GENETIC OF THYROID CANCER MOLECULAR ANALYSIS OF FINE NEEDLE ASPIRATION SAMPLES TO REFINE THE DIAGNOSIS OF THYROID CANCER

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GENETIC OF THYROID CANCER FAMILIAL NON MEDULLARY THYROID CANCER

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Telomeres and Thyroid Cancer

Telomeres are specialized structures at the ends of chromosomes, consisting of hundreds of repeated hexanucleotides (TTAGGG)n. Genetic integrity is partly maintained by the architecture of telomeres and it is gradually lost as telomeres progressively shorten with each cell replication, due to incomplete lagging DNA strand synthesis and oxidative damage. Telomerase is a reverse transcriptase enzyme that counteracts telomere shortening by adding telomeric repeats to the G-rich strand. It is composed of a telomerase RNA component and a protein component, telomerase reverse transcriptase. In the absence of telomerase or when the activity of the enzyme is low compared to the replicative erosion, apoptosis is triggered. Patients who have inherited genetic defects in telomere maintenance seem to have an increased risk of developing familial benign diseases or malignant diseases. At the somatic level, telomerase is reactivated in the majority of human carcinomas, suggesting that telomerase reactivation is a critical step for cancerogenesis

FASTING ENHANCES TKI EFFICACY ON THYROID CANCER CELLS

Tyrosine kinase inhibitors (TKIs) have emerged as a novel cancer therapy for patients with poorly differentiated, anaplastic or medullary carcinomas unresponsive to conventional treatments. The association between fasting mimicking diets and TKIs has been explored with encouraging results showing a better response with less side effects due to TKI toxicity. Here we report the role of fasting in reducing cell survival and in potentiating the anticancer activity of TKIs (Lenvatinib, Sorafenib, Vandetanib and Cabozatinib) in cultured medullary, follicular, papillary and anaplastic thyroid cancer cells. In particular, fast mimicking diet reduced cell growth in all cell types but potentiated the anticancer activity of TKIs only in follicular, medullary and TPC1 thyroid cells. TKIs significantly reduced ERK1-2 activation after 1 h in all cell types. Prolonged exposure to TKIs resulted in an improvement of ERK1-2 phosphorylation which was inhibited in the presence of starvation. We demonstrated thyroid cancer cell susceptibility to fasting and validated its role in potentiating anticancer activity of TKIs by strengthening ERK1/2 signalling inhibition

Lack of germline A339V mutation in thyroid transcription factor-1 (TITF-1/NKX2.1) gene in familial papillary thyroid cancer

Thyroid cancer may have a familial predisposition but a specific germline alteration responsible for the disease has not been discovered yet. We have shown that familial papillary thyroid cancer (FPTC) patients have an imbalance in telomere-telomerase complex with short telomeres and increased telomerase activity. A germline mutation (A339V) in thyroid transcription factor-1 has been described in patients with multinodular goiter and papillary thyroid cancer. In this report, the presence of the A339V mutation and the telomere length has been studied in FPTC patients and unaffected family members. All samples analyzed displayed a pattern typical of the homozygous wild type revealing the absence of the A339V mutation. Shortening of telomeres was confirmed in all patients. We concluded that the A339V mutation in thyroid transcription factor-1 (TITF-1/NKX2.1) is not correlated with the familial form of PTC, even when the tumor was in the context of multinodular goiter

Genetic heterogeneity of HER2 amplification and telomere shortening in papillary thyroid carcinoma

Extensive research is dedicated to understanding if sporadic and familial papillary thyroid carcinoma are distinct biological entities. We have previously demonstrated that familial papillary thyroid cancer (fPTC) cells exhibit short relative telomere length (RTL) in both blood and tissues and that these features may be associated with chromosome instability. Here, we investigated the frequency of HER2 (Human Epidermal Growth Factor Receptor 2) amplification, and other recently reported genetic alterations in sporadic PTC (sPTC) and fPTC, and assessed correlations with RTL and BRAF mutational status. We analyzed HER2 gene amplification and the integrity of ALK, ETV6, RET, and BRAF genes by fluorescence in situ hybridization in isolated nuclei and paraffin-embedded formalin-fixed sections of 13 fPTC and 18 sPTC patients. We analyzed BRAFV600E mutation and RTL by qRT-PCR. Significant HER2 amplification (p = 0.0076), which was restricted to scattered groups of cells, was found in fPTC samples. HER2 amplification in fPTCs was invariably associated with BRAFV600E mutation. RTL was shorter in fPTCs than sPTCs (p < 0.001). No rearrangements of other tested genes were observed. These findings suggest that the association of HER2 amplification with BRAFV600E mutation and telomere shortening may represent a marker of tumor aggressiveness, and, in refractory thyroid cancer, may warrant exploration as a site for targeted therapy

Proteomics Reveals How the Tardigrade Damage Suppressor Protein Teaches Transfected Human Cells to Survive UV-C Stress

