MiR-342-3p is a novel biomarker for the diagnosis and regulates tumorigenesis in thyroid papillary cancer through FOXQ1

The downregulated level of miR-342-3p has been reported in various kinds of human malignancies. It remains unclear the biological function of miR-342-3p in PTC. The purpose of this work aimed to assess the expression pattern of miR-342-3p and determine its potential role as biomarker in PTC, furthermore investigate its biological role during tumorigenesis. RT-qPCR was performed to measure the expression of miR-342-3p in 36 PTC tumor tissue, their paired adjacent normal tissue, TPC-1、B-CPAP and HTori-3 cells. Si- FOXQ1, miR-342-3p mimic and inhibitor were transfected into human TPC-1 and B-CPAP cells. CCK8 assay was used to examine the cell proliferation ability. The transwell assay was used to examine the cell invasive ability. Scratch healing assay was used to examine the cell migatory ability. Flow cytometry analysis was performed to examine cell cycle and apoptosis. Western blot was employed to analyze the protein level. The relationship between miR-342-3p and FOXQ1was explored by Dual-luciferase reporter assay. Our findings revealed that miR-342-3p was low expressed in PTC tissue specimens and cell lines. Meanwhile, decreased expression of miR-342-3p was related to the AJCC stage. miR-342-3p may be a novel potential marker for the diagnosis in PTC. Ectopic upregulation of miR-342-3p and knockdown of FOXQ1suppressed PTC cell proliferation, migration, invasion, induced apoptosis in TPC-1 cells. While miR-342-3p knockdown enhanced the aggressive behaviors. FOXQ1 was a target gene of miR-342-3p and its expression was mediated by miR-342-3p. We discovered that miR-342-3p regulates PTC cell proliferation and apoptosis through targeting FOXQ1 signaling pathway. These findings demonstrate that miR-342-3p/FOXQ1 play a significant role in PTC tumorigenesis and could be a diagnostic and therapeutic target for PTC.