Genetic alterations determine chemotherapy resistance in childhood T‐ALL: modelling in stage‐specific cell lines and correlation with diagnostic patient samples

Abstract

Summary Acquired drug resistance eventually leads to treatment failure in T‐cell acute lymphoblastic leukaemia (T‐ALL). Immunophenotypic and cytogenetic heterogeneities within T‐ALL influence susceptibility to cytotoxic therapy, and little is known about the mechanisms of drug resistance at specific stages of T‐cell ontogeny. We developed tolerance to therapeutic concentrations of daunorubicin (DNR) and l‐asparaginase (l‐asp) in Jurkat (CD1a−, sCD3+) and Sup T1 (CD1a+, sCD3−) cell lines, having respective ‘mature’ and ‘cortical’ stages of developmental arrest. DNR resistant cells acquired multidrug resistance: 310‐fold increased resistance to vincristine (VCR) and a 120‐fold increased resistance to prednisolone (PRED). Microarray analysis identified upregulation of asparagine synthetase (ASNS) and argininosuccinate synthase 1 (ASS1) to cell lines with acquired resistance to l‐asp, and in the case of DNR, upregulation of ATP‐binding cassette B1 (ABCB1). Suppression of ABCB1, ASNS and ASS1 by RNA interference revealed their functional relevance to acquired drug resistance. Expression profiling of these genes in 80 T‐ALL patients showed correlation with treatment response. This study expands the pool of available drug resistant cell lines having cortical and mature stages of developmental arrest, introduces three new drug resistant T‐ALL cell lines, and identifies gene interactions leading to l‐asp and DNR resistance.

Drug–Gene Modeling in Pediatric T-Cell Acute Lymphoblastic Leukemia Highlights Importance of 6-Mercaptopurine for Outcome

“…Critically, the model developed in this in vitro setting has been validated using primary material from 3 independent T-ALL patient cohorts, clearly showing the clinical relevance of these drug-gene signatures. This is not the first time that in vitro gene-expression profiles have been used to model drug-resistance and subsequent patient outcome in cancer (38)(39)(40)(41)(42). In particular, Lee and colleagues published a sophisticated algorithm to translate drug activities in the NCI-60 cell line panel to predict drugsensitivity and clinical outcome in multiple cancer types (40).…”

High-Throughput Screening for Daunorubicin-Mediated Drug Resistance Identifies Mometasone Furoate as a Novel ABCB1-Reversal Agent

“…10 To confirm that DNR-induced multidrug resistance was conferred by inducible upregulation of the ABCB1 gene, we measured relative changes in ABCB1 mRNA expression between the Jurkat wild-type and DNR-resistant cell lines. We observed that ABCB1 mRNA was selectively upregulated approximately 600-fold in the resistant cell line (see Fig.…”

“…Jurkat cells were purchased from American Tissue Culture Corporation (Manassas, VA). As previously described, 10 cells were grown in RPMI 1640 medium (Gibco BRL, Grand Island, NY) with 100 units/mL penicillin-streptomycin (Gibco), 0.5 μL/L ciprofloxacin (Bayer Pharmaceuticals, Berkeley, CA), and 10% heat-inactivated fetal bovine serum (FBS). Cells were incubated at 37 °C in a humidified atmosphere of air/5% CO 2 .…”

Pediatric Acute Leukemia Therapies Informed by Molecular Analysis of High-Risk Disease

“…45 Many ETP patients fail to achieve a first remission, which may be mediated by a G 0 G 1 cell-cycle arrest (Figure 3), protecting such cells from the cytotoxic drugs commonly used during induction. 26 These findings suggest that the ETP signature may be a heterogeneous group of mutations and molecular rearrangements that result in an immature T-cell phenotype, which subsequently confers an intrinsic resistance to conventional chemotherapy approaches.…”

“…ABCC1 (MRP1), multidrug resistance to conventional chemotherapy can be especially difficult to overcome. 25,26 The search for molecularly defined risk factors and targeted therapies stands at the forefront of translational research in pediatric ALL. Therapies directed to a specific signaling pathway should ideally include the identification of a driving molecular aberration that, in a leukemic clone, controls its growth and proliferation ("oncogene addiction") and can be specifically disrupted by a small molecule having little or no toxicity.…”