bims-almceb 2022-01-02 papers

Issue of 2022‒01‒02
seven papers selected by
Camila Kehl Dias
Federal University of Rio Grande do Sul

Front Cell Dev Biol. 2021 ;9 767510

Metabolic Reprogramming and Cell Adhesion in Acute Leukemia Adaptation to the CNS Niche.

Nitesh D Sharma, Esra'a Keewan, Ksenia Matlawska-Wasowska.

Involvement of the Central Nervous System (CNS) in acute leukemia confers poor prognosis and lower overall survival. Existing CNS-directed therapies are associated with a significant risk of short- or long-term toxicities. Leukemic cells can metabolically adapt and survive in the microenvironment of the CNS. The supporting role of the CNS microenvironment in leukemia progression and dissemination has not received sufficient attention. Understanding the mechanism by which leukemic cells survive in the nutrient-poor and oxygen-deprived CNS microenvironment will lead to the development of more specific and less toxic therapies. Here, we review the current literature regarding the roles of metabolic reprogramming in leukemic cell adhesion and survival in the CNS.

Keywords: CNS; acute lymphoblastic leukemia; acute myeloid leukemia; cell adhesion; central nervous system; meninges; metabolism

DOI: https://doi.org/10.3389/fcell.2021.767510

Semin Immunol. 2021 Dec 25. pii: S1044-5323(21)00114-7. [Epub ahead of print] 101583

Neutrophil metabolism in the cancer context.

Anita Bodac, Etienne Meylan.

Neutrophils are critical innate immune cells for the host anti-bacterial defense. Throughout their lifecycle, neutrophils are exposed to different microenvironments and modulate their metabolism to survive and sustain their functions. Although tumor cell metabolism has been intensively investigated, how neutrophil metabolism is affected in cancer remains largely to be discovered. Neutrophils are described as mainly glycolytic cells. However, distinct tumor-associated neutrophil (TAN) states may co-exist in tumors and adapt their metabolism to exert different or even opposing activities ranging from tumor cell killing to tumor support. In this review, we gather evidence about the metabolic mechanisms that underly TANs' pro- or anti-tumoral functions in cancer. We first discuss how tumor-secreted factors and the heterogenous tumor microenvironment can have a strong impact on TAN metabolism. We then describe alternative metabolic pathways used by TANs to exert their functions in cancer, from basic glycolysis to more recently-recognized but less understood metabolic shifts toward mitochondrial oxidative metabolism, lipid and amino acid metabolism and even autophagy. Last, we discuss promising strategies targeting neutrophil metabolism to combat cancer.

Keywords: Cancer metabolism; Neutrophil metabolism; Tumor-associated neutrophils

DOI: https://doi.org/10.1016/j.smim.2021.101583

Appl Microsc. 2021 Dec 29. 51(1): 20

Ultrastructural changes in cristae of lymphoblasts in acute lymphoblastic leukemia parallel alterations in biogenesis markers.

Ritika Singh, Ayushi Jain, Jayanth Kumar Palanichamy, T C Nag, Sameer Bakhshi, Archna Singh.

We explored the link between mitochondrial biogenesis and mitochondrial morphology using transmission electron microscopy (TEM) in lymphoblasts of pediatric acute lymphoblastic leukemia (ALL) patients and compared these characteristics between tumors and control samples. Gene expression of mitochondrial biogenesis markers was analysed in 23 ALL patients and 18 controls and TEM for morphology analysis was done in 15 ALL patients and 9 healthy controls. The area occupied by mitochondria per cell and the cristae cross-sectional area was observed to be significantly higher in patients than in controls (p-value = 0.0468 and p-value< 0.0001, respectively). The mtDNA copy numbers, TFAM, POLG, and c-myc gene expression were significantly higher in ALL patients than controls (all p-values< 0.01). Gene Expression of PGC-1α was higher in tumor samples. The analysis of the correlation between PGC-1α expression and morphology parameters i.e., both M/C ratio and cristae cross-sectional area revealed a positive trend (r = 0.3, p = 0.1). The increased area occupied by mitochondria and increased cristae area support the occurrence of cristae remodelling in ALL. These changes might reflect alterations in cristae dynamics to support the metabolic state of the cells by forming a more condensed network. Ultrastructural imaging can be useful for affirming changes occurring at a subcellular organellar level.

Keywords: Acute lymphoblastic leukemia; Cristae; Electron microscopy; Mitochondrial biogenesis; Mitochondrial morphology

DOI: https://doi.org/10.1186/s42649-021-00069-4

Epigenomes. 2020 Mar 01. pii: 3. [Epub ahead of print]4(1):

Epigenetic Modulation of Self-Renewal Capacity of Leukemic Stem Cells and Implications for Chemotherapy.

Richard L Momparler, Sylvie Côté, Louise F Momparler.

Most patients with acute myeloid leukemia (AML) have a poor prognosis. Curative therapy of AML requires the complete eradication of the leukemic stem cells (LSCs). One aspect of LSCs that is poorly understood is their low frequency in the total population of leukemic cells in AML patients. After each cell division of LSCs, most of the daughter cells lose their capacity for self-renewal. Investigations into the role of Isocitrate dehydrogenase (IDH) mutations in AML provide some insight on the regulation of the proliferation of LSCs. The primary role of IDH is to convert isocitrate to alpha-keto-glutarate (α-KG). When IDH is mutated, it converts α-KG to 2-hydroxyglutarate (2-HG), an inhibitor of the TET pathway and Jumonji-C histone demethylases (JHDMs). The demethylating action of these enzymes removes the epigenetic gene-silencing markers, DNA methylation, H3K27me3 and H3K9me2 and can lead to the differentiation of LSCs. This enzymatic action is blocked by 2-HG in mutated IDH (mut-IDH) AML patients, who can be induced into remission with antagonists of 2-HG. These observations suggest that there exists in cells a natural enzymatic mechanism that uses demethylation to reverse epigenetic gene-silencing, leading to a loss of the self-renewal capacity of LSCs. This mechanism limits the proliferative potential of LSCs. Epigenetic agents that inhibit DNA and histone methylation exhibit a synergistic antineoplastic action on AML cells. It is possible that the therapeutic potential of this epigenetic therapy may be enhanced by demethylation enzymes, resulting in a very effective treatment for AML.

Keywords: 3-deazaplanocin-A; 5-aza-2′-deoxycytidine; DNA methylation; epigenetics; histone methylation; leukemic stem cells; self-renewal

DOI: https://doi.org/10.3390/epigenomes4010003

Drug Resist Updat. 2021 Dec 16. pii: S1368-7646(21)00057-1. [Epub ahead of print] 100797

Impact of cancer metabolism on therapy resistance - Clinical implications.

Ana Cristina Gonçalves, Elena Richiardone, Joana Jorge, Bárbara Polónia, Cristina P R Xavier, Iris Chiara Salaroglio, Chiara Riganti, M Helena Vasconcelos, Cyril Corbet, Ana Bela Sarmento-Ribeiro.

Despite an increasing arsenal of anticancer therapies, many patients continue to have poor outcomes due to the therapeutic failures and tumor relapses. Indeed, the clinical efficacy of anticancer therapies is markedly limited by intrinsic and/or acquired resistance mechanisms that can occur in any tumor type and with any treatment. Thus, there is an urgent clinical need to implement fundamental changes in the tumor treatment paradigm by the development of new experimental strategies that can help to predict the occurrence of clinical drug resistance and to identify alternative therapeutic options. Apart from mutation-driven resistance mechanisms, tumor microenvironment (TME) conditions generate an intratumoral phenotypic heterogeneity that supports disease progression and dismal outcomes. Tumor cell metabolism is a prototypical example of dynamic, heterogeneous, and adaptive phenotypic trait, resulting from the combination of intrinsic [(epi)genetic changes, tissue of origin and differentiation dependency] and extrinsic (oxygen and nutrient availability, metabolic interactions within the TME) factors, enabling cancer cells to survive, metastasize and develop resistance to anticancer therapies. In this review, we summarize the current knowledge regarding metabolism-based mechanisms conferring adaptive resistance to chemo-, radio-and immunotherapies as well as targeted therapies. Furthermore, we report the role of TME-mediated intratumoral metabolic heterogeneity in therapy resistance and how adaptations in amino acid, glucose, and lipid metabolism support the growth of therapy-resistant cancers and/or cellular subpopulations. We also report the intricate interplay between tumor signaling and metabolic pathways in cancer cells and discuss how manipulating key metabolic enzymes and/or providing dietary changes may help to eradicate relapse-sustaining cancer cells. Finally, in the current era of personalized medicine, we describe the strategies that may be applied to implement metabolic profiling for tumor imaging, biomarker identification, selection of tailored treatments and monitoring therapy response during the clinical management of cancer patients.

