Correction: Epigenetic loss of AOX1 expression via EZH2 leads to metabolic deregulations and promotes bladder cancer progression

After publication of this Article, the Authors noticed errors in some of the Figures. In Figures 2e, 2f-g, 4a, 4j, 5a and 6b, unmatched β-actin was inadvertently used as loading control for the immunoblots. These have been corrected using repeat data from a similar set of samples and the revised Figures containing matched β-actin and their respective quantification data are included below. In Figure 7a, the same image was inadvertently used to represent tumors 3 and 5 in the control group. This error has been corrected using original images of tumors 3 and 5 in the control group. Additional corrections have been made in the Article and Figure legends to enhance the clarity of the description. NAD was replaced by NADP. NAD/NADP was replaced by NADP/NADPH. The description of the antibody source and dilution for the antigens PFKFB4 (Abcam, 1:1000), G6PD, and HK1 (Cell Signaling, 1:1,000) have been included in the Methods section for Western Blot. The legend for Figure 4e and 4j has been updated. The HTML and PDF versions of this Article have been corrected. The scientific conclusions of this paper have not been affected.

Epigenome environment interactions accelerate epigenomic aging and unlock metabolically restricted epigenetic reprogramming in adulthood

Our early-life environment has a profound influence on developing organs that impacts metabolic function and determines disease susceptibility across the life-course. Using a rat model for exposure to an endocrine disrupting chemical (EDC), we show that early-life chemical exposure causes metabolic dysfunction in adulthood and reprograms histone marks in the developing liver to accelerate acquisition of an adult epigenomic signature. This epigenomic reprogramming persists long after the initial exposure, but many reprogrammed genes remain transcriptionally silent with their impact on metabolism not revealed until a later life exposure to a Western-style diet. Diet-dependent metabolic disruption was largely driven by reprogramming of the Early Growth Response 1 (EGR1) transcriptome and production of metabolites in pathways linked to cholesterol, lipid and one-carbon metabolism. These findings demonstrate the importance of epigenome:environment interactions, which early in life accelerate epigenomic aging, and later in adulthood unlock metabolically restricted epigenetic reprogramming to drive metabolic dysfunction.

Early life exposure to environmental stressors, including endocrine disrupting chemicals (EDCs), can impact health later in life. Here, the authors show that neonatal EDC exposure in rats causes epigenetic reprogramming in the liver, which is transcriptionally silent until animals are placed on a Western-style diet.

DNA methylation patterns in bladder tumors of African American patients point to distinct alterations in xenobiotic metabolism

Racial/ethnic disparities have a significant impact on bladder cancer outcomes with African American patients demonstrating inferior survival over European-American patients. We hypothesized that epigenetic difference in methylation of tumor DNA is an underlying cause of this survival health disparity. We analyzed bladder tumors from African American and European-American patients using reduced representation bisulfite sequencing (RRBS) to annotate differentially methylated DNA regions. Liquid chromatography-mass spectrometry (LC-MS/MS) based metabolomics and flux studies were performed to examine metabolic pathways that showed significant association to the discovered DNA methylation patterns. RRBS analysis showed frequent hypermethylated CpG islands in African American patients. Further analysis showed that these hypermethylated CpG islands in patients are commonly located in the promoter regions of xenobiotic enzymes that are involved in bladder cancer progression. On follow-up, LC-MS/MS revealed accumulation of glucuronic acid, S-adenosylhomocysteine, and a decrease in S-adenosylmethionine, corroborating findings from the RRBS and mRNA expression analysis indicating increased glucuronidation and methylation capacities in African American patients. Flux analysis experiments with 13C-labeled glucose in cultured African American bladder cancer cells confirmed these findings. Collectively, our studies revealed robust differences in methylation-related metabolism and expression of enzymes regulating xenobiotic metabolism in African American patients indicate that race/ethnic differences in tumor biology may exist in bladder cancer.

