Investigation of ICAM-1 and β3 Integrin Gene Variations in Patients with Brain Tumors

Background: Primary brain tumors constitute a small percent of all malignant cancers, but their etiologyremains poorly understood. β3 integrin (ITGB3) has been recognized to play influential roles in angiogenesis,tumor growth and metastasis. Intercellular adhesion molecule-1 (ICAM-1) is a surface glycoprotein important fortumor invasion and angiogenesis. The aim of this study was to investigate whether specific genetic polymorphismsof ICAM-1 and ITGB3 could be associated with brain cancer development and progression in a Turkishpopulation. Our study is the first to our knowledge to investigate the relationship between brain tumor riskand ICAM-1 and β3 integrin gene polymorphisms. Materials and
Methods: The study covered 92 patients withprimary brain tumors and 92 age-matched healthy control subjects. Evaluation of β3 integrin (Leu33Pro (rs5918))and ICAM-1 (R241G (rs1799969) and K469E (rs5498)) gene polymorphisms was performed by polymerasechain reaction-restriction fragment length polymorphism (PCR-RFLP).
Results: According to results of ourresearch, the A allele of the ICAM-1 R241G gene polymorphism appeared to be a risk factor for primary braintumors (p<0.001). Similarly, the frequency of the A mutant allele of ICAM-1 R241G was statistically significantin patients with brain tumors classified as glioma (p<0.001). When allele and genotype distributions of ICAM-1 K469E, ICAM-1 R241G and β3 integrin Leu33Pro gene polymorphisms were evaluated with age, sex, andsmoking, there were no statistically significant differences. Haplotype analysis revealed that the frequencies ofGAC (rs1799969-rs5498-rs5918) and GAT (rs1799969-rs5498-rs5918) haplotypes were significantly lower inpatients as compared with controls (p=0.001; p=0.036 respectively).
Conclusions: This study provides the firstevidence that ICAM-1 R241G SNP significantly contributes to the risk of primary brain tumors in a Turkishpopulation. In addition, our results suggest that ICAM-1 R241G in combination ICAM-1 K469E may haveprotective effects against the development of brain cancer.