Expression of Notch3 and Notch intracellular domain in ovarian carcinoma and effect of N-[N-(3,5-difluorophenyl) acetyl-L-alanyl]-S-phenyl glycine t-butyl ester on ovarian carcinoma cell / 中华妇产科杂志

ABSTRACT

Objective To study the expression and clinical significance of Notch3 and Notch intracellular domain (NICD) in ovarian carcinoma and the effects of N-[N-(3 ,5-difluorophenyl) acetyl-L-alanyl]-S-phenyl glycine t-butyl ester (DAPT), a γ-secretase inhibitor on the proliferation and apoptosis in OVCAR3, A2780 ovarian carcinoma cell lines. Methods Western blot was used to detect the expression of NICD in the tissues from 58 ovarian carcinomas patients and 21 normal ovarie, who were admitted in Peking University First Hospital from July 2006 to June 2009. Immunohistochemistry was also used to detect the expression of Notch3 in these tissues. The relationship with clinical features of ovarian carcinoma was also analyzed. Proliferation of OVCAR3 and A2780 ovarian cancer cells was determined by methyl thiazolyl tetrazolium (MTT) assay, cell cycles and apoptosis and index of proliferation were detected by flow cytometry method. The expression of NICD in OVCAR3 and A2780 cells incubated with DAPT was detected by western blot. Results (1)The expression level of NICD in ovarian carcinomas was significantly higher than that in normal ovarian tissues (1.64 ±0. 19 vs. 0.98 ±0.20;P <0.05). The NICD expression was higher in ovarian cancers with low grade or advanced stage than those in high-middle grade or early stage,respectively (1.90 ± 0. 22 vs. 1.25 ± 0. 21,1.80 ± 0. 21 vs. 1.21 ± 0. 15; all P < 0. 05). The Notch3 protein was stained positively in cytoplasm, nuclear and cell membrane. The expression of Notch3 was higher in ovarian carcinomas than that in normal ovaries [78% (45/58) vs. 24% (5/21); P < 0. 01]. While,there were no stasistical difference in different pathological types, stages, differentiation of ovarian carcinoma. There was no difference between the patients with adjuvant chemotherapy or not. (2)After OVCAR3 and A2780 cells incubated with DAPT 24, 48, 72 hours, NICD expression was significantly lower than that in control group (P < 0. 05). The effects of DAPT inhibited the proliferation and prompted the apoptosis of OVCAR3 and A2780 cells were depended on the concentrations and times. Conclusions Notch3 and NICD may play a key role in the occurrence and progress of ovarian carcinoma. The mechanism of DAPT inhibited the proliferation and prompted the apoptosis of OVCAR3 and A2780 cells may be due to decreased the formation of NICD.