bims-instec 2024-07-07 papers

bims-instec

Biomed News

on Intestinal stem cells and chemoresistance in colon cancer and intestinal regeneration

Issue of 2024‒07‒07
twenty papers selected by
Maria-Virginia Giolito, Université Catholique de Louvain

MCT1-dependent lactate recycling is a metabolic vulnerability in colorectal cancer cells upon acquired resistance to anti-EGFR targeted therapy.
Homopolymer switches mediate adaptive mutability in mismatch repair-deficient colorectal cancer.
Resistance to immune checkpoint inhibitors in colorectal cancer with deficient mismatch repair/microsatellite instability: misdiagnosis, pseudoprogression and/or tumor heterogeneity?
Patient-derived mini-colons enable long-term modeling of tumor-microenvironment complexity.
Biomarkers to predict efficacy of immune checkpoint inhibitors in colorectal cancer patients: a systematic review and meta-analysis.
Inter-cell type interactions that control JNK signaling in the Drosophila intestine.
Sulfatide imaging identifies tumor cells in colorectal cancer peritoneal metastases.
Ribosomal Protein L9 Maintains Stemness of Colorectal Cancer via an ID-1 Dependent Mechanism.
Interactions of Fatty Acid and Cholesterol Metabolism with Cellular Stress Response Pathways in Cancer.
Selective PI3Kδ inhibitor TYM-3-98 suppresses AKT/mTOR/SREBP1-mediated lipogenesis and promotes ferroptosis in KRAS-mutant colorectal cancer.
Complete response of metastatic microsatellite-stable BRAF V600E colorectal cancer to first-line oxaliplatin-based chemotherapy and immune checkpoint blockade.
Loss-of-function mutation of REV1 (p.R704Q) mediates cetuximab primary resistance by activating autophagy in RAS-wild type metastatic colorectal cancer.
Expression of PD-L1 Is Increased by Methionine Restriction Using Recombinant Methioninase in Human Colorectal Cancer Cells.
Forkhead box M1 mediates metabolic reprogramming in human colorectal cancer cells.
In vivo organoid growth monitoring by stimulated Raman histology.
BRAF-mutant microsatellite-stable rectal cancer with acquired KRAS mutation leading to drug resistance in liver metastasis.
An in vitro platform for quantifying cell cycle phase lengths in primary human intestinal epithelial cells.
CRISPR screens reveal convergent targeting strategies against evolutionarily distinct chemoresistance in cancer.
Targeted delivery of FAK siRNA by engineered exosomes to reverse cetuximab resistance via activating paraptosis in colon cancer.
Organoids as regenerative medicine for inflammatory bowel disease.

Cancer Lett. 2024 Jul 02. pii: S0304-3835(24)00486-5. [Epub ahead of print] 217091

MCT1-dependent lactate recycling is a metabolic vulnerability in colorectal cancer cells upon acquired resistance to anti-EGFR targeted therapy.

Elena Richiardone, Rim Al Roumi, Fanny Lardinois, Maria Virginia Giolito, Jérôme Ambroise, Romain Boidot, Bernhard Drotleff, Bart Ghesquière, Akeila Bellahcène, Alberto Bardelli, Sabrina Arena, Cyril Corbet.

  Despite the implementation of personalized medicine, patients with metastatic CRC (mCRC) still have a dismal overall survival due to the frequent occurrence of acquired resistance mechanisms thereby leading to clinical relapse. Understanding molecular mechanisms that support acquired resistance to anti-EGFR targeted therapy in mCRC is therefore clinically relevant and key to improving patient outcomes. Here, we observe distinct metabolic changes between cetuximab-resistant CRC cell populations, with in particular an increased glycolytic activity in KRAS-mutant cetuximab-resistant CRC cells (LIM1215 and OXCO2) but not in KRAS-amplified resistant DiFi cells. We show that cetuximab-resistant LIM1215 and OXCO2 cells have the capacity to recycle glycolysis-derived lactate to sustain their growth capacity. This is associated with an upregulation of the lactate importer MCT1 at both transcript and protein levels. Pharmacological inhibition of MCT1, with AR-C155858, reduces the uptake and oxidation of lactate and impairs growth capacity in cetuximab-resistant LIM1215 cells both in vitro and in vivo. This study identifies MCT1-dependent lactate utilization as a clinically actionable, metabolic vulnerability to overcome KRAS-mutant-mediated acquired resistance to anti-EGFR therapy in CRC.

Keywords:  Colorectal cancer; KRAS; cetuximab; lactate; metabolism; monocarboxylate transporter; therapy resistance

DOI:  https://doi.org/10.1016/j.canlet.2024.217091
Nat Genet. 2024 Jul 03.

Homopolymer switches mediate adaptive mutability in mismatch repair-deficient colorectal cancer.

