The importance of SOCS1 − 1478 CA/del polymorphism and expression in breast cancer: a case–control study in the north of Iran

Purpose This project aimed to evaluate the relationship between the suppressor of cytokine signaling-1 ( SOCS1 ) − 1478 CA > del genetic variation and breast cancer susceptibility. Moreover, we investigated the SOCS1 mRNA expression level in cancerous tissues. Methods A total of 100 patients with breast cancer and 120 healthy individuals were selected. Genomic DNA was extracted from blood. SOCS1 genotyping and relative gene expression were performed using ARMS-PCR (Amplification-Refractory Mutation System-Polymerase Chain Reaction) and real-time PCR, respectively. Results In breast cancer patients, the prevalence of genotype frequencies of SOCS1 (− 1478 CA > del) CA/CA, CA/del, and del/del was 52, 31, and 17%, respectively. Among controls, the distribution of CA/CA, CA/del, and del/del was 63, 15, and 22%, respectively. The chi-square test reported that a significant difference was observed in the genotypic distribution of SOCS1 (− 1478 CA > del) polymorphism between cases and controls ( χ 2 = 8.08, P = 0.01). In addition, the presence of the CA/del genotype was associated with an elevated risk of breast cancer (in the codominant model: OR 2.51; 95% CI 1.27–4.96, P = 0.007 and in the over dominant model: OR 2.54; 95% CI 1.32–4.90, P = 0.005). However, there was no significant difference in allelic distributions between the groups ( P > 0.05). There was no significant difference in the breast cancer risk associated with the dominant and recessive genetic models when the reference was CA/CA and CA/CA + CA/del genotype, respectively ( P = 0.09 and P = 0.38). Moreover, the expression of SOCS1 decreased in cancerous tissues as compared to the adjacent non-cancerous tissues ( P del) may affect breast cancer susceptibility.