Abstract LB174: Diabetes-associated breast cancer is molecularly distinct and shows DNA repair deficiency

Abstract Diabetes commonly affects cancer patients. In breast cancer, it decreases patient survival. Diabetes also impacts African American women more so than European American women, potentially contributing to the breast cancer health disparity. In this study, we investigated the influence of diabetes on breast cancer biology in a diverse patient cohort using a three-pronged approach that included analysis of orthotopic human tumor xenografts, patient tumors, and breast cancer cells exposed to diabetes/hyperglycemia-like conditions. We aimed to identify shared phenotypes and molecular signatures by investigating the metabolome, transcriptome, and tumor mutational burden. Diabetes does not enhance cell proliferation but induces mesenchymal and stem cell-like phenotypes linked to increased mobility and odds of metastasis. It also promotes oxyradical formation and both transcriptome and mutational signatures of DNA repair deficiency. Moreover, food- and microbiome-derived metabolites tend to accumulate in breast tumors in presence of diabetes, potentially affecting tumor biology. Breast cancer cells cultured under hyperglycemia-like conditions acquire increased DNA damage and sensitivity to DNA repair inhibitors. Based on these observations, diabetes-associated breast tumors may show an increased drug response to DNA damage repair inhibitors that are cancer therapeutics. Key words: Breast cancer, diabetes, metabolome, transcriptome, metastasis, DNA repair, mutational signature, health disparity Citation Format: Gatikrushna Panigrahi, Julián Candia, Tiffany H. Dorsey, Wei Tang, Yuuki Ohara, Jung S. Byun, Tsion Zewdu Minas, Amy Zhang, Anuoluwapo Ajao, Ashley Cellini, Harris G. Yfantis, Dean Mann, Olga Ioffe, Xin W. Wang, Huaitian Liu, Christopher A. Loffredo, Ana Maria Napoles, Stefan Ambs. Diabetes-associated breast cancer is molecularly distinct and shows DNA repair deficiency [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB174.