[The effect of miR-497 on laryngeal squamous cell carcinoma invasion through modulating PlexinA4]

Objective: To study the roles of miR-497 and PlexinA4 in the progression of laryngeal squamous cell carcinoma. Methods: The expressions of miR-497 and PlexinA4 in fresh tumor specimens and adjacent normal mucosa tissues as well as in cell lines of laryngeal squamous cell carcinoma (LSCC) were detected with qRT-PCR and immunohistochemistry. The association of miR-497 and PlexinA4 expressions with clinicopathologic factors and their prognostic values in LSCC were evaluated PlexinA4 siRNA and pcDNA3.1 (+ )/PlexinA4 plasmid were transfected into the LSCC and measured by Transwell to evaluate their effect on the invasion of LSCC. Results: miR-497 was low expression in LSCC, which related to pathological differentiation, while PlexinA4 mRNA was high expression in LSCC. Kaplan-Meier method showed that the prognosis of patients with high miR-497 expression was better than that of patients with low miR-497 expression (χ(2)=10.342, P=0.001); . Cox regression analysis showed that miR-497 was an independent prognostic factor for LSCC. The double luciferase reporter gene showed that the variation of the fluorescence activity of wild type PlexinA4 was significantly different from that of the control group (P<0.01). In Hep-2 and TU212 cell line, the number of cells with PlexinA4 siRNA passing through the compartments was 70.00±10.85 and 85.00±6.45, significantly higher than control (F values were 30.251 and 23.936, both P<0.05), the number of cells with pcDNA3.1 (+ ) /PlexinA4 was 170.56±11.95 and 142.00±10.43, also significantly less than control (F values were 35.104 and 29.643, both P<0.05). Conclusion: The expression of miR-497 in LSCC is decreased, indicating poor prognosis, which is as an independent risk factor for prognosis of LSCC. miR-497 may modulate LSCC invasion through PlexinA4.