PARP1 Characterization as a Potential Biomarker for BCR::ABL1 p190+ Acute Lymphoblastic Leukemia.

Simple Summary: Acute lymphoblastic leukemia (ALL) is the most common childhood cancer and the presence of BCR::ABL1 fusion in p190 isoform is a marker for worse prognosis, associated with treatment resistance and reduced overall survival. We aim to determine the effectiveness of targeting poly-ADP-ribose polymerase (PARP) in a model of BCR::ABL1 p190+ ALL using a small molecule inhibitor, AZD2461, and we hope that our findings may help improve molecular stratification and prognosis of ALL patients. Detection of t(9;22), and consequent BCR::ABL1 fusion, is still a marker of worse prognosis for acute lymphoblastic leukemia (ALL), with resistance to tyrosine-kinase inhibitor therapy being a major obstacle in the clinical practice for this subset of patients. In this study, we investigated the effectiveness of targeting poly-ADP-ribose polymerase (PARP) in a model of BCR::ABL1 p190+ ALL, the most common isoform to afflict ALL patients, and demonstrated the use of experimental PARP inhibitor (PARPi), AZD2461, as a therapeutic option with cytotoxic capabilities similar to that of imatinib, the current gold standard in medical care. We characterized cytostatic profiles, induced cell death, and biomarker expression modulation utilizing cell models, also providing a comprehensive genome-wide analysis through an aCGH of the model used, and further validated PARP1 differential expression in samples of ALL p190+ patients from local healthcare institutions, as well as in larger cohorts of online and readily available datasets. Overall, we demonstrate the effectiveness of PARPi in the treatment of BCR::ABL1 p190+ ALL cell models and that PARP1 is differentially expressed in patient samples. We hope our findings help expand the characterization of molecular profiles in ALL settings and guide future investigations into novel biomarker detection and pharmacological choices in clinical practice. [ABSTRACT FROM AUTHOR]