Glycolysis In Pancreatic Cancer Research Articles

ROCK1 regulates glycolysis in pancreatic cancer via the c-MYC/PFKFB3 pathway

BackgroundDysregulation of Rho-associated coiled coil-containing protein kinases (ROCKs) is involved in the metastasis and progression of various malignant tumors. However, how one of the isomers, ROCK1, regulates glycolysis in tumor cells is incompletely understood. Here, we attempted to elucidate how ROCK1 influences pancreatic cancer (PC) progression by regulating glycolytic activity. MethodsThe biological function of ROCK1 was analyzed in vitro by establishing a silenced cell model. Coimmunoprecipitation confirmed the direct binding between ROCK1 and c-MYC, and a luciferase reporter assay revealed the binding of c-MYC to the promoter of the PFKFB3 gene. These results were verified in animal experiments. ResultsROCK1 was highly expressed in PC tissues and enriched in the cytoplasm, and its high expression was associated with a poor prognosis. Silencing ROCK1 inhibited the proliferation and migration of PC cells and promoted their apoptosis. Mechanistically, ROCK1 directly interacted with c-MYC, promoted its phosphorylation (Ser 62) and suppressed its degradation, thereby increasing the transcription of the key glycolysis regulatory factor PFKFB3, enhancing glycolytic activity and promoting PC growth. Silencing ROCK1 increased gemcitabine (GEM) sensitivity in vivo and in vitro. ConclusionsROCK1 promotes glycolytic activity in PC cells and promotes PC tumor growth through the c-MYC/PFKFB3 signaling pathway. ROCK1 knockdown can inhibit PC tumor growth in vivo and increase the GEM sensitivity of PC tumors, providing a crucial clinical therapeutic strategy for PC.

Tryptophan deficiency induced by indoleamine 2,3-dioxygenase 1 results in glucose transporter 1-dependent promotion of aerobic glycolysis in pancreatic cancer.

Indoleamine 2,3-dioxygenase 1 (IDO1), the key enzyme in the catabolism of the essential amino acid tryptophan (Trp) through kynurenine pathway, induces immune tolerance and is considered as a critical immune checkpoint, but its impacts as a metabolism enzyme on glucose and lipid metabolism are overlooked. We aim to clarify the potential role of IDO1 in aerobic glycolysis in pancreatic cancer (PC). Analysis of database revealed the positive correlation in PC between the expressions of IDO1 and genes encoding important glycolytic enzyme hexokinase 2 (HK2), pyruvate kinase (PK), lactate dehydrogenase A (LDHA) and glucose transporter 1 (GLUT1). It was found that IDO1 could modulate glycolysis and glucose uptake in PC cells, Trp deficiency caused by IDO1 overexpression enhanced glucose uptake by stimulating GLUT1 translocation to the plasma membrane of PC cells. Besides, Trp deficiency caused by IDO1 overexpression suppressed the apoptosis of PC cells via promoting glycolysis, which reveals the presence of IDO1-glycolysis-apoptosis axis in PC. IDO1 inhibitors could inhibit glycolysis, promote apoptosis, and exhibit robust therapeutic efficacy when combined with GLUT1 inhibitor in PC mice. Our study reveals the function of IDO1 in the glucose metabolism of PC and provides new insights into the therapeutic strategy for PC.

Cystatin B increases autophagic flux by sustaining proteolytic activity of cathepsin B and fuels glycolysis in pancreatic cancer: CSTB orchestrates autophagy and glycolysis in PDAC.

