Investigation of Interleukin-17 Gene Polymorphisms and Serum Levels in Patients with Basal Cell Carcinoma of the Skin

Interleukin 17 (IL-17) is a pro-inflammatory cytokine that plays an important role in cancer pathogenesis. To investigate the association of two IL-17 gene polymorphisms (rs2275913 and rs763780), as well as IL-17 serum levels with susceptibility to Basal Cell Carcinoma (BCC) of skin. Two hundred subjects with BCC and 200 healthy controls were recruited. DNA was extracted from peripheral blood leukocytes and genotypes were determined using PCR-RFLP methods. Serum levels were assessed by ELISA. At position rs2275913 in IL-17A, the frequencies of GG, AG and AA genotypes were 99 (49.5%), 76 (38%) and 25 (12.5%) in patients and 97 (48.5%), 84 (42%) and 19 (9.5%) in the control group. The distribution of AA, GA and GG genotypes at position rs763780 in IL-17F were 166 (83%), 34 (17%) and 0 (0%) in patients and 158 (79%), 40 (20%) and 2 (1%) in the control group. Haplotype analysis by Arlequin software package revealed that GA haplotype was the most frequent haplotype in both groups. No significant differences were found in alleles, genotypes, and haplotypes frequencies between study groups at both positions (P>0.05). While no difference in IL-17 serum levels was observed between individuals with different genotypes, statistical analysis showed higher IL-17A serum levels, but not IL-17F, in patients compared to controls (0.65 ± 0.11 and 0.03 ± 0.02 pg/ml), respectively, (P<0.001). Our findings do not support the association of rs763780 and rs2275913 gene polymorphisms in IL-17gene with susceptibility of Iranians with BCC. Increased IL-17A serum levels may still play a role in pathogenesis of BCC.