In vitro susceptibility to dexamethasone- and doxorubicin-induced apoptotic cell death in context of maturation stage, responsiveness to interleukin 7, and early cytoreduction in vivo in childhood T-cell acute lymphoblastic leukemia

Item Type:	Article
Title:	In vitro susceptibility to dexamethasone- and doxorubicin-induced apoptotic cell death in context of maturation stage, responsiveness to interleukin 7, and early cytoreduction in vivo in childhood T-cell acute lymphoblastic leukemia
Creators Name:	Wuchter, C. and Ruppert, V. and Schrappe, M. and Doerken, B. and Ludwig, W.D. and Karawajew, L.
Abstract:	Within childhood T-cell acute lymphoblastic leukemia (T-ALL), patients with a cortical (CD1a+) immunophenotype have been identified as a subgroup with favorable outcome in the acute lymphoblastic leukemia–Berlin-Frankfurt-Muenster (ALL-BFM), Cooperative study group for childhood acute lymphoblastic leukemia (COALL) and Pediatric Oncology Group studies. We investigated in leukemic samples of children with T-ALL (n = 81) whether the different in vivo therapy response could be linked to differential in vitro susceptibility to apoptotic cell death. The extent of dexamethasone- as well as doxorubicin-induced apoptosis, detected by annexin V staining, positively correlated with the expression levels of CD1a (Spearman correlation coefficient, rs = 0.3 and 0.4, respectively; P < .01). When compared to cortical T-ALL, mature (CD1a− , surface CD3+) T-ALL were significantly more resistant to doxorubicin, and immature, pro–/pre–T-ALL were more resistant to both drugs (P < .05). Apoptosis-related parameters (Bax, Bcl-2, CD95, and CD95-induced apoptosis) did not account for differential susceptibility to drug-induced apoptosis. By contrast, an interleukin 7–induced rescue of leukemic cells from spontaneous apoptosis, recently proposed to reflect distinct developmental stages and apoptotic programs in T-ALL, was highly associated with susceptibility to dexamethasone- but not doxorubicin-induced apoptosis (P < .001 versus P = .08). Analysis of clinical data showed that in vitro susceptibility to dexamethasone (but not to doxorubicin) closely correlated with early in vivo therapy response characterized by percentages of blast cells in bone marrow on day 15 (rs = −0.46, P = .001). Taken together, the in vitro assessment of drug-induced apoptosis revealed maturation-dependent differences within childhood T-ALL. The enhanced sensitivity to both drugs in cortical T-ALL might account for the better in vivo treatment response of this prognostically favorable T-ALL subgroup.
Keywords:	Apoptosis, CD Antigens, CD1 Antigens, CD2 Antigens, CD34 Antigens, Cultured Tumor Cells, Dexamethasone, Doxorubicin, Immunophenotyping, Interleukin-7, Myelomonocytic Differentiation Antigens, Neoplasm Drug Resistance, Neoplasm Staging, Precursor Cell Lymphoblastic Leukemia-Lymphoma, Sialic Acid Binding Ig-like Lectin 3
Source:	Blood
ISSN:	0006-4971
Publisher:	American Society of Hematology
Volume:	99
Number:	11
Page Range:	4109-4115
Date:	1 June 2002
Official Publication:	https://doi.org/10.1182/blood.V99.11.4109
PubMed:	View item in PubMed

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