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The identification of thyroid tumors with the potential for poor evolution is a major concern, as current management can range from simple active surveillance to aggressive therapeutic measures. MicroRNAs are small non-coding RNAs that play a key role in the regulation of gene expression and therefore in the pathogenesis and progression of different types of cancers. Here we employed several bioinformatics tools to investigate deregulated miRNAs in the lymph node metastasis (LNM) of two different types of thyroid tumors. Using thyroid cancer RNA-seq data available on Gene Expression Omnibus (GEO), we identified 14 common deregulated miRNAs in LNM of both medullary and papillary thyroid carcinomas, three of them still negatively deregulated when compared to their respective primary tumor: miR-199a-3p, miR-199a-5p, and miR-148a-5p. Public data available on TCGA confirmed the downregulation of miR-148a-5p in LNM and tumors with advanced AJCC stage. Looking at their predicted target genes, ITGA3, PVRL1 (also called NECTIN1), SNN, and FBXO28 genes were confirmed as positively deregulated in LNM papillary thyroid carcinomas when compared to normal tissues. Public data available on TCGA once again confirmed higher expression of the ITGA3 gene in LNM, larger and invasive tumors (T4a), and stage III and IV. Similar results were observed for PVRL1 (NECTIN1) and FBXO28, but not for SNN. These bioinformatic analysis findings suggest that miR-199a-3p, miR-199a-5p, and miR-148a-5p dysregulation, leading to epithelial-mesenchymal transition and cell adhesion failure, are associated with thyroid tumors’ LNM. Presentation: Saturday, June 11, 2022 12:45 p.m. - 1:00 p.m.

The melanocortin system in the hypothalamus controls food intake and energy expenditure. Its disruption causes severe obesity in mice and humans. cAMP-response element-binding protein 1 (CREB1) has been postulated to play an important role downstream of the melanocortin-4 receptor (MC4R), but this hypothesis has never been confirmed in vivo. To test this, we generated mice that lack CREB1 in SIM1-expressing neurons, of the paraventricular nucleus (PVN), which are known to be MC4R-positive. Interestingly, CREB1(ΔSIM1) mice developed obesity as a result of decreased energy expenditure and impairment in maintaining their core body temperature and not because of hyperphagia, defining a new role for CREB1 in the PVN. In addition, the lack of CREB1 in the PVN caused a reduction in vasopressin expression but did not affect adrenal or thyroid function. Surprisingly, MC4R function tested pharmacologically was normal in CREB1(ΔSIM1) mice, suggesting that CREB1 is not required for intact MC4R signaling. Thus CREB1 may affect other pathways that are implicated in the regulation of body weight.

We aimed to investigate the use of NIS mRNA and protein expression as a diagnostic and/or prognostic marker in patients with differentiated thyroid cancer (DTC).This is a case-control study.We studied 397 thyroid nodules tissue samples, including 224 papillary thyroid carcinomas (PTCs), 41 follicular carcinomas, 58 nodular goiters, 56 follicular adenomas and 18 normal tissues assembled in a tissue microarray.NIS protein was identified using a monoclonal antibody that labelled only the follicular cell basolateral membrane of all 397 tissue samples. In addition, NIS mRNA was quantified in 145 DTC patients and 85 PTC cases were screened for BRAF(V600E) mutation.We found low NIS mRNA expression and low or negative NIS protein expression in most DTC. NIS expression was lower in DTC patients over 45 years old and in tumours larger than 2 cm. There was a tendency for lower NIS expression in advanced stages and patients presenting recurrences. All 13 DTC patients who succumbed to the disease were NIS negative at immunohistochemistry and had very low mRNA expression. NIS expression was lower in PTC presenting BRAF(V600E) mutation. However, neither NIS immunohistochemical analysis nor NIS mRNA quantified expression could identify individuals with poor prognosis.Our data suggest that NIS expression may help characterize patients' risk and individuals with a poor response to therapy, but is not useful as a diagnostic or prognostic marker, reinforcing the current concept that an appropriate management of DTC patient is the most important and modifiable prognostic factor.