Investigation of genetic factors that play role in gliomagenesis

Gliomas are the most frequent type of cancer arising from the brain tissue. Isocitrate deyhdrogenase (IDH)" plays an important role in the development of gliomas. The aim of the research is to analyze these SNPs in Turkish populatiın for the first time and to investigate a possible relation with common oncogenic changes seen in gliomas. A total of 135 patients and 164 healthy controls were included in the study. Rs4295627 has been genotyped in genomic DNA from blood/tumor samples of glioma patients and from blood samples of healthy donors. Next, the relation between rs4295627 genotype and rs55705857 genotype and common oncogenic mutations in gliomas was analyzed Our results show that a strong relation exists between 8q24.21-localized rs4295627 genotype and increased glioma risk. The association was particularly strong for grade-2 and grade-3 gliomas and oligodendrogliomas, while the previously reported association with IDH-mutation was relatively weaker. On the other hand, analysis of the relation between rs4295627 genotype and oncogenic changes common to gliomas (1p19q codeletion, p53 expression by immunohistochemistry, p16 expression loss, PTEN expression loss, hTERT promotor mutations and particularly C228T mutation) did not reveal any statistically significant association by chi-square test. The same was true fort he relation between rs4295627 and the more recently identified SNP rs55705857, which was claimed to be the causal change that is responsible for rs4295627's association with glioma. Besides molecular changes, the relation between rs4295627 genotype and tumor grade was analyzed and a very strong association with lower grade (II and III) was observed.