金雀异黄酮对结肠癌细胞HT-29增殖及凋亡的影响

Effects of genistein on proliferation and apoptosis in HT-29 cells

目的观察植物雌激素金雀异黄酮(GS)对人结肠癌细胞HT-29增殖及凋亡的影响,并初步探讨其分子生物学作用机制.方法采用MTT比色法和流式细胞术检测GS对HT-29细胞增殖活力和细胞周期分布的影响;Cell Death ELISA和流式细胞术从不同方面检测GS对HT-29细胞凋亡的影响;RT-PCR和Westernhlot技术检测GS对核增殖抗原PCNA、bcl-2和bax mRNA和蛋白质表达的影响.结果与对照组相比,在15～120μmol/L浓度范围内,GS能够抑制HT-29细胞增殖活力;降低S细胞分布比例,将细胞周期滞留在G2/M期;显著性诱导HT-29细胞凋亡(＞30μmol/L,P＜0.05),并呈现出良好的剂量-效应关系.检测GS对PCNA、bcl-2和bax表达的影响显示,GS能够抑制PCNA和bcl-2 mRNA和蛋白质表达,对bax的表达则表现出促进作用.结论GS通过诱导HT-29细胞凋亡而抑制其增殖活力,这些效应与PCNA、bcl-2和bax的表达变化有关.这些资料可为结肠癌的早期预防提供膳食干预新途径,并为临床新药的开发提供新方案.

Objective The study is to explore the effects of genistein on proliferation and apoptosis in human colon cancer HT-29 cells and the likely underlying molecular mechanisms, Methods HT-29 cultures were maintained in DMEM containing 10% fetal bovine serum. Cell proliferation was determined by MTT assay and cell cycle distribution by cytometry. Apoptosis was detected by the Cell Death Detection ELISA and cytometry. The expressions of bax, bcl-2, and PCNA were examined using reverse transcriptase-polymerase chain reaction （RT-PCR） and Western-blot both at mRNA and protein levels, respectively. Results Genistein inhibited proliferation and induced G2/M phase arrest and apoptotic death in colon cancer HT-29 cells. We investigated the effects of genistein on molectdes that regulate apoptosis and cell cycle progress. Genistein increased expression of bax and significantly reduced PCNA with a slightly decrease in bcl-2 expression both at mRNA and protein level. Conclusion Our results demonstrated that genistein inhibited the viability of human colon cancer HT-29 cell via induction of apoptosis mainly through regulation of PCNA and Bax/Bcl-2 expression. These data suggested a role of genistein in prevention of colon tumor and might reduce colon tumor growth.