INTRODUCTION: Medulloblastoma is the most frequent type of embryonal tumor in 
the pediatric population, accounting for 20-25% of all brain tumors in children. 
Recently, the suspected contribution of the Polycomb group (PcG) genes in 
medulloblastoma development was described. PcG genes play an important role in 
developmental processes; they are also involved in the self-renewal of 
hematopoietic and neural stem cells as well as in malignant transformation.
PURPOSE: In this study, we evaluated the expression of BMI1and PCGF2, members of 
family of PcG genes, and their potential target, MYC oncogene, and analyzed 
their association with demographic and clinical data.
MATERIALS AND METHODS: Thirty-one children (18 males and 13 females, aged from 
0.4 to 17 years) with medulloblastoma were included in this study. The gene's 
expression level was measured by quantitative real-time PCR, obtained using the 
two-color multiplexing technique.
RESULTS: We found that the higher expression levels of BMI1 and PCGF2 genes were 
associated with significantly decreased patient survival (p = 0.02 and 
p = 0.012, respectively). Significant differences between gender were found, 
with a higher expression level of the PCGF2 gene observed among females 
(p = 0.02).
CONCLUSION: Our analysis showed correlation between BMI1 and PCGF2 gene's 
expression and survival in children with medulloblastoma.