bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract PR04: Germline loss of PK-M2 promotes metabolic syndrome and hepatocellular carcinoma
Authors: Dayton Talya L. , Gocheva Vasilena , Miller Kathryn M. , Israelsen William J. , Clish Clary B. , Bhutkar Arjun , Davidson Shawn M. , Luengo Alba , Heiden Matthew G. Vander , Jacks Tyler E.
Published: May 2016

The pyruvate kinase gene, Pkm, encodes the PK-M1 and PK-M2 isoforms, which are the result of alternative splicing of mutually exclusive exons. While PK-M1 is considered the adult pyruvate kinase isoform, PK-M2 has been closely linked to embryogenesis, tissue regeneration, stem cells, and cancer. Nonetheless, expression of PK-M2 is widespread in wild-type embryonic and adult tissues. To interrogate the functional requirement for PK-M2, we generated and characterized germline PK-M2 null mice (Pkm2-/-). We found that Pkm2-/- mice are viable and express PK-M1 throughout embryogenesis and into adulthood. Strikingly, PK-M2 loss leads to spontaneous hepatocellular carcinoma (HCC) that is preceded by progressive metabolic disease characterized by insulin resistance, inflammation, and hepatic steatosis. Therefore, in contrast to its role in modulating metabolism to promote cancer in a cell-intrinsic manner, PK-M2 plays a role in maintaining systemic metabolism, thereby preventing metabolic syndrome and HCC. To further dissect the contrasting systemic and cell-intrinsic roles of PK-M2 in the context of cancer, we have combined autochthonous mouse models of cancer from our lab with both the germline null allele of Pkm2, Pkm2-/-, and the conditional allele of Pkm2, Pkm2fl/fl. This study will allow us to elucidate the distinct cell-intrinsic and cell-extrinsic roles of PK-M2 in both maintaining normal systemic metabolism and aberrant proliferation in the context of cancer.

This abstract is also presented as Poster B25.

Citation Format: Talya L. Dayton, Vasilena Gocheva, Kathryn M. Miller, William J. Israelsen, Clary B. Clish, Arjun Bhutkar, Shawn M. Davidson, Alba Luengo, Matthew G. Vander Heiden, Tyler E. Jacks. Germline loss of PK-M2 promotes metabolic syndrome and hepatocellular carcinoma. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr PR04.
Abstract A08: The role of branched-chain amino acid metabolism in Myc-driven malignancies
Authors: Fernandez Mario R. , Damoulis Vanessa A. , Wang Wei , Radlwimmer Bernhard , Cleveland John L.
Published: May 2016

Cancer cells have high metabolic demands. Myc oncoproteins function as transcription factors and are overexpressed in a number of human malignancies. Myc induces the transcription of a number of genes involved in glycolysis and glutaminolysis, including those encoding transporters of glucose, glutamine, lactate and branched-chain amino acids (BCAA: valine, leucine and isoleucine, via LAT1/SLC7A5). Tumors driven by Myc are dependent on and utilize L-glutamine to feed carbon intermediates into the Krebs Cycle. We reasoned that Myc would also control the catabolism of BCAA, which also provides key metabolic intermediates, specifically acetoacetate, acetyl-CoA, proprionyl-CoA, NADH and FADH2. Consistent with this notion, expression analysis of premalignant and neoplastic B cells of Eμ-Myc transgenic mice, a validated model of human B cell lymphomas with Myc involvement, showed elevated mRNA and protein levels of BCAT1, which is a bona fide Myc transcription target and the first enzyme in BCAA catabolism. Further, elevated levels of several other enzymes involved in BCAA catabolism manifest in Eμ-Myc B cells. To assess the role of BCAT1 in tumor cell growth and survival, human B cell lymphoma and ovarian tumor cell lines that express high levels of BCAT1 were engineered to inducibly express shRNA that selectively silences BCAT1 expression. Notably, BCAT1 knockdown impaired tumor cell growth and survival, and long-term clonogenic growth. Moreover, treatment of Eμ-Myc B cells and BCAT1 overexpressing human tumor lines with a known BCAT1 inhibitor, Gabapentin, compromises growth and survival. Finally, the roles of BCAT1 in tumor maintenance in vivo will be presented. These findings lay the foundation for targeting BCAA catabolism in human tumors and tumor subtypes having MYC/MYCN involvement.

Citation Format: Mario R. Fernandez, Vanessa A. Damoulis, Wei Wang, Bernhard Radlwimmer, John L. Cleveland. The role of branched-chain amino acid metabolism in Myc-driven malignancies. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A08.
Abstract A39: Identification and biostatistical analysis of conserved metabolic profiles in breast tumors from transgenic mouse models
Authors: Dai Chen , Littlepage Laurie , Li Jun
Published: May 2016

Novel breast biomarkers with prognostic and therapeutic value include metabolites that are differentially expressed in breast tumors. The goal of this study is to identify global metabolic profiles of breast tumors derived from multiple established transgenic mouse models to gain insight into breast cancers of differing origin. We compared breast tumor samples to normal tissue and between cancer models from transgenic mouse breast cancer models overexpressing the following oncogenes: PyMT, PyMT-DB, Wnt1, Neu, and C3-TAg transgenic mice. Our breast tissue samples were analyzed on GC-MS and LC-MS/MS platforms, and analysis included 374 biochemical compounds of known identity.

