title: MicroRNA-363-3p inhibits papillary thyroid carcinoma progression by targeting PIK3CA.
abstract: MicroRNA-363-3p (miR-363-3p) reportedly plays crucial roles in tumor development and progression in many types of cancers. However, its role in papillary thyroid carcinoma (PTC) remain largely unclear. We therefore investigated the function and underlying mechanism of miR-363-3p in PTC. Here, we found that miR-363-3p was significantly downregulated in human PTC tissue samples and cell lines, and that miR-363-3p levels are negatively correlated with advanced clinical stage and lymph node metastasis. In addition to suppressing tumor growthin vivo, restoration of miR-363-3p in TPC-1 cells significantly inhibits proliferation, migration, and invasion and induced apoptosisin vitro. Mechanistically, miR-363-3p was verified to directly bind to 3'UTR of the phosphoinositide-3-kinase catalytic subunit alpha (PIK3CA) mRNA, and reduce its expression at both mRNA and protein levels, which further inhibits phosphatidylinositol 3-kinase/Akt signaling pathway. PIK3CA expression was also found to be increased in human PTC tissues, and were inversely correlated with miR-363-3p. Furthermore, restoration of PIK3CA partially rescued the miR-363-3p-induced inhibition effect on TPC-1 cell proliferation, migration and invasion. Taken together, these findings indicated for the first time that miR-363-3p functions as a tumor suppressor in PTC, and its suppressive effect is mediated by repressingPIK3CA.
authors.affiliation: Department of Thyroid Surgery, The First Hospital of Jilin University 71# Xinmin Street, Chaoyang District, Changchun 130021, Jilin, P. R. China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Thyroid Surgery, The First Hospital of Jilin University 71# Xinmin Street, Chaoyang District, Changchun 130021, Jilin, P. R. China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Thyroid Surgery, The First Hospital of Jilin University 71# Xinmin Street, Chaoyang District, Changchun 130021, Jilin, P. R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Thyroid Surgery, The First Hospital of Jilin University 71# Xinmin Street, Chaoyang District, Changchun 130021, Jilin, P. R. China.
authors.forename: Peiyou
authors.initials: P
authors.lastname: Ren
authors.affiliation: Department of Anesthesia, The First Hospital of Jilin University 71# Xinmin Street, Chaoyang District, Changchun 130021, Jilin, P. R. China.
authors.forename: Su
authors.initials: S
authors.lastname: Dong
keywords: PIK3CA; Papillary thyroid carcinoma; miR-363-3p; proliferation