miR-342-3p regulates thyroid cancer cell proliferation, migration and invasion by targeting Bcl-2 / 中华内分泌外科杂志

ABSTRACT

Objective:To investigate the effects of miR-342-3p on proliferation, migration and invasion of thyroid cancer cells and its potential mechanism.Methods:The expression levels of miR-342-3p in human thyroid cancer cell lines (FTC-133, TPC-1, BCPAP and SW1736) and human thyroid follicular epithelial cells (Nthy-ori3-1) were detected by qRT-PCR. Lipofectamine 2000 was used to transfect the FTC-133 cells in the logarithmic growth phase with miR-342-3p mimics (miR-342-3p mimics group) , negative control (miR-NC group) and FTC-133 cells without any transfection (Control group) . qRT-PCR was used to detect the mRNA level of miR-342-3p in each group after transfection to verify the transfection efficiency. CCK-8 assay was used to detect cell proliferation activity. Wound-healing assay and transwell assay were performed to evaluate cell migration and invasion. The dual luciferase reporter assay was used to verify the targeted regulation of Bcl-2 by miR-342-3p. The mRNA and protein expression levels of Bcl-2 were detected by qRT-PCR and Western blot.Results:The expression level of miR-342-3p in thyroid cancer cell lines was significantly lower than that of Nthy-ori3-1 cells ( F=5.732, P=0.011) . Compared with Control and miR-NC groups, the expression level of miR-342-3p was significantly increased ( F=8.613, P=0.003) , the proliferation activity of pcdna3.0-bcl-2 group was significantly increased ( F=11.257, P<0.001) , TP53 protein level was significantly decreased in pcdna3.0-bcl-2 group ( F=9.872, P=0.004) , and the level of TP53 protein in mir-342-3p mimics group was significantly increased ( F=12.548, P<0.001) . Conclusions:miR-342-3p mimics inhibits the proliferation, migration and invasion of FTC-133 cells by targeting and inhibiting Bcl-2 expression, which is expected to be a new target for diagnosis and treatment of thyroid cancer.