FGFR2 and miR‐889‐3p expression in oral cancer is associated with cervical lymph node metastasis

Abstract Objective Fibroblast growth factor receptor‐2 (FGFR2) and miR‐889‐3p expression in oral squamous cell carcinoma (OSCC) tumours were compared to normal controls. We then examined the relationship between miR‐889‐3p, FGFR2 expression and patient clinicopathological features. Materials and Methods The interaction of FGFR2 and miR‐889‐3p was investigated using bioinformatics. Then, OSCC tumour biopsies and normal gingiva were collected and processed for expression analysis of FGFR2‐specific mRNA and miR‐889‐3p using real‐time PCR. Immunohistochemistry evaluated the expression of the FGFR2 protein. Results The protein and mRNA expression levels of FGFR2 were significantly greater in tumours when contrasted with controls. Expression of miR‐889‐3p was significantly lower in OSCC compared to normal tissues. The FGFR2 and miR‐889‐3p expressions were inversely related (−0.86 and −0.73, respectively) in both cases and controls. Changes in miR‐889‐3p and FGFR2 expression in tumour tissues were associated with lymph node metastasis (LNM), with ~0.57 and ~3.0 folds of change in positive‐LNM patients, respectively. Conclusion Decreased expression of miR‐889‐3p in OSCC tumours suggests that miR‐889‐3p functions as a tumour suppressor gene. Overexpression of FGFR2 further proves the role of miR‐889‐3p in the regulation of the FGFR2 pathway. This was further confirmed by showing differences in miR‐889‐3p expression in positive and negative LNM cases.