RNA干扰HIF-1α降低宫颈癌细胞基质金属蛋白酶-2的表达

Interference of HIF-1α by RNA Reduces the Expression of Matrix Metalloproteinase-2 in Human Cervical Carcinoma HeLa Cells

背景与目的:缺氧诱导因子-1α(hypoxia inducible factor-1alpha,HIF-1α)是普遍存在于实体瘤组织中的缺氧应答调控因子,在维持细胞能量代谢、肿瘤血管生成及转移、细胞增殖与凋亡等诸多方面起着重要作用。本研究探讨RNA干扰HIF-1α对基质金属蛋白酶-2(matrix metalloproteinase-2,MMP-2)在宫颈癌HeLa细胞中表达的影响,初步探讨其机理。方法:①将15只裸鼠随机分为3组,分别用HeLa细胞、pGenesil-1-HeLa细胞和HIF-1α-HeLa细胞接种。②用免疫组化法检测各组移植瘤组织中HIF-1α、上皮细胞钙粘蛋白(E-cadherin)、钙紧张素(β-catenin)和MMP-2的表达。③将HeLa细胞、pGenesil-1-HeLa细胞,HIF-1α-HeLa细胞分别在乏氧(1%O2)及常氧条件下培养48h,用Western blot检测各组细胞中HIF-1α、E-cadherin、β-catenin和MMP-2的表达。结果:①免疫组化法检测结果显示,接种HeLa细胞、pGenesil-1-HeLa细胞和HIF-1α-HeLa细胞的裸鼠移植瘤组织中HIF-1α的表达分别为(69.0±12.1)%、(62.8±12.3)%、(17.4±8.8)%,E-cadherin的表达分别为1.00±0.07、1.00±0.10、3.21±0.25,β-catenin的表达分别为4.21±0.92、4.31±0.87、1.29±0.72,MMP-2的表达分别为4.84±0.67、4.50±0.71、1.00±0.83。②HIF-1α和MMP-2的表达呈正相关(r=0.521,P=0.035)。③Western blot分析结果显示,在抑制HIF-1α表达的HIF-1α-HeLa细胞中,乏氧与常氧条件下HIF-1α、β-catenin和MMP-2蛋白低表达,E-cadherin蛋白高表达;而在HeLa细胞和pGenesil-1-HeLa细胞中得到相反的结果。结论:在人宫颈癌HeLa细胞中干扰HIF-1α后MMP-2的表达下降。

BACKGROUND ＆ OBJECTIVE： Hypoxia inducible factor-1 alpha （HIF-1α） is a hypoxia-responsive factor, which commonly exists in the tissues of solid tumors. It plays crucial roles in maintaining cell energy metabolism, tumor angiogenesis and metastasis, cell proliferation and apoptosis. This study was to investigate the effect of silencing HIF-1α by RNA interference on the expression of matrix metalloproteinase-2 （MMP-2） in human cervical carcinoma HeLa cells, and to further explore the mechanism. METHODS： Fifteen nude mice were divided into three groups randomly, and were inoculated with HeLa cells, pGenesil-1-HeLa cells and HIF-1α-HeLa cells, respectively. Expressions of HIF-1α, E-cadherin, β-catenin, MMP-2 in the xenograft tumors of nude mice were detected by immunohistochemistry. pGenesil-1-HeLa or HIF-1α-HeLa cells were cultured under a hypoxic（1% O2） or normoxic environment for 48 h, while HeLa cells were cultured under the same condition as control. Expressions of HIF-1α, E-cadherin, β-catenin and MMP-2 were measured by Western blot. RESULTS： In HeLa, pGenesil-1- HeLa and HIF-la-HeLa cell xenograft groups, the positive rates of HIF-1α protein were （69.0±12.1）%, （62.8±12.3）% and （17.4±8.8）%, respectively; expressions of E-cadherin were 1.00 ±0.07, 1.00 ±0.10, 3.21±0.25; expressions of β-catenin were 4.21±0.92, 4.31±0.87, 1.29±0.72; and expressions of MMP-2 were 4.84±0.67, 4.50±0.71 and 1.00±0.83. HIF-1α and MMP-2 were positively correlated （correlation coefficient =0.521）. Expressions of HIF-1α, β-catenin and MMP-2 protein were low and that of Ecadherin protein was high in HIF-la-HeLa cells under hypoxia or normoxia for 48 h; while opposite results were obtained in HeLa and pGenesil-1-HeLa cells. CONCLUSION： Inhibition of HIF-1α could effectively down-regulate the expression of MMP-2 in human cervical carcinoma Hela cells.