Fig. 3

p62 and SOX9 are cytoprotective for HR⁻ BCa and PCa cell lines. (a) Western blot analysis was performed for MCF7 or LNCaP cells treated with vehicle control or 25 ng/ml IL-1 for 5 days (MCF7) or 3 days (LNCaP) or for untreated MDA-MB-231, BT549, PC3, and DU145 cells. p62 and SOX9 are induced by IL-1 in MCF7 and LNCaP cells concomitant with ERα or AR repression, respectively, and p62 and/or SOX9 protein is basally high in ERα⁻ MDA-MB-231, ERα⁻ BT549, AR⁻ PC3, and AR⁻ DU145 cells. MDA-MB-231, BT549, PC3, and DU145 cell lines were treated with 70 nM control siRNA, p62 siRNA, or SOX9 siRNA and (b) after 1 day in siRNA, RT-qPCR was performed to validate p62 or SOX9 knockdown, (c) MTT was performed after 1 day (MDA-MB-231) or 3 days (BT549, PC3, DU145) in siRNA, or (d) cell counts were recorded at day 0 (no treatment), day 1, 2, and 3. Loss of p62 or SOX9 is cytotoxic for the MDA-MB-231, BT549, PC3, and DU145 cell lines. N = 3–4 biological replicates; error bars, +/−STDEV; p-value, * ≤ 0.05, ** ≤ 0.005, *** ≤ 0.0005. mRNA fold change is normalized within each cell line to control siRNA. Cell viability is normalized to control siRNA for each cell line and cell counts are normalized to day 0 for each cell line. Western blot densitometry is shown