CBMT-40. THE RELATIONSHIP BETWEEN GLIOMA AND THE GUT-BRAIN AXIS

Recent studies demonstrate the potential role of the microbiome in immune-oncology, revealing specific microbial taxa can augment the effects of various therapeutic modalities against tumors. Gut dysbiosis, a disequilibrium in the host’s bacterial ecosystem, can potentially lead to overrepresentation of some bacteria and favor chronic inflammation and immunosuppression. However, the effects of microbial dysbiosis on non-gastrointestinal cancers in particular gliomas are unknown. Here, we explored the effects of glioma and Temozolomide (TMZ) on the fecal microbiome (FM) in mice (n=24) and FM and metabolome in humans (n=40). Aged C57/B6 mice were implanted with Gl261 tumor cells or vehicle and were assigned to one of the following treatment (oral) groups: vehicle, 5mg/kg TMZ or 25mg/kg TMZ beginning 14 days after surgery for 3-weeks following a 5 day on/2 day off treatment. Fecal samples were collected prior to surgery, at treatment initiation and weekly thereafter until sacrifice and sequenced for 16s RNA. Fecal samples were collected from humans with newly diagnosed glioma before resection, chemoradiation, and after chemoradiation (16s RNA, metabolomic, neurotransmitter analysis). In mice, FM beta diversity was significantly altered with glioma (p=0.003) while the alpha diversity remained unchanged. At a genus and family level analysis the relative abundance of Bacteroides (p=0.01) and Bacteroidaceae (p=0.02) was increased. Beta diversity of mice receiving 5mg/kg TMZ changed from baseline (p=0.02). Collectively, this suggests that glioma alters the FM, to what consequence remains to be explored. Alpha (Observed OTUs, p=0.029) and beta diversity (p=0.034) differences in mice correlated with survival (< 25 - >25 days). In humans, norepinephrine and 5-hydroxyindoleacetic acid were significantly lower in glioma patients at diagnosis compared to controls. Our findings demonstrate for the first time the relationship between glioma and the gut-brain axis. Understanding alterations in the FM in glioma patients may allow novel interventions and should be further investigated.

Liver- and Microbiome-derived Bile Acids Accumulate in Human Breast Tumors and Inhibit Growth and Improve Patient Survival

PURPOSE

Metabolomics is a discovery tool for novel associations of metabolites with disease. Here, we interrogated the metabolome of human breast tumors to describe metabolites whose accumulation affects tumor biology.

EXPERIMENTAL DESIGN

We applied large-scale metabolomics followed by absolute quantification and machine learning-based feature selection using LASSO to identify metabolites that show a robust association with tumor biology and disease outcome. Key observations were validated with the analysis of an independent dataset and cell culture experiments.

RESULTS

LASSO-based feature selection revealed an association of tumor glycochenodeoxycholate levels with improved breast cancer survival, which was confirmed using a Cox proportional hazards model. Absolute quantification of four bile acids, including glycochenodeoxycholate and microbiome-derived deoxycholate, corroborated the accumulation of bile acids in breast tumors. Levels of glycochenodeoxycholate and other bile acids showed an inverse association with the proliferation score in tumors and the expression of cell-cycle and G₂-M checkpoint genes, which was corroborated with cell culture experiments. Moreover, tumor levels of these bile acids markedly correlated with metabolites in the steroid metabolism pathway and increased expression of key genes in this pathway, suggesting that bile acids may interfere with hormonal pathways in the breast. Finally, a proteome analysis identified the complement and coagulation cascade as being upregulated in glycochenodeoxycholate-high tumors.

CONCLUSIONS

We describe the unexpected accumulation of liver- and microbiome-derived bile acids in breast tumors. Tumors with increased bile acids show decreased proliferation, thus fall into a good prognosis category, and exhibit significant changes in steroid metabolism.

Abstract 5274: Multi-omics integration analysis robustly predicts high grade patient survival and identified altered fatty acid metabolism in high grade bladder cancer

