LncRNA DS Cell Adhesion Molecule Antisense RNA 1 Facilitates Oral Squamous Cell Carcinoma Progression through The microRNA-138-5p/ Enhancer of Zeste 2 Polycomb Repressive Complex 2 Subunit Axis.

Abstract

A lot of lncRNAs are implicated in oral squamous cell carcinoma (OSCC) progression. The study aimed at investigating lncRNA DS cell adhesion molecule antisense RNA 1 (DSCAM-AS1)'s functional role and molecular mechanism in OSCC. In this experimental study, a total of 46 pairs of OSCC samples and para-cancerous tissues were collected during surgery. In OSCC tissues and cell lines, quantitative real time polymerase chain reaction (qRTPCR) was performed for detecting DSCAM-AS1 and microRNA-138-5p (miR-138-5p) expression levels. Western blot was conducted to examine the enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) expression level. Then, DSCAM-AS1 was knocked down with siRNA in OSCC cells and MTT and EdU assays were conducted to evaluate OSCC cell proliferation. Transwell assay was utilized for detecting OSCC cell migration and invasion capacities. Besides, the relationships among DSCAM-AS1, miR-138-5p, and EZH2 were explored through RNA immunoprecipitation, dual-luciferase reporter assay, qRT-PCR, and Western blot. DSCAM-AS1 expression was remarkably increased in OSCC tissues and cell lines, and DSCAM-AS1 knockdown could significantly restrain OSCC cell proliferation, migration, and invasion. MiR-138-5p was identified as a target of DSCAM-AS1, and its inhibitor could reverse the suppressive effects of DSCAM-AS1 knockdown on OSCC progression. EZH2 was verified as a target of miR-138-5p, and EZH2 knockdown could counteract the promotional impact of miR-138-5p inhibitor on OSCC progression. Additionally, DSCAM-AS1, as a ceRNA, could regulate EZH2 expression via miR-138-5p. DSCAM-AS1 can play a tumor-promoting role in OSCC via miR-138-5p/EZH2 axis.