; biological clock; body-fluid compartment; internal environment; regulation; stability
    DOI:  https://doi.org/10.1016/j.physbeh.2022.113712
  40. J Gastrointest Oncol. 2021 Dec;12(6): 3133-3140
    Durable clinical benefit from PARP inhibition in a platinum-sensitive, BRCA2-mutated pancreatic cancer patient after earlier progression on placebo treatment on the POLO trial: a case report.
    Douglas Rubinson, Brian M Wolpin, Ilana S Warsofsky, David P Ryan, Kimberly Perez, Osama Rahma, Harshabad Singh, Matthew B Yurgelun, Geoffrey I Shapiro, Andrew J Aguirre, Alan D D'Andrea, James M Cleary.
      Metastatic pancreatic adenocarcinoma is a deadly malignancy with limited treatment options. Based on the results of the phase 3 POLO trial, the PARP inhibitor olaparib was approved by the Food and Drug Administration as a maintenance therapy in germline BRCA1- and BRCA2-mutated metastatic pancreatic cancer patients whose cancers had not progressed on first-line platinum-based chemotherapy. While this approval was a step forward, there have been criticisms of the POLO study leaving doubts in the field about the effectiveness of PARP inhibition in pancreatic cancer. Here, we describe a patient with a germline BRCA2-mutated, metastatic pancreatic cancer who was randomized to the placebo-arm of the POLO trial. After progressing on the placebo-arm of the POLO study, her cancer again responded to platinum-based chemotherapy and has since been successfully treated for 4 years with off-protocol maintenance olaparib. The presence of placebo treatment in this case serves as an internal control demonstrating the efficacy of PARP inhibition in this patient. This case highlights the potential of PARP inhibitor maintenance therapy in appropriately selected metastatic pancreatic cancer patients.
    Keywords:  DNA repair; PARP inhibitor; Pancreatic cancer; case report; targeted therapy
    DOI:  https://doi.org/10.21037/jgo-21-197
  41. Clin Exp Metastasis. 2022 Jan 24.
    Current challenges in metastasis research and future innovation for clinical translation.
    Early Career Leadership Council of the Metastasis Research Society
      While immense strides have been made in understanding tumor biology and in developing effective treatments that have substantially improved the prognosis of cancer patients, metastasis remains the major cause of cancer-related death. Improvements in the detection and treatment of primary tumors are contributing to a growing, detailed understanding of the dynamics of metastatic progression. Yet challenges remain in detecting metastatic dissemination prior to the establishment of overt metastases and in predicting which patients are at the highest risk of developing metastatic disease. Further improvements in understanding the mechanisms governing metastasis have great potential to inform the adaptation of existing therapies and the development of novel approaches to more effectively control metastatic disease. This article presents a forward-looking perspective on the challenges that remain in the treatment of metastasis, and the exciting emerging approaches that promise to transform the treatment of metastasis in cancer patients.
    Keywords:  Dormancy; Immunotherapy; Latency; Liquid biopsy; Metastasis; Microenvironment
    DOI:  https://doi.org/10.1007/s10585-021-10144-5
  42. Small. 2022 Jan 24. e2106524
    Lipid Droplets Embedded in a Model Cell Membrane Create a Phospholipid Diffusion Barrier.
    Sevde Puza, Stefanie Caesar, Chetan Poojari, Michael Jung, Ralf Seemann, Jochen S Hub, Bianca Schrul, Jean-Baptiste Fleury.
      Lipid droplets (LDs) are ubiquitous, cytoplasmic fat storage organelles that originate from the endoplasmic reticulum (ER) membrane. They are composed of a core of neutral lipids surrounded by a phospholipid monolayer. Proteins embedded into this monolayer membrane adopt a monotopic topology and are crucial for regulated lipid storage and consumption. A key question is, which collective properties of protein-intrinsic and lipid-mediated features determine spatio-temporal protein partitioning between phospholipid bilayer and LD monolayer membranes. To address this question, a freestanding phospholipid bilayer with physiological lipidic composition is produced using microfluidics and micrometer-sized LDs are dispersed around the bilayer that spontaneously insert into the bilayer. Using confocal microscopy, the 3D geometry of the reconstituted LDs is determined with high spatial resolution. The micrometer-sized bilayer-embedded LDs present a characteristic lens shape that obeys predictions from equilibrium wetting theory. Fluorescence recovery after photobleaching measurements reveals the existence of a phospholipid diffusion barrier at the monolayer-bilayer interface. Coarse-grained molecular dynamics simulation reveals lipid specific density distributions along the pore rim, which may rationalize the diffusion barrier. The lipid diffusion barrier between the LD covering monolayer and the bilayer may be a key phenomenon influencing protein partitioning between the ER membrane and LDs in living cells.
