Aerobic Glycolysis In Cancer Cells Research Articles

Natural flavonoids as promising lactate dehydrogenase A inhibitors: Comprehensive in vitro and in silico analysis.

The inhibitory potential of 17 flavonoids on lactate dehydrogenase A (LDHA), a key enzyme in the downstream process of aerobic glycolysis in cancer cells, is investigated. Fisetin exhibited excellent inhibitory activity (IC50 = 0.066 µM). Quercetin 3-β-D-glucoside, quercetin 3-galactoside, luteolin, neoeriocitrin, and luteolin 7-O-β-D-glucoside showed good inhibitory activity (IC50 = 1.397-15.730 µM). Biochanin A, baicalein, quercetin, scutellarein-7-glucuronide, diosmetin, baicalein 7-O-β-D-glucuronide, and apigenin 7-apioglucoside demonstrated moderate inhibitory activity (IC50 = 33.007-86.643 µM). Eriodictyol, quercetin 7-O-β-D-glucoside, apigenin 7-O-β-D-glucoside, and epicatechin were inactive. The Lineweaver-Burk plot showed that fisetin competitively inhibits NADH binding (Ki = 0.024 µM). Ki values for other compounds were calculated using the Cheng-Prusoff equation (Ki = 0.2799-2.1661 µM). The study revealed that the inhibitory effect of flavonoids varies with the number and position of OH groups and bound sugars. Molecular docking analyses indicated that flavonoids exhibited strong interactions with the NADH binding site of LDHA through hydrophobic interactions and hydrogen bonds. Molecular dynamic simulations tested the stability of the fisetin-LDHA complex over 100 ns and showed fisetin's high binding affinity to LDHA, maintaining strong hydrogen bonds. The binding energy of fisetin with LDHA was -33.928 kcal/mol, indicating its effectiveness as an LDHA inhibitor. Consequently, flavonoids identified as strong inhibitors could be potential cancer treatment sources through LDHA inhibition.

Emerging Roles of ncRNAs Regulating PKM2 in Cancer Progression.

Cancer is one of the main reasons for death, and it threatens human life and health. Both the environment and genes can lead to cancers. It dates back more than a million years; more importantly, tumor cells can not be detected until they grow to a large number. Currently, cancers are treated with surgical excision or non-surgical procedures. By studying the interaction between ncRNAs and PKM2, we aim to provide new targets for diagnosis, treatment, and prognosis for cancers. Read relevant articles and made a summary and classification. Non-coding RNAs (ncRNAs) are RNAs that do not code for proteins. They perform a function in transcription and translation and can be used as targets for cancer therapy. Pyruvate kinase M2 (PKM2) is a form of PKM, and it catalyzes the glycolysis of the final cellular processes to promote tumorigenesis. Not only that, but it also plays non-metabolic functions, including the expression of the gene, cell proliferation, cell migration, and tumor angiogenesis in cancer cells. The existing studies have found that microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) can promote or inhibit the aerobic glycolysis of cancer cells by affecting PKM2, which increases or decrease the risk of cancers and affect the progression of cancers. This review focuses on the mechanism of ncRNAs regulating PKM2 in cancers and summarizes the roles of some ncRNAs.

Association of 18F- fluorodeoxyglucose uptake with the expression of metabolism-related molecules in papillary thyroid cancer

Objectives18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET/CT) is a diagnostic imaging method that is based on the Warburg effect, which is the increased uptake of glucose through aerobic glycolysis in cancer cells. The diagnostic value of 18F-FDG-PET/CT for thyroid cancer is controversial. However, uptake of 18F-FDG and the corresponding maximum standardized uptake value (SUVmax) is expected to reflect the metabolic status of cancer cells. In the present study, we sought to determine the relationship between 18F-FDG uptake and tumor metabolism- associated factors. MethodsThis was a single-center retrospective study. In the present study, SUVmax was compared with the expression of hexokinase 2 (HK2), glucose transporter 1 (GLUT1), vascular endothelial growth factor (VEGF), and glutaminase 1 (GLS1) in 41 patients with thyroid cancer. ResultsGLS1 expression was found to be moderately correlated with SUVmax (p < 0.001, r = 0.51), whereas HK2 and VEGF expression were weakly correlated (p = 0.011, r = 0.28, p = 0.008, r = 0.29, respectively) and GLUT1 did not correlate with SUVmax (p = 0.62, r = 0.06). ConclusionOur findings suggest 18F-FDG PET/CT reflects GLS1 expression in thyroid cancer and could be used to select suitable candidates for GLS1 inhibitor treatment.

