Project Abstract Breast cancer remains the second-leading cause of cancer-related death in the US. Obesity is an established risk factor for several aggressive breast cancer subtypes, and is also associated with increased breast cancer metastasis and mortality. On a mechanistic level, diet-induced obesity drives dysregulation of lipid metabolism that results in greater extracellular fatty acid availability, providing a rich energy source for tumor proliferation and migration. While this has been shown to increase the severity of breast cancer progression and metastasis, the therapeutic potential of this metabolic relationship has not yet been investigated. Dependent upon fatty acid availability and linked to metastatic progression of several cancer types, ferroptosis, a mechanism of cell death caused by lipid peroxidation, serves as a targetable mediator between obesity, fatty acid metabolism, and breast cancer progression. Our preliminary findings support the ferroptosis-metastasis link and suggest obesity-induced dysregulation of fatty acid metabolism may exacerbate this relationship. This proposal will use murine models of obesity and metastatic mammary cancer in concert with several advanced mechanistic approaches, including lipidomic quantification of tumor and plasma as well as high-throughput RNA sequencing for assessing transcriptional regulation of lipid metabolism in the primary and metastatic tumor microenvironment, to rigorously test the hypothesis that dysregulation of fatty acid metabolism associated with obesity promotes sensitivity to ferroptosis in murine models of TNBC. This hypothesis will be tested with two integrated specific aims: Aim 1. Quantify the impact of obesity and ferroptosis induction on murine mammary tumor growth, metastasis, and fatty acid metabolism in vivo. To isolate the effect of fatty acid availability from other components of the tumor microenvironment, in vitro exposure to serum from control or DIO mice will be used to assess changes in sensitivity to inhibition of xCT and GPX4 in TNBC. Aim 2. Determine whether the enzyme pyruvate carboxylase (PC), uniquely involved in both fatty acid and glutamate metabolism, protects against ferroptosis in obesity by assessing if suppression of PC promotes sensitivity to ferroptosis in both primary and metastatic tumors of DIO mice. Transcriptional dysregulation of lipid and glutamate metabolism in obese and control shPC TNBC tumors, comparing primary and metastatic tumors, will be quantified via RNAseq. This proposal aims to define molecular characteristics of fatty acid metabolism enriched in breast cancer of patients with obesity to identify therapeutic targets that can decrease breast cancer mortality by limiting tumor progression and metastasis. Combined with the exceptional training environment at UNC, comprehensive mentoring from Dr. Hursting, and a focused training plan, this fellowship will provide a critical foundation for developing my future career as an inde...