Mechanisms of drug resistance in acute lymphoblastic leukemia.

Outcomes of patients with acute lymphoblastic leukemia (ALL) have improved dramatically with conventional chemotherapy consisting of multiple agents. However, considering the major impact of tyrosine kinase inhibitors in the treatment of Philadelphia chromosome-positive ALL, sensitivities to each chemotherapeutic agent must be appreciated in individual cases to further improve therapeutic outcomes of ALL patients. Recent advances in genome-wide association and comprehensive genetic mutation studies with next-generation sequencing enable the involvement of single nucleotide polymorphisms and acquired genetic mutations in the drug resistance of ALL to be evaluated. Herein, we overview recent findings regarding the mechanisms of drug resistance in ALL. Our observations in a large panel of ALL cell lines are also presented.