Comparison of global metabolic profiles between the different mouse breast cancer and normal tissue revealed many metabolic differences between genetic models. The vast majority of metabolomic profiles demonstrated differential levels of biochemicals between normal and tumor tissues consistent with changes in metabolism that support rapid growth. Breast tumors had increased glucose metabolism, amino acid metabolism, catabolism, and levels of the TCA cycle intermediates, consistent with increased energy production and anaplerotic contributions from amino acid catabolism. We also saw increased phospholipid metabolism, cholesterol uptake, and nucleotide metabolites.

Combined with published gene expression data for these mouse models, we were able to conduct biostatistical analysis to search for correlation between gene expression and metabolite levels. We identified novel key metabolites and genes that correlate with the most other metabolites/genes; the list of these “hub” metabolites/genes could prove to be novel sites of regulation for breast cancer progression.

We identified novel metabolic profiles of breast cancer that will be foundational in identifying metabolites with clinical prognostic value. Currently we are using both 3D culture and preclinical animal models to examine the role of the differentially expressed metabolites in breast cancer progression and treatment.

Citation Format: Chen Dai, Laurie Littlepage, Jun Li. Identification and biostatistical analysis of conserved metabolic profiles in breast tumors from transgenic mouse models. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A39.
Abstract A42: Exploring differential metabolic plasticity for treatment of cancer
Authors: Rodriguez-Colman Maria J. , Meerlo Maaike , Verhoeven-Duif Nanda , Burgering Boudewijn
Published: May 2016

The metabolic properties of cancer cells diverge significantly from those of normal cells. Energy production in cancer cells is abnormally dependent on aerobic glycolysis even in the presence of sufficient oxygen concentration to perform OXPHOS in mitochondria. In the last years the understanding of cancer metabolism has increased, revealing its high complexity. In addition to the dependency on glycolysis, cancer cells have other atypical metabolic characteristics such as increased fatty acid synthesis and increased rates of glutamine metabolism. Emerging evidence shows that many features characteristic to cancer cells, such as deregulated Warburg-like glucose metabolism, fatty acid synthesis and glutaminolysis are linked to therapeutic resistance in cancer treatment. Therefore recently, there is a renewed interest in targeting metabolism as a resource for cancer treatment options. However, cancer heterogeneity and the variable mutational spectrum of cancer will likely hamper targeting metabolism in a manner similar to targeting deregulated signal transduction. Our work aims to analyze and correlate common cancer mutations with metabolic changes and thereby to rationalize metabolic personalized cancer treatment. For this purpose we combine metabolic measurements from genetically defined colon organoids (tumor progression organoid model and organoids derived from various genetically modified mice) and patient derived colon tumor organoids (biobank) from which the genome has been fully sequenced. Metabolism is profiled by various methods including Seahorse technology for the determination of bioenergetics, and untargeted metabolomics. This enables us to profile these organoids based on their metabolic program and to use this information for specific cancer treatment.

Citation Format: Maria J. Rodriguez-Colman, Maaike Meerlo, Nanda Verhoeven-Duif, Boudewijn Burgering. Exploring differential metabolic plasticity for treatment of cancer. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A42.
Abstract A62: Chemoresistance through the intratumoral metabolism of dichloroacetate
Authors: Jahn Stephan C. , Solaymen Mohamed H. , Lorenzo Ryan J. , Langaee Taimour , Stacpoole Peter W. , James Margaret O.
Published: May 2016

Dichloroacetate (DCA), a small molecule commonly used to treat metabolic disorders, is under investigation as an anti-cancer therapy due to its ability to reverse the Warburg effect and induce apoptosis. While DCA's mechanism of action is well-studied, other factors that influence its success as a cancer treatment have not been thoroughly studied. Here we present data showing that expression of glutathione transferase zeta 1 (GSTZ1), the enzyme responsible for the metabolism of DCA, is often misregulated in cancer, resulting in expression in tissues where there generally is none and a lack of expression in sites that have a high level of basal expression. Expression of GSTZ1 in a tumor would be expected to reduce intratumoral DCA concentrations. As we see a disconnect between GSTZ1 mRNA and protein expression in these tumors, control of expression is likely through miRNA. We also report that chloride concentrations, which strongly impact the stability of GSTZ1 in the presence of DCA, may be abnormal in tumors, further influencing DCA metabolism, concentration, and treatment success. Both two- and three-dimensional cell culture of cells expressing or not expressing GSTZ1 provide a proof of principle that GSTZ1 expression confers a level of resistance to DCA. These results have important clinical implications as GSTZ1 expression and chloride concentration could be used as markers to predict outcomes of DCA anticancer therapy.