Hamzeh Kayhanian, William Cross, Suzanne E M van der Horst, Panagiotis Barmpoutis, Eszter Lakatos, Giulio Caravagna, Luis Zapata, Arne Van Hoeck, Sjors Middelkamp, Kevin Litchfield, Christopher Steele, William Waddingham, Dominic Patel, Salvatore Milite, Chen Jin, Ann-Marie Baker, Daniel C Alexander, Khurum Khan, Daniel Hochhauser, Marco Novelli, Benjamin Werner, Ruben van Boxtel, Joris H Hageman, Julian R Buissant des Amorie, Josep Linares, Marjolijn J L Ligtenberg, Iris D Nagtegaal, Miangela M Laclé, Leon M G Moons, Lodewijk A A Brosens, Nischalan Pillay, Andrea Sottoriva, Trevor A Graham, Manuel Rodriguez-Justo, Kai-Keen Shiu, Hugo J G Snippert, Marnix Jansen.

Mismatch repair (MMR)-deficient cancer evolves through the stepwise erosion of coding homopolymers in target genes. Curiously, the MMR genes MutS homolog 6 (MSH6) and MutS homolog 3 (MSH3) also contain coding homopolymers, and these are frequent mutational targets in MMR-deficient cancers. The impact of incremental MMR mutations on MMR-deficient cancer evolution is unknown. Here we show that microsatellite instability modulates DNA repair by toggling hypermutable mononucleotide homopolymer runs in MSH6 and MSH3 through stochastic frameshift switching. Spontaneous mutation and reversion modulate subclonal mutation rate, mutation bias and HLA and neoantigen diversity. Patient-derived organoids corroborate these observations and show that MMR homopolymer sequences drift back into reading frame in the absence of immune selection, suggesting a fitness cost of elevated mutation rates. Combined experimental and simulation studies demonstrate that subclonal immune selection favors incremental MMR mutations. Overall, our data demonstrate that MMR-deficient colorectal cancers fuel intratumor heterogeneity by adapting subclonal mutation rate and diversity to immune selection.

DOI: https://doi.org/10.1038/s41588-024-01777-9
Explor Target Antitumor Ther. 2024 ;5(3): 495-507

Resistance to immune checkpoint inhibitors in colorectal cancer with deficient mismatch repair/microsatellite instability: misdiagnosis, pseudoprogression and/or tumor heterogeneity?

Nicola Normanno, Vincenza Caridi, Matteo Fassan, Antonio Avallone, Fortunato Ciardiello, Carmine Pinto.

  Colorectal carcinoma (CRC) with deficiency of the deficient mismatch repair (dMMR) pathway/microsatellite instability (MSI) is characterized by a high mutation load and infiltration of immune cells in the tumor microenvironment. In agreement with these findings, clinical trials have demonstrated a significant activity of immune checkpoint inhibitors (ICIs) in dMMR/MSI metastatic CRC (mCRC) patients and, more recently, in CRC patients with early disease undergoing neoadjuvant therapy. However, despite high response rates and durable clinical benefits, a fraction of mCRC patients, up to 30%, showed progressive disease when treated with single agent anti-programmed cell death 1 (PD-1) antibody. This article discusses the three main causes that have been associated with early progression of dMMR/MSI mCRC patients while on treatment with ICIs, i.e., misdiagnosis, pseudoprogression and tumor heterogeneity. While pseudoprogression probably does not play a relevant role, data from clinical studies demonstrate that some dMMR/MSI CRC cases with rapid progression on ICIs may be misdiagnosed, underlining the importance of correct diagnostics. More importantly, evidence suggests that dMMR/MSI mCRC is a heterogeneous group of tumors with different sensitivity to ICIs. Therefore, we propose novel diagnostic and therapeutic strategies to improve the outcome of dMMR/MSI CRC patients.

Keywords:  Colorectal carcinoma; deficient mismatch repair; immune checkpoint inhibitors; microsatellite instability; resistance; tumor heterogeneity

DOI:  https://doi.org/10.37349/etat.2024.00231
Nat Biotechnol. 2024 Jul 02.

Patient-derived mini-colons enable long-term modeling of tumor-microenvironment complexity.

L Francisco Lorenzo-Martín, Nicolas Broguiere, Jakob Langer, Lucie Tillard, Mikhail Nikolaev, George Coukos, Krisztian Homicsko, Matthias P Lutolf.

Existing organoid models fall short of fully capturing the complexity of cancer because they lack sufficient multicellular diversity, tissue-level organization, biological durability and experimental flexibility. Thus, many multifactorial cancer processes, especially those involving the tumor microenvironment, are difficult to study ex vivo. To overcome these limitations, we herein implemented tissue-engineering and microfabrication technologies to develop topobiologically complex, patient-specific cancer avatars. Focusing on colorectal cancer, we generated miniature tissues consisting of long-lived gut-shaped human colon epithelia ('mini-colons') that stably integrate cancer cells and their native tumor microenvironment in a format optimized for real-time, high-resolution evaluation of cellular dynamics. We demonstrate the potential of this system through several applications: a comprehensive evaluation of drug effectivity, toxicity and resistance in anticancer therapies; the discovery of a mechanism triggered by cancer-associated fibroblasts that drives cancer invasion; and the identification of immunomodulatory interactions among different components of the tumor microenvironment. Similar approaches should be feasible for diverse tumor types.

