Frontiers in Bioscience-Elite (FBE) is published by IMR Press from Volume 13 Issue 2 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
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Academic Editor: Anna Czarnecka
In the present study the role of tumour suppressor genes (TSGs) hypermethylation and genetic instability of LOH/MSI type in thyroid tumorigenesis was assessed. Expression, methylation status and presence of LOH/MSI were analyzed for 8 TSGs selected from imprinted (IR) and non-imprinted (NIR) chromosomal regions in papillary thyroid carcinomas (PTCs) and nodular goitres (NGs). The results show that methylation-induced gene silencing occurs at an early step of thyroid carcinogenesis and involves multiple genes. Genetic changes of LOH/MSI type are less frequent. In PTC samples, the lack of significant differences in the frequency of LOH in IR and NIR suggests that it is not a key mechanism changing the pattern of gene expression. Co-methylation observed both in NG and PTC raises a possibility that, in thyroid tissue, methylation-induced silencing may occur not only in malignant transformation but also in functional context. We did not recognize any of the studied TSGs – in regard to aberrant methylation status or LOH/MSI frequency – as a selective molecular marker in thyroid tumorigenesis.