Xie Tao, Yuan Xiang-Lin, Yu Shi-Ying, Yang Bin, Dong Lan-Lan
Cancer Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
Ai Zheng. 2008 Jun;27(6):600-5.
BACKGROUND & OBJECTIVE: Hypoxia inducible factor-1 alpha (HIF-1alpha) 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-1alpha by RNA interference on the expression of matrix metalloproteinase-2 (MMP-2) in human cervical carcinoma HeLa cells, and to further explore the mechanism.
Fifteen nude mice were divided into three groups randomly, and were inoculated with HeLa cells, pGenesil-1-HeLa cells and HIF-1alpha-HeLa cells, respectively. Expressions of HIF-1alpha, E-cadherin, beta-catenin, MMP-2 in the xenograft tumors of nude mice were detected by immunohistochemistry. pGenesil-1-HeLa or HIF-1alpha-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-1alpha, E-cadherin, beta-catenin and MMP-2 were measured by Western blot.
In HeLa, pGenesil-1-HeLa and HIF-1alpha-HeLa cell xenograft groups, the positive rates of HIF-1alpha 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 beta-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-1alpha and MMP-2 were positively correlated (correlation coefficient=0.521). Expressions of HIF-1alpha, beta-catenin and MMP-2 protein were low and that of E-cadherin protein was high in HIF-1alpha-HeLa cells under hypoxia or normoxia for 48 h; while opposite results were obtained in HeLa and pGenesil-1-HeLa cells.
Inhibition of HIF-1alpha could effectively down-regulate the expression of MMP-2 in human cervical carcinoma Hela cells.
缺氧诱导因子-1α（HIF-1α）是一种缺氧反应因子，常见于实体瘤组织中。它在维持细胞能量代谢、肿瘤血管生成与转移、细胞增殖和凋亡中发挥关键作用。本研究旨在探讨RNA干扰沉默HIF-1α对人宫颈癌HeLa细胞中基质金属蛋白酶-2（MMP-2）表达的影响，并进一步探讨其机制。
将15只裸鼠随机分为3组，分别接种HeLa细胞、pGenesil-1-HeLa细胞和HIF-1α-HeLa细胞。采用免疫组织化学法检测裸鼠移植瘤中HIF-1α、E-钙黏蛋白、β-连环蛋白、MMP-2的表达。将pGenesil-1-HeLa或HIF-1α-HeLa细胞在缺氧（1%O₂）或常氧环境下培养48 h，HeLa细胞作为对照在相同条件下培养。采用蛋白质印迹法检测HIF-1α、E-钙黏蛋白、β-连环蛋白和MMP-2的表达。
在HeLa、pGenesil-1-HeLa和HIF-1α-HeLa细胞移植瘤组中，HIF-1α蛋白阳性率分别为（69.0±12.1）%、（62.8±12.3）%和（17.4±8.8）%；E-钙黏蛋白表达分别为1.00±0.07、1.00±0.10、3.21±0.25；β-连环蛋白表达分别为4.21±0.92、4.31±0.87、1.29±0.72；MMP-2表达分别为4.84±0.67、4.50±0.71和1.00±0.83。HIF-1α与MMP-2呈正相关（相关系数=0.521）。缺氧或常氧培养48 h后，HIF-1α-HeLa细胞中HIF-1α、β-连环蛋白和MMP-2蛋白表达低，E-钙黏蛋白蛋白表达高；而HeLa和pGenesil-1-HeLa细胞则相反。
抑制HIF-1α可有效下调人宫颈癌Hela细胞中MMP-2的表达。