Cancer metabolism varies depending on tumor grade. Currently, there is an absence of integration of multi-omics data to predict Bladder cancer (BLCA) survival. We aimed to identify a metabolic signature in high-grade BLCA by integration of unbiased metabolomics, lipidomics and transcriptomics to predict patient survival and to discover novel therapeutic targets. In the current study, using a robust mass spectrometry platform, we conducted global unbiased metabolic and lipid profiling analysis. We identified 518 differential metabolites and 19 lipids of various classes using the NIST MS metabolomics compendium and lipidblast MS/MS libraries, respectively, between low-grade and high-grade BLCA then mapped them to associated genes. Pathway analysis revealed a unique set of biochemical pathways highly deregulated in high-grade BLCA. Integromics analysis identified a molecular gene signature associated with patient poor survival. Importantly, low expression of fatty acid associated enzymes in high-grade tumors was associated with low fatty acid β- oxidation and acyl carnitines in high-grade BLCA and confirmed using tissue microarray. Our key finding is that impaired fatty acid β-oxidation (FAO) by downregulation of fatty acid associate enzymes suggests a crucial role in the progression of low grade to high grade BLCA. Using a metabolic-centered multi-omics based integrative analysis provided a system-level perspective of BLCA that would facilitate the development of novel therapeutics for high-grade BLCA.

Note: This abstract was not presented at the meeting.

Citation Format: Venkata Rao Vantaku, Jianrong Dong, Chandrashekar R Ambati, Dimuthu Perera, Sri Ramya Donepudi, Chandra Sekhar Amara, Vasanta Putluri, Ravi Shiva Shankar, Matthew J Robertson, Danthasinghe Waduge Badrajee Piyarathna, Mariana Villanueva, Friedrich-Carl von Rundstedt, Balasubramanyam Karanam, Leomar Y Ballester, Martha K. Terris, Seth P. Lerner, Apolo B Andrea, Hugo Villanueva, Andrew Sikora, Yair Lotan, Arun Sreekumar, Cristian Coarfa, Nagireddy Putluri. Multi-omics integration analysis robustly predicts high grade patient survival and identified altered fatty acid metabolism in high grade bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5274.

Association between elevated placental polycyclic aromatic hydrocarbons (PAHs) and PAH-DNA adducts from Superfund sites in Harris County, and increased risk of preterm birth (PTB)

The preterm birth (PTB) rate in Harris County, Texas, exceeds the U.S. rate (11.4% vs.9.6%), and there are 15 active Superfund sites in Harris County. Polycyclic aromatic hydrocarbons (PAHs) are contaminants of concern (COC) at Superfund sites across the nation. In this investigation, we tested the hypothesis that higher levels of exposure to PAHs and PAH-DNA adducts in placenta of women living near Superfund sites contribute to the increased rate of PTBs. Levels of benzo[a]pyene (BP), benzo[b]fluorene (BbF) and dibenz[a,h]anthracene (DBA), were higher in placentae from preterm deliveries compared with term deliveries in women living near Superfund sites, whereas this was not the case for women living in non-Superfund site areas. Among the PAHs, DBA levels were significantly higher than BP or BbF, and DBA levels were inversely correlated with gestational age at delivery and birth weight. Bulky PAH-DNA adducts are more prevalent in placental tissue from individuals residing near Superfund sites. Expression of Ah receptor (AHR) and NF-E2-related factor 2 (NRF2) was decreased in preterm deliveries in subjects residing near Superfund sites. Unbiased metabolomics revealed alterations in pathways involved in pentose phosphate, inositol phosphate and starch and sucrose metabolism in preterm subjects in Superfund site areas. In summary, this is the first report showing an association between PAH levels, DNA adducts, and modulation of endogenous metabolic pathways with PTBs in subjects residing near Superfund sites, and further studies could lead to novel strategies in the understanding of the mechanisms by which PAHs contribute to PTBs in women.

Methionine-Homocysteine Pathway in African-American Prostate Cancer

African American (AA) men have a 60% higher incidence and two times greater risk of dying of prostate cancer (PCa) than European American men, yet there is limited insight into the molecular mechanisms driving this difference. To our knowledge, metabolic alterations, a cancer-associated hallmark, have not been reported in AA PCa, despite their importance in tumor biology. Therefore, we measured 190 metabolites across ancestry-verified AA PCa/benign adjacent tissue pairs (n = 33 each) and identified alterations in the methionine-homocysteine pathway utilizing two-sided statistical tests for all comparisons. Consistent with this finding, methionine and homocysteine were elevated in plasma from AA PCa patients using case-control (AA PCa vs AA control, methionine: P = .0007 and homocysteine: P < .0001), biopsy cohorts (AA biopsy positive vs AA biopsy negative, methionine: P = .0002 and homocysteine: P < .0001), and race assignments based on either self-report (AA PCa vs European American PCa, methionine: P = .001, homocysteine: P < .0001) or West African ancestry (upper tertile vs middle tertile, homocysteine: P < .0001; upper tertile vs low tertile, homocysteine: P = .002). These findings demonstrate reprogrammed metabolism in AA PCa patients and provide a potential biological basis for PCa disparities.

