伽马-分泌酶抑制剂下调Notch1可诱导卵巢癌细胞A2780生长抑制及凋亡

目的 探讨γ-分泌酶抑制剂对Notch1的抑制作用及对卵巢癌细胞生长抑制及凋亡的影响。方法 采用Western blot及实时定量PCR检测四株卵巢癌细胞（A2780, SKOV3, HO-8910, HO-8910PM）及一株卵巢上皮细胞（IOSE144）Notch1及其下游基因hes1的表达情况；采用MTT、流式细胞术、ELISA及克隆形成实验检测γ-分泌酶抑制剂（DAPT）对卵巢癌细胞的影响。结果 Notch1、hes1在IOSE 144及四株卵巢癌细胞系中均有表达，且在A2780细胞系中的表达最高；DAPT下调Notch1可抑制A2780细胞生长、诱导细胞G1期阻滞、诱导细胞凋亡并呈现时间和剂量依赖性，同时A2780细胞中DAPT 下游hes1基因的表达也呈现时间和剂量依赖性。结论 γ-分泌酶抑制剂DAPT可抑制卵巢癌细胞A2780生长、诱导细胞凋亡，γ-分泌酶抑制剂下调Notch1可能是卵巢癌治疗的潜在靶点。

Down-regulation of Notch1 by Gamma-secretase Inhibitor Contributes to Growth Inhibition and Apoptosis of Ovarian Cancer Cells A2780

Abstract: Objective To investigate the inhibiting effect of gamma-secretase inhibitor, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), on Notch1 and its effect on the growthand apoptosis of ovarian cancer cells. Methods Expression of Notch 1 and hes1 in four human ovariancancer cell lines, A2780, SKOV3, HO-8910 and HO-8910PM, and one ovarian surface cell line IOSE 144were detected by Western blot and quantitative real-time RT-PCR. The effects of DAPT on ovarian cancercells were measured by MTT assay, flow cytometry, ELISA and colony formation assay. Results Expressionof Notch1 and hes1 were found in IOSE144 and all the four human ovarian cancer cell lines, and they werethe highest in ovarian cancer cells A2780 compared with other four ovarian cells. Down-regulation of Notch1expression by DAPT was able to substantially inhibit the growth, induce G1 cell cycle arrest and the apoptosisof A2780 cells in a dose- and time-dependent manner. In addition, hes1 was found to be down-regulated ina dose- and time-dependent manner by DAPT in A2780. Conclusion DAPT could inhibit the growth andinduce the apoptosis of A2780 cells in a dose- and time-dependent manner. DAPT inhibiting Notch1 activityrepresents a potentially attractive strategy of targeted therapy for ovarian cancer.