    Keywords:  lipid bilayers; lipid diffusion; lipid droplets; monotopic membrane proteins; phospholipid monolayers; wetting
    DOI:  https://doi.org/10.1002/smll.202106524
  43. Mitochondrion. 2022 Jan 22. pii: S1567-7249(22)00006-X. [Epub ahead of print]
    Targeting the Mitochondrial Permeability Transition Pore for Drug Discovery: Challenges and Opportunities.
    Ibrahim Damilare Boyenle, Abdulquddus Kehinde Oyedele, Abdeen Tunde Ogunlana, Adeyemo Aishat Folashade, Sunday Faith Oyelere, Akinola Olateju Balkees, Temitope Isaac Adelusi, Leonard Ona Ehigie, Adeola Folashade Ehigie.
      Several drug targets have been amenable to drug discovery pursuit not until the characterization of the mitochondrial permeability transition pore (MPTP), a pore with an undefined molecular identity that forms on the inner mitochondrial membrane upon mitochondrial permeability transition (MPT) under the influence of calcium overload and oxidative stress. The opening of the pore which is presumed to cause cell death in certain human diseases also has implications under physiological parlance. The mitochondrial community has witnessed many protein candidates such as; voltage-dependent anion channel (VDAC), adenine nucleotide translocase (ANT), Mitochondrial phosphate carrier (PiC), Spastic Paralegin (SPG7), disordered proteins, and F1Fo ATPase. Also, different models for this pore have been postulated in the last six decades since it was characterized but genetic studies have cast out most of these candidates with only F1Fo ATPase currently under intense argument. Cyclophilin D (CyPD) remains the widely accepted positive regulator of the MPTP known to date, but no drug candidate has emerged as its inhibitor, raising concern issues for therapeutics. Thus, in this review, we discuss various models of MPTP reported with the hope of stimulating further research in this field. We went beyond the classical description of the MPTP to ascribe a 'two-edged sword property' to the pore for therapeutic function in human disease because its inhibition and activation have pharmacological relevance. We identified putative proteins upstream to CyPD that can regulate its activity and prevent cell deaths in neurodegenerative disease and ischemia-reperfusion injury.
    Keywords:  Cyclophilin D; Ischemia Reperfusion Injury; Mitochondrial permeability transition pore (MPTP); Neurodegenerative disease; drug discovery; mitochondrial permeability transition (MPT)
    DOI:  https://doi.org/10.1016/j.mito.2022.01.006
  44. Trends Cell Biol. 2022 Jan 20. pii: S0962-8924(21)00251-8. [Epub ahead of print]
    Nucleus segmentation: towards automated solutions.
    Reka Hollandi, Nikita Moshkov, Lassi Paavolainen, Ervin Tasnadi, Filippo Piccinini, Peter Horvath.
      Single nucleus segmentation is a frequent challenge of microscopy image processing, since it is the first step of many quantitative data analysis pipelines. The quality of tracking single cells, extracting features or classifying cellular phenotypes strongly depends on segmentation accuracy. Worldwide competitions have been held, aiming to improve segmentation, and recent years have definitely brought significant improvements: large annotated datasets are now freely available, several 2D segmentation strategies have been extended to 3D, and deep learning approaches have increased accuracy. However, even today, no generally accepted solution and benchmarking platform exist. We review the most recent single-cell segmentation tools, and provide an interactive method browser to select the most appropriate solution.
    Keywords:  deep learning; image processing; microscopy; nucleus segmentation; oncology; single-cell analysis
    DOI:  https://doi.org/10.1016/j.tcb.2021.12.004
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