Citation Format: Stephan C. Jahn, Mohamed H. Solaymen, Ryan J. Lorenzo, Taimour Langaee, Peter W. Stacpoole, Margaret O. James. Chemoresistance through the intratumoral metabolism of dichloroacetate. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A62.
Abstract A84: Regulation of 6-phosphofructo-2-kinase (PFKFB3) by estradiol and implications for the treatment of ER+ metastatic breast cancer
Authors: Clem Brian , Tapolsky Gilles , Chesney Jason
Published: May 2016

Estradiol (E2) administered to estrogen receptor positive (ER+) breast cancer patients stimulates glucose uptake by tumors. This E2-induced metabolic flare is predictive of the clinical effectiveness of anti-estrogens and downstream metabolic regulators of E2 are expected to have utility as targets for the development of anti-breast cancer agents. While the stimulation of glucose metabolism by E2 has been demonstrated, relatively little is known about the precise downstream effectors required for E2 to stimulate glucose metabolism in breast cancer. The family of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases (PFKFB1-4) control glycolytic flux via their product, fructose-2,6-bisphosphate (F26BP), which activates 6-phosphofructo-1-kinase (PFK-1). We recently demonstrated that PFKFB3 expression is elevated in breast cancer lymph node metastases and that exposure of human MCF-7 and T-47D breast cancer cells to E2 causes a rapid increase in 14C-glucose uptake and glycolysis that is coincident with an induction of PFKFB3 mRNA (via ER binding to its promoter), protein expression and the intracellular concentration of its product, F26BP. Importantly, we also found that selective inhibition of PFKFB3 expression and activity using siRNA or a PFKFB3 inhibitor, PFK158, markedly reduces the E2-mediated increase in F26BP, 14C-glucose uptake and glycolysis. In the current study, we sought to determine if co-administration of PFK158, with ICI 182,780 (fulvestrant), would offer a greater anti-tumor effect. In unpublished results, we demonstrated that the combination of the anti-estrogen, fulvestrant, with PFK158 results in greater regressions of MCF-7 xenografts than either drug alone in athymic BALB/C mice. In addition to regulating glucose metabolism, PFKFB3 has been found to be a regulator of the cell cycle via cyclin dependent kinases. We postulated that the combination of PFK158 with the newly FDA-approved CDK4/6 inhibitor palbociclib may result in a synergistic increase in apoptosis. We found that PFK158 markedly increased apoptosis caused by palbociclib in MCF-7 breast cancer cells but not in normal human mammary epithelial cells. Taken together, these data indicate that PFKFB3 inhibitors such as PFK158 may have clinical utility for the treatment of ER+ breast cancers when combined with anti-estrogen agents and/or CDK4/6 inhibitors.

Citation Format: Yoannis Imbert-Fernandez, Brian Clem, Gilles Tapolsky, Jason Chesney. Regulation of 6-phosphofructo-2-kinase (PFKFB3) by estradiol and implications for the treatment of ER+ metastatic breast cancer. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A84.
Abstract A86: LRP16, interacting with PKR, prolongs NF-kappaB activation and drives colorectal cancer tumorigenesis
Authors: Li Xiaolei , Wu Zhiqiang , Han Weidong
Published: May 2016

NF-kappaB frequently activated in colorectal cancer (CRC) is linked to rapid malignant progression of CRC and is also crucial for the maintenance of homeostasis and therapy resistance. However, the underlying mechanisms how NF-kappaB activation and the crosstalk of NF-kappaB with other transcription factors are controlled in CRC remain incompletely understood. Here, we show that LRP16 physically interacts with double-stranded RNA-dependent protein kinase (PKR) functions as a signal transducer in signaling pathways activated by different stimuli by a variety of effectors, including NF-kappaB. Overexpression of LRP16 confers PKR autophosphorylation leading to the phosphorylation and activation of the NF-kappaB complex. Modulation of NF-kappaB mediated gene expression in response to diverse signals is coordinated by PKR through the phosphorylation and activation of IKK complex and this process does not require PKR kinase activity. We identified PKR, an essential regulatory subunit of the IKK complex. Silencing PKR expression by RNA interference blocked LRP16 induced expression of NF-kappaB target genes. These cells were also not protected from apoptosis in response to chemotherapy. In vivo, overexpression of LRP16 promotes CRC tumorigenesis, in turn, inhibition of LRP16 or PKR blunts CRC tumorigenesis. These results demonstrated that LRP16 likely functions by recruiting PKR to the IKK complex and thus serves a regulatory function for NF-kappaB activation, suggesting that a novel role for LRP16 as mediator of chemotherapy resistance modulated in part through the protective effects of NF-kappaB activation and may be a novel strategy in the future to overcome chemotherapy resistance in CRC.

Citation Format: Xiaolei Li, Zhiqiang Wu, Weidong Han. LRP16, interacting with PKR, prolongs NF-kappaB activation and drives colorectal cancer tumorigenesis. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A86.
Abstract A90: Dichloroacetate can overcome drug resistance via decreased ABC drug transporter expression and PDK2 inhibition
Authors: Achuthan Santhi , Callaghan Richard , Blackburn Anneke C.
Published: May 2016

Introduction: The primary hurdle for effective chemotherapy is the inherent or acquired drug resistance of cancer cells. The glycolytic phenotype (or Warburg effect) is a major metabolic signature of cancer cells. Dichloroacetic acid (DCA) is a non-toxic drug, which can reverse the glycolytic phenotype by inhibiting pyruvate dehydrogenase kinases (PDKs). Recent studies have linked changes in cancer cell metabolism to multi-drug resistance (MDR) phenotypes. We have examined whether reversal of the glycolytic phenotype with DCA can restore sensitivity in drug resistant cancer cells.

