Targeting the Na(+)/K(+)-ATPase alpha1 subunit of hepatoma HepG2 cell line to induce apoptosis and cell cycle arresting.

Article Details

Citation

Xu ZW, Wang FM, Gao MJ, Chen XY, Hu WL, Xu RC

Targeting the Na(+)/K(+)-ATPase alpha1 subunit of hepatoma HepG2 cell line to induce apoptosis and cell cycle arresting.

Biol Pharm Bull. 2010;33(5):743-51.

PubMed ID
20460749 [ View in PubMed
]
Abstract

Recent research has shown that the Na(+)/K(+)-ATPase alpha1 subunit is a novel anti-cancer target, which plays pivotal roles in malignant cell ion transport, metabolism, migration and signal transduction. The purpose of the present study was to investigate the anti-cancer effects of ouabain and Na(+)/K(+)-ATPase alpha1 small interfering ribonucleic acid (siRNA) on HepG2 cell proliferation, apoptosis and cell cycle, and to explore the molecular mechanisms. The expression of Na(+)/K(+)-ATPase alpha1 subunit in human hepatocellular carcinoma (HCC), normal liver tissues and human HCC line (HepG2, SMMC-7721 and Bel-7402) has been investigated. Using the ouabain and Na(+)/K(+)-ATPase alpha1 subunit siRNA, which target the Na(+)/K(+)-ATPase, we have evaluated the effects of inhibiting Na(+)/K(+)-ATPase alpha1 in human HepG2 cells with respect to cell proliferation, morphology, cell cycle, impact on intracellular Ca2++, reactive oxygen species (ROS) concentration, and correlated gene expression level on messenger ribonucleic acid (mRNA) and protein. Our data showed that the expression Na(+)/K(+)-ATPase alpha1 subunit in HCC tissues is higher than that in normal liver tissues. Ouabain and Na(+)/K(+)-ATPase alpha1 siRNA could inhibit HepG2 cell proliferation. Ouabain could induce HepG2 cell apoptosis and generate S phase arrest, and siRNA could enhance the anti-cancer effect of ouabain that induced HepG2 cells apoptosis via an intracellular Ca(2+) and ROS increase-mediated, and generated cell cycle S phase arresting by decreasing the CyclinA1/cyclin-dependent kinase 2 (CDK2)/proliferating cell nuclear antigen (PCNA) complex product and increasing the expression of cyclin-dependent kinase inhibitor 1A (P21(CIP1)). We believe that targeting of the Na(+)/K(+)-ATPase alpha1 subunit in human HCC cells could provide new sight into the treatment of HCC.