Angiotensin II Type I Receptor—168A/G Polymorphism Is Associated with Increased the Risk of Glioma in Turkish Population

Gliomas are the most common primary tumors of the Central Nervous System. Despite advances in the elucidation of molecular pathogenesis, gliomas still remain incurable. In the study, it was aimed to investigate the possible connection between ACE and AGTR1 polymorphisms with glioma pathogenesis and also the relationship of some angiogenic markers with gliomagenesis. In this respect, 96 glioma patients and 104 healthy controls were included in the study. To determine the effect of genetic polymorphisms on the predisposition of diffuse infiltrative glial tumors in the Turkish population, angiotensin-converting enzyme gene ( ACE ) insertion/deletion, angiotensin II receptor type 1 gene ( AGTR1 ) ‒168A/G, ‒535C/T, ‒825T/A, and Vascular Endothelial Growth Factor gene ( VEGF ) +936C/T, ‒2578C/A polymorphisms were investigated by PCR-RFLP. Allele/genotype frequencies between patients and controls were determined. Besides, relative gene expressions of ACE, AGTR1, and VEGF were detected by real time-PCR, while ACE, VEGF, ET-1, eNOS, and NO levels were measured in both serum and tissue by ELISA. In AGTR1 ‒168A/G polymorphism, the risk of glioma in the AA genotype decreased, while increased by 2.27 times in the G allele. Allele frequency and genotype distributions of other polymorphisms were found similar between two groups. Serum levels of ACE, VEGF, eNOS, NO, and tissue levels of ACE, ET-1, eNOS, NO were also different between the patients and controls. ACE , AGTR1 , and VEGF expressions in patient group were found significantly higher than in control one. These results provide the first evidence linking ‒ 168A/G polymorphism in AGTR1 gene with glioma risk in the Turkish population.