茶多酚对膀胱肿瘤细胞端粒酶活性的影响

Effects of (-)-epigallocatechin gallate on telomerase activity of bladder neoplasma cells

目的探讨茶多酚(EGCG)对膀胱肿瘤细胞株T24和BIU87的端粒酶活性影响及其可能机制。方法用MTT法测定治疗组(EGCG)、阳性对照组(阿霉素)、阴性对照组的细胞抑制率,用流式细胞仪测定细胞凋亡率。将1/4IC50的EGCG和阿霉素作用于肿瘤细胞株24h、48h和72h后,用PCR-ELISA法测定肿瘤细胞的端粒酶活性。用1/4IC50的药物作用于肿瘤细胞株24h、48h和72h后,用半定量RT-PCR法测定人端粒酶逆转录酶(hTERT)和c-mycmRNA表达量。结果EGCG和阿霉素均表现为剂量和时间依赖的细胞抑制作用。IC50浓度的EGCG和阿霉素均能够导致肿瘤细胞的凋亡。用1/4IC50浓度的EGCG和阿霉素分别作用于细胞株72h后,T24细胞的端粒酶活性分别降低67.8%和34.1%,BIU87分别降低63.7%和23.2%。1/4IC50浓度的EGCG作用于肿瘤细胞株后,其hTERT和c-mycmRNA表达量降低。结论EGCG能够抑制膀胱肿瘤细胞株的端粒酶活性,作为端粒酶活性抑制剂,其用于肿瘤治疗的可能性还需进一步研究。

Objective To investigate the effects of （-）-epigallocatchin gallate （EGCG） on telomerase activity of bladder carcinoma cell line T24 and BIU87 and its possible mechanisms. Methods The experimental groups were treated with EGCG and the control groups with adriamycin. The inhibitory rate of cell proliferation, and the rate of cell apoptosis were determined by MTT, flow cytometer, respectively. The inhibitory rate of telomerase activity of the cells were determined by PCR-ELISA methods after the cells were treated with 1/4 IC50EGCG and adriamycin after 24 h, 48 h and 72 h. The expression quantity of hTERT and c-myc mRNA were determined by semiquantitative RT-PCR after treated by 1/4 IC50 EGCG and adriamycin after 24 h, 48 h and 72 h. Results Either EGCG or adriamycin showed time-dependent and dose-dependent cytotoxicity. The cell apoptosis could be induced by IC50 of EGCG and adriamycin. After the cells were treated with 1/4 IC50EGCG and adriamycin, The telomerase activity of T24 cell line decreased by 67.8% and 34.1%, respectively, and that of BIU87 cell line decreased by 63.7% and 23.2%, respectively. The expression of hTERT and c-myc mRNA also decreased. Conclusion Our study suggests that the telomerase activity of bladder neoplasma cells can be restrained by EGCG. The application of EGCG as a telomerase activity inhibitor in cancer treatment needs further study.