Gennifer Goode

MUC1 and HIF-1alpha Signaling Crosstalk Induces Anabolic Glucose Metabolism to Impart Gemcitabine Resistance to Pancreatic Cancer.

Poor response to cancer therapy due to resistance remains a clinical challenge. The present study establishes a widely prevalent mechanism of resistance to gemcitabine in pancreatic cancer, whereby increased glycolytic flux leads to glucose addiction in cancer cells and a corresponding increase in pyrimidine biosynthesis to enhance the intrinsic levels of deoxycytidine triphosphate (dCTP). Increased levels of dCTP diminish the effective levels of gemcitabine through molecular competition. We also demonstrate that MUC1-regulated stabilization of hypoxia inducible factor-1α (HIF-1α) mediates such metabolic reprogramming. Targeting HIF-1α or de novo pyrimidine biosynthesis, in combination with gemcitabine, strongly diminishes tumor burden. Finally, reduced expression of TKT and CTPS, which regulate flux into pyrimidine biosynthesis, correlates with better prognosis in pancreatic cancer patients on fluoropyrimidine analogs.

Silibinin-mediated metabolic reprogramming attenuates pancreatic cancer-induced cachexia and tumor growth

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths in the US. Cancer-associated cachexia is present in up to 80% of PDAC patients and is associated with aggressive disease and poor prognosis. In the present studies we evaluated an anti-cancer natural product silibinin for its effectiveness in targeting pancreatic cancer aggressiveness and the cachectic properties of pancreatic cancer cells and tumors. Our results demonstrate that silibinin inhibits pancreatic cancer cell growth in a dose-dependent manner and reduces glycolytic activity of cancer cells. Our LC-MS/MS based metabolomics data demonstrates that silibinin treatment induces global metabolic reprogramming in pancreatic cancer cells. Silibinin treatment diminishes c-MYC expression, a key regulator of cancer metabolism. Furthermore, we observed reduced STAT3 signaling in silibinin-treated cancer cells. Overexpression of constitutively active STAT3 was sufficient to substantially revert the silibinin-induced downregulation of c-MYC and the metabolic phenotype. Our in vivo investigations demonstrate that silibinin reduces tumor growth and proliferation in an orthotopic mouse model of pancreatic cancer and prevents the loss of body weight and muscle. It also improves physical activity including grip strength and latency to fall in tumor-bearing mice. In conclusion, silibinin-induced metabolic reprogramming diminishes cell growth and cachectic properties of pancreatic cancer cells and animal models.

GOT1-mediated anaplerotic glutamine metabolism regulates chronic acidosis stress in pancreatic cancer cells

The increased rate of glycolysis and reduced oxidative metabolism are the principal biochemical phenotypes observed in pancreatic ductal adenocarcinoma (PDAC) that lead to the development of an acidic tumor microenvironment. The pH of most epithelial cell-derived tumors is reported to be lower than that of plasma. However, little is known regarding the physiology and metabolism of cancer cells enduring chronic acidosis. Here, we cultured PDAC cells in chronic acidosis (pH 6.9-7.0) and observed that cells cultured in low pH had reduced clonogenic capacity. However, our physiological and metabolomics analysis showed that cells in low pH deviate from glycolytic metabolism and rely more on oxidative metabolism. The increased expression of the transaminase enzyme GOT1 fuels oxidative metabolism of cells cultured in low pH by enhancing the non-canonical glutamine metabolic pathway. Survival in low pH is reduced upon depletion of GOT1 due to increased intracellular ROS levels. Thus, GOT1 plays an important role in energy metabolism and ROS balance in chronic acidosis stress. Our studies suggest that targeting anaplerotic glutamine metabolism may serve as an important therapeutic target in PDAC.

MUC1 facilitates metabolomic reprogramming in triple-negative breast cancer

Background Mucin1 (MUC1), a glycoprotein associated with chemoresistance and an aggressive cancer phenotype, is aberrantly overexpressed in triple-negative breast cancer (TNBC). Recent studies suggest that MUC1 plays a role in modulating cancer cell metabolism and thereby supports tumor growth. Herein, we examined the role of MUC1 in metabolic reprogramming in TNBC. Methods MUC1 was stably overexpressed in MDA-MB-231 TNBC cells and stably knocked down in MDA-MB-468 cells. We performed liquid chromatography-coupled tandem mass spectrometry-assisted metabolomic analyses and physiological assays, which indicated significant alterations in the metabolism of TNBC cells due to MUC1 expression. Results Differential analyses identified significant differences in metabolic pathways implicated in cancer cell growth. In particular, MUC1 expression altered glutamine dependency of the cells, which can be attributed in part to the changes in the expression of genes that regulate glutamine metabolism, as observed by real-time PCR analysis. Furthermore, MUC1 expression altered the sensitivity of cells to transaminase inhibitor aminooxyacetate (AOA), potentially by altering glutamine metabolism. Conclusions Collectively, these results suggest that MUC1 serves as a metabolic regulator in TNBC, facilitating the metabolic reprogramming of glutamine utilization that influences TNBC tumor growth.