The genome sequencing of the tardigrade Ramazzottius varieornatus revealed a unique nucleosome-binding protein named damage suppressor (Dsup), which was discovered to be crucial for the extraordinary abilities of tardigrades in surviving extreme stresses, such as UV. Evidence in Dsup-transfected human cells suggests that Dsup mediates an overall response in DNA damage signaling, DNA repair, and cell cycle regulation, resulting in an acquired resistance to stress. Given these promising outcomes, our study attempts to provide a wider comprehension of the molecular mechanisms modulated by Dsup in human cells and to explore the Dsup-activated molecular pathways under stress. We performed a differential proteomic analysis of Dsup-transfected and control human cells under basal conditions and at 24 h recovery after exposure to UV-C. We demonstrate via enrichment and network analyses, for the first time, that even in the absence of external stimuli, and more significantly, after stress, Dsup activates mechanisms involved with the unfolded protein response, the mRNA processing and stability, cytoplasmic stress granules, the DNA damage response, and the telomere maintenance. In conclusion, our results shed new light on Dsup-mediated protective mechanisms and increases our knowledge of the molecular machineries of extraordinary protection against UV-C stress

EIF1AX c.338-2A>T splice site mutation in a patient with trabecular adenoma and cytological indeterminate lesion

SUMMARY The EIF1AX gene mutations have been recently associated with papillary thyroid carcinoma and anaplastic thyroid cancer. According with these reports, the gene as been considered as a drive gene for thyroid cancer development. However, the occurrence of these alterations in benign thyroid lesions is not known and is still under investigation. Some authors have already reported the presence of EIF1AX variants in follicular adenomas and hyperplastic nodules. Here, we describe for the first time a case of a man with the EIF1AX c.338-2A>T splice site mutation in an indeterminate FNA lesion with trabecular adenoma at final histology in the absence of other pathogenetic mutations, demonstrating that further studies are required to better understand EIF1AX role in the tumorigenesis of thyroid carcinoma

Follow-up after bariatric surgery: is it time to tailor it? Analysis of early predictive factors of 3-year weight loss predictors of unsuccess in bariatric patients

Bariatric surgery (BS) is the most effective treatment strategy for obesity. Nevertheless, a subset of patients does not reach a successful weight loss or experience long-term weight regain. Conflicting evidence exists regarding predictors of BS outcomes. We aimed to define the early factors linked to 3 year unsuccessful weight loss in order to promote a tailored close follow-up. We enrolled 443 patients who underwent BS from January 2014 to December 2018 with a 3 year follow-up. An unsuccessful BS outcome was defined as a percentage of total weight loss (%TWL) &lt;20. We compared the characteristics between successful and unsuccessful patients in order to identify predictor factors of unsuccess after surgery. We found that the proportion of patients with unsuccessful weight loss progressively increased from one to three years after BS. In a multiple regression model, only 1 month %TWL and sleeve gastrectomy (SG) were significantly associated with 3 year unsuccessful weight loss. We stratified our cohort in four groups according to the risk of BS unsuccess, in terms of 1 month %TWL and type of surgery (SG vs gastric bypass). Interestingly, groups showed a significant difference in terms of %TWL at each follow-up point. Patients submitted to SG with lower 1 month %TWL must be considered at higher risk of future weight regain; consequently, they require a tailored and closer follow-up.[GRAPHICS]. © 2022, The Author(s)

RARE POMC MUTATION IN A PATIENT WITH MYOTONIC DYSTROPHY TYPE 1 AND ADRENOCORTICOTROPIN HYPERRESPONSE TO CORTICOTROPIN-RELEASING HORMONE

Objective: Myotonic dystrophy (DM) is a monogenic disorder. It is caused by expansion of a cytosine-thymineguanine triplet in the DMPK gene which encodes for myotonic dystrophy protein kinase (DMPK). Methods: A 24-year-old man with DM and the DMPK mutation presented with elevated adrenocorticotropic hormone (ACTH) levels twice (152 and 185 pg/mL; normal value is 10 to 52 pg/mL) with normal cortisol levels (134.6 and 113.0 ng/mL, or 371.3 and 311.7 nmol/L; normal values are 67 to 226 ng/mL or 184.8 to 623.5 nmol/L). ACTH, corticotropin-releasing hormone (CRH) and insulin tolerance test (ITT) demonstrated normal cortisol response to ACTH and partial response to CRH and ITT tests, and ACTH hyperresponse to CRH and ITT. We suspected ACTH and/or ACTH receptor (ACTHR) mutations and evaluated the genetic profile for pro-opiomelanocortin (POMC), melanocortin 2 receptor (MC2R) and follicle-stimulating hormone receptor (FSHR) genes. Results: No mutations were found in either the MC2R or FSHR genes. The patient was heterozygous for the c.614A&gt;G mutation corresponding to a p.53D&gt;G substitution with a glycine instead of an aspartate in position 53 in POMC gene. This mutation was outside the sequence for ACTH (which spans amino acids 138 to 176) but was included in the part originating the N-terminal peptide of pro-opiomelanocortin (also called pro-γ-melanocyte stimulating hormone) which spans amino acids 27 to 102 and is involved in the regulation of adrenal steroidogenesis. Conclusion: The pathologic expansion of the cytosine-thymine-guanine triplet repeat in the 3' noncoding region of DMPK could explain the hyperresponse of ACTH typical of DM. The mutation of pro-γ-melanocyte-stimulating hormone could be associated with the abnormal response of cortisol, compatible with a partial adrenal insufficiency. Other studies are necessary to demonstrate this hypothesis