缺氧诱导宫颈癌Siha细胞发生上皮-间叶转化的研究

Epithelial to Mesenchymal Transition of Siha Cells Under Hypoxia in vitro

目的探讨宫颈癌Siha细胞在二氯化钴(CoCl2)诱导的化学缺氧环境中能否发生上皮-间叶转化(EMT),从而获得侵袭性表型,并初步分析其分子机制。方法划痕实验及Transwell体外侵袭实验检测化学缺氧对细胞迁移、侵袭及转移能力的影响;Western blot印迹法、细胞免疫化学及免疫荧光检测缺氧对Siha细胞缺氧诱导因子1α(HIF-lα)、上皮细胞标记分子E-cadherin、间叶细胞标记分子vimentin表达的影响;实时荧光定量聚合酶链反应(qRT-PCR)检测缺氧对EMT诱导因子snail、zeb、twist mRNA表达的影响。结果缺氧可促进人宫颈SCC Siha细胞的迁移、侵袭和转移能力;宫颈癌Siha细胞在常氧、缺氧12 h、缺氧24 h、缺氧48 h条件下E-cadherin蛋白的相对表达逐渐减少,vimentin蛋白的相对表达逐渐增加,缺氧组与常氧组比较差异有统计学意义(P<0.05);缺氧状态下HIF-1α在Siha细胞中聚集,发现Siha细胞形态发生明显变化、且伴有上皮性标记蛋白E-cadherin的表达减弱;Siha细胞twist及snail mRNA的表达与HIF-lαmRNA表达成正相关,且在缺氧12h后差异均有统计学意义(P<0.05)。结论缺氧微环境可能通过活化HIF-lα,调节twist、snail等转录因子的表达,促进宫颈癌细胞发生上皮-间叶转化,产生侵袭性表型。

Objective To investigate whether human cervical cancer cell line Siha underwent epithelialmesenchymal transition(EMT) and became more invasive under hypoxia environment, and to explore the underlying molecular mechanism. Methods CoCl2-treated cells were used to mimic the hypoxia model, then we performed the scratch assay and Transwell migration assays to assess the ability of cell motility, migration and invasion. The expression of EMT markers, E-cadherin and vimentin, as well as hypoxiainducible factor-1α(HIF-1α) were analyzed by immunofluorescence staining and Western blot. qRT-PCR was used to detect the mRNA expression of several EMT-induced transcription factors including snail, zeb and twist. Results Hypoxia microenvironment significantly induced Siha cells motility, migration and invasion properties. The relative expression of E-cadherin in normoxia, hypoxia groups at 12, 24, 48 h were gradually decreased, while that of vimentin was gradually increased. The difference between hypoxia and normoxia groups was significant(P<0.05). HIF-1α expression in Siha cells was up-regulated, and the morphology of Siha cells obviously was transformed and E-cadherin expression was significantly decreased. qRT-PCR demonstrated the relative expression level of twist and snail mRNA were positive correlated with HIF-1α mRNA expression under hypoxia microenvironment, and the difference was significant after 12 h(P<0.01). Conclusion Hypoxia microenvironment could induce EMT and enhance the metastasis of Siha cells through regulating twist and snail and activating HIF-1α.