Downregulation of miR-145 expression in oral squamous cell carcinomas and its clinical significance

Background: MicroRNAs have been reported to play roles as oncogenes or tumor suppressor genes in human cancers. However, the expression levels of miR-145 in oral squamous cell carcinoma (OSCC) are unclear. The purpose of this study was to investigate the status of miR-145 expression in OSCC and determine its clinical significance. Patients and Methods: We examined miR-145 levels in 62 OSCC tissue samples and cell lines by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The relationship between miR-145 expression and clinicopathologic factors of OSCC patients was analyzed. Results: The proportion of miR-145 low expression was 82.26% (51/62) among the 62 OSCC patients, and expression levels of miR-145 in OSCC tissue samples and cell lines were significantly lower than in non-tumor controls. miR-145 expression levels were not significantly associated with age (p = 0.607), sex (p = 0.213), location (p = 0.952), histology (p = 0.603), pT stage (p = 0.305), pTNM stage (p = 0.471), and lymphatic metastasis (p = 1.000). Conclusion: miR-145 may be involved in the early tumorigenesis of oral squamous cells, and might be a potential biomarker in the early diagnosis of OSCC.