Tyrosine kinase inhibitor resistance in de novo BCR::ABL1-positive BCP-ALL beyond kinase domain mutations.
Inge van Outersterp, Judith M Boer, Cesca van de Ven, Caitlin E J Reichert, Aurelie Boeree, Brian Kruisinga, Hester A de Groot-Kruseman, Gabriele Escherich, Aniko Sijs-Szabo, Anita W Rijneveld, Monique L den Boer
Author Information
Inge van Outersterp: Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands. ORCID
Judith M Boer: Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands. ORCID
Cesca van de Ven: Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
Caitlin E J Reichert: Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
Aurelie Boeree: Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
Brian Kruisinga: Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
Hester A de Groot-Kruseman: Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
Gabriele Escherich: Department of Pediatric Hematology and Oncology, University Medical Center Hamburg Eppendorf, Hamburg, Germany.
Aniko Sijs-Szabo: Department of Hematology, Leiden University Medical Center, Leiden, The Netherlands.
Anita W Rijneveld: Department of Hematology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
Monique L den Boer: Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
ABSTRACT: A better understanding of ABL1 kinase domain mutation-independent causes of tyrosine kinase inhibitor (TKI) resistance is needed for BCR::ABL1-positive B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Although TKIs have dramatically improved outcomes, a subset of patients still experiences relapsed or refractory disease. We aimed to identify potential biomarkers of intrinsic TKI resistance at diagnosis in samples from 32 pediatric and 19 adult patients with BCR::ABL1-positive BCP-ALL. Reduced ex vivo imatinib sensitivity was observed in cells derived from newly diagnosed patients who relapsed after combined TKI and chemotherapy treatment compared with cells derived from patients who remained in continuous complete remission. We observed that ex vivo imatinib resistance was inversely correlated with the amount of (phosphorylated) BCR::ABL1/ABL1 protein present in samples that were taken at diagnosis without prior TKI exposure. This suggests an intrinsic cause of TKI resistance that is independent of functional BCR::ABL1 signaling. Simultaneous deletions of IKZF1 and CDKN2A/B and/or PAX5 (IKZF1plus), as well as deletions of PAX5 alone, were related to ex vivo imatinib resistance. In addition, somatic lesions involving ZEB2, SETD2, SH2B3, and CRLF2 were associated with reduced ex vivo imatinib sensitivity. Our data suggest that the poor prognostic value of IKZF1(plus) deletions is linked to intrinsic mechanisms of TKI resistance other than ABL1 kinase domain mutations in newly diagnosed pediatric and adult BCR::ABL1-positive BCP-ALL.
References
J Clin Oncol. 2010 Nov 1;28(31):4755-61
[PMID: 20876426]