Abstract 3074: Regulating lactate levels in triple negative breast cancer presents a promising avenue for therapeutic intervention

Abstract Introduction: Among all subtypes of breast cancer, triple-negative breast cancer (TNBC) is associated with the most unfavorable prognosis, emphasizing the critical need to pinpoint therapeutic targets tailored to TNBCs. Lactate, produced as a by-product of aerobic glycolysis, acts as an oncometabolite and plays a substantial role in promoting tumor aggressiveness, particularly in TNBCs. In our ongoing laboratory investigations, we are actively exploring strategies to mitigate the influence of lactate on TNBCs. Methods: The experiments utilized two triple-negative breast cancer (TNBC) cell lines, i.e., MDA-MB231 and MDA-MB468. The inhibitors employed in this study are FOXY5, XAV939, PFK15, and Quercetin. Protein expression was examined using Western blotting and Immunofluorescence assays. Trans-well and wound healing assays were employed to assess cell migration and invasion. Colony formation assays (CFU) were utilized to investigate stem cell potential and proliferation. In vivo experiments were conducted using 4T1-orthotopic Balb/c mice. Results: Using triple-negative breast cancer (TNBC) cells, we have demonstrated the pivotal role of the WNT/β-catenin signaling pathway in promoting the generation of extracellular lactate, thus driving the progression and metastasis of TNBCs. Additionally, we have shown that inhibiting lactate production in TNBC cells, and consequently impeding cell migration and invasion, can be achieved by using recombinant WNT5A or its mimicking hexa-peptide FOXY5. Similarly, employing a β-catenin inhibitor such as XAV939 can yield comparable outcomes in relation to TNBC cells. In an alternative approach, we conducted inhibition experiments targeting PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase), a key regulator of aerobic glycolysis in cancer cells. Our findings indicate that a combined approach involving siPFKL and iPFKFB3 is more promising in suppressing lactate production in TNBCs when compared to the effects of individual iPFKFB3 treatment. Conclusions: Our present investigations suggest that employing inhibitors targeting the WNT/β-catenin signaling pathway, PFKP, and PFKEB3 could be a promising therapeutic strategy to effectively reduce lactate levels in TNBCs. Citation Format: Chandra Prakash Prasad, Sheikh Mohammad Umar, Arundhathi Dev J. R., Akanksha Kashyap, Meetu Rathee. Regulating lactate levels in triple negative breast cancer presents a promising avenue for therapeutic intervention [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3074.

Metabolic Signature of Warburg Effect in Cancer: An Effective and Obligatory Interplay between Nutrient Transporters and Catabolic/Anabolic Pathways to Promote Tumor Growth.

Aerobic glycolysis in cancer cells, originally observed by Warburg 100 years ago, which involves the production of lactate as the end product of glucose breakdown even in the presence of adequate oxygen, is the foundation for the current interest in the cancer-cell-specific reprograming of metabolic pathways. The renewed interest in cancer cell metabolism has now gone well beyond the original Warburg effect related to glycolysis to other metabolic pathways that include amino acid metabolism, one-carbon metabolism, the pentose phosphate pathway, nucleotide synthesis, antioxidant machinery, etc. Since glucose and amino acids constitute the primary nutrients that fuel the altered metabolic pathways in cancer cells, the transporters that mediate the transfer of these nutrients and their metabolites not only across the plasma membrane but also across the mitochondrial and lysosomal membranes have become an integral component of the expansion of the Warburg effect. In this review, we focus on the interplay between these transporters and metabolic pathways that facilitates metabolic reprogramming, which has become a hallmark of cancer cells. The beneficial outcome of this recent understanding of the unique metabolic signature surrounding the Warburg effect is the identification of novel drug targets for the development of a new generation of therapeutics to treat cancer.

Erianin promotes apoptosis and inhibits Akt-mediated aerobic glycolysis of cancer cells.

Highly activated aerobic glycolysis provides the metabolic requirements for tumor cell growth and proliferation. Erianin, a natural product isolated from Dendrobium chrysotoxum Lindl, has been reported to exert antitumor activity in multiple cancers. However, whether Erianin exerts inhibitory effects on aerobic glycolysis and the inherent mechanism remain poorly defined in non-small cell lung cancer (NSCLC). Here, we showed that Erianin inhibited the cell viability and proliferation, and induced apoptosis in NSCLC cells. Moreover, Erianin overtly suppressed aerobic glycolysis via decreasing HK2 expression. Mechanistically, Erianin dose-dependently curbed the Akt-GSK3β signaling pathway phosphorylation activation, which afterwards downregulated HK2 expression. Meanwhile, Erianin inhibited HCC827 tumor growth in vivo. Taken together, our results suggest that the natural product Erianin can suppress aerobic glycolysis and exert potent anticancer effects via the Akt-GSK3β signaling pathway in NSCLC cells.

Abstract 6141: Mechanisms by which Mito-lonidamine inhibits EGFR mutant lung cancer

Abstract Lung cancer remains the leading cause of cancer mortality. Efficacious targeted therapy options are urgently needed for lung cancer prevention and treatment. Epidermal growth factor receptor (EGFR) mutant lung cancer represents about 15% of lung cancer cases generally occurring in patients with minimal to no smoking history and with higher prevalence in females. Linkages to environmental exposures have been postulated. Our group synthesized Mito-lonidamine (Mito-LND), a mitochondrial targeted analog of lonidamine which inhibits aerobic glycolysis in cancer cells. We previously identified that Mito-LND induces mitophagy in KRAS mutant lung cells and inhibits lung tumorigenesis and brain metastasis in vivo. Yet, the cancer inhibitory capacity of Mito-LND in EGFR mutant lung cancer has not been investigated. Viability staining assessed Mito-LND induced cell death in EGFR mutant cell lines PC9 (parent) and PC9BrM3 (brain metastatic). Transcriptomic profiling was conducted following Mito-LND treatment and results analyzed in Metacore to assess molecular changes. Deconvolution analysis interrogated alterations in immune cell populations. To discern cell death mechanisms, we evaluated FDA-approved inhibitors for autophagy (chloroquine, CQ), mitophagy/apoptosis (cyclosporin A, CsA) and necrosis (Ponatinib) in EGFR mutant cell lines using viability assays with Mito-LND treatment. In PC9 cells, the IC50 for Mito-LND at 24h and 48h was 1.5µM and 0.5µM, respectively and in PC9BrM3 cells at 24h and 48h was 1.5µM and 0.7µM, respectively. These data support that EGFR mutant cell lines are &amp;gt;2-fold more sensitive to Mito-LND induced cell death compared to KRAS mutant lung cell lines H2030 and H2030BrM3. Transcriptomic profiling results show that Mito-LND treatment upregulated pathway maps linked to heat shock protein and HIF-1A signaling in both PC9 and PC9BrM3 cells. Process networks linked to unfolded protein response, response to hypoxia and oxidative stress, apoptosis and the immune response were upregulated with Mito-LND treatment. Deconvolution analysis revealed monocytes and macrophages were upregulated in Mito-LND treated EGFR mutant cell lines, with CD8+ T cells increased in PC9BrM3 cells and regulatory T cells increased in PC9 cells. Last, CsA significantly inhibited Mito-LND induced cell death in both cell lines, while CQ had no effect suggesting blocking apoptosis, but not late autophagy inhibits cell death induction in EGFR mutant cell lines. Further, necrosis inhibition with Ponatinib synergistically increased Mito-LND induced cell death in EGFR mutant cell lines. These results begin to define the cancer inhibitory mechanisms of Mito-LND in EGFR mutant lung cancer cells which appear to differ from those observed in KRAS mutant lung cancer cells. Future directions include dissecting apoptotic and necrosis driven Mito-LND induced cell death using additional pharmacological inhibitors and genetic approaches. Citation Format: Katherine M. Weh, Connor Howard, Yun Zhang, Jean-Jack Riethoven, Jennifer Clarke, Gang Cheng, Balaraman Kalyanaraman, Ming You, Laura Kresty. Mechanisms by which Mito-lonidamine inhibits EGFR mutant lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6141.

