Abstract: Objective To screen and identify the expression of non-coding microRNAs in oral squamous cell carcinoma (OSCC) and normal tissues in the elderly patients, and to analyze the clinical significance in the occurrence of OSCC. Methods A total of 44 OSCC specimens and 23 oral tissue specimens were collected, and the expression of non-coding microRNAs closely related to OSCC were screened. The transcription levels of microRNAs 200 family (miR-200a, miR-200b, miR-200c, miR-141 and miR-429) and U78 in OSCC tissues and normal tissues were detected by TaqMan quantitative PCR method. Then, the results were analyzed by statistical methods. Bioinformatics tools were used to predict the biological function. Results Microarray and TaqMan quantitative PCR results confirmed that the expression levels of microRNA-200 family and U78 in OSCC tissues were significantly higher than those in normal oral tissues. Bioinformatics analysis indicated that microRNA-200 family could target genes closely related to tumor development, such as β-catenin and transforming growth factor β2. Multiple linear regression analysis showed that the expression of U78 was significantly correlated with pathological grade (P=0.023), but not with clinical stage and metastasis. Conclusions MicroRNA-200 family and U78 may be involved in the occurrence of OSCC and may be potential biomarkers for the clinical diagnosis of OSCC.

Key words: oral squamous cell carcinoma, microRNA-200 family, U78