Both autophagy and glycolysis are essential for pancreatic ductal adenocarcinoma (PDAC) survival due to desmoplasia. We investigated whether targeting a hub gene which participates in both processes could be an efficient strategy for PDAC treatment. The expression pattern of glycolysis signatures (GS) and autophagy signatures (AS) and their correlation with cystatin B (CSTB) in PDAC were analysed. It was discovered how CSTB affected the growth, glycolysis, and autophagy of PDAC cells. We assessed competitive binding to cathepsin B (CTSB) between CSTB and cystatin C (CSTC) via immunoprecipitation (IP) and immunofluorescence (IF). Chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR) and luciferase reporter gene assays were used to unveil the mechanism underlying CSTB upregulation. The expression pattern of CSTB was examined in clinical samples and KrasG12D/+, Trp53R172H/+, Pdx1-Cre (KPC) mice. GS and AS were enriched and closely associated in PDAC tissues. CSTB increased autophagic flux and provided substrates for glycolysis. CSTB knockdown attenuated the proliferation of PDAC cells and patient-derived xenografts. The liquid chromatography-tandem mass spectrometry assay indicated CSTB interacted with CTSB and contributed to the proteolytic activity of CTSB in lysosomes. IF and IP assays demonstrated that CSTB competed with CSTC to bind to CTSB. Mutation of the key sites of CSTB abolished the interaction between CSTB and CTSB. CSTB was highly expressed in PDAC due to H3K27acetylation and SP1 expression. High expression of CSTB in PDAC was observed in tissue microarray and patients' serum samples. Our work demonstrated the tumorigenic roles of autophagy and glycolysis in PDAC. CSTB is a key role in orchestrating these processes to ensure energy supply of PDAC cells.

Hypoxia-induced circRNF13 promotes the progression and glycolysis of pancreatic cancer

Pancreatic cancer (PC) is one of the most malignant tumors. Rapid progression and distant metastasis are the main causes of patient death. Hypoxia is a hallmark of multiple cancers and is involved in tumor biology. However, little is known about the roles of circRNAs in glycolysis and hypoxia-mediated progression of PC. Here, the expression pattern of hypoxia-related circRNAs was analyzed using RNA sequencing. A unique circRNA termed circRNF13 was found to be upregulated in PC tissues and may be a potential prognostic indicator. HIF-1α and EIF4A3 are involved in regulating the biogenesis of circRNF13. Furthermore, circRNF13 was validated to exert a stimulative effect on cell proliferation, angiogenesis, invasion and glycolysis. Importantly, we found that circRNF13 promoted PDK3 levels by acting as a miR-654-3p sponge, thus promoting the PC malignant process. Collectively, our results reveal that hypoxia-induced circRNF13 mediated by HIF-1α and EIF4A3 promotes tumor progression and glycolysis in PC, indicating the potential of circRNF13 as a prognostic biomarker and therapeutic target for PC.

LINC00960 regulates cell proliferation and glycolysis in pancreatic cancer through the miR-326-3p/TUFT1/AKT-mTOR axis.

Pancreatic cancer (PC) is a common malignant cancer characterized by high mortality and poor prognosis. LINC00690 was involved in the occurrence and progression of PC, but the underlying mechanisms require further investigation. The goal of this study was to figure out how LINC00960 mediates glycolysis in PC. LINC00960, miR-326-3p, and Tuftelin 1 (TUFT1) expression levels were detected in PC cell lines. LINC00960 and TUFT1 expression levels were increased in PC cells when compared with normal pancreatic cells, whereas miR-326-3p expression levels were decreased. The expression levels of LINC00690 affected glycolysis in PC, and inhibition of LINC00960 inhibited tumor growth in vivo. LINC00690 targeted and suppressed the expression of miR-326-3p. MiR-326-3p bound to TUFT1, and miR-326-3p inhibited AKT-mTOR pathway activation via TUFT1. In conclusion, the depletion of LINC00960 repressed cell proliferation and glycolysis in PC by mediating the miR-326-3p/TUFT1/AKT-mTOR axis. Thus, we present a novel mechanism underlying the progression of PC that suggests LINC00960 is a potential therapeutic target for this cancer.

Combining Single-Cell and Transcriptomic Data Revealed the Prognostic Significance of Glycolysis in Pancreatic Cancer.

