Molecular signatures in thyroid carcinoma and in its potential precursor lesions

Introduction. The molecular profile of Papillary Thyroid Carcinoma (PTC) has been throughly investigated. However, to date, there is no information regarding the BRAF molecular profile of the non-neoplastic tissue surrounding PTCs. Exploring this molecular signature may help to better understand thyroid tumorigenesis. Aims of this project are: i) to establish whether BRAF mutations are present in non-malignant tissue surrounding PTC and to characterize their activity; ii) to set up a RNA-based panel that may provide diagnostic, predictive and prognostic information on thyroid nodules/neoplasms. Material and Methods. We screened 30 PTCs and 100 non-malignant tissues surrounding the tumor using Next Generation Sequencing. The kinase activity of mutated proteins was evaluated measuring the activation of the MAPK pathway. The RNA-based panel was designed to detect fusion and dysregulated gene-expression, in a set of 44 fresh-frozen samples. Results. Ten (33.3%) PTCs were BRAF-WT and 20 BRAF-positive (66.6%). In 9 non-malignant tissues (9.0%) we identified “uncommon” BRAF mutations. The BRAF-S607F and BRAF-S607P had the same kinase activity of the BRAF-WT protein; the BRAF-A598T and BRAF-G593D proteins showed decreased activity. All “uncommon” BRAF mutations had a lower kinase activity if compared to BRAF-V600E or BRAF-K601E. The samples harboring the BRAF p.V600E mutation or RAS mutations had dysregulated expression of the BRAF-like or RAS-like genes, respectively. Unsupervised hierarchical analysis identified three major clusters: i) non-malignant tissue; ii) malignant tissue; iii) non-follicular thyroid cell derived cancers. Conclusion. Aim 1: non-malignant thyroid tissue may harbor “uncommon” BRAF mutations but without affecting the BRAF-kinase activity and therefore do not possess the tumorigenic potential necessary for the development of PTC. Aim 2: the RNA-based panel identifies three main profiles corresponding to: i) non-malignant tissue; ii) malignant tissue; iii) non-follicular thyroid cell derived cancers. This novel RNA based panel may be very useful to complement the preoperative evaluation of thyroid nodules

RET mutation and increased angiogenesis in medullary thyroid carcinomas

Advanced medullary thyroid cancers (MTCs) are now being treated with drugs that inhibit receptor tyrosine kinases, many of which involved in angiogenesis. Response rates vary widely, and toxic effects are common, so treatment should be reserved for MTCs likely to be responsive to these drugs. RET mutations are common in MTCs, but it is unclear how they influence the microvascularization of these tumors. We examined 45 MTCs with germ-line or somatic RET mutations (RETmut group) and 34 with wild-type RET (RETwt). Taqman Low-Density Arrays were used to assess proangiogenic gene expression. Immunohistochemistry was used to assess intratumoral, peritumoral and nontumoral expression levels of VEGFR1, R2, R3, PDGFRa, PDGFB and NOTCH3. We also assessed microvessel density (MVD) and lymphatic vessel density (LVD) based on CD31-positive and podoplanin-positive vessel counts, respectively, and vascular pericyte density based on staining for a-smooth muscle actin (a-SMA), a pericyte marker. Compared with RETwt tumors, RETmut tumors exhibited upregulated expression of proangiogenic genes (mRNA and protein), especially VEGFR1, PDGFB and NOTCH3. MVDs and LVDs were similar in the two groups. However, microvessels in RETmut tumors were more likely to be a-SMA positive, indicating enhanced coverage by pericytes, which play key roles in vessel sprouting, maturation and stabilization. These data suggest that angiogenesis in RETmut MTCs may be more intense and complete than that found in RETwt tumors, a feature that might increase their susceptibility to antiangiogenic therapy. Given their increased vascular pericyte density, RETmut MTCs might also benefit from combined or preliminary treatment with PDGF inhibitors

Different Methods in HPV Genotyping of Anogenital and Oropharyngeal Lesions: Comparison between VisionArray® Technology, Next Generation Sequencing, and Hybrid Capture Assay

(1) Background: Human papillomaviruses (HPVs) are known to be related to the development of about 5% of all human cancers. The clinical relevance of HPV infection has been deeply investigated in carcinomas of the oropharyngeal area, uterine cervix, and anogenital area. To date, several different methods have been used for detecting HPV infection. The aim of the present study was to compare three different methods for the diagnosis of the presence of the HPV genome. (2) Methods: A total of 50 samples were analyzed. Twenty-five of them were tested using both next generation sequencing (NGS) and VisionArray® technology, the other 25 were tested using Hybrid Capture (HC) II assay and VisionArray® technology. (3) Results: A substantial agreement was obtained using NGS and VisionArray® (κ = 0.802), as well as between HC II and VisionArray® (κ = 0.606). In both analyses, the concordance increased if only high risk HPVs I(HR-HPVs) were considered as “positive”. (4) Conclusions: Our data highlighted the importance of technical choice in HPV characterization, which should be guided by the clinical aims, costs, starting material, and turnaround time for results