Discovery and validation of new Hv1 proton channel inhibitors with onco-therapeutic potential

The voltage-gated hydrogen channel Hv1 encoded in humans by the HVCN1 gene is a highly selective proton channel that allows large fluxes of protons across biological membranes. Hv1 form functional dimers of four transmembrane spanning proteins resembling the voltage sensing domain of potassium channels. Each subunit is highly selective for protons and is controlled by changes in the transmembrane voltage and pH gradient. Hv1 is most expressed in phagocytic cells where it sustains NADPH oxidase-dependent bactericidal function and was reported to facilitate antibody production by B cells and to promote the maturation and motility of spermatocytes. Hv1 contributes to neuroinflammation following brain damage and favors cancer progression possibly by extruding protons generated during aerobic glycolysis of cancer cells. Lack of specific Hv1 inhibitors has hampered translation of this knowledge to treat immune, fertility, or malignancy diseases. In this study, we show that the genetic deletion of Hv1 delays tumor development in a mouse model of granulocytic sarcoma and report the discovery and characterization of two novel bioavailable inhibitors of Hv1 channels that we validate by orthogonal assays and electrophysiological recordings.

MiR-19a-3p Promotes Aerobic Glycolysis in Ovarian Cancer Cells via IGFBP3/PI3K/AKT Pathway.

Aerobic glycolysis is a prominent feature of cancer. Here, we reported that miR-19a-3p promotes aerobic glycolysis in ovarian cancer cells SKVO3 and ES-2 by increased production of ATP, lactic acid, extracellular acidification (ECAR), and increased expression of PKM2, LDHA, GLUT1 and GLUT3. Further study showed that over-expression of IGFBP3, the target of miR-19a-3p, decreases aerobic glycolysis in ovarian cancer cells, while knockdown of IGFBP3 expression increases aerobic glycolysis. The rescue assay suggested that miR-19a-3p promotes aerobic glycolysis in ovarian cancer cells through targeting IGFBP3. Moreover, over-expression of miR-19a-3p or silencing of IGFBP3 expression promoted activation of AKT, which is important for aerobic glycolysis in cancer cells, indicating that miR-19a-3p promotes aerobic glycolysis in ovarian cancer cells through the IGFBP3/PI3K/AKT pathway. This suggests that miR-19a-3p and IGFBP3 may serve as potential treatment targets of ovarian cancer.

MiR-194-5p suppresses the warburg effect in ovarian cancer cells through the IGF1R/PI3K/AKT axis

Background: The Warburg effect is considered as a hallmark of various types of cancers, while the regulatory mechanism is poorly understood. Our previous study demonstrated that miR-194-5p directly targets and regulates insulin-like growth factor1 receptor (IGF1R). In this study, we aimed to investigate the role of miR-194-5p in the regulation of the Warburg effect in ovarian cancer cells. Methods: The stable ovarian cell lines with miR-194-5p overexpression or silencing IGF1R expression were established by lentivirus infection. ATP generation, glucose uptake, lactate production and extracellular acidification rate (ECAR) assay were used to analyze the effects of aerobic glycolysis in ovarian cancer cells. Gene expression was analyzed by quantitative polymerase chain reaction (qPCR) and western blot. Immunohistochemistry assays were performed to assess the expression of the IGF1R protein in ovarian cancer tissues. Results: Overexpression of miR-194-5p or silencing IGF1R expression in ovarian cancer cells decreases ATP generation, glucose uptake, lactate production, and ECAR and inhibits both the mRNA and protein expression of PKM2, LDHA, GLUT1, and GLUT3. While the knockdown of miR-194-5p expression led to opposite results. Overexpression of miR-194-5p or silencing IGF1R expression suppressed the phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathway, whose activation can sustain aerobic glycolysis in cancer cells, and the knockdown of miR-194-5p expression promoted the activation of the PI3K/AKT pathway. Conclusion: Our results suggest that miR- 194-5p can inhibit the Warburg effect by negative regulation of IGF1R and further repression of the PI3K/AKT pathway, which provides a theoretical basis for further test of miR-194-5p as a target in the treatment of ovarian cancer.

