![Dr. Bing Li Dr. Bing Li](/sites/pathology.medicine.uiowa.edu/files/styles/large/public/2024-07/wysiwyg_uploads/20220819_photo_bing_li.jpg?itok=0lqOWasz)
Epidemiologic studies have confirmed that obesity increases the risk and mortality of breast cancer (BC), but the molecular mechanisms of obesity/BC associations remain largely unknown. Our recent studies demonstrate that the lipid chaperone A-FABP (adipose fatty acid binding protein, also known as FABP4) promotes obesity-associated BC by intracellular regulation of pro-tumor activity in tumor associated macrophages (TAMs) and extracellular enhancement leading to an aggressive phenotype of BC cells. Thus, A-FABP might represent a new factor linking dysregulated lipid metabolism with obesity/BC risk. Moreover, we observed that obesity can be induced by consumption of different types of high-fat diets (HFDs), including saturated fats (e.g. cocoa butter) or unsaturated fats (e.g. olive oil, fish oil). However, cocoa butter HFD-induced obesity was associated with increased A-FABP expression and mammary tumor growth. These observations suggest a novel concept that not all HFD-induced obesity is tumorigenic. Given the undefined links underlying obesity-induced BC risk, we will determine if HFDs rich in saturated fats promote BC risk through A-FABP-mediated immune and metabolic regulation. As such, A-FABP offers a novel therapeutic target and biomarker for obesity-associated BC risk.