Expression of delayed rectifier potassium channels and their possible roles in proliferation of human gastric cancer cells.

Voltage-gated potassium (Kv) channels have been reported to be involved in the proliferation of many types of cells, including tumor cells. The overexpression of the Kv channels and related channel activity are involved in the neoplastic process. Our previous study has shown the existence of delayed rectifier potassium (IK) current in gastric cancer cells SGC7901. However, the expression and function of most delayed rectifier potassium (KD) channel subunits in gastric cancer cells are not completely resolved. Here we examine expression of KD channel subunits in Kv1-Kv3 families in immortalized gastric epithelial cells GES and various gastric cancer cells (including AGS, KATO¢U, MKN28, MKN45, MGC803, SGC7901, SGC7901/ADR, and SGC7901/VCR), and their roles in cell proliferation. RT-PCR analysis reveals that all cell lines examined express Kv1.3, Kv1.5, Kv1.6, Kv2.1, and Kv2.2. However, Kv1.2 and Kv3.2 genes are barely detectable in any given cancer cell lines. Kv1.5 protein, high mRNA levels in all cell lin...