Association between Genetic Polymorphisms in microRNA Machinery Genes and Risk of Papillary Thyroid Carcinoma.

Evidence suggests that the microRNAs are involved in tumorigenesis and progression of various types of malignant tumors. Therefore, the aim of current research was to examine association between genetic variants in the miRNA machinery genes and risk of papillary thyroid carcinoma(PTC) in Iranian population. Peripheral blood samples were collected from 120 PTC patients and 130 healthy subjects. Genotyping of polymorphisms in miRNA Machinery genes (DICER1 rs3742330, DROSHA rs6877842 and XPO5 rs11077) polymorphisms was performed using PCR-RFLP method. Chi square and independent sample t tests were applied for categorical and continuous variables, respectively. In this study, we found that frequency of DICER1 rs3742330G allele was significantly higher in controls compared to PTC patients. In addition, the DICER1 rs3742330 polymorphism was associated with lower risk of PTC in dominant (AG + GG vs. AA, OR = 0.5, 95%CI = 0.3-0.9, P = 0.03) model. No association was found between DROSHA rs6877842 and XPO5 rs11077 polymorphisms and PTC neither in dominant nor in recessive and allelic models. The frequency of DROSHA rs6877842GC genotype was higher in PTC patients with smaller tumor size (<1). Therefore, this polymorphism could be a protective factor for tumor development in PTC patients (OR = 0.3, 95%CI = 0.1-1, P = 0. 04). The current study indicated that DICER1 rs3742330 polymorphism was associated with lower risk of PTC. Furthermore, DROSHA rs6877842 polymorphism could be a protective factor for tumor development in PTC patients.