MicroRNA-382-5p Promotes Oral Squamous Cell Carcinoma Development and Progression by Negatively Regulating PTEN Expression.

ABSTRACT

PURPOSE: Oral squamous cell carcinoma (OSCC) local recurrence and distant metastasis remain a poorly understood clinical challenge. The objective of this study was to investigate how dysregulation of miR-382-5p impacts invasion and dissemination of OSCC. METHODS: Tissue samples were collected from 20 subjects with OSCC. Expression levels of miR-382-5p were determined by quantitative real-time polymerase chain reaction (qRT-PCR), and correlations with clinical characteristics were investigated. qRT-PCR was used to determine the miR-382-5p and peptidyl-prolyl cis/trans isomerase (PTEN) expression in tumor tissues, adjacent normal tissues, normal human oral keratinocyte line, and OSCC line (SCC-9). Cell proliferation, invasion, and migration of knock-in and knock-down miR-382-5p transfectants were assessed using cell counting kit-8 and Transwell assays. PTEN was confirmed to be a downstream target using a TargetScan prediction, dual-luciferase reporter assays, and western blot analysis. Statistical analysis of experimental data was performed with SPSS 22.0 software. RESULTS: We found high expression of miR-382-5p and significant downregulation of PTEN in tumor tissues and SCC-9 cells from OSCC patients (P < .05). miR-382-5p expression was lower in early stage (I + II) than in late stage (III + IV), while PTEN exhibited higher expression in early stage (I + II) instead of in late stage (III + IV) (P < .05). In addition, overexpression of miR-382-5p promoted the proliferation, invasion, and migration of OSCC cells. However, the proliferation, invasion, and migration of OSCC cells were inhibited after suppression of miR-382-5p. Finally, PTEN is downregulated by miR-382-5p. CONCLUSION: MiR-382-5p supports proliferation, invasion, and migration of OSCC cells through the PTEN pathway. Further investigation may improve our understanding of OSCC local recurrence and distant metastasis.