小干扰RNA沉默hPTTG1基因对卵巢癌细胞增殖和凋亡的影响

目的: 利用RNA干扰技术沉默人垂体瘤转化基因1( hPTTG1 )表达,观察卵巢癌细胞增殖能力和细胞凋亡的改变并探讨分子机制。方法: 化学合成靶定 hPTTG1 的小干扰RNA(siRNA)转染体外培养的A2780细胞,RT-PCR和Western blotting检测 hPTTG1 及c-myc表达水平;MTT法和 -TdR掺入实验检测 hPTTG1 对细胞增殖的影响;annexin V/PI染色流式细胞术和TUNEL法测定各组细胞凋亡情况。结果: hPTTG1 siRNA转染组 hPTTG1 mRNA和蛋白表达下降,抑制率分别为70.5%±3.9%和63.8%±4.5%;转染 hPTTG1 siRNA 24 h细胞吸光度值开始下降,48 h抑制效果最明显,抑制率为42.9%±5.2%;转染 hPTTG1 siRNA后细胞 -TdR放射性计数明显低于空白组和阴性对照组; hPTTG1 siRNA干扰组细胞存活率下降,细胞凋亡率和坏死率均增加;TUNEL染色分析结果可见 hPTTG1 siRNA干扰组凋亡指数明显高于空白组和阴性对照组; hPTTG1 干扰后c-myc mRNA和蛋白表达均下调。结论: hPTTG1 siRNA通过下调c-myc表达抑制A2780细胞增殖,诱导细胞凋亡, hPTTG1 可作为卵巢癌基因治疗的候选靶点。

Effect of hPTTG1 siRNA on proliferation and apoptosis of ovarian cancer cells

AIM: To observe the proliferation and apoptosis of ovarian cancer cells by silencing the expression of human pituitary tumor-transforming gene 1 ( hPTTG1 ) using RNA interference technique.METHODS: The chemically synthesized siRNA targeting hPTTG1 was transfected into ovarian cancer cell line A2780 in vitro. The expression levels of hPTTG1 and c-myc were examined by RT-PCR and Western blotting. Cell proliferation was measured by MTT colorimetric assay and -TdR incorporation test. Cell apoptosis was detected by flow cytometry with annexin V/PI and TUNEL labeling.RESULTS: The expression of hPTTG1 at mRNA and protein levels was inhibited after transfection of hPTTG1 siRNA. The inhibitory efficiency was 70.5%±3.9% and 63.8%±4.5%, respectively. The absorbance began to decrease 24 h after transfection of hPTTG1 siRNA,and the highest inhibitory rate was 42.9%±5.2% at 48 h post-transfection. Radioactive incorporation of -TdR in hPTTG1 siRNA group was lower than that in normal and negative groups. The survival rate declined while the apoptotic rate and necrotic rate increased in hPTTG1 siRNA group. Apoptotic index in hPTTG1 siRNA group was higher than that in normal and negative groups. The expression of c-myc at mRNA and protein levels was down-regulated.CONCLUSION: Cell proliferation is inhibited and cell apoptosis is induced by hPTTG1 siRNA through down-regulating the expression of c-myc. hPTTG1 can be regarded as a candidate gene for ovarian cancer gene therapy.