缺氧下神经生长因子受体p75在膀胱癌细胞中表达的变化及生物学特点

Effects of hypoxia on expression of nerve growth factor receptor p75 in human bladder carcinoma cells and its biological characteristics

目的:探讨缺氧条件下神经生长因子受体(p75 NGFR)在不同组织来源膀胱癌细胞株中表达的变化及生物学特性的变化。方法:选取不同膀胱癌组织来源的鳞癌细胞株SCaBER和中分化的移行细胞癌细胞株5637。采用免疫荧光细胞化学染色及RT-PCR检测常氧和缺氧24、48、72 h 2个膀胱癌细胞系中p75 NGFR蛋白和mRNA的表达情况,流式细胞术检测缺氧1、3、5、7 d膀胱癌细胞凋亡情况,MTT法检测丝裂霉素(MMC)处理24、48、72 h对缺氧条件下膀胱癌细胞的抑制率的影响。结果:p75 NGFR蛋白及mRNA表达在2个细胞系缺氧24、48 h有所下降,但与常氧组相比差异无统计学意义(P>0.05);在72 h有显著降低,与其余各组相比差异有统计学意义(P<0.05)。膀胱癌SCaBER、5637细胞在缺氧第3天开始凋亡率低于常氧组(P<0.05);缺氧48、72 h后MMC对膀胱癌细胞的抑制率低于常氧组(P<0.05)。结论:缺氧条件下,p75 NGFR在膀胱癌细胞的表达随时间逐渐降低,膀胱癌细胞的凋亡率降低,MMC对膀胱癌细胞的抑制率下降。

Aim： To explore the effects of hypoxia on the expression of nerve growth factor receptor p75（ p75 NGFR）in human bladder carcinoma cells and its biological characteristics. Methods： The protein and mRNA expressions of p75 NGFR in 2 bladder carcinoma cell lines（ SCaBER and 5637） which originated from different tissue were assessed by immunofluorescence staining and RT-PCR in the normoxic condition and in hypoxic condition（ 10% O2,5% CO2,85% N2）.Flow cytometry was used to detect the apoptosis of bladder cancer cells under hypoxia. Inhibition of mitomycin（ MMC） on bladder cancer cell growth under hypoxic conditions was assessed by MTT. Results： It was showed that under hypoxic conditions for 24 h and 48 h,the positive rate of p75 NGFR expression in 2 cell lines（ SCaB ER and 5637） decreased,but had no significant difference compared with normoxia group. Hypoxia for 72 h markedly down-regulated the expression of p75 NGFR of 2 cell lines,when compared with normoxia group and hypoxia for 24 h and 48 h groups（ P〈0. 05）. The apoptosis rate of SCaB ER and 5637 cells was significantly lower than that of normoxia group on the 3 rd day after hypoxia（ P〈0. 05）. It was found that the inhibition rates of MMC on bladder cancer cells under hypoxia for 48 h and 72 h were lower than those in normoxia group（ P〈0. 05）. Conclusion： Hypoxia might inhibit expression of p75 NGFR in SCaB ER and5637 cells in a time-dependent manner. The apoptosis of bladder cancer cells is decreased,and the inhibitory rate of MMC on bladder cancer cells is decreased.