Epigenetics in Medullary Thyroid Cancer : From Pathogenesis to Targeted Therapy

Background: Medullary thyroid carcinoma (MTC) originates from the parafollicular C cells of the thyroid gland. Mutations of the RET proto-oncogene are implicated in the pathogenesis of MTC. Germline activating mutations of this gene have been reported in about 88-98% of familial MTCs, while somatic mutations of RET gene have been detected in about 23-70% of sporadic forms. Although these genetic events are well characterized, much less is known about the role of epigenetic abnormalities in MTC. Objective: The present review reports a detailed description of epigenetic abnormalities (DNA methylation, histone modifications and miRNA profile), probably involved in the pathogenesis and progression of MTC. Methods: A systematic review was performed using Pubmed and Google patents databases. Results: We report the current understanding of epigenetic patterns in MTC and discuss the potential use of current knowledge in designing novel therapeutic strategies through epigenetic drugs, focusing on recent patents in this field. Conclusion: Taking into account the reversibility of epigenetic alterations and the recent development in this field, epigenetic therapy may emerge for clinical use in the near future for patients with advanced MTC.