DOI: https://doi.org/10.1038/s41587-024-02301-4
Clin Exp Med. 2024 Jul 03. 24(1): 143

Biomarkers to predict efficacy of immune checkpoint inhibitors in colorectal cancer patients: a systematic review and meta-analysis.

Hang Yu, Qingquan Liu, Keting Wu, Shuang Tang.

  Immune checkpoint inhibitors (ICIs) are approved to treat colorectal cancer (CRC) with mismatch-repair gene deficiency, but the response rate remains low. Value of current biomarkers to predict CRC patients' response to ICIs is unclear due to heterogeneous study designs and small sample sizes. Here, we aim to assess and quantify the magnitude of multiple biomarkers for predicting the efficacy of ICIs in CRC patients. We systematically searched MEDLINE, Embase, the Cochrane Library, and Web of Science databases (to June 2023) for clinical studies examining biomarkers for efficacy of ICIs in CRC patients. Random-effect models were performed for meta-analysis. We pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) for biomarkers predicting response rate and survival. 36 studies with 1867 patients were included in systematic review. We found that a lower pre-treatment blood neutrophil-to-lymphocyte ratio (n=4, HR 0.37, 95%CI 0.21-0.67) predicts good prognosis, higher tumor mutation burden (n=10, OR 4.83, 95%CI 2.16-10.78) predicts response to ICIs, and liver metastasis (n=16, OR 0.32, 95%CI 0.16-0.63) indicates resistance to ICIs, especially when combined with VEGFR inhibitors. But the predictive value of tumor PD-L1 expression (n=9, OR 1.01, 95%CI 0.48-2.14) was insignificant in CRC. Blood neutrophil-to-lymphocyte ratio, tumor mutation burden, and liver metastasis, but not tumor PD-L1 expression, function as significant biomarkers to predict efficacy of ICIs in CRC patients. These findings help stratify CRC patients suitable for ICI treatments, improving efficacy of immunotherapy through precise patient management. (PROSPERO, CRD42022346716).

Keywords:  Colorectal cancer; Immune checkpoint inhibitors; Immunotherapy; Predictive biomarkers; Prognosis; Response

DOI:  https://doi.org/10.1007/s10238-024-01408-x
Nat Commun. 2024 Jun 28. 15(1): 5493

Inter-cell type interactions that control JNK signaling in the Drosophila intestine.

Peng Zhang, Stephen M Pronovost, Marco Marchetti, Chenge Zhang, Xiaoyu Kang, Tahmineh Kandelouei, Christopher Li, Bruce A Edgar.

JNK signaling is a critical regulator of inflammation and regeneration, but how it is controlled in specific tissue contexts remains unclear. Here we show that, in the Drosophila intestine, the TNF-type ligand, Eiger (Egr), is expressed exclusively by intestinal stem cells (ISCs) and enteroblasts (EBs), where it is induced by stress and during aging. Egr preferentially activates JNK signaling in a paracrine fashion in differentiated enterocytes (ECs) via its receptor, Grindelwald (Grnd). N-glycosylation genes (Alg3, Alg9) restrain this activation, and stress-induced downregulation of Alg3 and Alg9 correlates with JNK activation, suggesting a regulatory switch. JNK activity in ECs induces expression of the intermembrane protease Rhomboid (Rho), driving secretion of EGFR ligands Keren (Krn) and Spitz (Spi), which in turn activate EGFR signaling in progenitor cells (ISCs and EBs) to stimulate their growth and division, as well as to produce more Egr. This study uncovers an N-glycosylation-controlled, paracrine JNK-EGFR-JNK feedforward loop that sustains ISC proliferation during stress-induced gut regeneration.

DOI: https://doi.org/10.1038/s41467-024-49786-w
Cancer Metab. 2024 Jun 28. 12(1): 18

Sulfatide imaging identifies tumor cells in colorectal cancer peritoneal metastases.

G M Sarcinelli, L Varinelli, S Ghislanzoni, F Padelli, D Lorenzini, A Vingiani, M Milione, M Guaglio, S Kusamura, M Deraco, G Pruneri, M Gariboldi, D Baratti, I Bongarzone.

  Even with systemic chemotherapy, cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy (HIPEC), peritoneal metastases (PM) remain a common site of disease progression for colorectal cancer (CRC) and are frequently associated with a poor prognosis. The mass spectrometry (MS) method known as Matrix-Assisted Laser Desorption/Ionization - Time of Flight (MALDI-TOF) is frequently used in medicine to identify structural compounds and biomarkers. It has been demonstrated that lipids are crucial in mediating the aggressive growth of tumors. In order to investigate the lipid profiles, particularly with regard to histological distribution, we used MALDI-TOF MS (MALDI-MS) and MALDI-TOF imaging MS (MALDI-IMS) on patient-derived tumor organoids (PDOs) and PM clinical samples. According to the MALDI-IMS research shown here, the predominant lipid signature of PDOs in PM tissues, glycosphingolipid (GSL) sulfates or sulfatides, or STs, is unique to the areas containing tumor cells and absent from the surrounding stromal compartments. Bioactive lipids are derived from arachidonic acid (AA), and AA-containing phosphatidylinositol (PI), or PI (18:0-20:4), is shown to be highly expressed in the stromal components. On the other hand, the tumor components contained a higher abundance of PI species with shorter and more saturated acyl chains (C34 and C36 carbons). The cellular subversion of PI and ST species may alter in ways that promote the growth, aggressiveness, and metastasis of tumor cells. Together, these findings suggest that the GSL/ST metabolic programming of PM may contain novel therapeutic targets to impede or halt PM progression.

