缺氧微环境对胰腺癌细胞发生上皮向间叶转化的诱导作用

目的 探讨胰腺癌细胞在缺氧微环境中通过发生上皮向间叶转化(EMT)从而获得侵袭性表型的可能机制.方法 在缺氧微环境下培养胰腺癌细胞Pane-1、Transwell侵袭小室对比检测细胞在缺氧微环境下侵袭能力的变化情况.Western blot、免疫荧光检测缺氧对Panc-1细胞上皮细胞标记分子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(PCR)检测缺氧对EMT诱导因子Snail表达的影响.将编码HIF-1α cDNA的真核表达载体pCD-NA 3.1-HIF-1α瞬时转染Panc-1细胞,Western blot检测HIF-1α对E-cadherin、vimentin表达的影响.结果 常氧组细胞每高倍镜视野穿透数为(84±3)个,缺氧组为(121±5)个,差异有统计学意义(P<0.01).Panc-1细胞在常氧、缺氧12 h、缺氧24 h、缺氧48 h条件下E-cadherin蛋白的相对值分别为(0.59±0.04、54.00±0.05、0.45±0.10、0.36±0.03);vimentin蛋白的相对值分别为:(0.36±0.05、0.41±0.04、0.48±0.06、0.58±0.05),缺氧同常氧组比较差异有统计学意义(P<0.05).缺氧微环境下Panc-1细胞Snail mRNA的表达量升高,在缺氧第3天后差异具有统计学意义(P<0.05).Panc-1细胞转染HIF-1α前后,E-cadherin蛋白的相对值分别为0.63±0.05、0.47±0.07;Vvi-mentin蛋白的相对值分别为0.47±0.07、0.32±0.04,转染前后差异有统计学意义(P<0.05).结论 缺氧微环境可能通过活化HIF-lα、Snail等转录因子,促进胰腺癌细胞发生上皮向间叶转化,产生侵袭性表型.

The epithelial to mesenchymal transition of pancreatic cancer cells under hypoxia

Objective To investigate whether hypoxic environment can promote the metastasis of pancreatic cancer cells by inducing epithelial to mesenchymal transition (EMT). Methods The Panc-1 cells were cultured in hypoxia environment. After cultured for indicated periods, the in vitro invasive ability of Pane-1 cells was compared with normoxia group using Transwell invasion assay. The epithelial marker E-cadherin and the mesenchymal marker vimentin were assayed by Western blot. The expression of Snail, a strong activator of EMT, was detected by real-time PCR. The HIF-1 α encoding cDNA was transiently trans-fected into the Pane-1 cells, and the E-cadherin and vimentin were analyzed. Results The number of cells invading to the lower side of the membrane under hypoxia was ( 121±5 ), whereas only ( 84±3 ) in no-morxia group ( P < 0.05 ). The relative expression of E-cadherin in normoxia, hyoxia groups at 12,24,48 hwas (0.59±0.04 vs 54.00±0.05,0.45±0.10,0.36±0.03 ), and that of vimentin was (0.36±0.05, 0.41±0.04,0.48±0.06,0.58±0.05 ) ( P < 0.05 ). The relative expression of Snail mRNA was in-creased in hypoxia environment, and the difference was significant after 72 h ( P < 0.05 ). Before and after HIF-1α cDNA was transfected into the Panc-1 cells, the relative expression of E-cadherin was 0.63± 0.05, and 0.47±0.07, and that of vimentin was 0.47±0.07, and 0.32±0.04 respectively ( P < 0.05 ). Conclusion Hypoxia microenvironment can activate HIF-1α and Snail to trigger EMT of pancreatic cancer cells.