[Bmi-1 as A Molecular Marker for Prognosis of Pediatric ALL]

To study whether the Bmi-1 gene can be a biomarker for analysis of clinical risk stratification and prognosis of ALL patients.

The expression level of Bmi-1 gene in bone marrow samples from 127 cases of newly diagnosed ALL was detected by qRT-PCR, at the same time the expression level of Bmi-1 protein in bone marrow samples from above-mentioned cases was detected by Western blot. The collected samples were divided into 3 groups: high, intermediate and low risk according to clinical risk stratfication, the relationship between Bmi-1 expression and risk grade of ALL patients was analyzed; at the same time the collected samples were divided into 2 groups: prednisone good response (PGR) and prednisone poor respouse (PPR) according to the sensitivity of prednison test, and the sensitivily to prednisone in 2 groups was compared; moreover, the collected samples were divided into 2 groups: high level and low level according to median of Bmi-1 level, and the relation of Bmi-1 level with prognosis of patients was analyzed by using the Kaplan-Meier method.

The expression level of Bmi-1 in low risk group was lowest, while that in high risk group was highest, however that in intermediat risk group was between the low and high risk groups, statistical analysis showed significant difference (P＜0.05). The expression level of Bmi-1 in PPR group was significantly higher than that in PGR group (P＜0.001). The Kaplan-Meier analysis showed that the RFS rate in Bmi-1 high expression group was significantly lower than that in Bmi-1 low expression group (73.0% vs 90.6%) (P＜0.001).

The Bmi-1 can be used as a molecular marker for the analysis of chinical risk and prognosis of pediatric ALL.