The Na+/K+ ATPase is an integral membrane heterodimer belonging to the P-type ATPase family. This ion channel uses the energy derived from ATP hydrolysis to maintain membrane potential by driving Na+ export and K+ import across the plasma membrane. It is composed of a large catalytic alpha subunit and a membrane-spanning auxiliary beta subunit. In humans, the Na+/K+ ATPase is a binary complex of an alpha subunit that has four isoforms (alpha1-alpha4) and a beta-subunit that has three isoforms (beta1, beta2, beta3). Na+/K+ ATPase subunit expression has been shown to be upregulated in cancers, and inhibition of Na+/K+ ATPase activity has anti-cancer effects. The beta3 subunit of Na+/K+ ATPase has increased expression in human gastric cancer tissues and cell lines, and its increased expression level predicts poor patient outcome. beta3 subunit knockdown significantly inhibited cell proliferation, colony-formation ability, migration, and invasion in human gastric carcinoma cell lines.