Keywords:  Lipid; MALDI-imaging; Organoids; Peritoneal carcinomatosis; Sulfatide

DOI:  https://doi.org/10.1186/s40170-024-00345-3
J Cancer Prev. 2024 Jun 30. 29(2): 25-31

Ribosomal Protein L9 Maintains Stemness of Colorectal Cancer via an ID-1 Dependent Mechanism.

Eun-Hye Jeon, So-Young Park, Keon Uk Park, Yun-Han Lee.

  The identification of therapeutic target genes that are functionally involved in stemness is crucial to effectively cure patients with metastatic carcinoma. We have previously reported that inhibition of ribosomal protein L9 (RPL9) expression suppresses the growth of colorectal cancer (CRC) cells by inactivating the inhibitor of DNA-binding 1 (ID-1) signaling axis, which is functionally associated with cancer cell survival. In addition to cell proliferation, ID-1 is also involved in the maintenance of cancer stemness. Thus, we aimed in this study to investigate whether the function of RPL9 could correlate with CRC stem cell-like properties. Here, we demonstrated that siRNA silencing of RPL9 reduced the invasiveness and migrative capabilities of HT29 and HCT116 parental cell populations and the capacity for sphere formation in the HT29 parental cell population. CD133+ cancer stem cells (CSCs) were then separated from CD133- cancer cells of the HT29 parental cell culture and treated with RPL9-specific siRNAs to verify the effects of RPL9 targeting on stemness. As a result, knockdown of RPL9 significantly suppressed the proliferative potential of CD133+ colorectal CSCs, accompanied by a reduction in CD133, ID-1, and p-IκBα levels. In line with these molecular alterations, targeting RPL9 inhibited the invasion, migration, and sphere-forming capacity of CD133+ HT29 CSCs. Taken together, these findings suggest that RPL9 promotes CRC stemness via ID-1 and that RPL9 could be a potential therapeutic target for both primary CRC treatment and the prevention of metastasis and/or recurrence.

Keywords:  Colorectal cancer; Inhibitor of DNA-binding 1; Ribosomal protein L9; Stemness

DOI:  https://doi.org/10.15430/JCP.24.004
Cold Spring Harb Perspect Med. 2024 Jul 01. pii: a041548. [Epub ahead of print]

Interactions of Fatty Acid and Cholesterol Metabolism with Cellular Stress Response Pathways in Cancer.

Alina M Winkelkotte, Kamal Al-Shami, Adriano B Chaves-Filho, Felix C E Vogel, Almut Schulze.

Lipids have essential functions as structural components of cellular membranes, as efficient energy storage molecules, and as precursors of signaling mediators. While deregulated glucose and amino acid metabolism in cancer have received substantial attention, the roles of lipids in the metabolic reprogramming of cancer cells are less well understood. However, since the first description of de novo fatty acid biosynthesis in cancer tissues almost 70 years ago, numerous studies have investigated the complex functions of altered lipid metabolism in cancer. Here, we will summarize the mechanisms by which oncogenic signaling pathways regulate fatty acid and cholesterol metabolism to drive rapid proliferation and protect cancer cells from environmental stress. The review also discusses the role of fatty acid metabolism in metabolic plasticity required for the adaptation to changing microenvironments during cancer progression and the connections between fatty acid and cholesterol metabolism and ferroptosis.

DOI: https://doi.org/10.1101/cshperspect.a041548
Cell Death Dis. 2024 Jul 03. 15(7): 474

Selective PI3Kδ inhibitor TYM-3-98 suppresses AKT/mTOR/SREBP1-mediated lipogenesis and promotes ferroptosis in KRAS-mutant colorectal cancer.

Ya-Nan Zheng, Si-Yue Lou, Jun Lu, Fan-Li Zheng, Yong-Mei Tang, En-Jun Zhang, Sun-Liang Cui, Hua-Jun Zhao.

