[Expression of lung resistance protein and multidrug resistance-associated protein in naive childhood acute leukemia and their clinical significance].

BACKGROUND & OBJECTIVE: Previous studies revealed that lung resistance protein (LRP) and multidrug resistance-associated protein (MRP) relate to drug resistance of childhood leukemia, which is not caused by only one mechanism. This study was to evaluate the expression of LRP and MRP genes in childhood leukemia and their correlation.

METHODS

The expression of LRP and MRP in 38 children with acute leukemia and 6 healthy children were measured with reverse transcription-polymerase chain reaction (RT-PCR); their clinical significance was analyzed according to complete remission (CR) rate of the patients after chemotherapy.

RESULTS

CR rate of the 38 patients was 68.4%. LRP was expressed in 11 of the 38 patients, and didn't express in healthy controls; CR rate was significantly lower in LRP-positive patients than in LRP-negative patients (27.3% vs. 85.2%, P < 0.05). MRP was overexpressed in 21 of the 38 patients; CR rate was significantly lower in MRP-positive patients than in MRP-negative patients (47.6% vs. 94.1%, P < 0.05). The positive rate of LRP was significantly lower in acute lymphoblastic leukemia (ALL) than in acute nonlymphocytic leukemia (ANLL) [18.5% (5/27) vs. 45.5% (6/11), P < 0.05]; however, the positive rate of MRP was 59.3% (16/27) in ALL, and 45.5% (5/11) in ANLL (P > 0.05). The positive rate of MRP was 28.6% in LRP-positive patients, and 29.4% in LRP-negative patients; there was no correlation between LRP and MRP.

CONCLUSION

Childhood acute leukemia patients with overexpression of LRP and MRP suffer severe disease and achieve low remission rateû lower remission rate of childhood ANLL patients may relate to LRP expression.