Genome-wide profiling of inflammatory cistrome reveals AP-1/c-Jun as a key regulator of TNFalpha-mediated triple-negative breast cancer progression [ChIP-seq]. Homo sapiens

Triple-negative breast cancer (TNBC) represents a highly aggressive form of breast cancer with limited treatment options. Proinflammatory cytokines such as TNF can facilitate tumor progression and metastasis. However, our knowledge of the molecular mechanisms underlying TNBC progression mediated by inflammation is still limited. Here, we define the AP-1 transcription factor c-Jun cistrome, which is comprised of 13800 binding sites responsive to TNFalpha-induced signaling in TNBC cells. In addition, we show that c-Jun regulates nearly a third of the TNFalpha-elicited transcriptome. Expression of the c-Jun-regulated pro-invasion gene program is strongly associated with clinical outcomes in TNBCs. Mechanistically; we demonstrate that c-Jun drives TNFalpha-mediated TNBC tumorigenicity by transcriptional regulation of Ninj1. As exemplified by the c-Jun bound CXC chemokine genes clustered on chromosome 4, we demonstrate that NF-kB might be a pioneer factor and is required for the regulation of TNFalpha-inducible inflammatory genes, whereas c-Jun has little effect. Together, our results uncover AP-1 as an important determinant for inflammation-induced cancer progression, rather than inflammatory response. Overall design: BT549 cells were serum-starved overnight and then treated with or without TNFalpha for 3 hours.