Cytokine gene polymorphisms in Egyptian cases with brain tumors.

Cytokines are proposed to play important roles in brain tumor biology as well as neurodegeneration or impaired neuronal function. To evaluate the association of polymorphisms of cytokine genes with brain tumors in Egyptian patients. This study included 45 cases affected by brain tumors. Their median age was 45, diagnosed as 24 benign cases and 21 malignant cases, and their sex included 20 males and 25 females. They were taken from the cases presenting to the Neurosurgery Department of Mansoura University Hospital, Egypt. Cases genotypes were compared to 98 healthy unrelated controls from the same locality. DNA was amplified using PCR utilizing sequence specific primers (SSP) for detection of polymorphisms related to TNF-alpha(-308) (G/A), IL-10(-1082) (G/A), IL-6(-174) (G/C) and IL-1Ra (VNTR). Cases affected with benign brain tumors, showed a significant higher frequency of IL-10(-1082) A/A genotype (OR = 8.04, P < 0.001), IL-6(-174) C/C genotype (OR = 6.3, P < 0.001) and TNF-alpha(-308) A/A (OR = 4.7, P < 0.05) with a significant lower frequency of IL-10(-1082) G/A genotype (OR = 0.1, P < 0.001), IL-6(-174) G/C (OR = 0.2, P = 0.001) and TNF-alpha(-308) G/A was found significantly low among the same groups (OR = 0.2, P < 0.001) compared to controls. On the other hand these cases have shown no significant difference regarding the distribution of IL-1Ra VNTR genotype and allele polymorphism compared to controls. Although the levels of different studied cytokines were not determined simultaneously in the serum, these cases are expected to have lower levels of IL-10 and high levels of TNF-alpha being homozygous for IL-10(-1082) allele A (low production allele) and TNF-alpha(-308) A (high production allele). The frequency of cytokines genotype and allele in malignant brain cases and controls. Malignant cases, on the other hand, showed significant higher frequency of IL-6(-174) C/C genotype (OR = 4.8, P < 0.05) and both TNF-alpha(-08) A/A (OR = 4.9, P < 0.001) and G/G (OR = 4.7, P < 0.05) genotypes as compared to controls. In the mean time these cases have shown a significant lower frequency of genotypes of IL-6(-174) G/C (OR = 0.2, P < 0.05) and TNF-alpha(-308) G/A (OR = 0.1, P < 0.05) compared to controls. On the other hand, these cases have not shown any statistical significant difference of polymorphic genotypes or alleles related to IL-10(-1082) (G/A) and IL-Ra VNTR genes compared to controls. Comparing studied genotype frequencies among benign and malignant brain tumor cases no significant difference was found in the frequencies of all studied genotypes and alleles with a non significant trend for the benign cases to have higher frequency of IL-10(-1082) AA genotype. In conclusion, cytokine gene polymorphisms have a certain pattern among brain tumor cases and can be considered a genetic marker of potential value in counseling and management.