Background: Pancreatic cancer (PC), the most common fatal solid malignancy, has a very dismal prognosis. Clinical computerized tomography (CT) and pathological TNM staging are no longer sufficient for determining a patient’s prognosis. Although numerous studies have suggested that glycolysis is important in the onset and progression of cancer, there are few publications on its impact on PC. Methods: To begin, the single-sample gene set enrichment analysis (ssGSEA) approach was used to quantify the glycolysis pathway enrichment fraction in PC patients and establish its prognostic significance. The genes most related to the glycolytic pathway were then identified using weighted gene co-expression network analysis (WGCNA). The glycolysis-associated prognostic signature in PC patients was then constructed using univariate Cox regression and lasso regression methods, which were validated in numerous external validation cohorts. Furthermore, we investigated the activation of the glycolysis pathway in PC cell subtypes at the single-cell level, performed a quasi-time series analysis on the activated cell subtypes and then detected gene changes in the signature during cell development. Finally, we constructed a decision tree and a nomogram that could divide the patients into different risk subtypes, according to the signature score and their different clinical characteristics and assessed the prognosis of PC patients. Results: Glycolysis plays a risky role in PC patients. Our glycolysis-related signature could effectively discriminate the high-risk and low-risk patients in both the trained cohort and the independent externally validated cohort. The survival analysis and multivariate Cox analysis indicated this gene signature to be an independent prognostic factor in PC. The prognostic ROC curve analysis suggested a high accuracy of this gene signature in predicting the patient prognosis in PC. The single-cell analysis suggested that the glycolytic pathway may be more activated in epithelial cells and that the genes in the signature were also mainly expressed in epithelial cells. The decision tree analysis could effectively identify patients in different risk subgroups, and the nomograms clearly show the prognostic assessment of PC patients. Conclusion: Our study developed a glycolysis-related signature, which contributes to the risk subtype assessment of patients with PC and to the individualized management of patients in the clinical setting.

SIRT6 promotes ferroptosis and attenuates glycolysis in pancreatic cancer through regulation of the NF‑κB pathway

Pancreatic cancer (PC) is a malignant tumor with high mortality worldwide. SIRT6 plays versatile roles in human cancers. However, SIRT6 has rarely been studied in PC. The purpose of the present study was to explore the function and potential mechanism of SIRT6 in PC. The expression of SIRT6 in PC tissues and cells was detected by reverse transcription-quantitative PCR and western blotting. The overall survival time was analyzed through the Kaplan Meier method. Cell viability was measured by the Cell Counting Kit-8 assay. The Fe2+ content, glucose uptake, lactic acid and ATP production were detected through the corresponding kits. ROS was evaluated using the DCFH-DA detection kit. Protein expression was assessed by immunohistochemistry or western blot analysis. In the present study, SIRT6 was lowly expressed in PC tissues and cells compared with normal tissues and cells. Moreover, the low expression of SIRT6 was associated with a poor prognosis in patients with PC. Upregulation of SIRT6 significantly promoted the ferroptosis and inhibited the glycolysis in PC cells. However, knockdown of SIRT6 resisted ferroptosis and increased glycolysis in PC cells. Further studies found that the activation of NF-κB could reverse the effect of SIRT6 on PC cells. In addition, overexpression of SIRT6 restrained the growth of xenografted tumors and suppressed the nuclear transcription of NF-κB in vivo. Collectively, the present study indicated that SIRT6 promoted ferroptosis and inhibited glycolysis through inactivating the NF-κB signaling pathway in PC. These findings suggested that SIRT6 may become a therapeutic target for PC.

MTAP Deficiency-Induced Metabolic Reprogramming Creates a Vulnerability to Cotargeting De Novo Purine Synthesis and Glycolysis in Pancreatic Cancer.

