【摘要】 目的　采用体内和体外实验观察褪黑素 (melatonin ,MLT)对小鼠肝癌H2 2细胞株的生长抑制作用 ,并探讨其机理。方法　MTT法分析MLT对培养H2 2细胞的抑制作用 ,流式细胞技术 (flowcytometry ,FCM)检测细胞周期分布 ,采用免疫组化方法进行体内和体外P5 3、cyclinE的检测 ,通过RT PCR方法进一步检测 p5 3mRNA水平。结果　 1.MTT显示MLT对H2 2细胞具有极显著抑制作用 (P <0 0 1) ;2 .FCM显示 :MLT可引起H2 2细胞G0 /G1期比例升高 ;3.免疫组化分析显示MLT使体内和体外P5 3蛋白水平显著增高 (P <0 0 1) ,cyclinE水平下降 (P <0 0 1) ,RT PCR方法证明p5 3mRNA水平增高。结论　MLT可引起细胞周期阻滞在G1期 ,其机理可能是通过P5 3抑制cyclinE的表达 ,从而阻止细胞进入S期的结果。更多还原

【Abstract】 ? Objective To investigate the mechanism of melatonin’s inhibitory effect on H22 hepatoma cells. Method Melatonin’s inhibition on the growth of H22 was studied by examining with MTT it’s influence on the cell culture in vitro. The percentage of cells in each cycle phasewas analysed by FCM. P53 and cyclin E were detected by immunohistochemical analysis in both vivo and vitro. The level of p53 mRNA was detected by RT-PCR. Result (1)We observed that the growth of H22 cells were inhibited by melatonin (2)FCM examination found that the cells were inhibited by melatonin in the G0/G1 phase. (3)p53 both in vivo and in vitro increased (P<0.01), while the level of cyclin E decreased (P<0.01). (4) p53 mRNA increased when compared with the controls.Conclusion Melatonin inhibits the H22 cell by arresting the cell in the G0/G1 stage, which may result from the increasing p53 that can indirectly down/regulate cyclin E. 〔更多还原