Transcriptome of senescent and non-senescent cells within PanIN pancreatic premalignant lesions in a KRas-driven mouse model

Cellular senescence is a central barrier to tumorigenesis, acting to block the proliferation of premalignant cells. However, senescent cells residing within tumor lesions can also exert paracrine effects influencing tumor growth and progression. Premalignant pancreatic intraepithelial neoplasia (PanIN) lesions contain senescent cells, yet whether these influence disease progression is unknown. Here we report that senescent cells in PanINs that develop in a Kras-driven mouse model express a pro-inflammatory gene signature, which includes high Cox2 levels. Pharmacologic Cox2 inhibition caused a dramatic reduction in PanIN growth. Senolytic treatment with the Bcl2-family inhibitor ABT-737 reduced the numbers of Cox2-expressing PanIN cells and blocked PanIN formation and progression to carcinoma. These findings indicate that senescent PanIN cells support tumor growth and progression through Cox2 activity, representing crosstalk between interspersed senescent and dividing premalignant cells. Targeted elimination of senescent cells may thus be effective in limiting progression of precancerous lesions.