Methylthioadenosine phosphorylase (MTAP) is a key enzyme associated with the salvage of methionine and adenine that is deficient in 20% to 30% of pancreatic cancer. Our previous study revealed that MTAP deficiency indicates a poor prognosis for patients with pancreatic ductal adenocarcinoma (PDAC). In this study, bioinformatics analysis of The Cancer Genome Atlas (TCGA) data indicated that PDACs with MTAP deficiency display a signature of elevated glycolysis. Metabolomics studies showed that that MTAP deletion-mediated metabolic reprogramming enhanced glycolysis and de novo purine synthesis in pancreatic cancer cells. Western blot analysis revealed that MTAP knockout stabilized hypoxia-inducible factor 1α (HIF1α) protein via posttranslational phosphorylation. RIO kinase 1 (RIOK1), a downstream kinase upregulated in MTAP-deficient cells, interacted with and phosphorylated HIF1α to regulate its stability. In vitro experiments demonstrated that the glycolysis inhibitor 2-deoxy-d-glucose (2-DG) and the de novo purine synthesis inhibitor l-alanosine synergized to kill MTAP-deficient pancreatic cancer cells. Collectively, these results reveal that MTAP deficiency drives pancreatic cancer progression by inducing metabolic reprogramming, providing a novel target and therapeutic strategy for treating MTAP-deficient disease. SIGNIFICANCE: This study demonstrates that MTAP status impacts glucose and purine metabolism, thus identifying multiple novel treatment options against MTAP-deficient pancreatic cancer.

LINC00941 promotes glycolysis in pancreatic cancer by modulating the Hippo pathway

Pancreatic ductal adenocarcinoma (PDAC) is one of most lethal cancers and is projected to be the second leading cause of cancer deaths in the United States by 2030. The lack of effective treatment and increased incidence in PDAC encourage a deeper knowledge of PDAC progression. By analyzing a long noncoding RNA (lncRNA) dataset, we found that increased LINC00941 expression led to poor outcomes in PDAC patients. Furthermore, in vitro and in vivo experiments revealed that LINC00941 promoted PDAC cancer cell growth by enhancing aerobic glycolysis. Mechanistically, LINC00941 was found to interact with mammalian STE20-like protein kinase 1 (MST1), which facilitated the protein phosphatase 2A (PP2A)-mediated dephosphorylation of MST1, resulting in Hippo pathway activation and consequently, enhanced glycolysis in PDAC. These results suggest that LINC00941 plays a key role in regulating PDAC tumorigenesis, potentially highlighting novel avenues for PDAC therapy.

UCHL3 promotes aerobic glycolysis of pancreatic cancer through upregulating LDHA expression.

Aerobic glycolysis has a pivotal role in the carcinogenic process. The current understanding of the functional role and mechanism of UCHL3-related aerobic glycolysis in pancreatic cancer is far from comprehensive, therefore requires an in-depth analysis on this aspect. In the present research, the expressions of ubiquitin carboxyl-terminal hydrolase L3 (UCHL3), lactate dehydrogenase A (LDHA) and Forkhead box protein M1 (FOXM1) were detected by qRT-PCR, Western blot and immunohistochemistry. The effects of UCHL3 knockdown or overexpression on pancreatic cancer cells were examined by determining cell viability and colony formation. Aerobic glycolysis was assessed according to glucose uptake, lactic acid production, and lactate dehydrogenase (LDH) activity. Dual-luciferase reporter assay was performed to detect LDHA promoter activity. The results showed that UCHL3 expression was significantly increased in the pancreatic cancer tissues and cells, and that knocking down UCHL3 noticeably inhibited cell viability and aerobic glycolysis. Further investigations revealed that LDHA expression was promoted by UCHL3 and could be reduced by shFOXM1, and that low-expressed LDHA partly reversed the inhibition of aerobic glycolysis induced by overexpressed UCHL3. To conclude, this study demonstrates that UCHL3 plays a carcinogenic role by promoting aerobic glycolysis in pancreatic cancer, suggesting that UCHL3 may be a potential diagnostic and therapeutic target for the treatment of cancer.

The CDK4/6 inhibitor PD0332991 stabilizes FBP1 by repressing MAGED1 expression in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most deadly solid tumors in the world. Aerobic glycolysis is among the characteristic features of pancreatic cancer. However, the regulatory process of aerobic glycolysis in pancreatic cancer is too complicated, and the underlying mechanism remains unexplained. Reportedly, CDK4/6 inhibitors repress breast cancer cell proliferation by modulating glucose metabolism. Here, we reveal that the CDK4/6 inhibitor, PD0332991 stabilized FBP1 to hinder aerobic glycolysis in pancreatic cancer. We also show that the CDK4/6-E2 F1 signaling pathway mediated an increase in MAGED1 expression, promoting FBP1 degradation in pancreatic cancer. We, therefore, might have identified a novel mechanism by which the CDK4/6 inhibitor, PD0332991 blocks the Warburg effect of pancreatic cancer by stabilizing FBP1.

Glutathione S-Transferase Mu-3 Predicts a Better Prognosis and Inhibits Malignant Behavior and Glycolysis in Pancreatic Cancer.

Background: Pancreatic cancer (PC) is a lethal malignancy with an extremely unfavorable 5-year survival rate and a high mortality rate. Glutathione S-transferase mu-3 (GSTM3) has been shown to exert different functions in the progression and development of various cancers, except for PC. This study aimed to explore the role of GSTM3 in the malignant behavior and metabolic aspects of PC, its clinical significance, and its possible molecular mechanism in pancreatic cancer.Methods: Tumor microarrays of pancreatic ductal adenocarcinoma (PDAC) were used to evaluate the clinicopathological variables and GSTM3 expression by immunohistochemical staining. Kaplan–Meier survival and Cox regression analyses were further performed to assess the prognosis. The effect of GSTM3 on PC aggressiveness was detected using overexpressing and silencing transfection methods. Western blot, RT-qPCR, CCK-8, and cell cycle assay were applied to evaluate the expression level and proliferation. A xenograft animal model was assessed. Reactive oxygen species (ROS) were measured using the laser confocal scanner and glycolysis was detected using an Agilent Seahorse kit. RNA sequencing was used to assess the underlying mechanism and the signaling pathway involved.Results: GSTM3 was relatively poorly expressed in PDAC tissues compared to para-tumoral tissues and a high level of GSTM3 indicated good overall survival. Functionally, overexpression of GSTM3 could significantly inhibit cell proliferation by delaying the G0/G1 transition, whereas the opposite results were found in the GSTM3 downregulation group. In addition, xenograft animal models further confirmed the effect on proliferation. Moreover, silencing of GSTM3 induced ROS accumulation and promoted glycolysis in PC, indicating its tumor suppressive effect, and vice versa when GSTM3 was upregulated. Finally, RNA sequencing results demonstrated that GSTM3 facilitates anti-tumorigenicity partly via the JAK-STAT signaling pathway in PC.Conclusion: GSTM3 inhibited tumor progression and altered the metabolic pattern in PC. This may be a potential predictive biomarker in PC and a prospective therapeutic target.

MicroRNA-7 as a Potential Biomarker for Prognosis in Pancreatic Cancer.

MicroRNAs play critical roles in tumor progression. Our recent study has indicated that microRNA-7 (miR-7) impairs autophagy-derived pools of glucose to suppress the glycolysis in pancreatic cancer progression. However, the roles of miR-7 in clinical significance and chemoresistance of pancreatic cancer remain unexplored. The aim of this study was to assess the expression of miR-7 in patients with pancreatic cancer and to evaluate the possibility of its usage as a prognostic molecular biomarker. MicroRNA array-based quantification analysis of 372 miRNAs was compared in serum between pancreatic cancer and healthy individuals, gemcitabine-sensitive and gemcitabine-resistance patients. We identified miR-7 showed the potential predictive power for gemcitabine-sensitive patients with pancreatic cancer. Then, the results were validated in pancreatic tissue microarray and The Cancer Genome Atlas (TCGA) dataset, demonstrating that lower miR-7 expression was correlated with more advanced tumor stages and worse prognosis in pancreatic cancer. The Cox proportional-hazards model analysis identified miR-7 to be an independent variable for prediction of the survival. Furthermore, the mechanistic exploration suggested the clinical significance of miR-7 involved its interference effect on autophagy and glycolysis in pancreatic cancer using pancreatic cancer tissue microarrays and TCGA data. Therefore, the results of the present study provide evidences that low microRNA-7 expression may contribute to tumor progression and poor prognosis in pancreatic cancer.

