title: Polycomb genes expression as a predictor of poor clinical outcome in children with medulloblastoma.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  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.
  
  
  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).
  
  
  CONCLUSIONS
  Our analysis showed correlation between BMI1 and PCGF2 gene's expression and survival in children with medulloblastoma.
authors: Department of Molecular Pathology and Neuropathology, Chair of Oncology, Medical University of Łódź, Czechosłowacka 8/10, Łódź, Poland. magdalena.zakrzewska@umed.lodz.pl
authors: Magdalena
authors: M
authors: Zakrzewska
authors: Krzysztof
authors: K
authors: Zakrzewski
authors: Sylwia M
authors: SM
authors: Grešner
authors: Sylwester
authors: S
authors: Piaskowski
authors: Beata
authors: B
authors: Zalewska-Szewczyk
authors: Paweł P
authors: PP
authors: Liberski
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000235:genetics*; D002528:Cerebellar Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D005260:Female; D015870:Gene Expression; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D008527:Medulloblastoma / Q000235:genetics* / Q000378:metabolism / Q000401:mortality; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics; D063150:Polycomb Repressive Complex 1; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D012097:Repressor Proteins / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016896:Treatment Outcome
chemical_list: C069077:BMI1 protein, human; D014408:Biomarkers, Tumor; D009687:Nuclear Proteins; C489348:PCGF2 protein, human; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1