环加氧酶-2 通过调控EMT促进乳腺癌MDA-MB-231 细胞的迁移和侵袭

摘要] 目的：探讨环加氧酶-2（COX-2）在乳腺癌转移中的作用及其可能的机制。方法：收集从2015 年10 月至2018 年4 月在云南省肿瘤医院接受乳腺切除术的患者中获得的原发乳腺癌组织和脑转移乳腺癌组织临床病理样本共45 例，其中原发30 例、脑转移15 例。采用qPCR检测COX-2 在原位乳腺癌和脑转移乳腺癌组织中的表达。将COX-2 过表达重组病毒（LV6-COX2）或敲减COX-2 重组病毒（LV3-COX2 shRNA1、LV3-COX2 shRNA2）感染人乳腺癌MDA-MB-231 细胞并获得稳转细胞株后,CCK-8法检测COX-2 表达对MDA-MB-231 细胞增殖的影响，划痕实验和Transwell 法检测对MDA-MB-231 细胞迁移和侵袭的影响。qPCR和WB实验分析各组细胞中COX-2 mRNA和蛋白的表达水平，qPCR检测COX-2 表达对MDA-MB-231 细胞内EMT相关基因表达的影响。结果：COX-2 表达水平在脑转移乳腺癌患者组织中显著高于原位乳腺癌组织（P<0.01）；并且与乳腺癌患者肿瘤TMN分期有关。成功构建稳定过表达/敲减COX-2 的MDA-MB-231 细胞株。过表达COX-2 促进MDA-MB-231 细胞的迁移和侵袭（均P<0.01），同时显著提高MMP2、MMP1、N-cadherin 和vimentin 的表达（均P<0.01），但对细胞增殖无明显影响；而沉默COX-2 则有相反的作用，且可促进细胞增殖（P<0.05）。结论：COX-2 在脑转移乳腺癌组织中高表达，其可能通过调控EMT过程促进乳腺癌MDA-MB-231 细胞的迁移和侵袭。

Cyclo-oxygenase-2 promotes migration and invasion of breast cancer MDA-MB-231 cells by regulating EMT

Abstract] Objective:To investigate the role of cyclo-oxygenase-2 (COX-2) in breast cancer metastasis and its possible mechanism. Methods: A total of 45 cases of primary breast cancer tissues and brain metastatic breast cancer tissues were collected from patients,who underwent mastectomy in Yunnan Cancer Hospital from October 2015 to April 2018, including 30 cases of primary lesions and 15 cases of brain metastasis. qPCR was used to detect the expression of COX-2 in breast cancer tissues and brain metastatic breast cancer tissues. Recombinant viruses with COX-2 over-expression (LV6-COX2) or COX-2 knockdown (LV3-COX2 shRNA1, LV3-COX2 shRNA2) were transfected into human breast cancer MDA-MB-231 cells; After obtaining the stable expression cell lines, the effect of COX-2 expression on the proliferation of MDA-MB-231 cells was detected by CCK-8, and the effects of COX-2 expression on the migration and invasion of MDA-MB-231 cells were detected by scratch test and Transwell assay, respectively. The mRNA and protein expressions of COX-2 in each group were examined by qPCR and WB, respectively. The effect of COX-2 expression on the expression of EMT-related genes in MDA-MB-231 cells was analyzed by qPCR. Results: The expression of COX-2 in tissues of patients with brain metastases was significantly higher than that in patients with primary breast cancer tissues (P<0.01), and it was correlated with tumor TMN stage in breast cancer patients. MDA-MB-231 cell lines with stable COX-2 over-expression/knockout were successfully construct-ed. Over-expression of COX-2 promoted the migration and invasion of MDA-MB-231 cells (all P<0.01), and significantly increased the expressions of MMP2, MMP1, N-cadherin and vimentin (all P<0.01), but exerted insignificant effect on cell proliferation. The effect of COX-2 silence exerted the opposite effect and promoted cell proliferation (P<0.05). Conclusion: COX-2 is highly expressed in brain metastatic breast cancer tissues, which may promote the migration and invasion of breast cancer MDA-MB-231 cells by regulating EMT processes.