It is critical to identify biomarkers and functional networks associated with aggressive thyroid cancer to anticipate disease progression and facilitate personalized patient management. We performed ...miRNome sequencing of 46 thyroid tumors enriched with advanced disease patients with a median follow‐up of 96 months. MiRNome profiles correlated with tumor‐specific histopathological and molecular features, such as stromal cell infiltration and tumor driver mutation. Differential expression analysis revealed a consistent hsa‐miR‐139‐5p downexpression in primary carcinomas from patients with recurrent/metastatic disease compared to disease‐free patients, sustained in paired local metastases and validated in publicly available thyroid cancer series. Exogenous expression of hsa‐miR‐139‐5p significantly reduced migration and proliferation of anaplastic thyroid cancer cells. Proteomic analysis indicated RICTOR, SMAD2/3 and HNRNPF as putative hsa‐miR‐139‐5p targets in our cell system. Abundance of HNRNPF mRNA, encoding an alternative splicing factor involved in cryptic exon inclusion/exclusion, inversely correlated with hsa‐miR‐139‐5p expression in human tumors. RNA sequencing analysis revealed 174 splicing events differentially regulated upon HNRNPF repression in our cell system, affecting genes involved in RTK/RAS/MAPK and PI3K/AKT/MTOR signaling cascades among others. These results point at the hsa‐miR‐139‐5p/HNRNPF axis as a novel regulatory mechanism associated with the modulation of major thyroid cancer signaling pathways and tumor virulence.
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Recurrent or metastatic thyroid cancer generally leads to worse outcomes and higher mortality. To search for a prognostic marker in such cases, these authors sequenced the microRNA expression profile, or miRNome, of 46 thyroid samples. They compared differential expression between patients with recurrent/metastatic disease and those who remained cancer free over the 8‐year follow‐up. One miRNA, hsa‐miR‐139‐5p, was associated with recurrent disease independent of genetic background. Expression of hsa‐miR‐139‐5p, they found, influences expression of an alternative splicing factor, HNRNPF, which in turn controls the transcript balance of genes involved in key cancer‐related pathways, a novel mechanism associated with tumor virulence.
One of the main problems we face with PPGL is the lack of molecular markers capable of predicting the development of metastases in patients. Telomere-related genes, such as TERT and ATRX, have been ...recently described in PPGL, supporting the association between the activation of immortalization mechanisms and disease progression. However, the contribution of other genes involving telomere preservation machinery has not been previously investigated. In this work, we aimed to analyze the prognostic value of a comprehensive set of genes involved in telomere maintenance. For this study, we collected 165 PPGL samples (97 non-metastatic/63 metastatic), genetically characterized, in which the expression of 29 genes of interest was studied by NGS. Three of the 29 genes studied, TERT, ATRX and NOP10, showed differential expression between metastatic and non-metastatic cases, and alterations in these genes were associated with a shorter time to progression, independent of SDHB-status. We studied telomere length by Q-FISH in patient samples and in an in vitro model. NOP10 overexpressing tumors displayed an intermediate-length telomere phenotype without ALT, and in vitro results suggest that NOP10 has a role in telomerase-dependent telomere maintenance. We also propose the implementation of NOP10 IHC to better stratify PPGL patients.
Medullary thyroid carcinoma (MTC) is a tumor that arises from parafollicular cells of the thyroid gland. MTC can occur sporadically (75%) or as part of inherited cancer syndromes (25%). In most ...cases, hereditary MTC evolves from preneoplastic C cell hyperplasia (CCH), so early detection of this pathology would evidently be critical. A recent study reports that alterations in succinate dehydrogenase (SDH) D are responsible for familial non-RET CCH. First, we studied SDHD in two families with hereditary non-RET CCH and found no alterations related to the inheritance of this disease. Then, we investigated whether the H50R variant could be a risk factor in the sporadic development of MTC in both Spanish and English patients. We found no evidence that the presence of the H50R is strongly associated with the risk of sporadic MTC, although we did observe an association with age at diagnosis of MTC in Spanish H50R carriers that we did not find in English patients. Finally, we looked for evidence of CCH or any other thyroid disease in a panel of germ-line SDH (B or D) mutation carriers and found none. We conclude that SDHD variants do not constitute a risk factor for developing CCH or sporadic MTC.
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