土荆皮酸对人卵巢癌细胞端粒酶活性及有关基因的影响

EFFECT OF PSEUDOLARIC ACID B ON TELOMERSE ACTIVITY AND RELATED GENES OF HUMAN OVARIAN CANCER CELLS

目的探讨土荆皮酸(PAB)对人卵巢癌细胞株A 2780细胞端粒酶活性的影响及其机制,为开发新的治疗及预防卵巢癌的天然化合物提供基础。方法采用改良的端粒重复扩增(TRAP)-ELISA方法检测土荆皮酸对A 2780细胞端粒酶活性的影响。半定量RT-PCR方法检测PAB作用后A 2780细胞端粒酶逆转录酶(hTERT)及c-myc原癌基因mRNA的表达水平。结果(1)PAB对A 2780细胞增殖珠抑制呈剂量依赖效应,IC50为5μmol.L-1;(2)端粒酶活性经过PAB处理后呈现明显的下降趋势,且具有时间-效应关系,培养48 h后,端粒酶活性受到显著抑制;(3)hTERT mRNAc、-myc mRNA表达量在5μmol.L-1PAB作用48 h后下降显著,较对照组分别下降了44.3%和53.4%(P<0.05)。结论土荆皮酸可通过下调hTERT基因转录抑制A 2780细胞的端粒酶活性,PAB很有可能是一种新的治疗并预防卵巢癌的天然化合物。

Objective To investigate the effect and mechanism of pseudolaric acid B（PAB） on telomerase activity of human ovarian cancer A 2780 ceils. Methods The telomerase activity of A 2780 ceils was examined by modified TRAP-ELISA assay. The expression of c-myc mRNA and human telomerase reverse transcriptase（hTERT） mRNA was examined using semi-quantitative RT-PCR assay. Results （1）The proliferation of A 2780 ceils was inhibited by PAB in dose dependent manner, IC50：5 μmol·L^-1. （2）Telomerase activity was inhibited by PAB in time-effect relatonship, and was significantly inhibited 48 h after culture（ P 〈 0.01）. （3）The expression of hTERT mRNA, and c-myc mRNA 48 h after treatment with 5 μmol·L^-1 of PAB was 44.3% ,and 53.4% less respectively than the control（ P 〈 0.05）. Conclusion PAB has significant inhibition on telomerase activity and hTERT mRNA, c-myc mRNA. The activity of telomerase of A 2780 cells may be inhibited by down regulation of hTERT mRNA transcription by PAB which may be a new natural compound for preventing and curing ovarian cancer.