title: Development of a double-drug-resistant human leukemia model to cytosine arabinoside and L-asparaginase: evaluation of cross-resistance to other treatment modalities.
abstract: We have developed an in vitro model of 38 T-lymphoblastic leukemia lines resistant to cytosine arabinoside (ara-C) and L-asparaginase (ASNase). Of these, 26 cell lines resistant to both drugs, 6 resistant to ara-C, and 6 resistant to ASNase were isolated. In 18 of these cell lines, all randomly selected, resistance to ara-C, ASNase and gamma radiation was documented by the MTT and trypan blue assays, as well as flow cytometry with Annexin V and propidium iodide (PI) staining. In these lines, p53, p21WAF1, and bcl-2 levels were measured by ELISA. Results show that P21WAF1 upregulation following p53 induction did not occur, suggesting that p53 function may be lost. Moreover, the data imply that upregulation of bcl-2 is critical in the development of resistance to ara-C and ASNase in these leukemic lines. In the CEM/0 parent line, p53 maintained its ability to interact with its DNA binding site as documented by the electrophoretic mobility shift assay (EMSA). But in one single- and one double-resistant leukemic cell line examined, p53 was not shown to maintain this ability. We conclude that double-resistant clones to ara-C and ASNase are refractory to both drugs, providing an excellent leukemic model to investigate the multiple-drug resistance.
authors: Division of Hematology/Oncology, University of Southern California, School of Medicine, Childrens Hospital Los Angeles, Los Angeles, CA, USA.
authors: F
authors: F
authors: Majlessipour
authors: R
authors: R
authors: Kwock
authors: S
authors: S
authors: Martin-Aragon
authors: K I
authors: KI
authors: Weinberg
authors: V I
authors: VI
authors: Avramis
mesh_terms: D017304:Annexin A5 / Q000737:chemistry; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001215:Asparaginase / Q000378:metabolism / Q000494:pharmacology*; D001217:Aspartate-Ammonia Ligase / Q000378:metabolism; D002999:Clone Cells; D004396:Coloring Agents / Q000737:chemistry; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism; D003561:Cytarabine / Q000494:pharmacology*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D005720:Gamma Rays; D006801:Humans; D015458:Leukemia, T-Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy; D008954:Models, Biological; D011419:Propidium / Q000737:chemistry; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D017304:Annexin A5; C493956:CDKN1A protein, human; D004396:Coloring Agents; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D003561:Cytarabine; D011419:Propidium; D001215:Asparaginase; D001217:Aspartate-Ammonia Ligase