title: Expression of bmi-1 in pediatric brain tumors as a new independent prognostic marker of patient survival.
abstract: Objectives. The B-cell-specific moloney leukemia virus insertion site 1 (the Bmi-1) gene is an important member in the family of polycomb group (PcG) genes that plays an oncogenic role in several types of cancer, but it's expression as a prognostic marker in pediatric brain tumors has not been indicated. Materials and Methods. The Bmi-1 gene expression, clinic pathological and prognostic significance in a series of pediatric brain tumors were examined by real-time PCR method in 56 pediatric brain tumors. Results. The Bmi-1 gene expression in various types of pediatric brain tumors compared to that in normal brain tissue was 4.85-fold. The relative expression varied from 8.64-fold in ependymomas to 2.89-fold in other types. Expression level in high-grade tumors compared to that in low-grade tumors was 2.5 times. In univariate survival analysis of the pediatric brain tumors, a significant association of high expression of the Bmi-1 with patient survival was demonstrated. In multivariate analysis, the Bmi-1 high expression provided significant independent prognostic factors. Conclusion. Increased expression of the Bmi-1 in pediatric brain tumors may be important in the acquisition of an aggressive phenotype. In addition, it can be used as a strong and independent molecular marker of prognosis in pediatric brain tumors.
authors.affiliation: Department of Genetics, Faculty of Biological Science, Shahid Beheshti University, GC, Tehran 1983963113, Iran. s farivar@sbu.ac.ir
authors.forename: Shirin
authors.initials: S
authors.lastname: Farivar
authors.forename: Reza
authors.initials: R
authors.lastname: Zati Keikha
authors.forename: Reza
authors.initials: R
authors.lastname: Shiari
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Jadali
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D002648:Child; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D063150:Polycomb Repressive Complex 1 / Q000235:genetics* / Q000378:metabolism; D011379:Prognosis; D016019:Survival Analysis
chemical_list: C069077:BMI1 protein, human; D014408:Biomarkers, Tumor; D063150:Polycomb Repressive Complex 1