Methodology: We examined DCA's effects in doxorubicin (DOX)-resistant MDA-MB-231 and MCF7 cells (made by continuous exposure to increasing DOX concentrations for one month) and their DOX-sensitive counterparts by neutral red cell viability assay. Intracellular drug uptake was measured by flow cytometry and expression of PDKs and drug transporters was measured by western blotting.

Results: DCA treatment (1mM for 48hrs) significantly (p<0.05) enhanced DOX toxicity in DOX-resistant cells restoring sensitivity to a level similar to parental cells. This is despite DCA having no effect on DOX toxicity in parental cells. PDK2 expression was higher in the drug-selected cells compared to parental cells suggesting the sensitising effect of DCA on drug resistant cells could be an on-target effect. DCA pre-treatment increased the intracellular retention of DOX and mitoxantrone. DCA effectively reduced the expression of ATP-binding cassette (ABC) drug transporters such as P-glycoprotein and ABCG2 in DOX-resistant MDA-MB-231 and MCF7 cells and in vivo in 4T1 mouse mammary tumors. DCA pre-treatment also sensitised the MDR cell line MCF7-FLV1000 towards mitoxantrone induced apoptosis.

Conclusion: DCA may be an effective chemo-sensitizing agent in a wide range of MDR cancers, acting by reducing drug transporter expression and inhibiting PDKs.

Citation Format: Santhi Achuthan, Richard Callaghan, Anneke C. Blackburn. Dichloroacetate can overcome drug resistance via decreased ABC drug transporter expression and PDK2 inhibition. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A90.
Abstract B13: Akt-independent PDK1 signaling in regulation of purine biosynthesis
Authors: An Songon
Published: May 2016

Molecular association of cancer cell metastasis with signaling pathways has been explicated so as to aid in the development of new prognostic models for better cancer therapies. However, those metastatic signaling pathways are barely explored to take account of the functions of enzymes involved in cellular metabolism. Particularly, the metabolic enzymes in de novo purine biosynthesis have been overlooked for their potential roles in cancer cell metastasis even though they have been successfully validated anti-cancer drug targets. Meanwhile, several lines of recent discoveries on de novo purine biosynthesis suggest that the spatiotemporal assembly of purine biosynthetic enzymes, the purinosome, is under controls of signaling pathways in cancer cells. The results of the inquiry reveal an unanticipated mechanism of action of 3-phosphoinositide-dependent protein kinase 1 (PDK1) signaling pathways in regulation of purine biosynthesis in an Akt-independent manner. Considering the biological action of the Akt-independent PDK1 signaling in anchorage-independent growth of breast cancer cells, we hypothesize that purinosome assembly and disassembly are regulated by Akt-independent PDK1 signaling pathways during breast cancer cell migration and invasion. Collectively, the research coupling two druggable anti-cancer targets will reveal the importance of the heretofore unrecognized molecular interaction between the Akt-independent PDK1 signaling and the purinosome, leading to therapeutic intervention in the management of breast cancer metastasis.

Citation Format: Songon An. Akt-independent PDK1 signaling in regulation of purine biosynthesis. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr B13.
Abstract B15: Metastatic breast tumors regulate gene expression at distal mammary sites that predicts patient outcome
Authors: Lee Jiyoung , Bainer Russell , Frankenberger Casey , Rabe Daniel , Saleh sadiq , Park Morag , An Gary , Gilad Yoav , Rosner Marsha Rich
Published: May 2016

The molecular interactions between cancer and stromal cells within the tumor microenvironment enable tumor invasion, intravasation, and metastasis at distant sites. However, the degree to which metastatic breast tumors reprogram stromal cells both locally and at distant mammary tissues is not well understood. To address this question, we used species-specific RNA sequencing in a mouse xenograft model to determine how the metastasis suppressor RKIP influences transcription in tumor and stroma tissues. Here we show that metastatic tumors prime mammary tissue at a distant site in a manner that reflects local stromal responses. In addition, gene expression in metastatic breast tumors is pervasively correlated with gene expression in local stroma of both mouse xenografts and human patients. Changes in local and distant stromal gene expression elicited by metastatic tumors are better predictors of subtype and patient survival than tumor gene expression, supporting the use of stromal-based strategies for the diagnosis and prognosis of breast cancer. One mechanism by which changes at contralateral distal mammary breast occur is through exosomes secreted by tumor cells. These results indicate that tumors prime contralateral mammary tissue in a manner that reflects local stromal changes and predicts metastatic disease. This study has future application to our understanding of contralateral breast cancer.

Citation Format: Jiyoung Lee, Russell Bainer, Casey Frankenberger, Daniel Rabe, sadiq Saleh, Morag Park, Gary An, Yoav Gilad, Marsha Rich Rosner. Metastatic breast tumors regulate gene expression at distal mammary sites that predicts patient outcome. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr B15.
Abstract B21: An mTORC1-Mdm2-Drosha axis for miRNA biogenesis in response to glucose- and amino acid-deprivation
Authors: Ye Peiying , Liu Yu , Chen Chong , Tang Fei , Wu Qi , Wang Xiang , Liu Chang-Gong , Liu Xiuping , Liu Runhua , Liu Yang , Zheng Pan
Published: May 2016

