MiR-222-3p promotes the proliferation, migration and invasion of papillary thyroid carcinoma cells through targeting SLC4A4

Abstract

Objective. An increasing number of studies indicate that miR-222-3p is upregulated in various cancers and can regulate tumor progression. This study aimed to explore the regulatory mechanism of miR-222- 3p in papillary thyroid carcinoma (PTC). Methods. TCGA database was used to dig differentially expressed miRNAs and mRNAs in PTC tissue. Relevant references were searched to determine target miRNA. StarBase, TargetScan and miRDB were applied to predict mRNAs that had binding sites with the target miRNA. Then, the mRNAs were intersected with differentially downregulated mRNAs in TCGA to determine the target mRNA. qRT-PCR was exerted to evaluate gene expression of miR-222-3p and SLC4A4 in PTC. Western blot was performed out to evaluate the protein expression of SLC4A4 in PTC cells. CCK-8, wound healing assay and cell invasion assay were undertaken to observe the proliferative, migratory, and invasive abilities of PTC cells. Dual-luciferase assay was employed to test the binding relationship between miR222-3p and SLC4A4. Results. MiR-222-3p was highly expressed in PTC while SLC4A4 was lowly expressed. Moreover, miR222-3p was able to promote the proliferation, invasion, and migration of PTC cells. SLC4A4 was able to reverse these promotive effects of miR-222-3p. Conclusion. MiR-222-3p can promote the proliferation, migration and invasion of PTC cells through targeting SLC4A4. MiR-222-3p is expected to be a molecular therapeutic target for PTC patients.