miR-122介导肝癌细胞凋亡的分子机制研究

摘要

目的：探讨微小RNA-122（miR-122）介导肝癌细胞凋亡的分子作用机制。方法将人工合成的miR-122类似物、对照片段NC转染到肝癌细胞HepG2（p53wt）、MHCC97H（p53 mutation）后，miR-122组（转染miR-122）、对照组（转染对照无意片段）和空白对照组均应用RT-PCR检测miR-122，Western blot检测p53、Bax蛋白，MTT法检测肝癌细胞增殖变化，流式细胞术检测肝癌细胞凋亡率。结果在HepG2中，miR-122组的miR-122的表达、p53蛋白和Bax蛋白表达量明显高于对照组和空白对照组，三组间差异均有统计学意义（χ2=13.41，F分别=15.35、16.88，P均＜0.05）。在MHCC97H中，miR-122组miR-122的表达和Bax蛋白表达量明显高于对照组和空白对照组，三组间差异均有统计学意义（χ2=12.98，F =18.91，P均＜0.05），而三组的p53蛋白测定值比较，差异无统计学意义（F=2.82，P＞0.05）。在HepG2和MHCC-97H细胞中，与对照组和空白对照组比较，miR-122组细胞增殖受到明显抑制，细胞凋亡率明显增加，差异均有统计学意义（χ2分别=8.53、7.81、11.64、12.45，P均＜0.05）。对照组和空白对照组的细胞增殖和细胞凋亡率无明显变化，差异均无统计学意义（χ2=0.08、0.05、0.12、0.09，P均＞0.05）。结论 miR-122可通过p53依赖途径及非p53依赖途径促进肝癌细胞凋亡。%Objective To investigate the mechanism of miR-122 induced hepatocarcinoma cell apoptosis. Methods The miR-122 analogue or NC as control were respectively transfected into HepG2 (p53wt)cells and MHCC97H (p53 mutation)cells to detect miR-122 by RT-PCR,the expression of p53 and Bax by western blot,the proliferation of hepatocarcinoma cells by MTT and apoptosis rate of hepatocarcinoma cells by flow cytometry. Results In HepG2 (p53wt) cells,the expression of miR-122,p53 and Bax proteins in miR-122 group were significantly higher than in control group and NC group (χ2 =13.41,F=15.35,16.88,P<0.05). In MHCC97H (p53 mutation)cells,the expression of miR-122 and Bax protein in miR-122 group were significantly higher than in control group and NC group (χ2=12.98,F=18.91,P<0.05). The p53 protein among three groups was not statistical different (F=2.82,P>0.05).In HepG2(p53wt)cells and MHCC97H (p53 mutation)cells,the cell proliferation in miR-122 group was obviously inhibited and cell apoptosis was obviously enhanced when compared to control group and NC group (χ2=8.53,7.81,11.64,12.45,P<0.05). The cell proliferation and apoptosis rate has no obvious change in control group and NC group,the difference were not significant(χ2=0.08、0.05、0.12、0.09,P>0.05). Conclusion MiR-122 could induce hepatocarcinoma cell apoptosis through both p53-dependent pathway and p53-independent pathway.