RESUMO
BACKGROUND: Multiple lines of evidence suggest that single nucleotide polymorphisms (SNPs) in genes encoding components of the microRNA processing machinery may underlie susceptibility to various human diseases, including cancer. OBJECTIVE: The present study aimed to investigate whether rs6877842, rs642321 and rs10719 SNPs of DROSHA, a key component of the miRNA biogenesis pathway, are associated with increased risk of breast cancer. METHODS: A total of 100 patients diagnosed with breast cancer and 100 healthy women were included. Following extraction of DNA, genotyping was performed by tetra primer- amplification refractory mutation system-PCR (T-ARMS-PCR) technique. Under the co-dominant, dominant and recessive inheritance models, the association between DROSHA SNPs and breast cancer risk was determined by logistic regression analysis. The association of DROSHA SNPs with patients' clinicopathological parameters was assessed. Also, haplotype analysis was performed to evaluate the combined effect of DROSHA SNPs on breast cancer risk. RESULTS: We observed a statistically significant association between DROSHA rs642321 polymorphism and breast cancer susceptibility (P < 0.05). Under the dominant inheritance model, DROSHA rs642321 polymorphism was significantly associated with increased risk of breast cancer (OR: 6.091; 95% CI: 3.291-11.26; P = 0.0001). Our findings demonstrated that DROSHA rs642321 T allele can contribute to the development of breast cancer (OR: 3.125; 95% CI: 1.984-4.923; P = 0.0001). We also found that GTC and GTT haplotypes conferred significant risk for breast cancer (OR: 2.367; 95% CI: 1.453-3.856; P = 0.0001 and OR: 7.944; 95% CI: 2.073-30.43; P = 0.0001, respectively). CONCLUSIONS: These results provide the first evidence that DROSHA rs642321 polymorphism is associated with increased risk of breast cancer. However, further studies are needed to firmly validate these findings.