Cell-autonomous IL6ST activation suppresses prostate cancer development via STAT3/ARF/p53-driven senescence and confers an immune-active tumor microenvironment

Prostate cancer ranks as the second most frequently diagnosed cancer in men worldwide. Recent research highlights the crucial roles IL6ST-mediated signaling pathways play in the development and progression of various cancers, particularly through hyperactivated STAT3 signaling. Here, we find that genetic cell-autonomous activation of the IL6ST receptor in prostate epithelial cells triggers active STAT3 signaling and significantly reduces tumor growth in vivo. Mechanistically, genetic activation of IL6ST signaling mediates senescence via the STAT3/ARF/p53 axis and anti-tumor immunity via recruitment of cytotoxic T-cells, ultimately impeding tumor progression. Our findings reveal a context-dependent role of IL6ST/STAT3 in carcinogenesis and a tumor-suppressive function in prostate cancer development. We challenge the prevailing concept of blocking IL6ST/STAT3 signaling as functional prostate cancer treatment and instead propose cell-autonomous IL6ST activation as a novel therapeutic strategy. Overall design: mRNA expression profiles of prostate epithelial cells derived from 19-week-old mice. Single cell suspension of mouse prostate tissue of wild type (B), mice with probasin promoter-controlled Cre-mediated homozygous deletion of Pten and/or insertion of L-gp130 construct resulting in L-gp130peKI/KI (C), Ptenpe?/? (E) and Ptenpe?/?;L-gp130peKI/KI (F) mice was done and magnetic cell separation was performed for EpCAM positive fraction. EpCAM expressing cells were enriched by MACS sorting.