Epigenetic regulation of RET receptor tyrosine kinase and non-coding RNAs in MTC

Molecular Basis and Natural History of Medullary Thyroid Cancer: It is (Almost) All in the RET

Medullary thyroid cancer (MTC) is a rare disease, which can be either sporadic (roughly 75% of cases) or genetically determined (multiple endocrine neoplasia type 2, due to REarranged during Transfection RET germline mutations, 25% of cases). Interestingly, RET pathogenic variants (mainly M918T) have also been reported in aggressive forms of sporadic MTC, suggesting the importance of RET signalling pathways in the pathogenesis of MTC. The initial theory of RET codon-related MTC aggressiveness has been recently questioned by studies suggesting that this would only define the age at disease onset rather than the aggressiveness of MTC. Other factors might however impact the natural history of the disease, such as RET polymorphisms, epigenetic factors, environmental factors, MET (mesenchymal-epithelial transition) alterations, or even other genetic alterations such as RAS family (HRAS, KRAS, NRAS) genetic alterations. This review will detail the molecular bases of MTC, focusing on RET pathways, and the potential mechanisms that explain the phenotypic intra- and interfamilial heterogeneity.

Real-world insights into the efficacy and safety of tyrosine kinase inhibitors against thyroid cancers

Based on clinical trials demonstrating favorable short-term efficacy and tolerable toxicity, several tyrosine kinase inhibitors have been approved for treating locally recurrent or metastatic, progressive radioiodine-refractory differentiated thyroid cancer, BRAF^V600E-mutant anaplastic thyroid cancer, and advanced or progressive medullary thyroid cancer. Longer term efficacy and safety of these treatments have been investigated in multiple real-world studies, demonstrating indispensable complementary value. Hereby, we summarize data from a total of 27 real-world studies with a focus on long-term survival data and rare but life-threatening adverse effects. An overall picture of current real-world study was drawn, and integrated experience of multiple centers would be helpful to clinical practice and further research.

LncRNAs as Potential Therapeutic Targets in Thyroid Cancer

Thyroid cancer (TC) is the most common cancer of endocrine system. TC can be subdivided into 4 different entities, papillary, follicular, medullary and anaplastic thyroid cancer. Among them, anaplastic thyroid cancer has the poorest prognosis. Exploring new therapeutic approach may entail favorable prediction as well as increasing overall survival rate of patients. Long non-coding RNAs (lncRNAs), have vast implications in different cancer types. Although they are not transcribed into proteins, they can act as a harness in regulating a plethora of biological functions. They have been implicated in a decisive role in gene expression via modulation of both coding and non-coding RNAs. This article discuss the multi-facet role of lncRNA in thyroid cancer biology.

Genetic and Epigenetic of Medullary Thyroid Cancer

Medullary thyroid carcinoma (MTC) is an infrequent, calcitonin producing neuroendocrine tumor and initiates from the parafollicular C cells of the thyroid gland. Several genetic and epigenetic alterations are collaterally responsible for medullary thyroid carcinogenesis. In this review article, we shed light on all the genetic and epigenetic hallmarks of MTC. From the genetic perspective, RET, HRAS, and KRAS are the most important genes that are characterized in MTC. From the epigenetic perspective, Ras-association domain family member 1A, telomerase reverse transcriptase promoter methylations, overexpression of histone methyltransferases, EZH2 and SMYD3, and wide ranging increase and decrease in non-coding RNAs can be responsible for medullary thyroid carcinogenesis.