mTOR senses nutrient and energy status to regulate cell survival and metabolism in response to environmental changes. Surprisingly, targeted mutation of Tsc1, a negative regulator of mTORC1, caused a broad reduction in miRNAs due to Drosha degradation. Conversely, targeted mutation of Raptor, an essential component of mTORC1, increased miRNA biogenesis. mTOR activation increased expression of Mdm2, which is hereby identified as the necessary and sufficient ubiquitin E3 ligase for Drosha. Drosha was induced by nutrient and energy deprivation and conferred resistance to glucose deprivation. Using a high-throughput screen of a miRNA library, we identified four miRNAs that were necessary and sufficient to protect cells against glucose-deprivation-induced apoptosis. These miRNA was regulated by glucose through the mTORC1-MDM2-DROSHA axis. Taken together, our data reveal an mTOR-Mdm2-Drosha pathway in mammalian cells that broadly regulates miRNA biogenesis as a response to alteration in cellular environment.

Citation Format: Peiying Ye, Yu Liu, Chong Chen, Fei Tang, Qi Wu, Xiang Wang, Chang-Gong Liu, Xiuping Liu, Runhua Liu, Yang Liu, Pan Zheng. An mTORC1-Mdm2-Drosha axis for miRNA biogenesis in response to glucose- and amino acid-deprivation. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr B21.
Abstract B46: The use of quantitative proteomics to increase the knowledge about metabolic symbiosis in a tumor microenvironment
Authors: Maes Evelyne , Wenes Mathias , Valkenborg Dirk , Mertens Inge , Prenen Hans , Mazzone Massimiliano , Baggerman Geert
Published: May 2016

For more than a century, it is known that in a solid tumor, malignant cancer cells co-reside with stromal cells including fibroblasts and immune cells. In addition, changes in metabolic requirements of malignant cells are necessary to cover their high proliferative rate. Although it has been demonstrated that complementary metabolic functions of tumor cells and their supporting local stroma (e.g. cancer-associated fibroblasts, adipocytes) contribute to the progression of cancer, less is known about the metabolic needs of immune cells in this local tumor microenvironment. However, in the context of cancer, immune cells, including tumor-associated macrophages (TAMs) are of high interest since it is known that these cells are able to influence tumor progression by allowing the establishment of an attractive environment for tumor growth and metastasis. Studying the expression profiles of proteins involved in metabolic processes of these cells might be a good strategy to elucidate this question.

In this study, we applied quantitative proteomics to study the differences in protein expression of TAMs vs. control macrophages (both bone marrow-derived and peritoneal macrophages) isolated from an in vivo murine model for non-small cell lung adenocarcinoma. In our peptide-centric two dimensional liquid chromatography (LC)- tandem mass spectrometry (MS/MS) setup where Tandem Mass Tag (TMT) labeling is applied, we were able to identify 1250 unique proteins, of which 1178 proteins were quantified with all six TMT reporter ions. Interestingly, analysis of the differentially expressed proteins indicate that several Gene Ontology terms regarding metabolic pathways including glutathione metabolic processes (p= 3.47 e-14) and pentose phosphate shunt (p= 2.29 e-8) were enriched. These data suggest that TAMs can reprogram their metabolism in order to survive to the oxidative stress existing in this kind of microenvironment.

In conclusion, our results illustrate that proteome analysis is a good strategy to obtain insights in the biology of tumor-associated macrophages.

Citation Format: Evelyne Maes, Mathias Wenes, Dirk Valkenborg, Inge Mertens, Hans Prenen, Massimiliano Mazzone, Geert Baggerman. The use of quantitative proteomics to increase the knowledge about metabolic symbiosis in a tumor microenvironment. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr B46.
Abstract B61: Effects of metformin on papillary thyroid cancer apoptosis and autophagy
Authors: Song Young Shin , Kim Eun Young , Sun Hyun Jin , Park Young Joo , Park Do Joon , Cho Sun Wook
Published: May 2016

Metformin, an anti-diabetic drug used in type 2 diabetes treatment, is reported to have therapeutic roles in several human cancers. The present study investigated the Effects of metformin on papillary thyroid cancer (PTC) cell apoptosis and autophagy. Metformin inhibited PTC cell viability and increased cell apoptosis in various doses (0.5-20mM) in two different PTC cell lines (BCPAP and BHP10-3SC). Additionally, metformin-treated PTC cells showed increased LC3B-II with ATG5-ATG12 complex suggesting the induction of autophagy. Interestingly, treatment of autophagy inhibitor, BafA1, enhenced metformin-mediated PTC cell apoptosis. In conclusion, the inhibition of autophagy might enhance the anticancer effects of metformin on PTC cells.

