Expression analysis of the epithelial Na+ channel δ subunit in human melanoma G-361 cells

Malignant melanoma is the most deadly form of skin cancer and its incidence is steadily increasing worldwide. The plasma membrane in melanoma cells possesses a variety of ion channels, so its profile is thought to lead to a novel target for medical treatment for malignant melanoma. Here we showed that human melanoma G-361 cells expressed the epithelial Na+ channel δ subunit (ENaC δ), which is largely unknown in physiological and pathological functions in non-neuronal tissues. Expression analyses at the level of mRNA clearly revealed that ENaC δ transcript was strongly expressed in human melanoma cells using reverse transcription-polymerase chain reaction and cell-based in situ hybridization techniques. Other ENaC subunits (α, β, and γ) were also distributed in human melanoma cells. In addition, human melanoma cells possessed an abundant expression of ENaC δ protein by immunocytochemistry. These results provide an attractive target for drug development of malignant melanoma.