Farmacogenomica della Clofarabina nel trattamento delle Leucemie Acute pediatriche: identificazione di nuovi bersagli molecolari e del profilo genomico associato all'efficacia terapeutica del farmaco antitumorale

Over the past decades, treatment of Acute Leukemia (AL) in children has improved dramatically. However, despite the remarkable progress in the treatment of AL, leukemia remaining the leading cause of death by disease in children. Advances in cure rates could be obtained by pharmacogenomics aimed at developing strategies to personalize treatment and tailor therapy to individual patients, optimizing efficacy and safety through better understanding of human genome variability and its influence on drug response. In this work, we studied the pharmacogenomics of the antitumoral agent Clofarabine (CLO) in pediatric AL in order to identify predictive markers of drug response of leukemic cells, to elucidate mechanisms of drug resistance and, finally, to discover new therapeutic targets for more specific and efficient curative approaches. In vitro sensitivity to CLO was performed on blasts from children affected by Acute Lymphoblastic and Myeloid leukemia (ALL and AML). We identified two T-ALL subgroups on the base of their CLO sensitivity. Gene Expression Profiling by DNA-microarrays allowed us to identify the genetic “signature” associated to T-ALL Clofarabine response. Moreover, analysis of the differentially expressed genes permitted the identification of potential biomarkers of drug resistance providing mechanistic insights into the pharmacological basis of T-ALL drug resistance and suggesting a new therapeutic target for the treatment of T-ALLs resistant to CLO. In conclusion, our study identified set of genes and pathways of biological relevance for T-ALL response to CLO suggesting genetic biomarkers able to identify patients that could benefit from CLO treatment or new targets to develop innovative therapeutic strategies. Our study could be a paradigm for the application of pharmacogenomic studies in other human cancers.