Citation Format: Young Shin Song, Eun Young Kim, Hyun Jin Sun, Young Joo Park, Do Joon Park, Sun Wook Cho. Effects of metformin on papillary thyroid cancer apoptosis and autophagy. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr B61.
Abstract IA26: Identifying metabolic liabilities in obesity-associated pancreatic cancer
Authors: Zaytouni Tamara , Dubois Cory , Hitchcock Daniel , Stylopoulos Nicholas , Clish Clary , Kalaany Nada
Published: May 2016

Obesity is a rising pandemic that is increasingly being recognized for its striking correlation with the incidence of/mortality from cancers of different tissues, particularly that of the pancreas. Ranking as the fourth leading cause of cancer death in the United States, pancreatic ductal adenocarcinoma (PDAC) is a highly lethal, insidious malignancy whose poor prognosis is reflected in a 5-year survival rate of only 5%. In an obese state characterized by elevated circulating levels of insulin and insulin-like growth factor-1 (IGF-1), metabolic signaling pathways, including PI3K/Akt might be aberrantly regulated, altering tumor cell metabolism and driving the maintenance of PDAC. Recognized as a hallmark of cancer formation, altered cellular metabolism is evident in Kras-driven PDAC tumors. However, the specific metabolic impact of obesity and increased insulin and IGF-1 levels on PDAC tumors has not been thoroughly investigated. We performed a large orthotopic xenograft experiment involving the injection of human pancreatic cancer cells modified to either express constitutively active, myristoylated Akt, or a control fluorescent protein (CFP) into the pancreata of lean or diet-induced obese immunodeficient mice. We find that control CFP-tumors grown in obese mice and all Akt-tumors, independent of obesity, are significantly larger than CFP-tumors grown in lean mice. Gene expression and metabolomics analyses demonstrate a striking representation of distinct metabolic pathways, including the nitrogen/arginine or urea cycle pathway in pancreatic tumors grown in obese versus lean mice. This pathway enrichment partially overlaps with that observed in the Akt-driven tumors, independent of obesity. Here we describe the validation of these results by altering urea cycle gene expression in the human PDAC cells and assessing their effect on PDAC cell proliferation, survival, metabolism, and response to arginine deprivation both in tissue culture in vitro and as orthotopic xenografts in the pancreata of lean or diet-induced obese mice in vivo. These studies will help identify metabolic dependencies in Akt-driven or non-Akt-driven pancreatic tumors grown under either obese/hyperinsulinemic or lean states, that could be targeted therapeutically in PDAC patients.

Citation Format: Tamara Zaytouni, Cory Dubois, Daniel Hitchcock, Nicholas Stylopoulos, Clary Clish, Nada Kalaany. Identifying metabolic liabilities in obesity-associated pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr IA26.
Abstract PR05: Aspartate metabolism links the urea cycle with nucleic acid synthesis in cancerous proliferation
Authors: Rabinovich Shiran , Yizhak Keren , Sun Qin , Brandis Alexander , Helbling Daniel , Dimmock David , Nagamani Sandesh , Ruppin Eytan , Erez Ayelet
Published: May 2016

Argininosuccinate synthase (ASS1) is a urea cycle cytosolic enzyme that conjugates aspartate transported across the mitochondria and citrulline. In the liver, this is a critical step in conversion of nitrogenous waste to urea, whereas in most other tissues, it is the penultimate step in arginine synthesis. Citrullinemia is a urea cycle disorder caused by germline mutations that lead to decreased flux through ASS1. Citrullinemia type I (CTLN I) is caused by ASS1 deficiency and citrullinemia type II (CTLN II) is caused by deficiency in mitochondrial aspartate transporter Citrin. In contrast to the established role of ASS1 in ureagenesis, it was found to be somatically silenced in multiple cancers for which the purpose is unknown. Whereas ASS1 silencing renders the tumors auxotrophic for arginine, we hypothesized that down-regulation of ASS1 has an arginine-independent survival effect by redirecting of aspartate towards pyrimidine synthesis.

Supported by computational modeling and using multiple methodologies including studies of fibroblasts from patients with CTLN I and CTLN II, cancer cells, clinical data, robust informatics analysis of multiple tumors, we show that ASS1 is a key regulator of the mitochondria-derived aspartate flux. Silencing of ASS1, leads to preferential diversion of aspartate away from the synthesis of arginine and urea to pyrimidine synthesis. Decreasing aspartate flux to pyrimidine synthesis by either expressing ASS1 in cancer cells that have endogenous silencing, or by blocking the transport of aspartate through the mitochondrial membrane by inhibiting Citrin, decreases cell proliferation due to decreased nucleic acid synthesis.

Our results demonstrate that ASS1 silencing is a novel mechanism to support nucleic acid synthesis in cancers and provides the first metabolic link between the urea cycle enzymes and pyrimidine synthesis.

Citation Format: Shiran Rabinovich, Keren Yizhak, Qin Sun, Alexander Brandis, Daniel Helbling, David Dimmock, Sandesh Nagamani, Eytan Ruppin, Ayelet Erez. Aspartate metabolism links the urea cycle with nucleic acid synthesis in cancerous proliferation. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr PR05.
Abstract PR10: Serine biosynthesis from glucose regulates folate availability
Authors: Lewis Caroline A. , Fiske Brian P. , Pacold Michael E. , Hosios Aaron M. , Mattaini Katherine R. , Sabatini David M. , Heiden Matthew G. Vander
Published: May 2016

