缺氧对人乳腺癌细胞系 MCF -7生物学行为的影响

摘要

Objective:To study the effects of hyPoxia on the biological characteristics of breast cancer cell line MCF - 7. With the interference of exPression of eIF - 1α,we tested the imPortant role of eIF - 1α(hyPoxic - induc-ible 1α)in this Process,moreover,to investigate the mechanism. Methods:Lentivirus infections were carried on to obtain the MCF - 7 - NC that exPression of eIF - 1α is normal,and MCF - 7 - eIF△ that exPression of eIF - 1α was interfered. Breast cancer cell lines were cultured under low O2 saturation( ﹤ 1% O2 )or adding chemical reagent des-ferrioxamine(DFO)to induce hyPoxia. MTT,Transwell assays were used to detect the effect of eIF - 1α exPression on the Proliferation and invasion of breast cancer cells. Confocal immunofluorescence was used to detect EMT of breast cancer cells. Results:MTT assays demonstrated the Proliferation of MCF - 7 - NC decreased visibly after hyPoxic cul-tivation(P ﹤ 0. 05),while MCF - 7 - eIF△ showed no difference. Transwell assays illustrated the remarkable in-crease of invasion ability in MCF - 7 - NC after hyPoxic cultivation(P ﹤ 0. 05),but hyPoxia seemed to have no influ-ence on the invasion ability of MCF - 7 - eIF△. After induced hyPoxia condition,EMT occurred in MCF - 7 - NC,the ePithelial markers down - regulated while the mesenchymal markers uP - regulated. In MCF - 7 - eIF△,EMT did not take Place. Confocal immunofluorescence confirmed the Phenomenon. Conclusion:eyPoxia affected breast cancer cell line MCF - 7,leads to the decrease of cell Proliferation and increase of invasion,as well as the EMT. When the ex-Pression of eIF - 1α was interfered,the effects of hyPoxia on breast cancer cells disaPPeared.%目的：研究缺氧对人乳腺癌细胞系 MCF -7的生物学行为，增殖、侵袭能力的影响。通过影响缺氧诱导因子1α（hyPoxic - inducible factor 1α，eIF -1α）的表达，检验其在这一过程中的作用，并进一步探讨作用机制。方法：慢病毒感染细胞，干扰乳腺癌细胞系 MCF -7中 eIF -1α的表达，得到 eIF -1α表达正常的乳腺癌细胞系 MCF -7- NC 和 eIF -1α表达受干扰的细胞系 MCF -7- eIF△。分别低氧培养及化学药物诱导缺氧，用 MTT 法检测2组细胞系在缺氧和正常培养条件下的增殖能力，ANOVA 检验检测其增殖能力的区别。Transwell 实验检验缺氧和正常培养条件下人乳腺癌细胞的侵袭能力，计数通过 Transwell 小室的细胞，ANOVA检验检测细胞侵袭能力的区别。共聚焦免疫荧光法检测缺氧后2组乳腺癌细胞的上皮和间质标记物的表达，检验细胞系是否发生了上皮-间质转化（ePithelial - mesenchymal transition，EMT）。结果：MTT 实验结果：正常表达 eIF -1α的 MCF -7- NC 的增殖能力在缺氧后与正常培养条件下相比明显减弱，其差别具有统计学意义（P ﹤0.05）。eIF -1α表达受干扰的 MCF -7- eIF△的增殖能力在缺氧和正常培养条件下相比无显著区别。Transwell 实验检测细胞的侵袭能力，缺氧后正常表达 eIF -1α的 MCF -7- NC 的侵袭能力较正常培养的细胞明显增强，其差别具有统计学意义（P ﹤0.05）。eIF -1α表达受干扰的 MCF -7- eIF△侵袭能力在缺氧和正常培养下无显著区别。缺氧后，正常表达 eIF -1α的细胞系 MCF -7- NC 发生上皮-间质转化（ePithelial - mesenchymal transition，EMT）。共聚焦荧光染色显示：在诱导缺氧后，正常表达 eIF -1α的 MCF-7- NC 细胞极性发生变化，呈长梭形改变，上皮标志物人广谱角蛋白（Pan - cytokeratin，P - CK）表达下调，间质标志物人α平滑肌动蛋白（α- SMA）表达上调；而 eIF -1α表达受干扰的 MCF -7- eIF△无明显 EMT变化。结论：在体外条件下，缺氧可以引起乳腺癌细胞系 MCF -7增殖能力减弱、侵袭能力增强，可以诱导乳腺癌细胞 MCF -7发生 EMT，干扰缺氧诱导因子亚基 eIF -1α的表达，则缺氧对乳腺癌细胞增殖、侵袭的影响消失。