title: Variants in mitochondrial tRNA gene may not be associated with thyroid carcinoma.
abstract: Thyroid cancer is a very common form of endocrine system malignancy. To date, the molecular mechanism underlying thyroid cancer remains poorly understood. Studies of oncocytic tumors have led to a hypothesis which proposes that defects in oxidative phosphorylation (OX- PHOS) may result in a compensatory increase in mitochondrial replication and gene expression. As a result, mitochondrial DNA (mtDNA) mutation analysis has become a useful tool to explore the molecular basis of this disease. Among these mutations, mitochondrial transfer RNAs (mttRNAs) are the hot spots for pathogenic mutations associated with thyroid cancer. However, due to its high mutation rate, the role of mt-tRNA variants in thyroid cancer is still controversial. To address this problem, in this study, we reassessed seven reported mt-tRNA variants: tRNAAspG7521A, tRNAArgT10411C and T10463C, tRNALeu(CUN)A12308G, tRNAIleG4292C and C4312T, and tRNAAlaT5655C, in clinical manifestations of thyroid cancer. We first performed the phylogenetic conservation analysis for these variants; moreover, we used a bioinformatic tool to compare the minimum free energy (G) of mt-tRNA with and without mutations. Most strikingly, none of these variants caused the significant change of the G between the wild-type and the mutant form, suggesting that they may not play an important roles in thyroid cancer. In addition, we screened the frequency of the "pathogenic" A12308G alternation in 300 patients with thyroid cancer and 200 healthy controls. We found that there were five patients and three control subjects carrying this variant. It seemed that the A12308G variant may be a common polymorphism in the human population. Taken together, our study indicated that variants in mt-tRNA genes may not play active roles in patients with thyroid cancer.
authors: Department of Breast Surgery, Henan Provincial People's Hospital, Zhengzhou, People's Republic of China.
authors: F
authors: F
authors: Lv
authors: Department of Endocrinology, Ningbo Fourth Hospital, Xiangshan, People's Republic of China.
authors: G
authors: G
authors: Qian
authors: Department of Breast Surgery, Henan Provincial People's Hospital, Zhengzhou, People's Republic of China.
authors: W
authors: W
authors: You
authors: College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, People's Republic of China.
authors: H
authors: H
authors: Lin
authors: College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, People's Republic of China.
authors: X F
authors: XF
authors: Wang
authors: Department of Endocrinology, Ningbo Fourth Hospital, Xiangshan, People's Republic of China.
authors: G S
authors: GS
authors: Qiu
authors: Department of Endocrinology, Ningbo Fourth Hospital, Xiangshan, People's Republic of China.
authors: Y S
authors: YS
authors: Jiang
authors: College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, People's Republic of China.
authors: L X
authors: LX
authors: Pang
authors: School of Basic Medical Sciences, Inner Mongolia Medical University, Hohhot, People's Republic of China.
authors: Y M
authors: YM
authors: Kang
authors: School of Basic Medical Sciences, Inner Mongolia Medical University, Hohhot, People's Republic of China.
authors: B F
authors: BF
authors: Jia
authors: Department of Clinical Pharmacy, the Affiliated Wenling Hospital of Wenzhou Medial University, Wenling, People's Republic of China.
authors: J Z
authors: JZ
authors: Xu
authors: Department of Breast Surgery, Henan Provincial People's Hospital, Zhengzhou, People's Republic of China.
authors: Y
authors: Y
authors: Yu
keywords: Association; Mitochondrial DNA (mtDNA); Mitochondrial transfer RNA (mt-tRNA); Thyroid cancer; Variants