It has been established that de novo serine biosynthesis is important for some cancers. We have previously shown that phosphoglycerate dehydrogenase (PHGDH), the enzyme responsible for catalyzing the first step in glycolytic serine biosynthesis, is amplified in certain cancers, including breast cancer and melanoma. Knockdown of PHGDH results in decreased proliferation of PHGDH-amplified cells, demonstrating a dependence on PHDGH in these cells; however, it has not been possible to rescue this defect with exogenous serine, suggesting that glycolytic serine biosynthesis has an alternate function in cells. Here we have investigated four mutually exclusive hypotheses each consistent with the inability of serine to rescue decreased glycolytic serine biosynthesis: 1: There exists an alternative function of PHGDH; 2: Pathway activity is important for TCA cycle anapleurosis; 3: Metabolic channeling of de novo serine; and 4: A unique product of this pathway other than serine is critical for proliferation. Using a combination of genetic and biochemical approaches, we show that flux through the serine biosynthesis pathway is required for cytosolic serine-glycine conversion via serine hydroxymethyltransferase 1 (SHMT1). In many cells flux through SHMT1 occurs in the glycine-to-serine direction, including PHDGH-dependent cell lines, and loss of PHGDH activity results in wasting of folates from the one-carbon pool to make serine. This reduces availability of one-carbon units in the folate pool for nucleotide biosynthesis, resulting in S-phase arrest and eventual cell death. These data link serine biosynthesis from glucose with the regulation of one-carbon folate metabolism, and provide an explanation for why cancer cells are dependent on de novo serine production even when serine is abundant.

Citation Format: Caroline A. Lewis, Brian P. Fiske, Michael E. Pacold, Aaron M. Hosios, Katherine R. Mattaini, David M. Sabatini, Matthew G. Vander Heiden. Serine biosynthesis from glucose regulates folate availability. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr PR10.
Abstract A13: Transferrin facilitates the formation of DNA-double strand breaks via transferrin receptor 1 in fallopian tube epithelial cells.
Authors: Shigeta Shogo , Toyoshima Masafumi , Kitatani Kazuyuki , Ishibashi Masumi , Usui Toshinori , Yaegashi Nobuo
Published: May 2016

Objectives: High-grade serous ovarian cancer (HGSOC) is now believed to arise from fallopian tube epithelium (FTE), and p53 signatures are indicated to be the early oncogenic change in HGSOC. Although accumulation of DNA-double strand breaks (DNA-DSBs) are frequently observed in p53 signatures, the mechanism of DNA-DSBs formation in FTE has not been revealed yet. Hydroxyl radicals, which strongly induce DNA-DSBs, are the most active reactive oxygen species (ROS) in a living organism, and hydroxyl radicals are produced in a Fenton reaction catalyzed by free iron ions. Focusing on transferrin, which is a transporter of iron ion and exists abundantly in the follicular fluid or retrograde menstrual blood, we inspected the role of transferrin and transferrin receptor family in DNA-DSBs formation at FTE.

Materials and methods: The expressions of transferrin receptor 1(TfR1) and 2 (TfR2) in human FTE were assessed by immunohistochemistry. Immortalized fallopian tube secretory epithelial cells (kindly provided by Dr. Ronny Drapkin, Dana-Farber Cancer institute) and A2780 ovarian cancer cells were cultured with holo-transferrin or vehicle, and the extent of DNA-DSBs was compared. γH2AX was adopted as a marker of DNA-DSBs. ROS were also measured to verify whether transferrin promotes a Fenton reaction. The involvement of TfR1 and TfR2 were assessed with siRNA knockdown strategy. Further, the ex vivo study were performed using murine fallopian tubes.

Results: In immunohistochemistry, both TfR1 and TfR2 were ubiquitously positive in human FTE. Transferrin administration significantly increased the γH2AX expression in these cells and led ROS formation. In addition, transferrin treatment also amplified hydrogen peroxide-inducing γH2AX expression. TfR1 knockdown cancelled the uptake of transferrin, subsequent γH2AX expression and ROS formation but TfR2 knockdown didn't. Also we confirmed that transferrin treatment facilitated γH2AX formation in murine FTE ex vivo.

Conclusion: We identified transferrin-TfR1 axis facilitates DNA-DSBs by promoting a Fenton reaction. It is possible that FTE exposed to the extracellular transferrin highly concentrated in the follicular fluid or retrograde menstrual blood is deeply involved with the carcinogenesis of HGSOC.

Citation Format: Shogo Shigeta, Masafumi Toyoshima, Kazuyuki Kitatani, Masumi Ishibashi, Toshinori Usui, Nobuo Yaegashi. Transferrin facilitates the formation of DNA-double strand breaks via transferrin receptor 1 in fallopian tube epithelial cells. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A13.
Abstract A16: Regulation of TRAIL and NF-kappaB pathways in ovarian cancer.
Authors: Anees Mariam , Batool Umaima , Bukhari Sidra , Yousaf Sohail
Published: May 2016

Objective: The equilibrium between apoptotic and survival pathways determines the fate of cells. Dysregulation in any one mechanism often leads to cancer. The present study was designed to determine the crosstalk between TRAIL and NF-kappaB pathways through study of the much controversial role of DcR2 in the induction of NF-kappaB.

Methodology: A total of 50 epithelial ovarian tissue samples were used for immunohistochemical staining of DcR2 and NF-kappaB (p65) proteins along with the other players of TRAIL pathway including DR4, DR5, DcR1, FLIP and TRAIL. Correlations were drawn and survival analysis was performed using Kaplan Meier's method.

