• Genetic Alterations in Thyroid Cancers
  • Mehrshid Mousaviyon,1,*
    1. Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran


  • Introduction: Cancer is the uncontrolled growth of cells. Today, about 3.2% of people have thyroid cancer. The thyroid is a butterfly-shaped gland located in front of the neck. Thyroid hormones are involved in body metabolism. There are different types of thyroid cancer. Papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC) are the most common types of this cancer. PTC and FTC arise from follicular epithelial cells. Thyroid cancer is caused by various genetic mutations in the DNA. Defective RET gene and epigenetics changes are among the factors that can be mentioned. Epigenetics includes DNA methylation, histone modification, and RNA methylation without changing the sequence of DNA nucleotides, which causes a change in the regulation of gene expression. In this article, we study the role of different genes in the occurrence and progression of thyroid cancer.
  • Methods: A comprehensive search was conducted in MEDLINE, EMBASE, Scopus, and other databases to discover published articles related to genetic alterations in thyroid cancers with search terms included, genetic alterations, thyroid cancers, diagnosis, prognosis, and related keywords.
  • Results: One of the important genes in thyroid cancer is the BRAF gene. The point of activating substitutions (mutations) in this gene activates the MAPK pathway and causes abnormal growth of cells. These point substitutions are mostly seen in papillary thyroid cancer (Papillary Thyroid Cancer) or PTC. RET gene (rs77709286) also plays an important role in thyroid cancer. The most common RET M918T mutation, especially in medullary thyroid cancer, leads to the activation of signaling pathways that lead to abnormal cell growth and increased thyroid production. Mutations in other NTRK, MEK, TP53, and RAS genes are other examples of mutations at the DNA level in this cancer. DNA methylation occurs when DNA methyltransferase (DNMT) adds cytosine residues to CAG dinucleotides. Studies have shown that 12 CpG regions in PTC tissue located in the miR-204 promoter were reduced by hypermethylation, which increased the expression of the TRPM3 target gene, which may be associated with tumor invasion, lymph node metastasis, and BRAFV600E mutations.
  • Conclusion: Genetic alterations cause thyroid cancer. By identifying the types of genetic alterations in thyroid cancers, new treatment methods can be provided, especially in personalized thyroid cancer treatment.
  • Keywords: Genetic Alterations, Thyroid, Cancers, Epigenetics, treatment