title: Arsenic trioxide reduces drug resistance to adriamycin in leukemic K562/A02 cells via multiple mechanisms.
abstract: The present study aimed to study the mechanisms by which low dose arsenic trioxide (As(2)O(3)) reduces multidrug resistance. The potential influence of As(2)O(3) on cytotoxicity was examined by methyl thiazolyl tetrazolium (MTT) assay and the intracellular mean fluorescence intensity (MFI) of Adriamycin (ADM) was examined by flow cytometry. The gene expression of mdr1 mRNA was determined by RT-PCR. The change of cellular expression levels of drug resistant-related proteins, including P-gp, bcl-2, Topo-II, and GST-π, were measured by Western-blotting or immunocytochemistry assay. Data showed As(2)O(3) at non-cytotoxic concentration (2μM) significantly increased the cytotoxicity of ADM on K562/A02 cells. Cotreatment of As(2)O(3) and ADM significantly increased the ADM MFI than ADM alone (P<0.01). Following pretreatment of K562/A02 cells with As(2)O(3), the expression of Topo-II was increased while the expression of GST-π and bcl-2 was decreased. No obvious alternation of expression of mdr1 mRNA or P-gp was observed. Thus, low dose As(2)O(3) partially reduced drug resistance to ADM in K562/A02 cells via multiple mechanisms, which selectively inhibited the efflux pump GST-π but not P-gp, as well as modulated the expression of MDR-related proteins such as Topo-II and bcl-2, in line with previous studies. In conclusions: The effect of As(2)O(3) on reducing MDR may have wide clinical application in chemotherapy regimens for leukemia.
authors.affiliation: Department of Hematologic Neoplasms, the First Affiliated Hospital, Jilin University, 71 Xinmin Avenue, Changchun, 130021, China.
authors.forename: Dianfeng
authors.initials: D
authors.lastname: Zhao
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Jiang
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Dong
authors.forename: Ziling
authors.initials: Z
authors.lastname: Liu
authors.forename: Beibei
authors.initials: B
authors.lastname: Qu
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ning
authors.initials: N
authors.lastname: Ma
authors.forename: Qingkun
authors.initials: Q
authors.lastname: Han
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis / Q000235:genetics; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004250:DNA Topoisomerases, Type II / Q000096:biosynthesis / Q000235:genetics; D004317:Doxorubicin / Q000493:pharmacokinetics / Q000494:pharmacology*; D004347:Drug Interactions; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D019254:Genes, bcl-2; D051549:Glutathione S-Transferase pi / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D020014:K562 Cells; D010087:Oxides / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D001152:Arsenicals; D010087:Oxides; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D004317:Doxorubicin; D051549:Glutathione S-Transferase pi; D004250:DNA Topoisomerases, Type II; D000077237:Arsenic Trioxide