熊果酸对前列腺癌细胞雄激素非依赖性的逆转作用

目的 探讨中药成分熊果酸对雄激素非依赖性前列腺癌(AIPC)的治疗作用及其机制.方法 应用熊果酸处理体外培养的人雄激素依赖性前列腺癌(ADPC)细胞株LNCaP和AIPC细胞株DU145,噻唑蓝(MTT)比色法检测细胞活性及对人工合成雄激素R1881的反应性,免疫细胞化学检测熊果酸对雄激素受体(AR)、糖皮质激素受体(GR)、前列腺特异性抗原(PSA)及成活因子HSP90和白细胞介素(IL)-6表达的影响,逆转录.聚合酶链反应(RT-PCR)检测熊果酸对DU145细胞AR mRNA表达的影响.结果 熊果酸对不同浓度雄激素下的LNCaP细胞均呈浓度和时间依赖性生长抑制,20 mg/L的熊果酸作用96 h对LNCaP细胞的抑制率近50%.0.1 nmoL/L的R1881为最适生长浓度,熊果酸作用后,LNCaP细胞生长的最适雄激素浓度上升了10倍;熊果酸对DU145细胞的生长有浓度和时间依赖性抑制效应,DU145细胞对AR阻断剂羟氟他胺缺乏反应,熊果酸作用同时再应用氟他胺比单纯熊果酸的作用更明显,对细胞抑制率明显上升.熊果酸作用后,LNCaP和DUl45细胞IL-6、HSF90表达均明显下降(P＜0.05),DU145细胞GR表达明显降低(P＜0.01),AR和PSA蛋白及AR mRNA出现再表达.结论 熊果酸能改善前列腺癌细胞对雄激素的反应性,使LNCaP细胞对雄激素的依赖性加强,并诱发了DU145细胞对雄激素的反应性,其部分机制是降低了GR、HSP90、IL-6的表达并促进AR再表达.

Effect of ursolic acid on prostate cancer cells

Objective To study the therapeutic action of ursdic acid on androgen independent prostate cancer. Methods The human androgen-dependent prostate cancer (ADPC) cell line LNCaP and androgen-independent prostate cancer (AIPC) cell line DU145 were cultured in vitro, ursolic acid was used to treat cultured cells, and the effects of ursolic acid on the proliferation of both cell lines were ana-lyzed by MTT assay. The expression of AR, GR, HSP90, PSA and IL-6 protein was assessed by immunocy-tochemistry,and the expression of AR mRNA in DUI45 cells by RT-PCR. Results Ursolic acid inhibited the growth of LNCaP cells in a dose-and time-dependent manner at different concentrations of R1881. Inhi-bition rate of LNCaP cells treated with 20 mg/L Ursolie acid to at the 96th h was up to 50%. 0.1 nmol/L R1881 was the optimal growth concentration, and the optimal androgen concentration for LNCaP growth was increased more than tenfold after treatment with ursolic acid. The growth of DU145 cells was independent on androgen,lacking reaction to AR antagonist flutamide. Ursolic acid exerted a significant time-and dose-dependent growth inhibition on DU145 cells,and ursolic acid together with flutamide had stronger inhibi-tion than ursolic acid alone. Ursolic acid treatment resulted in a significant decrease in the expression of HSP90 and IL-6 in both cell lines (P ＜ 0.05), and a significant decrease in the GR expression (P ＜0.01) and re-expression of AR and PSA in DU145 cells. Conclusion Ursolie acid improves the response of prostate cancer cells to androgen, increasing the dependence of LNCaP cells on androgen and evoking the responsibility of DU145 cells to AR antagonist. The mechanisms in which may partially attribute to the capability of ursolic acid are to decrease the expression of GR, HSP90 and IL-6, and to induce the re-ex-pression of AR in DU145 cells.