Multi-omics Integration Analysis Robustly Predicts High-Grade Patient Survival and Identifies CPT1B Effect on Fatty Acid Metabolism in Bladder Cancer

PURPOSE

The perturbation of metabolic pathways in high-grade bladder cancer has not been investigated. We aimed to identify a metabolic signature in high-grade bladder cancer by integrating unbiased metabolomics, lipidomics, and transcriptomics to predict patient survival and to discover novel therapeutic targets.

EXPERIMENTAL DESIGN

We performed high-resolution liquid chromatography mass spectrometry (LC-MS) and bioinformatic analysis to determine the global metabolome and lipidome in high-grade bladder cancer. We further investigated the effects of impaired metabolic pathways using in vitro and in vivo models.

RESULTS

We identified 519 differential metabolites and 19 lipids that were differentially expressed between low-grade and high-grade bladder cancer using the NIST MS metabolomics compendium and lipidblast MS/MS libraries, respectively. Pathway analysis revealed a unique set of biochemical pathways that are highly deregulated in high-grade bladder cancer. Integromics analysis identified a molecular gene signature associated with poor patient survival in bladder cancer. Low expression of CPT1B in high-grade tumors was associated with low FAO and low acyl carnitine levels in high-grade bladder cancer, which were confirmed using tissue microarrays. Ectopic expression of the CPT1B in high-grade bladder cancer cells led to reduced EMT in in vitro, and reduced cell proliferation, EMT, and metastasis in vivo.

CONCLUSIONS

Our study demonstrates a novel approach for the integration of metabolomics, lipidomics, and transcriptomics data, and identifies a common gene signature associated with poor survival in patients with bladder cancer. Our data also suggest that impairment of FAO due to downregulation of CPT1B plays an important role in the progression toward high-grade bladder cancer and provide potential targets for therapeutic intervention.

A Prospective Targeted Serum Metabolomics Study of Pancreatic Cancer in Postmenopausal Women

To examine the association between metabolic deregulation and pancreatic cancer, we conducted a two-stage case-control targeted metabolomics study using prediagnostic sera collected one year before diagnosis in the Women's Health Initiative study. We used the LC/MS to quantitate 470 metabolites in 30 matched case/control pairs. From 180 detectable metabolites, we selected 14 metabolites to be validated in additional 18 matched case/control pairs. We used the paired t test to compare the concentrations of each metabolite between cases and controls and used the log fold change (FC) to indicate the magnitude of difference. FDR adjusted q-value < 0.25 was indicated statistically significant. Logistic regression model and ROC curve analysis were used to evaluate the clinical utility of the metabolites. Among 30 case/control pairs, 1-methyl-l-tryptophan (L-1MT) was significantly lower in the cases than in the controls (log₂ FC = -0.35; q-value = 0.03). The area under the ROC curve was 0.83 in the discrimination analysis based on the levels of L-1MT, acadesine, and aspartic acid. None of the metabolites was validated in additional independent 18 case/control pairs. No significant association was found between the examined metabolites and undiagnosed pancreatic cancer.

Serum Metabolic Profiling Identified a Distinct Metabolic Signature in Bladder Cancer Smokers: A Key Metabolic Enzyme Associated with Patient Survival

BACKGROUND

The current system to predict the outcome of smokers with bladder cancer is insufficient due to complex genomic and transcriptomic heterogeneities. This study aims to identify serum metabolite-associated genes related to survival in this population.

METHODS

We performed LC/MS-based targeted metabolomic analysis for >300 metabolites in serum obtained from two independent cohorts of bladder cancer never smokers, smokers, healthy smokers, and healthy never smokers. A subset of differential metabolites was validated using Biocrates absoluteIDQ p180 Kit. Genes associated with differential metabolites were integrated with a publicly available cohort of The Cancer Genome Atlas (TCGA) to obtain an intersecting signature specific for bladder cancer smokers.

