title: Downregulation of miR-221/222 by a microRNA sponge promotes apoptosis in oral squamous cell carcinoma cells through upregulation of PTEN.
abstract: MicroRNA-221 and microRNA-222 (miR-221/222) have been identified as oncogenes and confirmed to be overexpressed in various types of cancer. However, the regulation mechanism of miR-221/222 in oral squamous cell carcinoma (OSCC) remains to be fully elucidated. Previously, an miR-221/222 sponge was successfully constructed and its effect on the downregulation of miR-221/222 expression was investigated. In the present study, the dual luciferase reporter assay revealed a phosphatase and tensin homolog (PTEN) deletion on chromosome 10 to be a target gene of miR-221/222. It was also demonstrated that miR-221/222 suppression by transfection with an miR-221/222 spongein vitroresulted in upregulation of PTEN. Notably, the proliferation and invasiveness of the miR-221/222 sponge-transfected cells was significantly inhibited, while apoptosis was promoted, when determined by Cell Counting Kit-8, Transwell assays and flow cytometry. The results of the present study prove that miR-221/222 may downregulate the expression of PTEN in OSCC cells and function as oncogenes, providing a novel insight into the underlying mechanism of OSCC tumorigenesis. The present study suggests that upregulating the expression of PTEN by downregulation of miR-221/222 may be a potential treatment for OSCC.
authors.affiliation: Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong 510055, P.R. China; Department of Stomatology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, P.R. China.
authors.forename: Lijie
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong 510055, P.R. China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Jiang
authors.affiliation: Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong 510055, P.R. China.
authors.forename: Xijuan
authors.initials: X
authors.lastname: Chen
authors.affiliation: Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong 510055, P.R. China.
authors.forename: Zifeng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong 510055, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Ouyang
authors.affiliation: Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong 510055, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong 510055, P.R. China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Yu
keywords: apoptosis; microRNA-221/222; oral squamous cell carcinoma; phosphatase and tensin homologue; sponge