Expression of the voltage-gated potassium channel Kv3.4 in oral leucoplakias and oral squamous cell carcinomas.

AIMS: The expression of the voltage-gated potassium channel Kv3.4 was investigated in both oral squamous cell carcinomas (OSCC) and oral leucoplakias to establish its clinical significance during the development and progression of OSCC. MATERIALS AND METHODS: Tissue specimens from 62 patients with oral leucoplakia were collected prospectively and 100 patients with OSCC who underwent surgical treatment were collected retrospectively, and Kv3.4 expression was analysed by immunohistochemistry. RESULTS: Thirty-nine of 100 tumours exhibited Kv3.4-positive expression, and staining was associated with the degree of differentiation (P = 0.05) but showed no impact on patient prognosis. Abnormal Kv3.4 expression was detected in 16% (7 of 43) hyperplastic lesions and at a significantly higher proportion in oral dysplasias (50%, 8 of 16 cases; P = 0.008), whereas expression was negligible in normal adjacent epithelia. Furthermore, patients carrying Kv3.4-positive lesions exhibited a higher progression risk than those with Kv3.4-negative lesions; however, histology but not Kv3.4 expression predicted oral cancer development significantly in this prospective cohort. CONCLUSION: This study provides original evidence to demonstrate the early occurrence and high prevalence of abnormal Kv3.4 expression in oral leucoplakias. Our results support a role for Kv3.4 potassium channel in OSCC tumorigenesis rather than tumour progression and disease outcome.