Colorectal cancer (CRC) is one of the most common tumors of the digestive system worldwide. KRAS mutations limit the use of anti-EGFR antibodies in combination with chemotherapy for the treatment of CRC. Therefore, novel targeted therapies are needed to overcome the KRAS-induced oncogenesis. Recent evidence suggests that inhibition of PI3K led to ferroptosis, a nonapoptotic cell death closely related to KRAS-mutant cells. Here, we showed that a selective PI3Kδ inhibitor TYM-3-98 can suppress the AKT/mTOR signaling and activate the ferroptosis pathway in KRAS-mutant CRC cells in a concentration-dependent manner. This was evidenced by the lipid peroxidation, iron accumulation, and depletion of GSH. Moreover, the overexpression of the sterol regulatory element-binding protein 1 (SREBP1), a downstream transcription factor regulating lipid metabolism, conferred CRC cells greater resistance to ferroptosis induced by TYM-3-98. In addition, the effect of TYM-3-98 was confirmed in a xenograft mouse model, which demonstrated significant tumor suppression without obvious hepatoxicity or renal toxicity. Taken together, our work demonstrated that the induction of ferroptosis contributed to the PI3Kδ inhibitor-induced cell death via the suppression of AKT/mTOR/SREBP1-mediated lipogenesis, thus displaying a promising therapeutic effect of TYM-3-98 in CRC treatment.

DOI: https://doi.org/10.1038/s41419-024-06848-7
Oncoimmunology. 2024 ;13(1): 2372886

Complete response of metastatic microsatellite-stable BRAF V600E colorectal cancer to first-line oxaliplatin-based chemotherapy and immune checkpoint blockade.

Anne Hansen Ree, Eirik Høye, Ying Esbensen, Ann-Christin R Beitnes, Anne Negård, Linn Bernklev, Linn Kruse Tetlie, Åsmund A Fretland, Hanne M Hamre, Christian Kersten, Eva Hofsli, Marianne G Guren, Halfdan Sorbye, Hilde L Nilsen, Kjersti Flatmark, Sebastian Meltzer.

  The randomized METIMMOX trial (NCT03388190) examined if patients with previously untreated, unresectable abdominal metastases from microsatellite-stable (MSS) colorectal cancer (CRC) might benefit from potentially immunogenic, short-course oxaliplatin-based chemotherapy alternating with immune checkpoint blockade (ICB). Three of 38 patients assigned to this experimental treatment had metastases from BRAF-mutant MSS-CRC, in general a poor-prognostic subgroup explored here. The ≥70-year-old females presented with ascending colon adenocarcinomas with intermediate tumor mutational burden (6.2-11.8 mutations per megabase). All experienced early disappearance of the primary tumor followed by complete response of all overt metastatic disease, resulting in progression-free survival as long as 20-35 months. However, they encountered recurrence at previously unaffected sites and ultimately sanctuary organs, or as intrahepatic tumor evolution reflected in the terminal loss of initially induced T-cell clonality in liver metastases. Yet, the remarkable first-line responses to short-course oxaliplatin-based chemotherapy alternating with ICB may offer a novel therapeutic option to a particularly hard-to-treat MSS-CRC subgroup.

Keywords:  BRAF mutation; T-cell receptor; colorectal cancer; immune checkpoint blockade; metastasis; microsatellite-stable; oxaliplatin

DOI:  https://doi.org/10.1080/2162402X.2024.2372886
Cancer Lett. 2024 Jul 03. pii: S0304-3835(24)00498-1. [Epub ahead of print] 217103

Loss-of-function mutation of REV1 (p.R704Q) mediates cetuximab primary resistance by activating autophagy in RAS-wild type metastatic colorectal cancer.

Ning Zhu, Yuwei Ding, Mi Mi, Jiawen Yang, Mengyuan Yang, Dan Li, Yan Zhang, Xuefeng Fang, Shanshan Weng, Ying Yuan.

  Cetuximab in combination with FOLFIRI/FOLFOX is the standard first-line treatment for patients with RAS wild-type metastatic colorectal cancer (mCRC). However, some patients experience rapid tumor progression after treatment with cetuximab (primary resistance). Our previous research identified a gene mutation, REV1 p.R704Q, which may be a key biomarker for primary cetuximab resistance. This study aimed to study the mechanism of cetuximab resistance caused by REV1 p.R704Q mutation and reveal a novel mechanism to induce cetuximab resistance. Sanger sequencing and multivariate clinical prognostic analysis of 208 patients with mCRC showed that REV1 p.R704Q mutation is an independent risk factor for tumor progression after treatment with cetuximab in patients with RAS wild-type mCRC (Hazard ratio=2.481, 95% Confidence interval: 1.389-4.431, P = 0.002). The sensitivity of REV1 p.R704Q mutant cell lines to cetuximab decreased in vitro Cell Counting Kit-8 assay and in vivo subcutaneous tumor model. In vitro, we observed that decreased stability and accelerated degradation of REV1 mutant protein results in REV1 dysfunction, which activated autophagy and mediated cetuximab resistance. These findings suggested that REV1 p.R704Q mutation could predict cetuximab primary resistance in mCRC. REV1 p.R704Q mutation caused decreased stability and degradation of REV1 protein, as well as dysfunction of p.R704Q protein. REV1 p.R704Q mutation activates autophagy and mediates cetuximab resistance; further, inhibition of autophagy could reverse cetuximab resistance.

Keywords:  Autophagy; Cetuximab; DNA Translesion synthesis; Drug resistance; Metastatic colorectal cancer; REV1

DOI:  https://doi.org/10.1016/j.canlet.2024.217103
Cancer Genomics Proteomics. 2024 Jul-Aug;21(4):21(4): 395-398

Expression of PD-L1 Is Increased by Methionine Restriction Using Recombinant Methioninase in Human Colorectal Cancer Cells.