BRAF and MLH1 Analysis Algorithm for the Evaluation of Lynch Syndrome Risk in Colorectal Carcinoma Patients: Evidence-Based Data from the Analysis of 100 Consecutive Cases

settingsOrder Article Reprints Open AccessFeature PaperArticle BRAF and MLH1 Analysis Algorithm for the Evaluation of Lynch Syndrome Risk in Colorectal Carcinoma Patients: Evidence-Based Data from the Analysis of 100 Consecutive Cases by Thais Maloberti 1,2,†ORCID,Antonio De Leo 1,2,†ORCID,Viviana Sanza 2,Lidia Merlo 2,Michela Visani 1ORCID,Giorgia Acquaviva 1,Sara Coluccelli 1,2ORCID,Annalisa Altimari 2,3,Elisa Gruppioni 2,3,Stefano Zagnoni 2,3,Daniela Turchetti 4,Sara Miccoli 4,Michelangelo Fiorentino 5,6ORCID,Antonietta D’Errico 3ORCID,Dario de Biase 7,*,‡ORCID andGiovanni Tallini 1,2,‡ORCID 1 Department of Experimental, Diagnostic and Specialty Medicine, Anatomic Pathology Unit-University of Bologna Medical Center, 40138 Bologna, Italy 2 Solid Tumor Molecular Pathology Laboratory, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy 3 Department of Pathology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy 4 Unit of Medical Genetics, IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico), Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy 5 Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy 6 Pathology Department, Maggiore Hospital, 40133 Bologna, Italy 7 Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy * Author to whom correspondence should be addressed. † These authors contributed equally to this work. ‡ These authors contributed equally to this work. J. Mol. Pathol. 2022, 3(3), 115-124; https://doi.org/10.3390/jmp3030011 Received: 30 March 2022 / Revised: 27 May 2022 / Accepted: 21 June 2022 / Published: 25 June 2022 (This article belongs to the Collection Feature Papers in Journal of Molecular Pathology) Download Browse Figures Versions Notes Abstract Several causes may lead to CRC, either extrinsic (sporadic forms) or genetic (hereditary forms), such as Lynch syndrome (LS). Most sporadic deficient mismatch repair (dMMR) CRC cases are characterized by the methylation of the MLH1 promoter gene and/or BRAF gene mutations. Usually, the first test performed is the mismatch repair deficiency analysis. If a tumor shows a dMMR, BRAF mutations and then the MLH1 promoter methylation status have to be assessed, according to the ACG/ASCO screening algorithm. In this study, 100 consecutive formalin-fixed and paraffin-embedded samples of dMMR CRC were analyzed for both BRAF mutations and MLH1 promoter methylation. A total of 47 (47%) samples were BRAF p.V600E mutated, while MLH1 promoter methylation was found in 77 cases (77.0%). The pipeline “BRAF-followed-by-MLH1-analysis” led to a total of 153 tests, while the sequence “MLH1-followed-by-BRAF-analysis” resulted in a total of 123 tests. This study highlights the importance of performing MLH1 analysis in LS screening of BRAF-WT specimens before addressing patients to genetic counseling. We show that MLH1 analysis performs better as a first-line test in the screening of patients with LS risk than first-line BRAF analysis. Our data indicate that analyzing MLH1 methylation as a first-line test is more cost-effective

Long-Term Transplantation Outcomes in Patients With Primary Hyperoxaluria Type 1 Included in the European Hyperoxaluria Consortium (OxalEurope) Registry

INTRODUCTION: In primary hyperoxaluria type 1 (PH1), oxalate overproduction frequently causes kidney stones, nephrocalcinosis, and kidney failure. As PH1 is caused by a congenital liver enzyme defect, combined liver–kidney transplantation (CLKT) has been recommended in patients with kidney failure. Nevertheless, systematic analyses on long-term transplantation outcomes are scarce. The merits of a sequential over combined procedure regarding kidney graft survival remain unclear as is the place of isolated kidney transplantation (KT) for patients with vitamin B6-responsive genotypes. METHODS: We used the OxalEurope registry for retrospective analyses of patients with PH1 who underwent transplantation. Analyses of crude Kaplan–Meier survival curves and adjusted relative hazards from the Cox proportional hazards model were performed. RESULTS: A total of 267 patients with PH1 underwent transplantation between 1978 and 2019. Data of 244 patients (159 CLKTs, 48 isolated KTs, 37 sequential liver–KTs [SLKTs]) were eligible for comparative analyses. Comparing CLKTs with isolated KTs, adjusted mortality was similar in patients with B6-unresponsive genotypes but lower after isolated KT in patients with B6-responsive genotypes (adjusted hazard ratio 0.07, 95% CI: 0.01–0.75, P = 0.028). CLKT yielded higher adjusted event-free survival and death-censored kidney graft survival in patients with B6-unresponsive genotypes (P = 0.025, P < 0.001) but not in patients with B6-responsive genotypes (P = 0.145, P = 0.421). Outcomes for 159 combined procedures versus 37 sequential procedures were comparable. There were 12 patients who underwent pre-emptive liver transplantation (PLT) with poor outcomes. CONCLUSION: The CLKT or SLKT remains the preferred transplantation modality in patients with PH1 with B6-unresponsive genotypes, but isolated KT could be an alternative approach in patients with B6-responsive genotypes