A 15 Year Evolution of Dichloroacetate-Based Metabolic Cancer Therapy: A Review with Case Reports

Despite Otto Warburg’s discovery of aerobic glycolysis in cancer cells in the 1920’s, the potential for developing therapeutics that targeted cancer cell metabolism was essentially ignored until 2007 when a groundbreaking publication was released from a group of Canadian researchers. Bonnet et al. (who paradoxically were not specialized in oncology) discovered that the generic drug dichloroacetate sodium (“DCA”) could reverse the Warburg phenotype in cancer cells in vitro and in vivo resulting in natural cancer cell suicide and tumour shrinkage in rats. This phenomenon was previously thought to be impossible as it was believed that mitochondria in malignant cells were permanently altered and unable to trigger apoptosis. Despite the fact that no large clinical trial of DCA as a cancer therapy was ever completed, a small number of doctors in North America and Europe rapidly translated this new knowledge into clinical cancer protocols through independent observational research and creative thinking. Since off-label drug use is permitted in most jurisdictions, clinicians initially began to use DCA in patients who had failed all conventional therapies. Over the years, further novel anti-cancer mechanisms of DCA were discovered such as angiogenesis inhibition, immune activation and cancer stem cell targeting. Around 2011, the work of Seyfried (USA) began to illuminate the importance of glutamine inhibition and suggested that a multi-energetic targeted approach was superior to glycolysis inhibition alone. A collaborative effort of the authors incorporating Seyfried’s concepts resulted in the creation of a new metabolic protocol named “MOMENTUM” (Metabolic, Oncologic, Multi-ENergetic Targeted, Universal, Modified). In this protocol, glucose and glutamine metabolism were targeted simultaneously with a combination of multiple natural and pharmacologic agents administered intravenously. Surprising preliminary clinical results in several difficult cancer cases confirmed that metabolic multi-targeted methods are extremely promising, and more so than metabolic monotherapy. Life threatening side effects of this approach to cancer management are virtually non-existent and therapy costs are manageable. A disappointing absence of industry funding for large clinical trials has not curtailed the development of the metabolic approach as a clinically viable methodology, proving that unadulterated medical science can conquer the ongoing push for multibillion-dollar economic reward.

Abstract PR001: Mechanisms by which Mito-LND inhibits KRAS mutant lung cancer

Abstract Lung cancer remains the most frequently diagnosed cancer and leading cause of cancer mortality in the United States and worldwide. Efficacious targeted options are urgently needed for lung cancer prevention and treatment. Approximately 30% of non-small cell lung cancer cases have KRAS mutations, yet pharmacological targeting has eluded the scientific community due to structural and biochemical properties of the KRAS protein. We recently synthesized Mito-lonidamine (Mito-LND), a mitochondrial targeted analog of lonidamine which inhibits aerobic glycolysis in cancer cells. We identified that Mito-LND induces autophagy, specifically mitophagy, preferentially in KRAS mutant lung adenocarcinoma cells and inhibits lung tumor development and brain metastasis in vivo. The cancer inhibitory mechanisms by which Mito-LND induces mitophagy, including requisite receptors and effects on immune signaling cascades remains unknown. We evaluated FDA-approved cell death inhibitors for autophagy (chloroquine; CQ), mitophagy (cyclosporin A; CsA) and necrosis (ponatinib) in KRAS (H2030 and H2030BrM3) mutant cells using cellular viability assays in combination with Mito-LND. siRNA was utilized to knockdown autophagy/mitophagy receptors (P62, PINK1, NDP52, OPTN and BECN1) in KRAS mutant cells, followed by Mito-LND treatment and viability assessments. Last, KRAS mutant cells were treated with Mito-LND to evaluate transcriptomic changes by RNA sequencing and deconvolution analysis performed to interrogate alterations in immune cell populations. CQ and CsA significantly inhibited Mito-LND induced cell death in H2030BrM3 cells. Interestingly, necrosis inhibition with ponatinib synergistically increased Mito-LND induced cell death in both cell lines. Of the receptors tested (P62, PINK1, OPTN and NDP52), NDP52 in H2030BrM3 cells appears requisite for Mito-LND induced cell death. Following transcriptomic sequencing, we conducted pathway analysis in Metacore on the significantly dysregulated genes (P and FDR&amp;lt;0.05). Mito-LND significantly upregulated heat shock protein signaling, HIF1A transcriptional targets, ER stress and the immune response. Downregulation of cell adhesion was noted in both cell lines, with changes in EMT and WNT signaling noted only in H2030 cells. Gene set enrichment analysis revealed TNFα signaling via NF-κB as the only hallmark significantly enriched by Mito-LND. Deconvolution analysis discerned alterations to T and B cell populations, highlighting a potential role for Mito-LND in modulating adaptive immunity. These results begin to define the cancer inhibitory mechanisms by which Mito-LND induces cancer cell death, including requisite receptors, signaling pathways and immune cell populations in KRAS mutant cells. Future directions include evaluating potential synergy of Mito-LND in combination with additional cell death and KRAS-targeting drugs as well as characterizing autophagy/mitophagy receptors in vivo utilizing chemically induced and genetically driven mouse models of lung carcinogenesis. Citation Format: Katherine M. Weh, Connor L. Howard, Yun Zhang, Jean-Jack Riethoven, Jennifer L. Clarke, Balaraman Kalyanaraman, Ming You, Laura A. Kresty. Mechanisms by which Mito-LND inhibits KRAS mutant lung cancer. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr PR001.

