【摘要】 目的:探讨西咪替丁对体外培养的人结肠癌细胞株LoVo的抑制和诱导细胞凋亡的作用。方法:采用MTT比色法、流式细胞术、形态学观察和TUNEL法检测不同浓度的西咪替丁溶液处理LoVo细胞后的生长状况、形态学、分子生物学改变。结果:西咪替丁可抑制LoVo细胞的增殖,且有剂量依赖性的趋势:1×10 -2 mol/L西咪替丁处理LoVo细胞4 8h后,在光镜、电镜检测中,可见典型的凋亡细胞;流式细胞术检测凋亡率为32 .7% ,bcl- 2相关蛋白表达率为36 .74 % ;TUNEL法进一步从分子生物学角度证实凋亡的发生。结论:西咪替丁对结肠癌细胞LoVo有抑制作用,主要机制为诱导其发生凋亡,凋亡发生的原因与西咪替丁可下调bcl- 2蛋白的表达有关。更多还原

【Abstract】 Objective:To investigate the regulatory effect of cimetidine on proliferation and apoptosis of colon cancer cells LoVo in vitro.Methods:Colon cancer cell line LoVo originated from human colon carcinoma was cultured in vitro.Cell proliferation was measured by MTT colorimetric assay.Cell cycle and apoptotic percentage were detected by flow cytometry (FCM),morphological changes of apoptotic cell were observed by light and electron microscopy,and apoptotic cells were quantitatively determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL).In addition,expression of intracellular bcl-2 protein was analysed by flow cytometric indirect immunofluorescent technique.Results:Cimetidine (1×10 -2 mol/L～3×10 -2 mol/L) inhibited LoVo cells growth significantly in a dose-dependent manner.After 48 hours of exposure to cimetidine(1×10 -2 mol/L),the enhanced degree of apoptotic percentage was 32.7%.There were many morphologic features of apoptosis,including cell shrinkage,nuclear condensation,DNA fragmentation and formation of apoptotic bodies;apoptotic cells were also statistically significant than those of control group( P <0.05).The analysis on expression of intracellular bcl-2 protein showed cimetidine could down-regulate bcl-2 to 36.74% compared with 67.41% in the control.Conclusion:It is suggested that cimetidine can inhibit the proliferation of LoVo cell.Its anticancer effect may be related to induction of apoptosis,which appeared as a result of down-regulation of the anti-apoptotic protein bcl-2.Advanced research need to be done.更多还原