Effects of microRNA-127-3p on proliferation, invasion and migration of papillary thyroid cancer cells

Objective To investigate the effects of microRNA-127-3p (miR-127-3p) on proliferation, invasion and migration of papillary thyroid cancer cells, and to clarify the targeting relationship between miR-127-3p and tumor cell invasion inhibitor (SCAI) gene.

Methods Papillary thyroid carcinoma cell line TPC1 and normal human thyroid cell line Nthy-ori 3-1 were selected as study objects.The well-grown TPC1 cell lines were divided into blank group (NC group, without treatment), miR-NC group (transfected with miR-127-3p overexpressed empty vector), miR-127-3p group (transfected miR-127-3p-mimics), si-NC group (transfected with empty vector of knockdown SCAI) and si-SCAI group (transfected si-SCAI) according to different transfection modes. The cell proliferation was detected by Methyl Thiazolyl Tetrazolium (MTT); cell migration and invasion was detected by transwell assay; the levels of miR-127-3p and SCAI mRNA were detected by real-time fluorescence quantitative polymerase chain reaction (PCR); the expression of SCAI protein was detected by Western blot.The relationship between miR-127-3p and SCAI was predicted by bioinformatics, and luciferase assay was used to verify its reliability.

Results The level of miR-127-3p in TPC1 cells was lower than that in Nthy-ori 3-1 cells, and the levels of SCAI protein and SCAI mRNA were higher than those in Nthy-ori 3-1 cells (P < 0.01). Compared with NC group and miR-NC group, the abilities of proliferation, cell migration and invasion of the miR-127-3p group were decreased at 48 and 72 h (P < 0.01). Compared with NC group and Si-NC group, the proliferation ability, cell migration and invasion ability of the si-SCAI group increased at 48 and 72 h, and the differences were statistically significant (P < 0.01). Compared with NC and miR-NC groups, the level of SCAI protein in the miR-127-3p group was higher (P < 0.01).The luciferase activity of cells transfected with WT-SCAI in the miR-127-3p group was higher than that of cells transfected with WT-SCAI in the NC group (P < 0.05).

Conclusion The expression of miR-127-3p and SCAI is low in papillary thyroid carcinoma cells.The miR-127-3p overexpression may inhibit the proliferation, invasion and migration of papillary thyroid carcinoma cells by promoting SCAI expression.