RESULTS

Forty metabolites (FDR < 0.25) were identified to be differential between bladder cancer never smokers and smokers. Increased abundance of amino acids (tyrosine, phenylalanine, proline, serine, valine, isoleucine, glycine, and asparagine) and taurine were observed in bladder cancer smokers. Integration of differential metabolomic gene signature and transcriptomics data from TCGA cohort revealed an intersection of 17 genes that showed significant correlation with patient survival in bladder cancer smokers. Importantly, catechol-O-methyltransferase, iodotyrosine deiodinase, and tubulin tyrosine ligase showed a significant association with patient survival in publicly available bladder cancer smoker datasets and did not have any clinical association in never smokers.

CONCLUSIONS

Serum metabolic profiling of bladder cancer smokers revealed dysregulated amino acid metabolism. It provides a distinct gene signature that shows a prognostic value in predicting bladder cancer smoker survival.

IMPACT

Serum metabolic signature-derived genes act as a predictive tool for studying the bladder cancer progression in smokers.

Measurement of methylated metabolites using Liquid Chromatography-Mass Spectrometry and its biological application

Methylation aberrations play an important role in many metabolic disorders including cancer. Methylated metabolites are direct indicators of metabolic aberrations, and currently, there is no Liquid chromatography - Mass spectrometry (LC-MS) based method available to cover all classes of methylated metabolites at low detection limits. In this study, we have developed a method for the detection of methylated metabolites, and it's biological application. In this approach, we used a HILIC based HPLC with MS to measure methylated organic acids, amino acids, and nucleotides. These metabolites were separated from each other by their hydrophobic interactions and analyzed by targeted metabolomics of single reaction monitoring by positive and negative mode of electrospray ionization. These metabolites were quantified, and the interday reproducibility was <10% relative standard deviation. Furthermore, by applying this method, we identified high levels of methylated metabolites in bladder cancer cell lines compared to benign cells. In vitro treatment of cancer cells with methylation inhibitor, 5- aza-2'-deoxycytidine showed a decrease in these methylated metabolites. This data indicates that HPLC analysis using this HILIC based method could be a powerful tool for measuring methylated metabolites in biological specimens. This method is rapid, sensitive, selective, and precise to measure methylated metabolites.

Large-scale profiling of serum metabolites in African American and European American patients with bladder cancer reveals metabolic pathways associated with patient survival

BACKGROUND

African Americans (AAs) experience a disproportionally high rate of bladder cancer (BLCA) deaths even though their incidence rates are lower than those of other patient groups. Using a metabolomics approach, this study investigated how AA BLCA may differ molecularly from European Americans (EAs) BLCA, and it examined serum samples from patients with BLCA with the aim of identifying druggable metabolic pathways in AA patients.

METHODS

Targeted metabolomics was applied to measure more than 300 metabolites in serum samples from 2 independent cohorts of EA and AA patients with BLCA and healthy EA and AA controls via liquid chromatography-mass spectrometry, and this was followed by the identification of altered metabolic pathways with a focus on AA BLCA. A subset of the differential metabolites was validated via absolute quantification with the Biocrates AbsoluteIDQ p180 kit. The clinical significance of the findings was further examined in The Cancer Genomic Atlas BLCA data set.

RESULTS

Fifty-three metabolites, mainly related to amino acid, lipid, and nucleotide metabolism, were identified that showed significant differences in abundance between AA and EA BLCA. For example, the levels of taurine, glutamine, glutamate, aspartate, and serine were elevated in serum samples from AA patients versus EA patients. By mapping these metabolites to genes, this study identified significant relations with regulators of metabolism such as malic enzyme 3, prolyl 3-hydroxylase 2, and lysine demethylase 2A that predicted patient survival exclusively in AA patients with BLCA.

CONCLUSIONS

This metabolic profile of serum samples might be used to assess risk progression in AA BLCA. These first-in-field findings describe metabolic alterations in AA BLCA and emphasize a potential biological basis for BLCA health disparities.

