The increase of voltage-gated potassium channel Kv3.4 mRNA expression in oral squamous cell carcinoma

Background: Potassium channels have been reported to be involved in the proliferation of many types of cells, including tumor cells. The overexpression of the K+ channel and related channel activity are involved in the neoplastic process. Methods: We examined the expression of an A-type voltage-gated K+ channel, K(v)3.4, in oral squamous cell carcinoma (OSCC) and esophageal squamous cell carcinoma (ESCC) compared with non-cancerous matched tissue (NCMT) using RT-PCR analysis. In addition, administration of an A-type K+ channel blocker, 4-aminopyridine (4-AP), and an antisense oligodeoxynucleotide (ODN) directed specifically against K(v)3.4 were performed to identify the involvement of K(v)3.4 in the growth of OSCC cells. Results: A significantly increase in the frequency of K(v)3.4 mRNA expression was identified in OSCC (64%) compared to corresponding NCMT (29%) (P = 0.05). The increase of K(v)3.4 mRNA expression was also eminent in ESCC. Growth of OSCC cells was significantly inhibited by 4-AP in a dose-dependent manner at different time point of treatment. In OECM-1 OSCC cells, a significant growth inhibition was noted in antisense ODN-treated cells compared to control cells. Conclusion: We provide novel evidences of the increase of K(v)3.4 mRNA expression in OSCC. The abrogation of K(v)3.4 inhibits the growth of OSCC cells.