OBJECTIVETo investigate the inhibition of the expression of steroid receptor coactivator-1 (SRC-1) in the LNCap cell line through RNA interference (RNAi) and the effect of the silenced SRC-1 gene on LNCap cells.

METHODSThe experiment included four groups: siRNA transfection, siRNA negative control, bland vehicle (with Lipofectamine 2000 but no siRNA), and blank control (with neither Lipofectamine 2000 nor siRNA). LNCap cells were transfected with designed siRNA using the liposomes method, the expressions of SRC-1 determined by Q-PCR and Western blot, and the proliferation of the LNCap cells detected by the CCK-8 method.

RESULTSThe expression of SRC-1 mRNA in the transfected LNCap cells was decreased by 35% at 24 hours and 77% at 48 hours, with statistically significant differences from the blank control group (P < 0.05). The SRC-1 protein expression of the transfected group was 0.359 +/- 0.034 at 24 hours and 0.257 +/- 0.065 at 48 hours, markedly decreased as compared with that of the negative control (0.782 +/- 0.078 and 0.766 +/- 0.043) , bland vehicle (0.840 +/- 0.013 and 0.786 +/- 0.051), and blank control group (0.816 +/- 0.065 and 0.805 +/- 0.107) (P < 0.05). The LNCap cell growth inhibition rates were 25%, 52%, 55% and 60% at 24, 48, 72 and 96 hours, respectively.

CONCLUSIONThe expression of SRC-1 is correlated with the growth of LNCap cells; its high expression in androgen-independent prostate cancer cells may be involved in the progression to androgen-independence. Inhibiting the expression of SRC-1 may be an option for the treatment of androgen-dependent prostate cancer.