The Clinical And Biological Significance Of Breast Cancer Resistance Protein Expression In Acute Leukemia

Objective To evaluate the clinical and biological significance of breast cancer resistance protein (BCRP) expression in acute leukemia. Methods The expression of breast cancer resistance protein (BCRP) mRNA was measured in 62 patients with acute leukemia and in 20 normal control by using reverse transcription polymerase chain reaction (RT-PCR). and the expression of P-glycoprotein (P-gp) was investigated in 25 patients by using indirect immunnofluorescence methods. In this paper, ?2-MG (a 330bp of PCR product) was selected as an internal control for semi-quantitative analysis of BCRP(a 446bp of PCR product).Results The BCRP positive rate and the level of BCRP expression in previously untreated group was 58.1%, significantly higher than that in control group (20%). BCRP was expressed in 73.08% Of clinical resistant group, higher than in 22.22% of CR group. The CR rate in ANLL differed significantly between BCRP+ group (32%) and BCRP" group (74%) (P<0.05), whereas there was no appreciable correlation between the CR rate and the level of BCRP expression in ALL. The BCRP positive rate in normal control and CR group was very low. The BCRP expression was not correlated with French-American-British Cooperative Group (FAB) classification, immunophenotype and P-gp expression. Conclusions The BCRP expression in newly diagnosed cases was higher than that in normal control group. The level of BCRP expression in CR group was lower than that in clinical resistant group. The BCRP expression correlated with chemotherapeutic effect and prognosis. It is anunfavorable prognostic factor for untreated patients with acute leukemia.