Girdin Promotes Tumorigenesis and Chemoresistance in Lung Adenocarcinoma by Interacting with PKM2.

Girdin, an Akt substrate, has been reported to promote tumorigenesis in various tumors. However, the role of Girdin in a spontaneous tumor model has not yet been explored. Here, we studied the role of Girdin in lung adenocarcinoma (LUAD) using the autochthonous mouse model and found that Girdin led to LUAD progression and chemoresistance by enhancing the Warburg effect. Mechanistically, Girdin interacted with pyruvate kinase M2 (PKM2), which played a vital role in aerobic glycolysis. Furthermore, Girdin impaired Platelet Derived Growth Factor Receptor Beta (PDGFRβ) degradation, which in turn, promoted PKM2 tyrosine residue 105 (Y105) phosphorylation and inhibited PKM2 activity, subsequently promoting aerobic glycolysis in cancer cells. Taken together, our study demonstrates that Girdin is a crucial regulator of tumor growth and may be a potential therapeutic target for overcoming the resistance of LUAD cells to chemotherapy.

Natural products targeting human lactate dehydrogenases for cancer therapy: A mini review.

Reprogramming cancer metabolism has become the hallmark of cancer progression. As the key enzyme catalyzing the conversion of pyruvate to lactate in aerobic glycolysis of cancer cells, human lactate dehydrogenase (LDH) has been a promising target in the discovery of anticancer agents. Natural products are important sources of new drugs. Up to now, some natural compounds have been reported with the activity to target LDH. To give more information on the development of LDH inhibitors and application of natural products, herein, we reviewed the natural compounds with inhibition of LDH from diverse structures and discussed the future direction of the discovery of natural LDH inhibitors for cancer therapy.

Mitochondrial metabolic determinants of multiple myeloma growth, survival, and therapy efficacy.

Multiple myeloma (MM) is a plasma cell dyscrasia characterized by the clonal proliferation of antibody producing plasma cells. Despite the use of next generation proteasome inhibitors (PI), immunomodulatory agents (IMiDs) and immunotherapy, the development of therapy refractory disease is common, with approximately 20% of MM patients succumbing to aggressive treatment-refractory disease within 2 years of diagnosis. A large emphasis is placed on understanding inter/intra-tumoral genetic, epigenetic and transcriptomic changes contributing to relapsed/refractory disease, however, the contribution of cellular metabolism and intrinsic/extrinsic metabolites to therapy sensitivity and resistance mechanisms is less well understood. Cancer cells depend on specific metabolites for bioenergetics, duplication of biomass and redox homeostasis for growth, proliferation, and survival. Cancer therapy, importantly, largely relies on targeting cellular growth, proliferation, and survival. Thus, understanding the metabolic changes intersecting with a drug’s mechanism of action can inform us of methods to elicit deeper responses and prevent acquired resistance. Knowledge of the Warburg effect and elevated aerobic glycolysis in cancer cells, including MM, has allowed us to capitalize on this phenomenon for diagnostics and prognostics. The demonstration that mitochondria play critical roles in cancer development, progression, and therapy sensitivity despite the inherent preference of cancer cells to engage aerobic glycolysis has re-invigorated deeper inquiry into how mitochondrial metabolism regulates tumor biology and therapy efficacy. Mitochondria are the sole source for coupled respiration mediated ATP synthesis and a key source for the anabolic synthesis of amino acids and reducing equivalents. Beyond their core metabolic activities, mitochondria facilitate apoptotic cell death, impact the activation of the cytosolic integrated response to stress, and through nuclear and cytosolic retrograde crosstalk maintain cell fitness and survival. Here, we hope to shed light on key mitochondrial functions that shape MM development and therapy sensitivity.

