title: Targeting the Na(+)/K(+)-ATPase alpha1 subunit of hepatoma HepG2 cell line to induce apoptosis and cell cycle arresting.
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.
authors.affiliation: Tianjin Key Laboratory for Biomarkers of Occupational and Environmental Hazard, TianJin 300162, China.
authors.forename: Zhong-Wei
authors.initials: ZW
authors.lastname: Xu
authors.forename: Feng-Mei
authors.initials: FM
authors.lastname: Wang
authors.forename: Mo-Jie
authors.initials: MJ
authors.lastname: Gao
authors.forename: Xiao-Yi
authors.initials: XY
authors.lastname: Chen
authors.forename: Wen-Liang
authors.initials: WL
authors.lastname: Hu
authors.forename: Rui-Cheng
authors.initials: RC
authors.lastname: Xu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D056750:Cyclin A1 / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2 / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008113:Liver Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D016196:S Phase / Q000187:drug effects; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; C493956:CDKN1A protein, human; D056750:Cyclin A1; D050759:Cyclin-Dependent Kinase Inhibitor p21; D010936:Plant Extracts; D018809:Proliferating Cell Nuclear Antigen; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D010042:Ouabain; D051357:Cyclin-Dependent Kinase 2; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium