title: Characterization of cytarabine-resistant leukemic cell lines established from five different blood cell lineages using gene expression and proteomic analyses.
abstract: Cytarabine (ara-C) is the key drug for treatment of acute myeloid leukemia. Since intracellular cytarabine triphosphate (ara-CTP) is an active metabolite of ara-C, factors that reduce the amount of ara-CTP are known to induce drug resistance. However, these factors do not fully explain the development of resistance to ara-C. The present study was conducted to search for new candidate ara-C resistance factors, including those that are unrelated to ara-CTP production. For this purpose, we newly established five ara-C-resistant leukemic clones from different blood cell lineage leukemic cell lines (HL-60, K562, CEM, THP1 and U937). The resistant subclones were 5-58-fold more ara-C-resistant than their parental counterparts. All of the ara-C-resistant subclones, except for ara-C-resistant CEM cells, displayed alteration of ara-CTP-related factors such as ara-C membrane transport capacity, deoxycytidine kinase activity or cytosolic nucleotidase II activity. To identify new candidate factors, we used two comprehensive approaches: DNA microarray and proteome analyses. The DNA microarray analysis revealed eight genes (C19orf2, HSPA8, LGALS1, POU4F3, PSAP, AKT1, MBC2 and CACNA2D3) that were altered in all five ara-C-resistant lines compared to parental cells. Both proteome and DNA microarray analyses further detected a reduced protein level of stathmin1 in the ara-C-resistant CEM subclone compared to its parental line. Thus, the present findings suggested the involvement of novel multiple mechanisms in mediating the ara-C resistance of leukemic cells. The role of some of these molecules in resistance is still unclear.
authors.affiliation: Department of Hematology and Oncology, Faculty of Medical Sciences, University of Fukui, 23-3 Shimoaizuki, Matsuoka, Eiheiji, Fukui 910-1193, Japan.
authors.forename: Eiju
authors.initials: E
authors.lastname: Negoro
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamauchi
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Urasaki
authors.forename: Rie
authors.initials: R
authors.lastname: Nishi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hori
authors.forename: Takanori
authors.initials: T
authors.lastname: Ueda
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D045744:Cell Line, Tumor / Q000187:drug effects* / Q000378:metabolism; D019070:Cell Lineage; D002470:Cell Survival; D003561:Cytarabine / Q000494:pharmacology*; D003842:Deoxycytidine Kinase / Q000378:metabolism; D019008:Drug Resistance, Neoplasm; D015180:Electrophoresis, Gel, Two-Dimensional; D057075:Enzyme Assays; D020869:Gene Expression Profiling; D052138:Genes, Neoplasm; D006801:Humans; D007938:Leukemia / Q000473:pathology*; D020411:Oligonucleotide Array Sequence Analysis; D020543:Proteome / Q000378:metabolism*
chemical_list: D000964:Antimetabolites, Antineoplastic; D020543:Proteome; D003561:Cytarabine; D003842:Deoxycytidine Kinase; D015720:5'-Nucleotidase; C508048:NT5C2 protein, human