HENT1 reverses chemoresistance by regulating glycolysis in pancreatic cancer.

Gemcitabine (GEM) chemotherapy, as the first-line regimen for pancreatic cancer, tends to induce drug resistance, which ultimately worsens the prognosis of patients with pancreatic cancer. Our previous study indicated a close correlation between pancreatic cancer progression and glucose metabolism, especially at the chemoresistant stage, highlighting the importance of the application of 18F-FDG PET dual-phase imaging in the early detection of pancreatic cancer. We speculate that glycolysis, participates in the development of chemoresistance in pancreatic cancer. In this article, we wanted to determine whether manipulating hENT1 expression in pancreatic cancer cells can reverse GEM chemoresistance and whether glucose transport and glycolysis are involved during this process. We found that hENT1 reversed GEM-induced drug resistance by inhibiting glycolysis and altering glucose transport mediated by HIF-1α in pancreatic cancer. Our findings also suggest that 18F-FDG PET dual-phase imaging after the 4th chemotherapy treatment can accurately identify drug-resistant pancreatic tumors and improve hENT1 reversal therapy. Our findings highlight that the dynamic observation of (retention index) RI changes from the beginning of treatment can also be helpful for evaluating the therapeutic effect.

Ikarugamycin inhibits pancreatic cancer cell glycolysis by targeting hexokinase 2.

Mangrove-derived actinobacteria strains are well-known for producing novel secondary metabolites. The polycyclic tetramate macrolactam (PTM), ikarugamycin (IKA) isolated from Streptomyces xiamenensis 318, exhibits antiproliferative activities against pancreatic ductal adenocarcinoma (PDAC) in vitro. However, the protein target for bioactive IKA is unclear. In this study, whole transcriptome-based profiling revealed that the glycolysis pathway is significantly affected by IKA. Metabolomic studies demonstrated that IKA treatment induces a significant drop in glucose-6-phosphate and a slight increase in intracellular glucose level. Analysis of glucose consumption, lactate production, and the extracellular acidification rate confirmed the inhibitory role of IKA on the glycolytic flux in PDAC cells. Surface plasmon resonance (SPR) experiments and docking studies identified the key enzyme of glycolysis, hexokinase 2 (HK2), as a molecular target of IKA. Moreover, IKA reduced tumor size without overt cytotoxicity in mice with PDAC xenografts and increased chemotherapy response to gemcitabine in PDAC cells in vitro. Taken together, IKA can block glycolysis in pancreatic cancer by targeting HK2, which may be a potential drug candidate for PDAC treatment.

Abstract B32: Mutant KRAS downregulates LIFR to enhance glycolysis in pancreatic cancer