Kohei Mizuta, Byung Mo Kang, Qinghong Han, Yutaro Kubota, Sei Morinaga, Motokazu Sato, Michael Bouvet, Yasunori Tome, Kotaro Nishida, Robert M Hoffman.

  BACKGROUND/AIM: It has been recently demonstrated that a methionine-restricted diet increases the response to immune checkpoint inhibitors (ICIs) via an increase in PD-L1 in a syngeneic mouse colorectal-cancer model. Our laboratory has developed recombinant methioninase (rMETase) to restrict methionine. The aim of the present study was to determine if rMETase can increase PD-L1 expression in a human colorectal cancer cell line in vitro.MATERIALS AND METHODS: We evaluated the half-maximal inhibitory concentration (IC50) value of rMETase on HCT-116 human colorectal cancer cells. HCT-116 cells were treated with rMETase at the IC50 Western immunoblotting was used to compare PD-L1 expression in HCT-116 cells treated with and without rMETase.
RESULTS: The IC50 value of rMETase on HCT-116 was 0.79 U/ml. Methionine restriction using rMETase increased PD-L1 expression compared to the untreated control (p<0.05).
CONCLUSION: Methionine restriction with rMETase up-regulates PD-L1 expression in human colorectal cancer cells and the combination of rMETase and ICIs may have the potential to improve immunotherapy in human colorectal cancer.

Keywords:  Colorectal cancer; PD-L1; immune checkpoints; methionine restriction; recombinant methioninase (rMETase)

DOI:  https://doi.org/10.21873/cgp.20457
Am J Physiol Gastrointest Liver Physiol. 2024 Jul 02.

Forkhead box M1 mediates metabolic reprogramming in human colorectal cancer cells.

Po-Chen Li, Sheng-Yu Dai, Yu-Shun Lin, Yu-Tsen Chang, Chen-Chia Liu, I-Ching Wang, Ming-Fen Lee.

  Metabolic reprogramming is recognized as a hallmark of cancer, enabling cancer cells to acquire essential biomolecules for cell growth, often characterized by upregulated glycolysis and/or fatty acid synthesis-related genes. The transcription factor forkhead box M1 (FOXM1) has been implicated in various cancers, contributing significantly to their development, including colorectal cancer (CRC), a major global health concern. Despite FOXM1's established role in cancer, its specific involvement in the Warburg effect and fatty acid biosynthesis in CRC remains unclear. We analyzed The Cancer Genome Atlas (TCGA) Colonic Adenocarcinoma and Rectal Adenocarcinoma (COADREAD) datasets to to derive the correlation of the expression levels between FOXM1 and multiple genes and the survival prognosis based on FOXM1 expression. Using two human CRC cell lines, HT29 and HCT116, we conducted RNAi or plasmid transfection procedures, followed by a series of assays, including RNA extraction, quantitative real-time polymerase chain reaction, Western blot analysis, cell metabolic assays, and immunofluorescence analysis. Higher expression levels of FOXM1 correlated with a poorer survival prognosis, and the expression of FOXM1 was positively correlated with glycolysis-related genes SLC2A1 and LDHA, de novo lipogenesis-related genes ACACA and FASN, and MYC. FOXM1 appeared to modulate AKT/mTOR signaling, the expression of c-Myc, proteins related to glycolysis and fatty acid biosynthesis, as well as extracellular acidification rate in HT29 and HCT116 cells. In summary, FOXM1 plays a regulatory role in glycolysis, fatty acid biosynthesis, and cellular energy consumption, thereby influencing CRC cell growth and patient prognosis.

Keywords:  FOXM1; Warburg effect; colorectal cancer; de novo lipogenesis; metabolic reprogramming

DOI:  https://doi.org/10.1152/ajpgi.00032.2024
Npj Imaging. 2024 ;2(1): 18

In vivo organoid growth monitoring by stimulated Raman histology.

Barbara Sarri, Véronique Chevrier, Flora Poizat, Sandro Heuke, Florence Franchi, Louis De Franqueville, Eddy Traversari, Jean-Philippe Ratone, Fabrice Caillol, Yanis Dahel, Solène Hoibian, Marc Giovannini, Cécile de Chaisemartin, Romain Appay, Géraldine Guasch, Hervé Rigneault.

  Patient-derived tumor organoids have emerged as a crucial tool for assessing the efficacy of chemotherapy and conducting preclinical drug screenings. However, the conventional histological investigation of these organoids necessitates their devitalization through fixation and slicing, limiting their utility to a single-time analysis. Here, we use stimulated Raman histology (SRH) to demonstrate non-destructive, label-free virtual staining of 3D organoids, while preserving their viability and growth. This novel approach provides contrast similar to conventional staining methods, allowing for the continuous monitoring of organoids over time. Our results demonstrate that SRH transforms organoids from one-time use products into repeatable models, facilitating the efficient selection of effective drug combinations. This advancement holds promise for personalized cancer treatment, allowing for the dynamic assessment and optimization of chemotherapy treatments in patient-specific contexts.