MUC1-Mediated Metabolic Alterations Regulate Response to Radiotherapy in Pancreatic Cancer

Purpose: MUC1, an oncogene overexpressed in multiple solid tumors, including pancreatic cancer, reduces overall survival and imparts resistance to radiation and chemotherapies. We previously identified that MUC1 facilitates growth-promoting metabolic alterations in pancreatic cancer cells. The present study investigates the role of MUC1-mediated metabolism in radiation resistance of pancreatic cancer by utilizing cell lines and in vivo models. Experimental Design: We used MUC1-knockdown and -overexpressed cell line models for evaluating the role of MUC1-mediated metabolism in radiation resistance through in vitro cytotoxicity, clonogenicity, DNA damage response, and metabolomic evaluations. We also investigated whether inhibition of glycolysis could revert MUC1-mediated metabolic alterations and radiation resistance by using in vitro and in vivo models. Results: MUC1 expression diminished radiation-induced cytotoxicity and DNA damage in pancreatic cancer cells by enhancing glycolysis, pentose phosphate pathway, and nucleotide biosynthesis. Such metabolic reprogramming resulted in high nucleotide pools and radiation resistance in in vitro models. Pretreatment with the glycolysis inhibitor 3-bromopyruvate abrogated MUC1-mediated radiation resistance both in vitro and in vivo, by reducing glucose flux into nucleotide biosynthetic pathways and enhancing DNA damage, which could again be reversed by pretreatment with nucleoside pools. Conclusions: MUC1-mediated nucleotide metabolism plays a key role in facilitating radiation resistance in pancreatic cancer and targeted effectively through glycolytic inhibition. Clin Cancer Res; 23(19); 5881–91. ©2017 AACR.

Erratum: MUC1 and HIF-1alpha Signaling Crosstalk Induces Anabolic Glucose Metabolism to Impart Gemcitabine Resistance to Pancreatic Cancer (Cancer Cell (2017) 32(1) (71–87.e7) (S1535610817302544) (10.1016/j.ccell.2017.06.004))

Surendra K. Shukla, Vinee Purohit, Kamiya Mehla, Venugopal Gunda, Nina V. Chaika, Enza Vernucci, Ryan J. King, Jaime Abrego, Gennifer D. Goode, Aneesha Dasgupta, Alysha L. Illies, Teklab Gebregiworgis, Bingbing Dai, Jithesh J. Augustine, Divya Murthy, Kuldeep S. Attri, Oksana Mashadova, Paul M. Grandgenett, Robert Powers, Quan P. Ly, Audrey J. Lazenby, Jean L. Grem, Fang Yu, José M. Matés, John M. Asara, Jung-whan Kim, Jordan H. Hankins, Colin Weekes, Michael A. Hollingsworth, Natalie J. Serkova, Aaron R. Sasson, Jason B. Fleming, Jennifer M. Oliveto, Costas A. Lyssiotis, Lewis C. Cantley, Lyudmyla Berim, and Pankaj K. Singh* *Correspondence: pankaj.singh@unmc.edu http://dx.doi.org/10.1016/j.ccell.2017.08.008

Evaluating the Metabolic Impact of Hypoxia on Pancreatic Cancer Cells

Hypoxia is frequently observed in human cancers and induces global metabolic reprogramming that includes an increase in glucose uptake and glycolysis, alterations in NAD(P)H/NAD(P)+ and intracellular ATP levels, and increased utilization of glutamine as the major precursor for fatty acid synthesis. In this chapter, we describe in detail various physiological assays that have been adopted to study the metabolic shift propagated by exposure to hypoxic conditions in pancreatic cell culture model that includes glucose uptake, glutamine uptake, and lactate release by pancreatic cancer cell lines. We have also elaborated the assays to evaluate the ratio of NAD(P)H/NAD(P)+ and intracellular ATP estimation using the commercially available kit to assess the metabolic state of cancer cells.

Abstract 4413: Targeting glutamine metabolism in MUC1 expressing triple negative breast cancer

Breast cancer, the second leading cause of cancer deaths in women, accounts for nearly 1 in 3 cancer cases diagnosed in the U.S. women. Triple negative breast cancer (TNBC) accounts for approximately 15-25% of all breast cancer cases and has an increased incidence of metastasis, high recurrence within 1-3 years and a high mortality rate. Therefore, identifying factors that facilitate tumor growth and metastasis have the potential to serve as novel molecular targets for breast cancer therapy. Mucin1 (MUC1), a glycoprotein associated with chemoresistance, is aberrantly overexpressed in TNBC and facilitates growth and metastasis of TNBC cells. Recent studies suggest a role for MUC1 in modulating cancer cell metabolism to support tumor growth. In the present study we examined the role that MUC1 plays in TNBC tumor metabolism; thus facilitating tumor growth. Our results indicate that MUC1 expression facilitates glutamine metabolism. A correlation between MUC1 expression, glutamine dependency, and amino-oxyacetate (AOA) sensitivity was established. These alterations can be attributed in part to alterations in the expression of genes regulating glutamine metabolism. Collectively, these findings suggest that MUC1 serves as a metabolic regulator in TNBC, facilitating metabolic reprogramming of glutamine that influences growth of TNBC. Additionally, the findings with AOA’s effectiveness provide evidence for potential therapeutic utility, particularly for MUC1 overexpressing TNBC. Citation Format: Gennifer D. Goode, Venugopal Gunda, Pankaj Singh. Targeting glutamine metabolism in MUC1 expressing triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4413. doi:10.1158/1538-7445.AM2017-4413