Abstract One of the hallmarks of pancreatic cancer is aberrant activity of oncogenic KRAS, which is mutated and constitutively activated in greater than 90% of pancreatic adenocarcinomas. While KRAS itself is a challenging therapeutic target, we have focused on understanding the key signaling pathways driven by KRAS, which may reveal dependencies that are amenable to therapeutic intervention. By performing bioinformatics analysis on primary human pancreatic cancers coupled with validation in cancer cell lines, we found that the receptor for the cytokine leukemia inhibitory factor (LIF) was downregulated by mutant KRAS. Furthermore, downregulation of the LIF receptor (LIFR) was necessary for KRAS-mediated neoplastic transformation. One of the key features of KRAS-driven cancer is enhanced glycolysis. We found LIFR exerts inhibitory effects on KRAS-mediated transformation by inhibiting expression of the glucose transporter GLUT1, a key mediator of the enhanced glycolysis found in KRAS-driven malignancies. Interestingly, this downregulation of GLUT1 by LIFR is mediated by the transcription factor STAT3, indicating a tumor-suppressive role for STAT3 within cancer cells with mutated KRAS. Finally, reflecting a clinically important tumor-suppressive role of LIFR, decreased LIFR expression correlates with shorter survival in pancreatic cancer patients with mutated KRAS. Similar findings were found in non-small cell lung cancers driven by mutated KRAS, suggesting that silencing LIFR is a generalized mechanism of KRAS-mediated cellular transformation. These findings highlight the intriguing concept that the LIFR/STAT3 pathway may mediate either tumor-promoting or tumor-suppressive signaling pathways, depending on cellular genetic background and specific cell types, even within one cancerous tissue. For example, while LIF in the tumor microenvironment may act on pancreatic stellate cells to promote dense stromal formation, activation of LIFR/STAT3 within pancreatic cancer cells limits cell survival. The inhibition of LIFR expression in pancreatic cancer cells upregulates GLUT1 levels in order to support the enhanced glycolysis necessary for malignant transformation. This selective silencing of LIFR within cancer cells allows the pancreatic cancer cells to evade the inhibitory effects of LIF, while other cells in the tumor microenvironment have increased function in the presence of LIF. Therefore, the elucidation of the complex role of the LIF/LIFR/STAT3 axis in pancreatic cancer is essential to allow the design of rational therapeutic interventions for patients with pancreatic cancer. Citation Format: Suhu Liu, Helen I. Gandler, Sarah R. Walker, Darwin Q. Ye, Zachary T. Giaccone, Jonathan A. Nowak, Andrew J. Aguirre, Brian M. Wolpin, David A. Frank. Mutant KRAS downregulates LIFR to enhance glycolysis in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B32.

Glycolysis promotes the progression of pancreatic cancer and reduces cancer cell sensitivity to gemcitabine

Previous studies have reported that increased glycolytic activity enhances chemotherapy resistance in some types of malignancies. However, whether glycolysis influences the curative effect of gemcitabine (GEM) on pancreatic cancer (PC) cells remains unclear. The aim of this study was to investigate the status of glycolysis in PC and its association with tolerance to GEM. Data from The Cancer Genome Atlas (TCGA) were used to analyze the correlation between glycolysis-related gene (GRG) expression and PC progression and prognosis. 2-Deoxy-D-glucose (2-DG) was applied to assess the effect of glycolysis inhibition on PC cell death and GEM tolerance. Expression of some GRGs, such as HK1, GAPDH, PKM2, and LDHA, was significantly associated with the prognosis of PC. Furthermore, HK1, PKLR, and LDHA expression correlated positively with PC progression. Further analysis revealed that cancer cell death was markedly enhanced following glycolysis inhibition and that the sensitivity of cancer cells to GEM was notably increased in the presence of 2-DG. Our findings indicate that abnormally increased glycolytic activity promotes the development of PC and enhances drug tolerance to GEM. 2-DG combined with GEM is a potential therapy for PC.

The enhancement of glycolysis regulates pancreatic cancer metastasis.

Pancreatic ductal adenocarcinoma is prone to distant metastasis and is expected to become the second leading cause of cancer-related death. In an extremely nutrient-deficient and hypoxic environment resulting from uncontrolled growth, vascular disturbances and desmoplastic reactions, pancreatic cancer cells utilize "metabolic reprogramming" to satisfy their energy demand and support malignant behaviors such as metastasis. Notably, pancreatic cancer cells show extensive enhancement of glycolysis, including glycolytic enzyme overexpression and increased lactate production, and this is caused by mitochondrial dysfunction, cancer driver genes, specific transcription factors, a hypoxic tumor microenvironment and stromal cells, such as cancer-associated fibroblasts and tumor-associated macrophages. The metabolic switch from oxidative phosphorylation to glycolysis in pancreatic cancer cells regulates the invasion-metastasis cascade by promoting epithelial-mesenchymal transition, tumor angiogenesis and the metastatic colonization of distant organs. In addition to aerobic glycolysis, oxidative phosphorylation also plays a critical role in pancreatic cancer metastasis in ways that remain unclear. In this review, we expound on the intracellular and extracellular causes of the enhancement of glycolysis in pancreatic cancer and the strong association between glycolysis and cancer metastasis, which we expect will yield new therapeutic approaches targeting cancer metabolism.