Keywords:  Biomedical engineering; Cancer imaging; Multiphoton microscopy

DOI:  https://doi.org/10.1038/s44303-024-00019-1
Int Cancer Conf J. 2024 Jul;13(3): 189-192

BRAF-mutant microsatellite-stable rectal cancer with acquired KRAS mutation leading to drug resistance in liver metastasis.

Kunitoshi Shigeyasu, Hideki Yamamoto, Toshiaki Takahashi, Kazuya Moriwake, Masashi Kayano, Sho Takeda, Yuki Matsumi, Yuzo Umeda, Yoshitaka Kondo, Fuminori Teraishi, Kazuya Yasui, Tomokazu Fuji, Shunsuke Kagawa, Toshiyoshi Fujiwara.

  BRAF-mutant microsatellite-stable colorectal cancer (CRC), metastasized to distant sites, is associated with a poor prognosis. However, the BEACON CRC regimen, comprising a BRAF inhibitor, MEK inhibitor, and anti-EGFR antibody, offered a prolonged prognosis. Nonetheless, resistance to this regimen may occur, as observed in our reported case of CRC, where a KRAS mutation was identified in addition to the BRAF V600E mutation. Here, we present a case of 74-year-old woman with rectal cancer (pT4bN1bM0 Stage IIIc) harboring the BRAF V600E mutation. After resection of the primary tumor and during adjuvant chemotherapy using CAPOX (capecitabine and oxaliplatin), liver and lung metastases became apparent, and a companion diagnosis test revealed the presence of a BRAF V600E mutation. The new lesions were deemed resistant to the CAPOX regimen, and we decided to introduce encorafenib and cetuximab. After resection of liver metastases, encorafenib and cetuximab were reintroduced, but a new lesion appeared in hepatic S7, indicating resistance to the encorafenib and cetuximab regimen. The resistant liver metastasis was subsequently resected. To elucidate the resistance mechanism, we conducted a comprehensive analysis using the FoundationOne CDx cancer gene panel test, revealing the presence of a KRAS Q61H mutation alongside the BRAF V600E mutation. Subsequent liquid biopsy after liver recurrence confirmed the persistence of the KRAS Q61H mutation. Our results highlight the significance of cancer genome profiling tests (CGP tests) and liquid biopsies in guiding treatment strategies for BRAF-mutant colorectal cancer. Therefore, CGP testing offers valuable information for treatment, even if it does not lead to new drug administrations.

Keywords:  BRAF; Colorectal cancer; KRAS; Resistance

DOI:  https://doi.org/10.1007/s13691-024-00678-2
Sci Rep. 2024 07 02. 14(1): 15195

An in vitro platform for quantifying cell cycle phase lengths in primary human intestinal epithelial cells.

Michael J Cotton, Pablo Ariel, Kaiwen Chen, Vanessa A Walcott, Michelle Dixit, Keith A Breau, Caroline M Hinesley, Katarzyna M Kedziora, Cynthia Y Tang, Anna Zheng, Scott T Magness, Joseph Burclaff.

  The intestinal epithelium dynamically controls cell cycle, yet no experimental platform exists for directly analyzing cell cycle phases in non-immortalized human intestinal epithelial cells (IECs). Here, we present two reporters and a complete platform for analyzing cell cycle phases in live primary human IECs. We interrogate the transcriptional identity of IECs grown on soft collagen, develop two fluorescent cell cycle reporter IEC lines, design and 3D print a collagen press to make chamber slides for optimal imaging while supporting primary human IEC growth, live image cell cycle dynamics, then assemble a computational pipeline building upon free-to-use programs for semi-automated analysis of cell cycle phases. The PIP-FUCCI construct allows for assigning cell cycle phase from a single image of living cells, and our PIP-H2A construct allows for semi-automated direct quantification of cell cycle phase lengths using our publicly available computational pipeline. Treating PIP-FUCCI IECs with oligomycin demonstrates that inhibiting mitochondrial respiration lengthens G1 phase, and PIP-H2A cells allow us to measure that oligomycin differentially lengthens S and G2/M phases across heterogeneous IECs. These platforms provide opportunities for future studies on pharmaceutical effects on the intestinal epithelium, cell cycle regulation, and more.

Keywords:  Cell cycle phase; Collagen press; Fluorescent reporter; Intestinal stem cell; Live imaging analysis

DOI:  https://doi.org/10.1038/s41598-024-66042-9
Nat Commun. 2024 Jun 29. 15(1): 5502

CRISPR screens reveal convergent targeting strategies against evolutionarily distinct chemoresistance in cancer.

Chunge Zhong, Wen-Jie Jiang, Yingjia Yao, Zexu Li, You Li, Shengnan Wang, Xiaofeng Wang, Wenjuan Zhu, Siqi Wu, Jing Wang, Shuangshuang Fan, Shixin Ma, Yeshu Liu, Han Zhang, Wenchang Zhao, Lu Zhao, Yi Feng, Zihan Li, Ruifang Guo, Li Yu, Fengyun Pei, Jun Hu, Xingzhi Feng, Zihuan Yang, Zhengjia Yang, Xueying Yang, Yue Hou, Danni Zhang, Dake Xu, Ren Sheng, Yihao Li, Lijun Liu, Hua-Jun Wu, Jun Huang, Teng Fei.

