title: The overexpression of multidrug resistance-associated proteins and gankyrin contribute to arsenic trioxide resistance in liver and gastric cancer cells.
abstract: Arsenic trioxide has been used as a therapeutic agent for acute promyelocytic leukemia and recently for some solid tumors. Although arsenic trioxide has been shown to significantly inhibit the growth of solid tumor cells in vitro, clinical trials indicate that arsenic trioxide alone is pool active against non-hematologic malignant diseases. To understand the mechanisms of arsenic resistance in solid tumor cells, we established two arsenic-resistant solid tumor cell lines, HepG2/AS and SGC7901/AS, isolated from human liver cancer cell line HepG2 and human gastric cancer cell line SGC7901, respectively, by a series of stepwise selections via treatment with increasing concentrations of arsenic trioxide. Three ABC transporter proteins, ABCB1, ABCC1 and ABCC2, were expressed increasingly and differently in two arsenic-resistant cell lines. Further, tumor suppressor p53 was overexpressed in two arsenic-resistant cell lines, but the levels of p53 mediators MDM2 and gankyrin, which regulate the ubiquitination of p53, increased simultaneously. In addition, an increase in the phosphorylation of Rb at Ser795 in the two cell lines might also result from the presence of MDM2 and gankyrin, which suggest that the inactivation of p53 and Rb contribute to drug resistance. These two arsenic-resistant solid tumor cell lines, HepG2/AS and SGC7901/AS, may be useful for studying the mechanism of arsenic resistance in solid tumors and may provide a way to overcome it.
authors.affiliation: General Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, P.R. China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Mu
authors.initials: M
authors.lastname: Zhang
authors.forename: Lian-Xin
authors.initials: LX
authors.lastname: Liu
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010087:Oxides / Q000494:pharmacology*; D010766:Phosphorylation; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D015854:Up-Regulation; D014700:Verapamil / Q000494:pharmacology
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D000077237:Arsenic Trioxide; D001152:Arsenicals; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D010087:Oxides; D046988:Proteasome Endopeptidase Complex; D011518:Proto-Oncogene Proteins; D051736:Proto-Oncogene Proteins c-mdm2; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; D014700:Verapamil; C513055:ABCB1 protein, human; C000715087:ABCC2 protein, human; C403591:PSMD10 protein, human; C495901:TP53 protein, human; C497206:MDM2 protein, human; C421109:multidrug resistance-associated protein 1