De novo pyrimidine synthesis fuels glycolysis and confers chemoresistance in gastric cancer

Metabolic reprogramming is a hallmark in multiple types of malignancies. Fast-growing cancer cells require facilitated synthesis of essential metabolites and excessive energy production. However, whether they are internally coordinated remains largely unknown. Herein, we found that de novo pyrimidine synthesis enhanced aerobic glycolysis in cancer cells. Mechanistically, pyrimidine biosynthesis augmented Notch signaling and transcriptionally increased c-Myc expression, leading to up-regulation of critical glycolytic enzymes. Further studies revealed that pyrimidine synthesis could stabilize γ-secretase subunit Nicastrin at post-translational N-linked glycosylation level, thereby inducing the cleavage and activation of Notch. Besides, we found that up-regulation of the key enzymes for de novo pyrimidine synthesis CAD and DHODH conferred the chemotherapeutic resistance of gastric cancer via accelerating glycolysis, and pharmacologic inhibition of pyrimidine biosynthetic pathway sensitized cancer cells to chemotherapy in vitro and in vivo. Collectively, our findings provide more insights into the regulation of aerobic glycolysis and a metabolic vulnerability that can be exploited to enhance chemotherapy efficacy in gastric cancer.

Abstract 5666: MyD88 in myofibroblasts regulates aerobic glycolysis-driven hepatocarcinogenesis via ERK-dependent PKM2 nuclear relocalization and activation

Abstract Hepatic stellate cells (HSCs) and cancer-associated fibroblasts (CAFs) play critical roles in liver fibrosis and hepatocellular carcinoma (HCC). MyD88 controls the expression of several key modifier genes in liver tumorigenesis; however, whether and how MyD88 in myofibroblasts contributes to the development of fibrosis-associated liver cancer remain elusive. Here, we used an established hepatocarcinogenesis mouse model involving apparent liver fibrogenesis, in which MyD88 was selectively depleted in myofibroblasts. Myofibroblast MyD88-deficient (Fib-MyD88 KO) mice developed significantly fewer and smaller liver tumor nodules. MyD88 deficiency in myofibroblasts attenuated liver fibrosis and aerobic glycolysis in hepatocellular carcinoma tissues. Mechanistically, MyD88 signaling in myofibroblasts increased the secretion of CCL20, which promoted aerobic glycolysis in cancer cells. This process was dependent on the CCR6 receptor and ERK/PKM2 signaling. Furthermore, liver tumor growth was greatly relieved when the mice were treated with a CCR6 inhibitor. Our data revealed a critical role for MyD88 in myofibroblasts in the promotion of hepatocellular carcinoma by affecting aerobic glycolysis in cancer cells and might provide a potential molecular therapeutic target for HCC. Citation Format: Qi Yuan, Jinhua Zhang. MyD88 in myofibroblasts regulates aerobic glycolysis-driven hepatocarcinogenesis via ERK-dependent PKM2 nuclear relocalization and activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5666.

Epigenetics, cell cycle and stem cell metabolism. Formation of insulin-producing cells

Stem cell (SC) differentiation requires a series of chromatin rearrangements to establish cell identity. Posttranslational modifications of histones usually regulate the dynamics of heterochromatin. Histones are subjected to various modifications, such as acetylation, methylation, phosphorylation and ubiquinination, and thus contribute to regulation of chromatin status and transcriptional activity. The chemically stable pattern of methylated histones promotes cellular memory relative to external stimuli, maintaining transcription levels of adaptive genes even after elimination of environmental signals. Chromatin modifications play an important role in the maturation of pancreatic islet cells, the establishment of a secretion pattern that stimulates the regulation of insulin secretion. MicroRNAs, a class of endogenous small noncoding RNAs in eukaryotes, are important regulators of gene expression at the level of posttranscriptional mechanisms. MicroRNAs regulate insulin secretion, pancreatic development, and β-cell differentiation. Pluripotent SCs are characterized by a high rate of proliferation, the ability to self-repair and the potential for differentiation in different cell types. This rapid proliferation is due to a modified cell cycle that allows cells to rapidly transition from DNA synthesis to cell division by reducing the time of gap (G1 and G2) phases. The canonical WNT/β-catenin signaling pathway is characterized as a major driver of cell growth and proliferation. At G1, WNT signaling induces a transition to the S-phase. Compared to their somatic counterparts, pluripotent SCs exhibit a high rate of glycolysis similar to aerobic glycolysis in cancer cells, a phenomenon known as the Warburg effect, which is important for maintaining SC properties. In stem cells, the extracellular influx of Ca2+ into the cytoplasm is mediated mainly by depot-controlled Ca2+ channels. Extracellular calcium has been shown to promote SC proliferation and thus may be involved in transplant therapy.

The Role of Endoplasmic Reticulum and Mitochondria in Maintaining Redox Status and Glycolytic Metabolism in Pluripotent Stem Cells.

Pluripotent stem cells (PSCs), including embryonic stem cells and induced pluripotent stem cells (iPSCs), can be applicable for regenerative medicine. They strangely rely on glycolysis metabolism akin to aerobic glycolysis in cancer cells. Upon differentiation, PSCs undergo a metabolic shift from glycolysis to oxidative phosphorylation (OXPHOS). The metabolic shift depends on organelles maturation, transcriptome modification, and metabolic switching. Besides, metabolism-driven chromatin regulation is necessary for cell survival, self-renewal, proliferation, senescence, and differentiation. In this respect, mitochondria may serve as key organelle to adapt environmental changes with metabolic intermediates which are necessary for maintaining PSCs identity. The endoplasmic reticulum (ER) is another organelle whose role in cellular identity remains under-explored. The purpose of our article is to highlight the recent progress on these two organelles' role in maintaining PSCs redox status focusing on metabolism. Topics include redox status, metabolism regulation, mitochondrial dynamics, and ER stress in PSCs. They relate to the maintenance of stem cell properties and subsequent differentiation of stem cells into specific cell types.

MyD88 in myofibroblasts regulates aerobic glycolysis-driven hepatocarcinogenesis via ERK-dependent PKM2 nuclear relocalization and activation.

Hepatic stellate cells (HSCs) and cancer-associated fibroblasts (CAFs) play critical roles in liver fibrosis and hepatocellular carcinoma (HCC). MyD88 controls the expression of several key modifier genes in liver tumorigenesis; however, whether and how MyD88 in myofibroblasts contributes to the development of fibrosis-associated liver cancer remains elusive. Here, we used an established hepatocarcinogenesis mouse model involving apparent liver fibrogenesis in which MyD88 was selectively depleted in myofibroblasts. Myofibroblast MyD88-deficient (Fib-MyD88 KO) mice developed significantly fewer and smaller liver tumor nodules. MyD88 deficiency in myofibroblasts attenuated liver fibrosis and aerobic glycolysis in hepatocellular carcinoma tissues. Mechanistically, MyD88 signaling in myofibroblasts increased the secretion of CCL20, which promoted aerobic glycolysis in cancer cells. This process was dependent on the CCR6 receptor and ERK/PKM2 signaling. Furthermore, liver tumor growth was greatly relieved when the mice were treated with a CCR6 inhibitor. Our data revealed a critical role for MyD88 in myofibroblasts in the promotion of hepatocellular carcinoma by affecting aerobic glycolysis in cancer cells and might provide a potential molecular therapeutic target for HCC. © 2021 The Pathological Society of Great Britain and Ireland.