BMI1 gene expression in myeloid leukemias and its impact on prognosis

BMI1 is a polycomb group (PcG) protein and is overexpressed in leukemia. It plays a key role in the self-renewal of stem cells. Leukemic cells lacking BMI1 underwent proliferation arrest and showed signs of differentiation and apoptosis.

This study was aimed to investigate the expression and impact of BMI1 in myeloid leukemias. Expression levels of BMI1 in 100 acute myeloid leukemia (AML), 100 chronic myeloid leukemia (CML) patients and 20 healthy controls were measured by real time quantitative polymerase chain reaction (RQ-PCR).

The results showed that the expression of BMI1 was significantly higher in AML and CML versus control subjects (p<0.001 for both). The 2-year overall and disease free survival rates were significantly lower in patients expressing higher BMI1. Multivariate analysis showed that BMI1 was independent prognostic factor for OS for AML cases (p=0.015, HR=3.204, 95% CI=1.250-8.212). Accelerated and blastic phases in CML cases expressed higher BMI1 than chronic phase (p<0.001).

We concluded that detecting BMI1 is helpful for predicting the survival in AML patients and monitoring the aggressiveness and progression in patients with CML.