[St]udy of NDRG2 and TGFβ1 Gene Promoter Methylation and Protein Expression in Different Grades of Brain Gliomas

Abstract

Background: The majority of malignant tumors that occur within the central nervous system arise from supportive tissues know as the neuroglia. The neuroglia is composed of glial cells, several types of which can develop into tumors. The most common type of glial cell tumor is the astrocytoma, which can be classified according malignancy in four grades: from low grade glioma (LGG; grade I-II astrocytoma) to high grade (grade III astrocytoma, grade IV astrocytoma (glioblastoma)). In cancer, one of the epigenetic proceses - global alterations of DNA methylation play an important role in tumor initiation and progression. Hypermethylation mostly occurs at the promoter CpG Island of genes that are involved in processes leading to tumor formation and progression. Aberrant expression of NDRG2 (N-Myc downstream-regulated) gene could play a tumor suppressor role in carcinogenesis. NDRG2 seems to be more abundantly expressed in normal tissues, and is involved in the regulation of proliferation, apoptosis and differentiation. NDRG2 expression is reportedly decreased by promoter methylation in a variety of malignancies. TGFβ1 (transforming growth factor, beta 1) is a multifunctional cytokine that controls tissue homeostasis and embryonic development. TGFβ1 acts as a tumor suppressor in normal epithelial cells and earlystage tumors and becomes an oncogenic factor in advanced tumors. We investigate promoter methylation and protein expression of NDRG2 and TGFβ1in different grades of glioma. Material and Methods: The methylation specific polymerase chain reaction (MSP) was performed using bisulfite treated DNA. Proteins were separated according to their molecular weight by electrophoresis in 10 % (NDRG2) and 12 % (TGFβ1) polyacrylamide gels. Western blot was used to compare levels of protein expression between different grade gliomas. Results: The research of NDRG2 gene promoter methylation showed that methylation fre...[...].