MicroRNA-106a促进乳腺癌MDA-MB-231细胞侵袭的机制研究

Mechanism of microRNA-106a promoting invasion of breast cancer MDA-MB-231 cells

目的:探讨微小RNA-106a(microRNA-106a)促进人乳腺癌MDA-MB-231细胞侵袭的可能机制。方法:采用qPCR检测脂质体转染microRNA-106a抑制物(microRNA-106a inhibitor)及microRNA-106a模拟物(microRNA-106a mimic)的转染效率,采用qPCR及Western blot实验检测转染microRNA-106a mimic的MDA-MB-231细胞中金属蛋白酶组织抑制物2(TIMP-2)、基质金属蛋白酶2(MMP2)及基质金属蛋白酶9(MMP9)的表达情况,采用Transwell实验检测microRNA-106a对MDA-MB-231细胞侵袭能力的影响,采用萤光素酶报告基因实验检测microRNA-106a对TIMP-2通路的调控作用。结果:乳腺癌MDA-MB-231细胞转染microRNA-106a inhibitor 48 h后,microRNA-106a的表达水平降低(P<0.05);转染microRNA-106a mimic 48 h后,microRNA-106a的表达水平增加(P<0.05);转染microRNA-106a inhibitor能够降低MDA-MB-231细胞的体外侵袭能力(P<0.05);转染microRNA-106a mimic能够下调TIMP-2的表达,上调MMP2及MMP9的表达(P<0.05);microRNA-106a inhibitor能够增强含有TIMP-2基因3’非翻译区的报告质粒的萤光素酶活性(P<0.05),而microRNA-106a mimic则降低了报告质粒的萤光素酶活性(P<0.05)。结论:乳腺癌MDA-MB-231细胞高表达microRNA-106a能够促进细胞体外侵袭能力,可能与抑制TIMP-2通路活性有关。MicroRNA-106a在乳腺癌MDA-MB-231细胞的侵袭中发挥着重要作用。

AIM： To investigate the possible mechanism of microRNA-106a promoting the invasion of human breast cancer MDA-MB-231 cells. METHODS： The efficiencies of transfection with microRNA-106a inhibitor and microRNA-106a mimic by liposome were detected by qPCR. The mRNA and protein expression levels of tissue inhibitor of metalloproteinase 2（ TIMP-2）,matrix metalloproteinase 2（ MMP2） and matrix metalloproteinase 9（ MMP9） in the MDAMB-231 cells transfected with microRNA-106a mimic were detected by qPCR and Western blot. The effect of microRNA-106a on the invasion ability of MDA-MB-231 cells was measured by Transwell assay. The luciferase reporter assay was used to detect the regulatory effect of microRNA-106a on the TIMP-2 pathway. RESULTS： In the MDA-MB-231 cells,the expression level of microRNA-106a decreased at 48 h after transfection with microRNA-106a inhibitor（ P〈0. 05）,and the expression level of microRNA-106a increased at 48 h after transfection with microRNA-106a mimic（ P〈0. 05）. The microRNA-106a inhibitor decreased the invasion ability of MDA-MB-231 cells in vitro（ P〈0. 05）. The microRNA-106a mimic down-regulated the expression of TIMP-2 and up-regulated the expression of MMP2 and MMP9（ P〈0. 05） in the MDAMB-231 cells. The microRNA-106a inhibitor enhanced the luciferase activity of the reporter plasmids containing the 3＇-untranslated region of TIMP-2 gene（ P〈0. 05）,while the microRNA-106a mimic decreased the luciferase activity of the reporter plasmid（ P〈0. 05）. CONCLUSION： High expression of microRNA-106a promotes the invasion ability of breast cancer MDA-MB-231 cells in vitro,which may be related to the inhibition of TIMP-2 pathway. MicroRNA-106a plays an important role in the invasion of breast cancer MDA-MB-231 cells.