Fig. 1. SAL induces cellular senescence in both CSPC and CRPC cells associated with an increase of CDKN2B / p15INK4b levels.
Androgen-dependent LNCaP and castration-resistant C4-2 PCa cell lines were incubated for 72 h with DMSO, as solvent control, 1 pM R1881 (methyltrionolone) defined as low androgen levels (LAL), or 1 nM R1881 as supraphysiological androgen level (SAL) [4]. A Upper panel: Representative pictures of SA-β-Gal staining of LNCaP and C4-2 cells at 200x magnification. Lower panel: quantification of SA-β-Gal-positive stained cells. Bar graphs represent mean ± SD (n = 3). B Detection of CDKN2B mRNA expression by qRT-PCR normalized to the house-keeping genes TBP and GAPDH. Bar graphs represent mean ± SEM (n = 3). C Changes of p15INK4B protein level were detected by Western blotting. Values of control samples were set arbitrarily as 1. Quantification of bands was performed by LabImage D1 normalized to the loading control β-actin (n = 3). **p ≤ 0.01, ***p ≤ 0.001, ****p ≤ 0.0001.