Mitochondrial pyruvate import is a metabolic vulnerability in androgen receptor-driven prostate cancer

Specific metabolic underpinnings of androgen receptor (AR)-driven growth in prostate adenocarcinoma (PCa) are largely undefined, hindering the development of strategies to leverage the metabolic dependencies of this disease when hormonal manipulations fail. Here we show that the mitochondrial pyruvate carrier (MPC), a critical metabolic conduit linking cytosolic and mitochondrial metabolism, is transcriptionally regulated by AR. Experimental MPC inhibition restricts proliferation and metabolic outputs of the citric acid cycle (TCA) including lipogenesis and oxidative phosphorylation in AR-driven PCa models. Mechanistically, metabolic disruption resulting from MPC inhibition activates the eIF2α/ATF4 integrated stress response (ISR). ISR signaling prevents cell cycle progression while coordinating salvage efforts, chiefly enhanced glutamine assimilation into the TCA, to regain metabolic homeostasis. We confirm that MPC function is operant in PCa tumors in-vivo using isotopomeric metabolic flux analysis. In turn, we apply a clinically viable small molecule targeting the MPC, MSDC0160, to pre-clinical PCa models and find that MPC inhibition suppresses tumor growth in hormone-responsive and castrate-resistant conditions. Collectively, our findings characterize the MPC as a tractable therapeutic target in AR-driven prostate tumors.

Distinct Lipidomic Landscapes Associated with Clinical Stages of Urothelial Cancer of the Bladder

BACKGROUND

The first global lipidomic profiles associated with urothelial cancer of the bladder (UCB) and its clinical stages associated with progression were identified.

OBJECTIVE

To identify lipidomic signatures associated with survival and different clinical stages of UCB.

DESIGN, SETTING, AND PARTICIPANTS

Pathologically confirmed 165 bladder-derived tissues (126 UCB, 39 benign adjacent or normal bladder tissues). UCB tissues included Ta (n=16), T1 (n=30), T2 (n=43), T3 (n=27), and T4 (n=9); lymphovascular invasion (LVI) positive (n=52) and negative (n=69); and lymph node status N0 (n=28), N1 (n=11), N2 (n=9), N3 (n=3), and Nx (n=75).

RESULTS AND LIMITATIONS

UCB tissues have higher levels of phospholipids and fatty acids, and reduced levels of triglycerides compared with benign tissues. A total of 59 genes associated with altered lipids in UCB strongly correlate with patient survival in an UCB public dataset. Within UCB, there was a progressive decrease in the levels of phosphatidylserine (PS), phosphatidylethanolamines (PEs), and phosphocholines, whereas an increase in the levels of diacylglycerols (DGs) with tumor stage. Transcript and protein expression of phosphatidylserine synthase 1, which converts DGs to PSs, decreased progressively with tumor stage. Levels of DGs and lyso-PEs were significantly elevated in tumors with LVI and lymph node involvement, respectively. Lack of carcinoma in situ and treatment information is the limitation of our study.

CONCLUSIONS

To date, this is the first study describing the global lipidomic profiles associated with UCB and identifies lipids associated with tumor stages, LVI, and lymph node status. Our data suggest that triglycerides serve as the primary energy source in UCB, while phospholipid alterations could affect membrane structure and/or signaling associated with tumor progression.

PATIENT SUMMARY

Lipidomic alterations identified in this study set the stage for characterization of pathways associated with these altered lipids that, in turn, could inform the development of first-of-its-kind lipid-based noninvasive biomarkers and novel therapeutic targets for aggressive urothelial cancer of the bladder.

Analysis of cerebrospinal fluid metabolites in patients with primary or metastatic central nervous system tumors

Cancer cells have altered cellular metabolism. Mutations in genes associated with key metabolic pathways (e.g., isocitrate dehydrogenase 1 and 2, IDH1/IDH2) are important drivers of cancer, including central nervous system (CNS) tumors. Therefore, we hypothesized that the abnormal metabolic state of CNS cancer cells leads to abnormal levels of metabolites in the CSF, and different CNS cancer types are associated with specific changes in the levels of CSF metabolites. To test this hypothesis, we used mass spectrometry to analyze 129 distinct metabolites in CSF samples from patients without a history of cancer (n = 8) and with a variety of CNS tumor types (n = 23) (i.e., glioma IDH-mutant, glioma-IDH wildtype, metastatic lung cancer and metastatic breast cancer). Unsupervised hierarchical clustering analysis shows tumor-specific metabolic signatures that facilitate differentiation of tumor type from CSF analysis. We identified differences in the abundance of 43 metabolites between CSF from control patients and the CSF of patients with primary or metastatic CNS tumors. Pathway analysis revealed alterations in various metabolic pathways (e.g., glycine, choline and methionine degradation, dipthamide biosynthesis and glycolysis pathways, among others) between IDH-mutant and IDH-wildtype gliomas. Moreover, patients with IDH-mutant gliomas demonstrated higher levels of D-2-hydroxyglutarate in the CSF, in comparison to patients with other tumor types, or controls. This study demonstrates that analysis of CSF metabolites can be a clinically useful tool for diagnosing and monitoring patients with primary or metastatic CNS tumors.

