miR-2909 regulates ISGylation system via STAT1 signalling through negative regulation of SOCS3 in prostate cancer.

One of the well-document strategies adopted by tumour cells for progression is to evade immune surveillance mechanisms. An understanding of the tight interaction between immunity and progression of cancer can provide novel treatment options for different malignancies including prostate cancer (PCa). Here, we have shown that AATF genome encoded miR-2909, known to play role both in immunity and cancer upregulates various interferon stimulating genes (ISGs) including ISGylation system through STAT1. Our results revealed that miR-2909 up-regulates STAT1 through negative regulation of SOCS3 and not through up-regulation of Type 1 interferon (IFN) production. It was observed that inhibition of ISGylation reduced the proliferation potential of PCa cells. Furthermore, androgens were found to negatively regulate ISGylation in LNCaP cells through androgen receptor signalling independently of miR-2909. TGF-β mediated SMAD3 signalling was also seen to be suppressed by miR-2909 through induction of SMAD7 via enhanced STAT1 expression. Collectively, these studies suggest that miR-2909 could play a vital role in prostate carcinogenesis through modulation of ISGylation system and TGFβ signalling via STAT1.