Aneesha Dasgupta

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-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

Hypoxia-induced metabolomic alterations in pancreatic cancer cells

Hypoxic conditions in the pancreatic tumor microenvironment lead to the stabilization of hypoxia-inducible factor-1 alpha (HIF-1α), which acts as the master regulator of cancer cell metabolism. HIF-1α-mediated metabolic reprogramming results in large-scale metabolite perturbations. Characterization of the metabolic intermediates and the corresponding metabolic pathways altered by HIF-1α would facilitate the identification of therapeutic targets for hypoxic microenvironments prevalent in pancreatic ductal adenocarcinoma and other solid tumors. Targeted metabolomic approaches are versatile in quantifying multiple metabolite levels in a single platform and, thus, enable the characterization of multiple metabolite alterations regulated by HIF-1α. In this chapter, we describe a detailed metabolomic approach for characterizing the hypoxia-induced metabolomic alterations using pancreatic cancer cell lines cultured in normoxic and hypoxic conditions. We elaborate the methodology of cell culture, hypoxic exposure, metabolite extraction, and relative quantification of polar metabolites from normoxia- and hypoxia-exposed cell extracts, using a liquid chromatography-coupled tandem mass spectrometry approach. Herein, using our metabolomic data, we also present the methods for metabolomic data representation.

Abstract LB-267: Metabolic alterations in tumors cause cachexia in pancreatic cancer

Cancer-associated cachexia is a complex metabolic syndrome which leads to excessive loss of skeletal muscle and adipose deposits. Up to 80% of pancreatic cancer patients suffer from cachexia and nearly one third die due to complexities related to the syndrome. Treatment of cachexia will not only improve the standard of living of pancreatic cancer patients but would also improve the patient survival. In the clinic, the majority of cancer patients are diagnosed at the refractory phase of cachexia, which cannot be reversed by dietary interventions. Till late, cachexia has mainly been attributed to systemic inflammation caused by cytokines released from the host and the tumor. But anti-inflammatory therapies have not shown promising results in clinical trials. Hence, there is an urgent need to identify new targets to combat cancer cachexia. It has been previously shown that there are constant metabolic interactions between the host body and the tumor. Increase in tumor burden and its demand for nutrition forces the host body to reprogram its metabolism leading to the breakdown of host body proteins into amino acids, which gets taken up and converted into carbohydrates by the tumor. To study the role of metabolic pathways in tumor cells on cachectic factor secretion, we pre-treated pancreatic cancer cells with metabolic inhibitors 3-Bromopyruvic acid and bis-2-(5-phenylacetomido-1, 2, 4-thiadiazol-2-yl) ethyl sulfide (BPTES). The conditioned media from control and treated cells were then evaluated for myotube degeneration potential in C2C12-dfferentitaed myotubes by measuring myotube thickness, protein content and expression of muscle specific ubiquitin ligases. We observed that that pre-treated conditioned-media had reduced myotubes degenerating potential as compared to controls. Furthermore, we inhibition of glycolytic flux in tumor cells by treatment with ketone bodies also diminished myotubes degenerating potential. Tumor-bearing mice had decreased tumor growth and cachexia when fed on a ketogenic diet. In conclusion, metabolic reprograming of tumor cells plays an important role in inducing pancreatic cancer-induced cachexia and delineating the metabolic pathways is crucial to elucidate important therapeutic targets for cancer cachexia. Citation Format: Aneesha Dasgupta, Surendra K. Shukla, Venugopal Gunda, Nina V. Chaika, Pankaj K. Singh. Metabolic alterations in tumors cause cachexia in pancreatic 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 LB-267. doi:10.1158/1538-7445.AM2017-LB-267

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.