Abstract 1059: Pancreatic cancer cells acclimatize to low pH by increasing glutamine metabolism

Pancreatic cancer (PC) is the fourth leading cause of cancer related deaths in the United States. PC has a five-year survival rate of only 6%; this is due to the lack of specific symptoms at the earliest stages of disease progression. Currently, surgery is the only treatment option with a reasonable hope of cure; however, due to late detection of the disease, only 15-25% of patients are eligible for surgery. Pancreatic tumors are characterized by increased glucose uptake, high glycolysis rate, and reduced flux to the TCA cycle. This metabolic phenotype, also known as the Warburg effect, is typical of rapidly dividing tumor cells and forms the basis of imaging by utilizing [18F]-FDG-PET (glucose analog). The consequence of this metabolic behavior is the continuous acidification of the tumor microenvironment. Acidification of the tumor microenvironment (TME) and its effects in cancer cell metabolism are not well defined. In this study we analyzed metabolic adaptations of PC cells experiencing physiological pH 7.4 versus cells cultured in 6.8∼7.0 pH that is similar to the pH range observed in the pancreatic TME. Using high performance liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) analysis to determine the metabolite levels of PC cells cultured in these TME conditions, we observed a marked reduction in glycolysis metabolites in cells cultured at low pH. We observed reduced glucose uptake, as well as, reduced lactate secretion in low pH culture conditions. Furthermore, we observed that cells in low pH microenvironment were able to survive upon glucose deprivation, but not upon glutamine deprivation. In contrast, cells in normal physiologic pH culture could not survive upon glucose deprivation. Based on the up regulation of metabolites in the glutaminolysis pathway identified through LC/MS/MS analysis, and the increase in metabolic enzyme mRNA levels, as well as the increased sensitivity to inhibitors of this pathway, we conclude that glutamine metabolism is essential for survival of pancreatic cancer cells under low pH conditions. Furthermore, due to the increased levels of ATP and sensitivity of low-pH cultured cells to oligomycin, we conclude that oxidative phosphorylation is essential for the maintenance of cellular homeostasis at low pH. Such changes result in reduced Warburg Effect, denoted by reduced lactate release. This is the first study to establish glutamine dependence of PC cells under low pH conditions. Our results may provide novel therapeutic opportunities for targeting metabolic adaptations in pancreatic cancer cells in response to changes in the microenvironment. Citation Format: Jaime Abrego, Venugopal Gunda, Pankaj K. Singh, Gennifer Goode. Pancreatic cancer cells acclimatize to low pH by increasing glutamine metabolism. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1059.

Abstract 10: Silibinin exhibits anti-cachectic and anti-cancerous property by modulating metabolic properties of pancreatic cancer cells

Cancer cachexia is a systemic syndrome characterized by progressive weight loss of the patient due to muscle wasting and fat depletion with or without anorexia. About 80% of pancreatic ductal adenocarcinoma (PDAC) patients exhibits cachectic phenotype and it significantly contributes in mortality and morbidity of the disease. In present study we have evaluated the effect of bioactive molecule silibinin on pancreatic cancer progression and cachectic properties by utilizing in vitro as well as in vivo models of PDAC. We observed that silibinin inhibits growth and induces apoptosis in multiple pancreatic cancer cell lines in a dose-dependent manner. We also observed silibinin-mediated reduction in the expression of key glycolytic genes and inhibition of glucose uptake and lactate secretion. By performing LC-MS/MS based metabolomics, we observed that silibinin treatment leads to global metabolic alterations in pancreatic cancer cells. Pancreatic cancer cells treated with silibinin exhibited reduced expression of c-MYC level, a key metabolic regulator. Furthermore, we observed that silibinin-mediated STAT3 inhibition leads to reduced c-MYC expression. Ectopic expression of constitutively active STAT3 significantly attenuated the effect of silibinin on c-MYC expression and metabolic phenotype of pancreatic cancer cells. Silibinin treatment also inhibited tumor growth and progression of cachexia. Silibinin treatment to tumor-bearing mice also lead to increased food intake, increased grip strength and body coordination. Overall, our results demonstrate that silibinin exhibits anti-cachectic and anti-cancerous properties by inducing metabolic reprogramming in pancreatic cancer cells. Citation Format: Surendra K. Shukla, Aneesha Dasgupta, Kamiya Mehla, Venugopal Gunda, Enza Vernucci, Joshua Soucheck, Gennifer Goode, Ryan King, Anusha Mishra, Ibha Rai, Sangeetha Natrajan, Nina Chaika, Fang Yu, Pankaj K. Singh. Silibinin exhibits anti-cachectic and anti-cancerous property by modulating metabolic properties of pancreatic cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 10.