Molecular study of BRAF gene polymorphisms and the association with mtDNA copy number in thyroid cancer

Abstract

TC is one of the most common types of endocrine cancer in the world, the incidence of thyroid cancer has increased recently, ranking 13th among the most common cancers and the most sixth among women. Females had the highest incidence of illness and death compared to males. Thyroid cancer has been associated with genetic changes where mtDNA and its relationship to the Cancer have been studied, the morphological variations in the BRAF gene and their effect on TC patients have been studied.. The study samples were collected from patients of Warith International Cancer Institute in Kerbala / Iraq, the study included (100 samples) were 50 for patients and 50 for control , DNA measured inside mitochondria by Quantitive Polymerase Chain Reaction (QPCR) , and morphological variations of the BRAF gene were detected on 5 samples of patients against one of control sample with the sequencing the result of this study was shown that there is two new SNPs (rs2128998142 and rs2128998351) were detected in the BRAF gene and the current study found an association with thyroid cancer. The mtDNA content was associated with the risk of thyroid cancer, copy number of mitochondrial DNA for the ND1 gene compared to the normal HGB gene increased by a very large percentage in patients with thyroid cancer for the control group. Our findings lead us to hypothesize that an increase in the number of mitochondrial DNA copies in leukocytes may be associated with oxidative DNA damage and operate as a separate risk factor for thyroid cancer ( TC )