Resistance to chemotherapy has been a major hurdle that limits therapeutic benefits for many types of cancer. Here we systematically identify genetic drivers underlying chemoresistance by performing 30 genome-scale CRISPR knockout screens for seven chemotherapeutic agents in multiple cancer cells. Chemoresistance genes vary between conditions primarily due to distinct genetic background and mechanism of action of drugs, manifesting heterogeneous and multiplexed routes towards chemoresistance. By focusing on oxaliplatin and irinotecan resistance in colorectal cancer, we unravel that evolutionarily distinct chemoresistance can share consensus vulnerabilities identified by 26 second-round CRISPR screens with druggable gene library. We further pinpoint PLK4 as a therapeutic target to overcome oxaliplatin resistance in various models via genetic ablation or pharmacological inhibition, highlighting a single-agent strategy to antagonize evolutionarily distinct chemoresistance. Our study not only provides resources and insights into the molecular basis of chemoresistance, but also proposes potential biomarkers and therapeutic strategies against such resistance.

DOI: https://doi.org/10.1038/s41467-024-49673-4
Apoptosis. 2024 Jul 03.

Targeted delivery of FAK siRNA by engineered exosomes to reverse cetuximab resistance via activating paraptosis in colon cancer.

Yiting Geng, Wei Xia, Xiao Zheng, Lujun Chen, You Zhou, Jun Feng, Ye Yuan, Mingyue Zhang, Jianwen Lu, Shanshan Wei, Wenwei Hu.

  BACKGROUND: Cetuximab is extensively used in the treatment of metastatic colorectal cancer (mCRC). However, resistance poses a significant challenge to successful therapy. Recently, paraptosis, a non-classical programmed cell death, has garnered increased attention for its potential application value in antitumor treatments. We aimed to identify the essential pathways and signaling molecules involved in paraptosis inhibition and select them as therapeutic targets in cetuximab resistance. Additionally, engineered exosome technology is used as a drug delivery system with both targeted and effector properties.RESULTS: By comparing the differential expression of paraptosis-related genes between drug-resistant colon cancer cells and sensitive cells, it was observed that the paraptosis level induced by cetuximab was significantly downregulated in drug-resistant cells. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified the focal adhesion kinase (FAK) signaling pathway as a key pathway involved in the suppression of paraptosis. The biological function of FAK in cetuximab-resistant cells was investigated through cell morphology observation, CCK-8 assay, colony formation assay, RT-qPCR, Western Blot, and loss-of-function experiments. The results showed that the FAK signaling pathway was significantly upregulated in cetuximab-resistant colon cancer cells, and siRNA interference targeting FAK could notably inhibit cell proliferation while upregulating the paraptosis level. Based on this, engineered colon cancer cells targeted and FAK siRNA loaded exosomes (CT-Exo-siFAK1) were constructed. In vitro experiments, CT-Exo-siFAK1 could effectively activate paraptosis and inhibit the proliferation of drug-resistant colon cancer cells. In vivo experiments also confirmed that CT-Exo-siFAK1 significantly suppressed tumor growth and metastasis while upregulating the paraptosis level.
CONCLUSION: This study suggests that FAK signaling pathway-mediated inhibition of paraptosis levels is crucial in the sensitivity of cetuximab targeted therapy in colon cancer, and the use of engineered exosomes to deliver FAK siRNA may be an effective strategy to reverse cetuximab resistance.

Keywords:  Cetuximab resistance; Colorectal cancer; Engineered exosome; FAK; Paraptosis

DOI:  https://doi.org/10.1007/s10495-024-01986-x
iScience. 2024 Jun 21. 27(6): 110118

Organoids as regenerative medicine for inflammatory bowel disease.

Alexander Hammerhøj, Deepavali Chakravarti, Toshiro Sato, Kim Bak Jensen, Ole Haagen Nielsen.

  Inflammatory bowel disease (IBD) is a chronic disorder with an increasing global prevalence. Managing disease activity relies on various pharmacological options. However, the effectiveness of current therapeutics is limited and not universally applicable to all patients and circumstances. Consequently, developing new management strategies is necessary. Recent advances in endoscopically obtained intestinal biopsy specimens have highlighted the potential of intestinal epithelial organoid transplantation as a novel therapeutic approach. Experimental studies using murine and human organoid transplantations have shown promising outcomes, including tissue regeneration and functional recovery. Human trials with organoid therapy have commenced; thus, this article provides readers with insights into the necessity and potential of intestinal organoid transplantation as a new regenerative therapeutic option in clinical settings and explores its associated challenges.

Keywords:  Cell biology; Immunology; Molecular biology; Stem cells research

DOI:  https://doi.org/10.1016/j.isci.2024.110118