Keywords: Cancer metabolism; Glycolysis; Intratumor heterogeneity; Metabolic plasticity; Oxidative phosphorylation; Therapy resistance; Tumor microenvironment

DOI: https://doi.org/10.1016/j.drup.2021.100797

Front Oncol. 2021 ;11 797941

A Combined Histone Deacetylases Targeting Strategy to Overcome Venetoclax Plus Azacitidine Regimen Resistance in Acute Myeloid Leukaemia: Three Case Reports.

Bin-Ru Wang, Chao-Ling Wan, Song-Bai Liu, Qiao-Cheng Qiu, Tian-Mei Wu, Jun Wang, Yan-Yan Li, Shuai-Shuai Ge, Yan Qiu, Xiang-Dong Shen, Sheng-Li Xue, Zheng Li.

The management of patients with relapsed or refractory (R/R) acute myeloid leukaemia (AML) remains a challenge with few reliably effective treatments. Chidamide, a new selective HDAC inhibitor, has demonstrated some effectiveness in AML patients. Herein, we reported three patients with R/R AML who were unresponsive to venetoclax plus azacitidine (VA) but were successfully treated with VA when chidamide was added to the regimen. MCL1 is one of the anti-apoptotic proteins. Chidamide targets the MCL1 protein, which may permit venetoclax resistance when upregulated. We determined MCL1 protein expression in different AML cell lines, and chidamide could downregulate MCL1 expression in venetoclax resistance AML cells. In general, our experience showed that the chidamide/VA combination could improve the condition of R/R AML patients who are resistant to VA. Formally evaluating this regimen in R/R AML patients may be meaningful.

Keywords: R/R acute myeloid leukemia AML; chidamide; histon deacetylase inhibitors (HDACi); targeted therapy; venetoclax (BCL2 inhibitor)

DOI: https://doi.org/10.3389/fonc.2021.797941

Cell Rep. 2021 Dec 28. pii: S2211-1247(21)01651-X. [Epub ahead of print]37(13): 110155

SIRT2 regulates mitochondrial dynamics and reprogramming via MEK1-ERK-DRP1 and AKT1-DRP1 axes.

Young Cha, Taewoo Kim, Jeha Jeon, Yongwoo Jang, Patrick B Kim, Claudia Lopes, Pierre Leblanc, Bruce M Cohen, Kwang-Soo Kim.

During somatic reprogramming, cellular energy metabolism fundamentally switches from predominantly mitochondrial oxidative phosphorylation toward glycolysis. This metabolic reprogramming, also called the Warburg effect, is critical for the induction of pluripotency, but its molecular mechanisms remain poorly defined. Notably, SIRT2 is consistently downregulated during the reprogramming process and regulates glycolytic switch. Here, we report that downregulation of SIRT2 increases acetylation of mitogen-activated protein kinase (MAPK) kinase-1 (MEK1) at Lys175, resulting in activation of extracellular signal-regulated kinases (ERKs) and subsequent activation of the pro-fission factor dynamin-related protein 1 (DRP1). In parallel, downregulation of SIRT2 hyperacetylates the serine/threonine protein kinase AKT1 at Lys20 in a non-canonical way, activating DRP1 and metabolic reprogramming. Together, our study identified two axes, SIRT2-MEK1-ERK-DRP1 and SIRT2-AKT1-DRP1, that critically link mitochondrial dynamics and oxidative phosphorylation to the somatic reprogramming process. These upstream signals, together with SIRT2's role in glycolytic switching, may underlie the Warburg effect observed in human somatic cell reprogramming.

Keywords: AKT1; DRP1; MEK1-ERK axis; OXPHOS; SIRT2; Warburg-like effect; human somatic cell reprogramming; induced pluripotent stem cells; metabolic reprogramming; mitochondrial remodeling

DOI: https://doi.org/10.1016/j.celrep.2021.110155