Figure 2. The miR-139-mediated IFN-β response is dependent on RIG-1 expression. (A) PC3, HEK293T, Du145 and LNCaP cells were treated for 3 days (PC3, HEK293T, Du145) or 7 days (LNCaP) with either miR-139 or negative mimic, followed by WB with antibodies against IFN-β or RIG-1, with β tubulin as loading control. (B) PC3 or HEK293T cells were treated with either miR-139 or negative mimic for 3 days, followed by WB with anti-STAT1p, stripped and reprobed with anti-STAT1 total and β tubulin for loading control. (C) PC3, Du145, HEK293T and LNCaP cells were transfected with RIG-1 plasmid for 3 days. WB of conditioned medium (CM) for IFN-β is shown. WB of lysates with the indicated antibodies are also shown. WB were stripped and reprobed for loading controls with anti-β tubulin. Two alternatively spliced isoforms of STAT1 exist, the antibody used detects both of them.