Results: A total of 72% ovarian carcinomas showed positive DR4 expression, 68% showed positive DR5 expression, 42% showed positive DcR1 expression, 48% showed positive DcR2 expression, 44% had positive FLIP expression, 46% had positive TRAIL expression in epithelium while 28% had positive TRAIL expression in stroma. NF-kappaB was positive in 46% of the tissue samples. A strong but non-significant correlation was seen between DcR2 and NF-kappaB expression. Interestingly a similar correlation was also found between DR4 and NF-kappaB expression. Survival analysis showed better survival for patients with positive NF-kappaB expression as compared to negative expression.

Conclusion: Coexpression of DcR2 and NF-kappaB suggests a potential therapeutic approach of targeting NF-kappaB through TRAIL pathway by using anti-DcR2 antibodies. However, the study may be elaborated with increased sample size to get significant results.

Note: This abstract was not presented at the conference.

Citation Format: Mariam Anees, Umaima Batool, Sidra Bukhari, Sohail Yousaf. Regulation of TRAIL and NF-kappaB pathways in ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A16.
Abstract A21: Ovarian tumor cells' adhesion and cell signaling pathways are regulated by ARID3B.
Authors: Bobbs Alexander S. , Hallas William Morgan , Dahl. Karen D. Cowden
Published: May 2016

Patients with ovarian cancer are often diagnosed with late-stage metastatic cancer resulting in poor survival rates. To improve both diagnostics and therapeutics, we need to increase our understanding of the genetic programming that leads to metastatic ovarian cancer. We found that the DNA-binding protein AT-Rich Interactive Domain 3B (ARID3B) is over-expressed in ovarian cancer. Nuclear expression of ARID3B correlates with relapse following chemotherapy. Furthermore, ARID3B increases tumor growth in a xenograft model of ovarian cancer. We hypothesize that ARID3B modulates adhesion and survival by regulating genes in the Wnt and TNF pathways. We identified and validated direct target genes of ARID3B by chromatin immunoprecipitation (ChIP), and characterized the binding site for ARID3B. ARID3B regulates target genes in the Wnt signaling pathway including Wnt5A, FZD5, and APC. ARID3B increases adhesion to extra-cellular matrix at least in part through regulation of FZD5. In addition to regulation of adhesion through Wnt signaling, we found that decreased ARID3B leads to a reduction in fibronectin and vitronectin adhesion. ARID3B also seems to play a role in regulating cell death and survival. We found that ARID3B regulates genes in the TNF and TRAIL signaling pathways. In particular, TNF, TNFR2, and TRAIL are ARID3B regulated genes. We are investigating the impact of TNF and TRAIL regulation on cell death and survival. This study directly demonstrates that ARID3B is a transcription factor that regulates target expression of key components of the Wnt and TNF signaling pathways.

Citation Format: Alexander S. Bobbs, William Morgan Hallas, Karen D. Cowden Dahl. Ovarian tumor cells' adhesion and cell signaling pathways are regulated by ARID3B. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A21.
Abstract A24: Hypoxia signaling pathway plays a role in ovarian cancer chemoresistance.
Authors: Cutter Noelle L. , Walther Tyler , Gallagher Liam , Lucito Robert , Wrzeszczynski Kazimierz
Published: May 2016

Epithelial ovarian cancer (EOC) is the leading cause of gynecologic cancer mortality worldwide. These cancers are highly heterogeneous and while chemotherapy is the preferred treatment many patients are intrinsically resistant or quickly develop resistance. Furthermore, all tumors that recur ultimately become resistant. Understanding the molecular alterations of primary tumor cells has become a common method to identify genes critical to the development of a drug-resistance phenotype and progression of cancer and could lead to the development of novel therapeutic strategies for successful treatment of patients. DNA copy number alterations are a common occurrence in all cancers. Specific chromosomal regions and focal points favor either gains or losses in DNA and are important in the regulation of various oncogenes and tumor suppressors. Contributions from The Cancer Genome Atlas as well as recent bioinformatic results have identified key players involved in ovarian cancer deregulation. Specifically, we examined the datasets to identify copy number alterations in genes that segregate with platinum response, and further filtered with expression data to identify genes that were amplified.

Our analysis revealed correlations for expression and CNV for several genes. Of the genes identified in the screen we further characterized one gene involved in hypoxia, HIF1α. Hypoxia is a microenvironmental factor which plays a critical role in the development and progression of cancer, chemoresistance, and poor survival. Epithelial-to-mesenchymal transition (EMT) is the process by which adherent epithelial cells convert to motile mesenchymal cells and is now known to also occur in a variety of diseases including the progression of cancer. EMT may reflect an adaptation of cancer cells to survive cytotoxic drug activity, and may thus be responsible for chemosensitivity. Our results have indicated that the gain of HIF1α decreased the level of apoptosis in response to carboplatin. Furthermore, ovarian cell lines undergoing hypoxia are more invasive, have migratory ability, and display a transformed EMT phenotype. Taken together, we provide the evidence of a role for HIF1α as an important regulator of chemoresistance in ovarian cancer and hypothesize EMT as the underlying mechanisms. These results suggest that the inactivation of HIF-1α signaling by novel strategies may be a potential targeted therapeutic approach for overcoming EMT and chemoresistance induced by hypoxia.

Note: This abstract was not presented at the conference.

Citation Format: Noelle L. Cutter, Tyler Walther, Liam Gallagher, Robert Lucito, Kazimierz Wrzeszczynski. Hypoxia signaling pathway plays a role in ovarian cancer chemoresistance. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A24.