PRMT5 enhances tumorigenicity and glycolysis in pancreatic cancer via the FBW7/cMyc axis

BackgroundThe epigenetic factor protein arginine methyltransferase 5 (PRMT5) has been reported to play vital roles in a wide range of cellular processes, such as gene transcription, genomic organization, differentiation and cell cycle control. However, its role in pancreatic cancer remains unclear. Our study aimed to investigate the roles of PRMT5 in pancreatic cancer prognosis and progression and to explore the underlying molecular mechanism.MethodsReal-time PCR, immunohistochemistry and analysis of a dataset from The Cancer Genome Atlas (TCGA) were performed to study the expression of PRMT5 at the mRNA and protein levels in pancreatic cancer. Cell proliferation assays, including cell viability, colony formation ability and subcutaneous mouse model assays, were utilized to confirm the role of PRMT5 in cell proliferation and tumorigenesis. A Seahorse extracellular flux analyzer, a glucose uptake kit, a lactate level measurement kit and the measurement of 18F-FDG (fluorodeoxyglucose) uptake by PET/CT (positron emission tomography/computed tomography) imaging were used to verify the role of PRMT5 in aerobic glycolysis, which sustains cell proliferation. The regulatory effect of PRMT5 on cMyc, a master regulator of oncogenesis and aerobic glycolysis, was explored by quantitative PCR and protein stability measurements.ResultsPRMT5 expression was significantly upregulated in pancreatic cancer tissues compared with that in adjacent normal tissues. Clinically, elevated expression of PRMT5 was positively correlated with worse overall survival in pancreatic cancer patients. Silencing PRMT5 expression inhibited the proliferation of pancreatic cancer cells both in vitro and in vivo. Moreover, PRMT5 regulated aerobic glycolysis in vitro in cell lines, in vivo in pancreatic cancer patients and in a xenograft mouse model used to measure 18F-FDG uptake. We found that mechanistically, PRMT5 posttranslationally regulated cMyc stability via F-box/WD repeat-containing protein 7 (FBW7), an E3 ubiquitin ligase that controls cMyc degradation. Moreover, PRMT5 epigenetically regulated the expression of FBW7 in pancreatic cancer cells.ConclusionsThe present study demonstrated that PRMT5 epigenetically silenced the expression of the tumor suppressor FBW7, leading to increased cMyc levels and the subsequent enhancement of the proliferation of and aerobic glycolysis in pancreatic cancer cells. The PRMT5/FBW7/cMyc axis could be a potential therapeutic target for the treatment of pancreatic cancer.

Zinc finger E-box-binding homeobox 1 mediates aerobic glycolysis via suppression of sirtuin 3 in pancreatic cancer.

AIMTo uncover the roles of tumor-promoting gene ZEB1 in aerobic glycolysis regulation and shed light on the underlying molecular mechanism.METHODSEndogenous zinc finger E-box binding homeobox-1 (ZEB1) was silenced using a lentivirus-mediated method, and the impact of ZEB1 and methyl-CpG binding domain protein 1 (MBD1) on aerobic glycolysis was measured using seahorse cellular flux analyzers, reactive oxygen species quantification, and mitochondrial membrane potential measurement. The interaction between ZEB1 and MBD1 was assessed by co-immunoprecipitation and immunofluorescence assays. The impact of ZEB1 and MBD1 interaction on sirtuin 3 (SIRT3) expression was confirmed by quantitative polymerase chain reaction, western blotting, and dual-luciferase and chromatin-immunoprecipitation assays.RESULTSZEB1 was a positive regulator of aerobic glycolysis in pancreatic cancer. ZEB1 transcriptionally silenced expression of SIRT3, a mitochondrial-localized tumor suppressor, through interaction with MBD1.CONCLUSIONZEB1 silenced SIRT3 expression via interaction with MBD1 to promote aerobic glycolysis in pancreatic cancer.