Head and neck squamous cells carcinoma, DNMT3B gene and folate pathway: A review.

The head and neck cancer includes the oral cavity (40%), pharynx (25%) and larynx (15%), and is currently considered the fifth most common type in the world and is associated with a high mortality rate when diagnosed in advanced stages. The most common histological type (90% of cases) is squamous cell carcinoma. The main risk factors include the consumption of tobacco and alcohol, viral infections and deficiencies or imbalances of vitamins and micronutrients such as folate. Accumulative genetic alterations have been associated with phenotypic progression of SCCHN, resulting in the inactivation of several tumor suppressor genes and activation of oncogenes. DNA methylation is a modification that has multiple functional roles, including control of gene expression, chromatin structure stability and maintenance of genomic stability. DNA methylation is the transfer of methyl groups to the position 5 of cytosine residues located in cytosine-guanine dinucleotides (CpG) through reactions catalyzed by proteins named DNA methyltransferases (DNMTs). An abnormal methylation may play an important role in the development of several diseases, especially by acting directly on the process of tumorigenesis and / or silencing tumor suppressor genes containing CpG islands in their promoter regions. DNMT3B gene contains single nucleotide polymorphisms (SNPs) that affect gene function. Your overexpression has been associated with inactivation of tumor suppressor genes, suggesting an oncogenic role....
Source: Head and Neck Oncology - Category: Cancer & Oncology Source Type: research