Determinants of Kidney Failure in Primary Hyperoxaluria Type 1:Findings of the European Hyperoxaluria Consortium

INTRODUCTION: Primary hyperoxaluria type 1 (PH1) has a highly heterogeneous disease course. Apart from the c.508G&gt;A (p.Gly170Arg) AGXT variant, which imparts a relatively favorable outcome, little is known about determinants of kidney failure. Identifying these is crucial for disease management, especially in this era of new therapies. METHODS: In this retrospective study of 932 patients with PH1 included in the OxalEurope registry, we analyzed genotype-phenotype correlations as well as the impact of nephrocalcinosis, urolithiasis, and urinary oxalate and glycolate excretion on the development of kidney failure, using survival and mixed model analyses.RESULTS: The risk of developing kidney failure was the highest for 175 vitamin-B6 unresponsive ("null") homozygotes and lowest for 155 patients with c.508G&gt;A and c.454T&gt;A (p.Phe152Ile) variants, with a median age of onset of kidney failure of 7.8 and 31.8 years, respectively. Fifty patients with c.731T&gt;C (p.Ile244Thr) homozygote variants had better kidney survival than null homozygotes ( P = 0.003). Poor outcomes were found in patients with other potentially vitamin B6-responsive variants. Nephrocalcinosis increased the risk of kidney failure significantly (hazard ratio [HR] 3.17 [2.03-4.94], P &lt; 0.001). Urinary oxalate and glycolate measurements were available in 620 and 579 twenty-four-hour urine collections from 117 and 87 patients, respectively. Urinary oxalate excretion, unlike glycolate, was higher in patients who subsequently developed kidney failure ( P = 0.034). However, the 41% intraindividual variation of urinary oxalate resulted in wide confidence intervals. CONCLUSION: In conclusion, homozygosity for AGXT null variants and nephrocalcinosis were the strongest determinants for kidney failure in PH1. </p

BRAF Exon 15 Mutations in Papillary Carcinoma and Adjacent Thyroid Parenchyma: A Search for the Early Molecular Events Associated with Tumor Development

BRAF exon 15 mutations are the most common molecular alterations found in papillary thyroid carcinoma (PTC). To date, there is no information regarding BRAF alterations in the thyroid parenchyma surrounding the tumor. To explore the early events associated with the development of PTC, we used massively parallel sequencing to investigate BRAF exon 15 in 30 PTCs and in 100 samples from the thyroid parenchyma surrounding the tumor. BRAF p.V600E was identified in 19/30 PTCs (63.3%). BRAF p.V600E mutations were identified in the tissue adjacent the PTC only in samples containing psammoma bodies. The other samples were either BRAF wild type (WT) or carried BRAF non p.V600E mutations. Specifically, BRAF p.G593D, -p.A598T, -p.V600M, -p.R603Q, -p.S607F, and -p.S607P were identified in 4 of 36 (11.1%) samples with follicular cell atypia, in 2 of 16 (12.5%) with follicular cell hyperplasia, and in 1 of 33 (3.0%) histologically normal samples&mdash;Only in tissue surrounding BRAF p.V600E mutated PTCs. These mutations are predicted to affect protein function in silico but, in vitro, have kinase activity and BRAF phosphorylation levels similar to BRAF WT. No BRAF exon 15 mutations were identified in samples adjacent to PTCs that were BRAF WT. A mutagenic process affecting BRAF exon 15 occurs in a subset of thyroid glands that develop BRAF p.V600E mutated PTCs

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and their clinicopathological relevance

Thyroid cancer is the most common endocrine malignancy. Knowledge of the molecular pathology of thyroid tumours originating from follicular cells has greatly advanced in the past several years. Common molecular alterations, such as BRAF p.V600E, RAS point mutations, and fusion oncogenes (RET-PTC being the prototypical example), have been, respectively, associated with conventional papillary carcinoma, follicular-patterned tumours (follicular adenoma, follicular carcinoma, and the follicular variant of papillary carcinoma/non-invasive follicular thyroid neoplasm with papillary-like nuclear features), and with papillary carcinomas from young patients and arising after exposure to ionising radiation, respectively. The remarkable correlation between genotype and phenotype shows how specific, mutually exclusive molecular changes can promote tumour development and initiate a multistep tumorigenic process that is characterised by aberrant activation of mitogen-activated protein kinase and phosphoinositide 3-kinase/PTEN/AKT signalling. Molecular alterations are becoming useful biomarkers for diagnosis and risk stratification, and as potential treatment targets for aggressive forms of thyroid carcinoma. What follows is a review of the principal genetic alterations of thyroid tumours originating from follicular cells and of their clinicopathological relevance