Abstract
Epidemiological studies have established a positive association between obesity and the incidence of postmenopausal (PM) breast cancer. However, the molecular mechanisms underlying this correlation are not well defined. A central phenotypic characteristic of obese individuals is increased circulating and interstitial abundance of free fatty acids. Here we demonstrate that long-term exposure to palmitic acid (PA) drives cancer cell dedifferentiation towards a cancer stem-like phenotype and enhanced tumor formation capacity. We demonstrate that this process is governed epigenetically through increased chromatin occupancy of CCAAT/enhancer-binding protein beta (C/EBPB). C/EBPB regulates cancer stem-like properties by modulating the expression of key downstream regulators of the extracellular matrix (ECM) including SERPINB2 and LCN2. Collectively, our findings demonstrate that C/EBPB plays a critical role in the initiation of cancer cells in obesity.
Statement of Significance Cellular adaptation to obesity-induced palmitic acid drives tumor initiation through activation of a C/EBPB-dependent transcriptional network. This highlights a mechanistic connection between obesity and postmenopausal hormone receptor negative breast cancer.
Competing Interest Statement
The authors have declared no competing interest.