低氧对食管癌Eca109细胞体外迁移及侵袭的影响

Effects of hypoxia on migration and invasion of esophageal carcinoma Eca109 cells

目的探讨低氧对食管癌迁移及侵袭能力的影响及其作用机制。方法采用CoCl2化学低氧法模拟肿瘤低氧微环境,半定量RT-PCR和免疫细胞化学分别检测不同低氧时相时食管癌Eca109细胞中低氧诱导因子-1α(HIF-1α)、E-钙黏蛋白及基质金属蛋白酶-2(MMP-2)mRNA及蛋白的表达。Western印迹法检测雷帕霉素联合低氧处理Eca109细胞后,HIF-1α、E-钙黏蛋白及MMP-2的变化。细胞划痕试验和Transwell实验检测雷帕霉素联合低氧对Eca109细胞迁移及侵袭能力的影响。结果 Eca109细胞在低氧状态下,HIF-1αmRNA无明显变化,仅蛋白表达增多;E-钙黏蛋白的mRNA表达明显降低(P<0.05),蛋白表达减少;MMP-2 mRNA表达明显升高(P<0.05),蛋白表达增多。雷帕霉素在低氧状态下可显著抑制HIF-1α及MMP-2表达,促进E-钙黏蛋白高表达。经雷帕霉素处理后,Eca109细胞在低氧状态下,迁移速度减慢,侵袭穿膜细胞数减少(P<0.05)。结论低氧使Eca109细胞中HIF-1α蛋白表达增多,后者可能通过下调E-钙黏蛋白、上调MMP-2表达促进食管癌在低氧状态下的迁移及侵袭。

Objective To explore the effect of hypoxia on migration and invasion of esophageal carcinoma and its mechanism. Methods CoCl2 was used as a chemical hypoxia-inducing reagent to simulate tumor hypoxic microenvi- ronment, mRNA and protein levels of HIF-1a, E-cadherin and MMP-2 at different hypoxic culture phases were detec- ted by semi-quantitative RT-PCR and immunohistochemistrym, respectively. After treatment with rapamycin com- bined with hypoxia, the protein expression of HIF-1a, E-cadherin and MMP-2 were assayed by Western blot. The effect of rapamycin combined with hypoxia on migration and invasion was tested by cell scratch assay and transwell chambers. Results In situation of hypoxia, mRNA level of HIF-1a had no significant change, while its protein level increased obviously; mRNA and protein levels of E-cadherin were down-regnlated of MMP-2 were up-regulated. Under hypoxia, rapamycin inhibited the expression of herin was up-regulated. The migration and the number of invading cells decreased but the mRNA and protein levels HIF-1a and MMP-2, but E-cad- （P 〈 0. 05 ） after the treatment ofrapamycin under hypoxia. Conclusion Hypoxia increases protein level of HIF-lot in esophageal carcinoma, which promote migration and invasion possibly through down-regulating E-cadherin and up-regulating MMP-2.