Overexpression and lack of copy number variation in the BMI-1 gene in human glioma

Malignant gliomas are neoplasms of the brain that are associated with a poor prognosis. The B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) gene is one of the major cancer stem cell factors responsible for treatment failure in glioma. In the present study, the DNA-RNA-protein alterations in the BMI-1 gene were assessed in 50 glioma samples. Copy number variations in the BMI-1 gene were analyzed using SYBR (R) Green quantitative polymerase chain reaction. Gene expression analysis was performed using a Taqman assay and protein quantitation was performed using western blotting. A comparative Ct analysis showed the absence of copy number variations in all glioma samples. BMI-1 mRNA expression was found to be overexpressed in 36 out of 50 samples ( 72.0%), and 37 out of 50 samples showed overexpression (74.0%) of BMI-1 protein; this was statistically significant when compared with non-glioma tissues. It was observed that the protein and RNA expression in glioma were concordant. In this study on the BMI-1 gene, transcription and translation in glioma were observed and BMI-1 overexpression was found to be a common phenomenon.