[Preliminary study on the role of voltage-gated sodium channel subtype Nav1.5 in lymph node metastasis of oral squamous cell carcinoma].

Objective: To investigate the relationship between the expression of voltage-gated sodium channel subtype Nav1.5 in oral squamous cell carcinoma (OSCC) and the occurrence and lymph node metastasis of OSCC. Methods: Totally 10 samples of normal oral mucosa tissue as control group, 26 samples of OSCC as the experimental group was divided into non-metastatic group (n=16) and metastatic group (n=10) according to the presence or absence of lymph node metastasis. Quantitative real-time PCR (qPCR), Western blotting, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) were used to detect the expression of Nav1.5 in control group and experimental groups at mRNA and protein levels. The data were analyzed by one-way analysis. Results: The expression of Nav1.5 mRNA in the experimental group (non-metastatic group: 2.311±0.134, metastatic group: 4.462±0.362) was higher than those in the control group (1.054±0.162) (P=0.037; P=0.029), and the metastasis group was significantly higher than the non-metastasis group (P=0.031). Western blotting showed the expression of Nav1.5 in experimental groups (non-metastatic: 0.143±0.005, metastatic: 0.253±0.015) was up-regulated significantly compared with control group (0.080±0.010) (P=0.034, P=0.026), and the metastasis group was significantly higher than the non-metastasis group (P=0.033). The immunohistochemistry show the positive expression rates of Nav1.5 in normal and OSCC tissues were 1/10 and 92% (24/26). The differences were statistically significant (P=0.016), and the metastasis group was significantly higher than the non-metastasis group (P=0.028). The ELISA results revealed that the level of Nav1.5 in control was control group (0.834±0.103) μg/L, in non-metastasis group was (1.578±0.167) μg/L, in metastasis group was (3.882±0.422) μg/L (P=0.041; P=0.032), and the metastasis group was significantly higher than the non-metastasis group (P=0.030). Conclusions: Nav1.5 was highly expressed in poorly differentiated OSCC and the expression was significantly different with or without lymph node metastasis. Nav1.5 may be involved in the occurrence and metastasis of OSCC.