Mechanism of miRNA-146b regulating proliferation, metastasis and apoptosis of thyroid papillary carcinoma cells / 中华内分泌外科杂志

ABSTRACT

Objective:To investigate the role and mechanism of miR-146b in the proliferation, metastasis and apoptosis of thyroid papillary carcinoma cells.Methods:qRT-PCR was used to detect the expression of miR-146b in thyroid papillary carcinoma cells (NPA, GLAG-66, ONCNO-DG1 and B-CPAP) and normal human thyroid cell line HTori3. After B-CPAP cells were transfected with miR-146b inhibitor, the inhibition efficiency was detected by qRT-PCR, the effect of miR-146b on PTC cells proliferation was detected by MTT assay, the effect of miR-146b on PTC cells invasion was studied by Transwell assay, and the effect of miR-146b on tumor cell apoptosis was detected by flow cytometry. SiRNA-IRAK1 was transfected into B-CPAP cell line. The cell proliferation rate, migration ability and apoptosis rate were detected by MTT, cell scratch test and flow cytometry respectively. The target gene of miR-146b, interleukin-1 associated receptor kinase 1 (IRAK1) , was predicted by bioinformatics software, and the regulatory effect of miR-146b on IRAK1 was verified by double fluorescein reporter gene experiment.Results:QRT-PCR showed that the expression of miR-146b in NPA87, KAT-5, FTC-133 and B-CPAP cell lines was significantly higher than that in normal cell HTori3, especially B-CPAP ( P<0.05) . MiR-146b inhibitor transfection could significantly reduce the expression level of miR-146b in B-CPAP cells ( P<0.01) . MTT results showed that miR-146b inhibitor could inhibit the proliferation of B-CPAP cells ( P<0.05) . Flow cytometry showed that miR-146b inhibitor could promote the apoptosis of B-CPAP cells ( P<0.05) . Transwell results showed that miR-146b inhibitor could reduce the invasive ability of B-CPAP cells ( P<0.05) . After transfection with siRNA-IRAK1, the proliferation rate of B-CPAP cells increased significantly (MTT test) , the migration ability increased (cell scratch test) , and the apoptosis rate decreased significantly (flow cytometry) ( P<0.05) . The results of double luciferase reporter gene showed that irak1 was the target gene of miR-146b, and miR-146b inhibitor could significantly up regulate the expression level of irak1 protein in B-CPAP cells. Conclusion:miR-146b may play a role in promoting the proliferation and metastasis and inhibiting cell apoptosis of PTC cells by inhibiting the downstream target protein IRAK1.