MicroRNA-155对甲状腺乳头状癌细胞生物学行为的作用及机制研究

目的探讨miR-155在甲状腺乳头状癌(papillary thyroid carcinoma,PTC)细胞生长、侵袭与转移过程中的作用及可能的作用机制。方法构建人的miR-155类似物并体外转染PTC BCPAP细胞,通过CCK8及transwell试验观察细胞增殖及侵袭能力的变化。miR-155类似物体外转染BCPAP细胞并用Western blot方法检测MAPK通路相关蛋白本底及磷酸化表达。给予ERK通路抑制剂U0126观察能否逆转miR-155过表达造成的甲状腺癌细胞异常增殖及侵袭能力增强。结果过表达miR-15548 h后通过CCK8试验检测发现BCPAP细胞明显增殖,过表达miR-15524h、48 h后通过transwell试验发现甲状腺癌细胞侵袭能力明显增强(P<0.05);利用Western blot检测MAPK信号通路相关蛋白JNK、ERK、P38的表达均明显上调(P<0.05)。同时检测细胞内p-ERK蛋白表达升高(P<0.05),利用ERK通路抑制剂U0126与miR-155共同处理细胞发现p-ERK表达较miR-155组明显降低(P<0.05)。同时,我们检测各组细胞的增殖及侵袭情况,发现U0126能逆转miR-155造成的促增殖及促侵袭作用。结论miR-155能通过激活MAPK通路的ERK通路,进而促进PTC BCPAP细胞的增殖以侵袭能力,为治疗甲状腺癌提供了潜在的靶点。

Effect and mechanism of microRNA-155 on cell biological behavior of thyroid papillary carcinoma cells

Objective To study the role of miR-155 in the differentiation of papillary thyroid carcinoma(PTC)cells,and to explore the possible mechanism.Methods Human miR-155 analogues were constructed and transfected into PTC BCPAP cells in vitro.CCK8 test and Transwell test were used to observe the changes of cell proliferation and invasiveness.The miR-155 was transfected into BCPAP cells in vitro and the protein background and phosphorylation expression of MAPK pathway were detected by Western blot.ERK pathway inhibitor U0126 was given to observe whether it could reverse the abnormal proliferation and invasion of thyroid cancer cells caused by over-expression of miR-155.Results The proliferation of BCPAP cells was detected by CCK8 test 48 hours after overexpression of miR-155,and the invasiveness of thyroid cancer cells was significantly enhanced by Transwell test 48 hours after overexpression of miR-155(P<0.05);Western blot method found that the expression of JNK,ERK and p38 in MAPK signal pathway was significantly up-regulated(P<0.05).At the same time,the expression of p-ERK protein in the cells was increased significantly(P<0.05).The expression of p-ERK in the cells treated with ERK pathway inhibitor U0126 and miR-155 was significantly lower than that in the miR-155 group(P<0.05).By detecting the proliferation and invasion of cells in each group,we found that the U0126 could reverse the proliferation and invasion promoting effect caused by miR-155.Conclusion miR-155 can promote the proliferation and invasion of PTC BCPAP cells by activating the ERK pathway of MAPK pathway,which provides a potential target for the treatment of thyroid cancer.