Tyrosine kinase inhibitor resistance in chronic myeloid leukemia cell lines: investigating resistance pathways

• Published in: Leukemia & lymphoma 2011-11, Vol.52 (11), p.2139-2147
• Main Authors: Tang, Carine, Schafranek, Lisa, Watkins, Dale B., Parker, Wendy T., Moore, Sarah, Prime, Jodi A., White, Deborah L., Hughes, Timothy P.
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing - metabolism; Antineoplastic Agents - pharmacology; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1 - metabolism; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters - metabolism; Benzamides; Blotting, Western; Cell Line, Tumor; cell lines and animal models; Dasatinib; Dose-Response Relationship, Drug; Drug resistance; Drug Resistance, Neoplasm; Flow Cytometry; Fusion Proteins, bcr-abl - genetics; Gene Expression Regulation, Neoplastic; Humans; Imatinib Mesylate; In Situ Hybridization, Fluorescence; Inhibitory Concentration 50; K562 Cells; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - genetics; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - metabolism; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - pathology; Mutation; myeloid leukemias and dysplasias; Neoplasm Proteins - metabolism; Nuclear Proteins - metabolism; Phosphorylation - drug effects; Piperazines - pharmacology; Protein Kinase Inhibitors - pharmacology; Pyrimidines - pharmacology; Reverse Transcriptase Polymerase Chain Reaction; Thiazoles - pharmacology
• ISSN: 1042-8194; 1029-2403
• DOI: 10.3109/10428194.2011.591013

Abstract There are three currently identified secondary resistance mechanisms observed in patients with chronic myeloid leukemia (CML) receiving tyrosine kinase inhibitors (TKIs). These are BCR-ABL kinase domain (KD) mutations, increased BCR-ABL expression, and overexpression of drug-efflux proteins (ABCB1 and ABCG2). To investigate the interplay between these three modes of resistance, three CML blast crisis cell lines (K562, its ABCB1-overexpressing variant K562 Dox, and KU812) were cultured in gradually increasing concentrations of imatinib to 2 μM, or dasatinib to 200 nM. Eight imatinib- and two dasatinib-resistant cell lines were established. Two imatinib-resistant K562 lines both had increased BCR-ABL expression as the apparent mode of resistance. However, when a dasatinib-resistant K562 culture was generated we observed gradually increasing BCR-ABL expression which peaked prior to identification of the T315I mutation. BCR-ABL overexpression followed by mutation development was observed in a further 4/10 cell lines, each with different KD mutations. In contrast, three imatinib-resistant K562 Dox lines exhibited only a further increase in ABCB1 expression. All TKI-resistant cell lines generated had increased IC50 (dose of drug required to reduce phosphorylation of the adaptor protein p-Crkl by 50%) to imatinib, dasatinib, and nilotinib, regardless of which TKI was used to induce resistance. This suggests that currently available TKIs share the same susceptibilities to drug resistance.