Expression of Long Noncoding RNA YIYA Promotes Glycolysis in Breast Cancer

Long noncoding RNA (lncRNA) is yet to be linked to cancer metabolism. Here, we report that upregulation of the lncRNA LINC00538 (YIYA) promotes glycolysis, cell proliferation, and tumor growth in breast cancer. YIYA is associated with the cytosolic cyclin-dependent kinase CDK6 and regulated CDK6-dependent phosphorylation of the fructose bisphosphatase PFK2 (PFKFB3) in a cell-cycle-independent manner. In breast cancer cells, these events promoted catalysis of glucose 6-phosphate to fructose-2,6-bisphosphate/fructose-1,6-bisphosphate. CRISPR/Cas9-mediated deletion of YIYA or CDK6 silencing impaired glycolysis and tumor growth in vivo In clinical specimens of breast cancer, YIYA was expressed in approximately 40% of cases where it correlated with CDK6 expression and unfavorable survival outcomes. Our results define a functional role for lncRNA in metabolic reprogramming in cancer, with potential clinical implications for its therapeutic targeting.Significance: These findings offer a first glimpse into how a long-coding RNA influences cancer metabolism to drive tumor growth. Cancer Res; 78(16); 4524-32. ©2018 AACR.

Abstract B92: Metabolomic landscape of African American prostate cancer: Insights into the biologic basis of the racial disparity

African American (AA) men have an approximately 60% higher incidence of prostate cancer (PCa) and have about two times greater risk of dying of the disease than their European American (EA) counterparts. Despite this staggeringly unequal burden of PCa incidence and outcome between AA and EA men, there is limited insight into the molecular mechanisms associated with this racial disparity. Using state-of-the-art mass spectrometry platform, we uncovered the very first metabolic and lipidomics landscape in PCa/benign adjacent tissue pairs and paired plasma and urine containing epidemiologic meta-data from ancestry-typed AA and EA men. A total of 190 polar and mid-polar metabolites and 495 lipids were measured in tissues and 183 metabolites and lipids were examined in the plasma and urine samples. AA PCa tissue and plasma signatures had unique alterations in metabolites and key enzymes associated with the methionine-homocysteine pathway, including adenosine and inosine levels, compared to corresponding tissues and plasma from EA case controls and EA PCa tissues. Intriguingly, methionine levels in AA PCa were also portrayed by distinct dietary practices in these patients. In addition, AA PCa tissues demonstrated unique patterns of bioenergetic metabolites and accumulated lipids reflecting impaired mitochondrial activity and TCA cycle. Further characterization of these first-in-the-field findings demonstrating reprogrammed metabolism in AA PCa relative to EA tumors could reveal insights into the biologic basis of PCa disparities and novel areas for therapeutic intervention.

Citation Format: Stacy M. Lloyd*, Jie H. Gohlke*, Sumanta Basu*, Vasanta Putluri,Shaiju K Vareed, Rebeca San Martin, Thekkelnaycke Rajendiran, Tiffany A. Dorsey, Bandana Prasad, Rajni Sonavane, Uttam Rasaily, James Henderson, Balasubramanyam Karanam, Harene Venghatakrishnan, Salil Bhowmik, Alexander Zaslavsky,Nilanjan Guha, Rick Kittles, Stefan Ambs, Michael Ittmann,David Rowley, Ganesh Palapattu, Nagireddy Putluri,George Michailidis, Arun Sreekumar. Metabolomic landscape of African American prostate cancer: Insights into the biologic basis of the racial disparity [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr B92.

