Increased expression of lung resistance-related protein and multidrug resistance-associated protein messenger RNA in childhood acute lymphoblastic leukemia

Immunophenotype might be an important indicator for multidrug resistance (M DR) profiles in childhood acute lymphoblastic leukemia (ALL). The authors a nalyzed the messenger RNA (mRNA) levels of MDR1, multidrug resistance-assoc iated protein (MRP), and lung resistance-related protein (LRP) by reverse t ranscriptase-polymerase chain reaction (RT-PCR) in childhood pre-B ALL, T-c ell ALL, and acute nonlymphoblastic leukemia (ANLL). Results showed that MR P and LRP, but not MDR1, mRNAs are overexpressed, particularly in children with pre-B ALL compared with T-cell ALL and ANLL tested. In addition, the M RP and LRP mRNA expression levels in initial diagnosis and first relapse sa mples of one patient with pre-B ALL were similar. Consequently, these preli minary results suggest that the expression of these MDR-related genes in ch ildhood ALL might be regulated differently in a lineage dependent manner.