ZIA BC 010887 (ZIA) | |||
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Title | Novel Markers for Disease Outcome in Breast Cancer | ||
Institution | NCI, Bethesda, MD | ||
Principal Investigator | Ambs, Stefan | NCI Program Director | N/A |
Cancer Activity | N/A | Division | CCR |
Funded Amount | $488,242 | Project Dates | 00/00/0000 - 00/00/0000 |
Fiscal Year | 2016 | Project Type | Intramural |
Research Topics w/ Percent Relevance | Cancer Types w/ Percent Relevance | ||
Cancer (100.0%) Chemotherapy (20.0%) Genetic Testing (20.0%) |
Breast (100.0%) | ||
Research Type | |||
Cancer Progression & Metastasis Interactions of Genes and/or Genetic Polymorphisms with Exogenous and/or Endogenous Factors |
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Abstract | |||
Project 1: We continued to comprehensively examine the metabolome, proteome and transcriptome of ER-positive and ER-negative breast tumors from African-American and European-American patients for biomarker discovery. The promise of the study is the discovery of novel biomarkers for prognosis, and for elucidating what may drive the aggressiveness of breast cancer in African-American women. Using an untargeted discovery approach and validation of key metabolites, we characterized the metabolomic profile of human breast tumors and uncovered intrinsic metabolite signatures in these tumors. Importantly, the oncometabolite, 2-hydroxyglutarate (2HG), accumulated in a subset of tumors and human breast cancer cell lines. 2HG reached mmolar concentrations comparable to those in isocitrate dehydrogenase (IDH)-mutant gliomas, despite the absence of IDH mutations. Instead, we discovered a significant association between increased 2HG levels and MYC pathway activation in breast cancer, which was corroborated in human mammary epithelial and breast cancer cells with inducible MYC overexpression and knockdown. Further analyses showed a global increase of DNA methylation in 2HG-high tumors and identified a poor survival tumor subtype with distinct DNA methylation, high tissue 2HG, and heightened occurrence in African-American patients. Tumors of this subtype had a stem cell-like transcriptional signature with WNT and MYC pathway activation. These tumors over-expressed glutaminase, suggesting a functional relationship between glutamine and 2HG metabolism in breast cancer. Accordingly, 13C-labeled glutamine was metabolized into 2HG in cells with aberrant 2HG accumulation, whereas pharmacologic and siRNA-mediated inhibition of glutaminase markedly reduced 2HG. Our findings highlight 2HG as a candidate breast cancer oncometabolite associated with MYC activation and poor prognosis. These studies are being continued, and we are currently evaluating the oncogenic effects of 2HG and how they relate to the expression of ADHFE1, a mitochondrial enzyme that produces 2HG. Current data show that 2HG is a breast cancer oncometabolite that increases stem cell-like and metastatic features of human breast cancer cells while overexpression of ADHFE1 induces the same phenotypes and enhances reductive carboxylation in cancer cells, leading to increased 2HG. In a different study, focusing on the breast cancer proteome, we performed an integrated proteotranscriptomic characterization of breast tumors. We measured global proteome and transcriptome expression in 118 human breast tumors and adjacent non-cancerous tissues. Comparing proteome with transcriptome data, we found that the proteome describes differences between cancerous and non-cancerous tissue that are not captured by the transcriptome. Moreover, the proteome and transcriptome highlighted partially different tumor biologies. When we applied an integrated analysis of both technologies, the approach revealed a global increase in protein-mRNA concordance in tumors. Highly correlated protein-gene pairs were enriched in protein processing and disease metabolic pathways, and occurred more commonly in tumors of African-American patients. The increased concordance between transcript and protein levels was further associated with aggressive disease, including basal-like/triple-negative tumors, and decreased patient survival. Our study indicates that an integrated analysis of the proteome and transcriptome in cancer can uncover disease characteristics beyond the ability of a single technology. Project 2: Inflammation is widely recognized as an inducer of cancer progression. Inducible nitric oxide synthase (NOS2), cyclooxygenase-2 and cystathionine beta synthase are inflammation markers and are involved in wound healing, angiogenesis, and carcinogenesis. NOS2 up-regulation and increased nitric oxide (NO) production also affects the redox state of cells and induces protein, lipid, and DNA modifications. Recent research |