Abstract 2394: Racial disparity in bladder cancer and identification of altered metabolism in African American compared to European American bladder cancer

This abstract has been withheld from publication due to its inclusion in the AACR Annual Meeting 2018 Official Press Program. It will be posted online following its presentation.

Citation Format: Venkata Rao Vantaku, Sri Ramya Donepudi, Tiffany Dorsey, Vasanta Putluri, Chandrashekar Ambati, Tang Wei, Michael M. Ittmann, Martha K. Terris, Seth Lerner, Stefan Ambs, Yair Lotan, Arun Sreekumar, Nagireddy Putluri. Racial disparity in bladder cancer and identification of altered metabolism in African American compared to European American bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2394.

Abstract 1331: Inhibition of mitochondrial reprogramming regulated c-Src in triple-negative breast cancer activates autophagy-mediated survival mechanism

c-Src is a proto-oncogene involved in signaling that culminates in the control of multiple biological functions. Src is also one of the most frequently upregulated pathways in triple negative breast cancer (TNBC). Dysregulation of Src has been detected in TNBC and is strongly associated with tumor metastasis and poor prognosis. However, even after promising preclinical studies, Src inhibitors did not show major clinical advantage in unselected TNBC populations. Thus, understanding the mechanism of drug resistance to Src inhibition has major clinical significance in TNBC patients. The full activation of Src signature depends on the autophosphorylation at Y419 that allows the substrate to gain access. We have previously published that metastatic TNBC has high energy-dependency to mitochondrial fatty acid beta-oxidation (FAO) and FAO activate Src by inducing autophosphorylation at Y419. However, our recent analysis suggests that as observed with the Src inhibitors, treatment with FAO inhibitors only attenuate the TNBC tumor growth, but do not result in complete regression. Evaluation of their drug resistance mechanism revealed that while short-term inhibition of FAO or Src induces autophagic and apoptotic cell deaths, long-term inhibition results in autophagy-mediated drug resistance and survival. Studies using p53 knocked out TNBC cells confirmed that the autophagy-mediated resistance to Src inhibition is independent of their p53 status. Further analyses suggest that FAO and Src inhibitors increase the phosphorylation of ERK1/2 in TNBC. Treatment with MAPK/ERK inhibitors abolished the FAO or Src inhibitor-mediated autophagy activation. Validation of in vitro findings using in vivo TNBC patient-derived xenograft (PDX) models confirmed that Src inhibition enhances ERK1/2 activity and induces autophagy in TNBC. Overall, our results suggest that long-term FAO or Src inhibition results in ERK-mediated autophagy activation and therapeutic resistance in TNBC. This finding will have major therapeutic impact in the management of currently non-targetable aggressive TNBC.

Citation Format: Kwang Hwa Jung, Jun Hyoung Park, Tirupataiah Sirupangi, Dongya Jia, Shivanand Pudakalakatti, Nishant Gandhi, Jessica Elswood, Vasanta Putluri, Chad J. Creighton, Weston Porter, Michael T. Lewis, Xi Chen, Nagireddy Putluri, Pratip K. Bhattacharya, Lee-Jun C. Wong, Gokul M. Das, Benny A. Kaipparettu. Inhibition of mitochondrial reprogramming regulated c-Src in triple-negative breast cancer activates autophagy-mediated survival mechanism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1331.

Dimethyl fumarate targets GAPDH and aerobic glycolysis to modulate immunity

Activated immune cells undergo a metabolic switch to aerobic glycolysis akin to the Warburg effect, thereby presenting a potential therapeutic target in autoimmune disease. Dimethyl fumarate (DMF), a derivative of the Krebs cycle intermediate fumarate, is an immunomodulatory drug used to treat multiple sclerosis and psoriasis. Although its therapeutic mechanism remains uncertain, DMF covalently modifies cysteine residues in a process termed succination. We found that DMF succinates and inactivates the catalytic cysteine of the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in mice and humans, both in vitro and in vivo. It thereby down-regulates aerobic glycolysis in activated myeloid and lymphoid cells, which mediates its anti-inflammatory effects. Our results provide mechanistic insight into immune modulation by DMF and represent a proof of concept that aerobic glycolysis is a therapeutic target in autoimmunity.