Biochemical & Biophysical Research Communications, 2010, 393(2):319-324.

Lipid raft cholesterol and genistein inhibit the cell viability of prostate cancer cells via the partial contribution of EGFR-Akt/p70S6k pathway and down-regulation of androgen receptor

Hea Young Oh, Sung Joon Hong, et al

Department of Urology, Urological Science Institute, Brain Korea 21 Project for Medical Sciences, Yonsei University College of Medicine, 120-752 Seoul, Republic of Korea; et al

Soy isoflavones and cholesterol have been reported as dietary factors related to the incidence of prostate cancer. In this study, we investigated whether cell survival could be suppressed by a combination of the dispersion of lipid raft microdomains and treatment with genistein, a well-known potential isoflavone, in LNCaP prostate cancer cells. Cell viability was assayed by the property of reagent change upon reduction of resazurin to resorufin and apoptosis was evaluated by ethidium bromide/acridine orange (EB/AO) staining and PARP and caspase-3 expression. Signal transduction was investigated by immunoblot analysis. Cell viability decreased significantly more following successive double treatment with genistein and the cholesterol-lowering agent 2-hydroxypropyl-beta-cyclodextrin (HPCD) than in response to either agent alone. Apoptotic cell staining and cleavage of PARP and caspase-3 appeared more clearly in double-treated cells than in those treated with genistein alone. In cell signaling, both HPCD and genistein decreased the protein expressions of pAkt as well as the androgen receptors stimulated by EGF and DHT, respectively, in concentration-dependent manners. This pattern was also present in protein levels of pAkt and the androgen receptor located in the lipid raft fraction. Furthermore, the phosphorylation cascade of Akt, GSK-3beta and p70S6k was markedly inhibited by the combination treatment. These data suggest that prostate cancer cells could be effectively inhibited by combination treatment of cholesterol-lowering strategies and genistein. The mechanism is likely to be partially via both the EGFR-mediated Akt or p70S6k pathways and a down-regulation of androgen receptor in the lipid raft microdomain.

美国《生物化学与生物物理学研究通讯》，2010年3月

脂质筏胆固醇和金雀异黄素通过 EGFR-Akt/p70S6k 通路的部分贡献和雄激素受体的下调来抑制前列腺癌细胞的细胞活力

全慧彬，洪成俊等

韩国延世大学21 项目医学科学泌尿外科泌尿科学研究所

大豆异黄酮和胆固醇作为饮食因素曾经被报道与前列腺癌的发病率有关。在此研究中，我们探究了在 LNCaP 前列腺癌细胞中分散在脂筏微区中的金雀异黄素抑制细胞存活的可能性。通过从刃天青减少到试卤灵的试剂变化属性测定细胞活性，并且通过溴化乙锭溴/吖啶橙 (EB/AO) 染色和 PARP 以及半胱氨酸蛋白酶-3 表达对细胞凋亡进行了检测。采用免疫印迹分析，研究了信号转导。用染料木素和降胆固醇试剂2-羟丙基-β-环糊精 (HPCD)连续性双处理导致的细胞活力下降明显多于比任何单独的试剂。凋亡细胞染色和PARP与半胱氨酸蛋白酶-3卵裂和在双治疗细胞中表现比单独用金雀异黄素处理更明显。在细胞信号下，糊精和金雀异黄素以浓度依赖的方式均降低了pAkt和EGF与DHT诱导的雄激素受体的蛋白表达。这种模式也出现在位于脂质筏部分的pAkt 和雄激素受体的蛋白水平。此外，联合治疗法明显抑制了Akt，GSK-3beta 和 p70S6的磷酸化。这些数据表明，胆固醇降低战略和染料木黄酮联合治疗能有效地抑制前列腺癌细胞。机制可能是部分通过 EGFR 介导的 Akt 或 p70S6k 通路以及雄激素受体在脂筏微区的下调。