Clinical, genetic, and immunohistochemical characterization of 70 Ukrainian adult cases with post-Chornobyl papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) exhibits various molecular abnormalities, both when sporadic and radiation-related. PTC is still diagnosed in adult individuals who were younger than 18 years at the time of the Chornobyl accident in 1986 and lived within the contaminated area. The preoperative diagnosis of PTC is based on ultrasound-guided fine needle aspiration cytology (FNAC), which is highly informative in up to 90% of biopsies. FNAC is not informative for the discrimination of follicular thyroid carcinoma (FTC) from follicular thyroid adenoma (FTA). Moreover, FNAC is often unreliable for diagnosis of cystic PTC due to its common presentation as a mural nodule in a cystic mass. In case of cystic PTC, biopsy sometimes reveals a cystic fluid containing insufficient amount of representative cells for cytology. In this work, PTC was characterized in relation to irradiation from radioactivity at childhood. Possible preoperative diagnostic markers for discrimination between PTC and other follicular thyroid neoplasms were identified, and their validity was tested. In Study I molecular, genetic and clinical characteristics in 70 post-Chornobyl PTCs were investigated. A common BRAF 1799T>A mutation was detected in 26 cases, overrepresentation of RET/PTC1 in 20 whereas RET/PTC3 was found in 4 cases. BRAF mutation was observed 3.5 times less frequent in the PTC accompanied by chronic lymphocytic thyroiditis (PTC/CLT) as compared to PTC only (12% vs. 44%). Greater expression of cyclin A was observed in PTC ≥ 2 cm as compared to PTC < 2 cm (1.2% vs. 0.6%). In conclusion, BRAF mutation and RET/PTC1 rearrangement as well as other molecular features of adult post-Chornobyl PTC were partly overlapping with other reported PTC cohorts. In Study II the SELDI-TOF mass spectrometry method was applied for PTC, FTC, FTA and normal thyroid tissue (NT). Significant overexpression of the protein S100A6 was identified in PTC as compared to FTC, FTA and NT (p < 0.05). This result was verified both by Western blot (WB), using the same samples, and by IHC in these and additionally in the PTC samples investigated in Study I. Moreover, the presence of two post-translational modifications of S100A6 was observed and verified by LC-MS/MS. S100A6 expression is strongly associated with PTC, and can therefore be tested for discrimination between follicular thyroid tumors and PTC. In Study III a two dimensional gel electrophoresis followed by MALDI-TOF mass spectrometry for proteomic profiling of PTC, FTC and FTA was performed. 25 protein spots showing significantly different expression between studied groups were identified. Of these, 9 protein spots were selected for further analyses by WB using the initially studied samples and by IHC using these as well as samples from Study I. The findings suggest additional proteins to be deregulated in thyroid tumors, and their clinical significance can now be further studied. In Study IV preoperative diagnostic markers for PTC in cystic lesions were identified by applying LC-MS/MS method. Out of all 1581 identified proteins, annexin A3 (ANXA3), carboxymethylenebutenolidase homolog (CMBL) cytokeratin 19 (CK- 19) and S100A13 were selected for validation by IHC and WB. ANXA3 and CMBL showed overexpression in both controls and PTCs, whereas S100A13 and CK-19 were up-regulated in PTC only (p < 0.05), suggesting their possible role for discrimination between cystic PTC and benign thyroid cysts

Genome Haploidisation with Chromosome 7 Retention in Oncocytic Follicular Thyroid Carcinoma

Contains fulltext : 108012.pdf (publisher's version ) (Open Access)BACKGROUND: Recurrent non-medullary thyroid carcinoma (NMTC) is a rare disease. We initially characterized 27 recurrent NMTC: 13 papillary thyroid cancers (PTC), 10 oncocytic follicular carcinomas (FTC-OV), and 4 non-oncocytic follicular carcinomas (FTC). A validation cohort composed of benign and malignant (both recurrent and non-recurrent) thyroid tumours was subsequently analysed (n = 20). METHODS: Data from genome-wide SNP arrays and flow cytometry were combined to determine the chromosomal dosage (allelic state) in these tumours, including mutation analysis of components of PIK3CA/AKT and MAPK pathways. RESULTS: All FTC-OVs showed a very distinct pattern of genomic alterations. Ten out of 10 FTC-OV cases showed near-haploidisation with or without subsequent genome endoreduplication. Near-haploidisation was seen in 5/10 as extensive chromosome-wide monosomy (allelic state [A]) with near-haploid DNA indices and retention of especially chromosome 7 (seen as a heterozygous allelic state [AB]). In the remaining 5/10 chromosomal allelic states AA with near diploid DNA indices were seen with allelic state AABB of chromosome 7, suggesting endoreduplication after preceding haploidisation. The latter was supported by the presence of both near-haploid and endoreduplicated tumour fractions in some of the cases. Results were confirmed using FISH analysis. Relatively to FTC-OV limited numbers of genomic alterations were identified in other types of recurrent NMTC studied, except for chromosome 22q which showed alterations in 6 of 13 PTCs. Only two HRAS, but no mutations of EGFR or BRAF were found in FTC-OV. The validation cohort showed two additional tumours with the distinct pattern of genomic alterations (both with oncocytic features and recurrent). CONCLUSIONS: We demonstrate that recurrent FTC-OV is frequently characterised by genome-wide DNA haploidisation, heterozygous retention of chromosome 7, and endoreduplication of a near-haploid genome. Whether normal gene dosage on especially chromosome 7 (containing EGFR, BRAF, cMET) is crucial for FTC-OV tumour survival is an important topic for future research. MICROARRAYS: Data are made available at GEO (GSE31828)

Proteomics identifies neddylation as a potential therapy target in small intestinal neuroendocrine tumors.

Patients with small intestinal neuroendocrine tumors (SI-NETs) frequently develop spread disease; however, the underlying molecular mechanisms of disease progression are not known and effective preventive treatment strategies are lacking. Here, protein expression profiling was performed by HiRIEF-LC-MS in 14 primary SI-NETs from patients with and without liver metastases detected at the time of surgery and initial treatment. Among differentially expressed proteins, overexpression of the ubiquitin-like protein NEDD8 was identified in samples from patients with liver metastasis. Further, NEDD8 correlation analysis indicated co-expression with RBX1, a key component in cullin-RING ubiquitin ligases (CRLs). In vitro inhibition of neddylation with the therapeutic agent pevonedistat (MLN4924) resulted in a dramatic decrease of proliferation in SI-NET cell lines. Subsequent mass spectrometry-based proteomics analysis of pevonedistat effects and effects of the proteasome inhibitor bortezomib revealed stabilization of multiple targets of CRLs including p27, an established tumor suppressor in SI-NET. Silencing of NEDD8 and RBX1 using siRNA resulted in a stabilization of p27, suggesting that the cellular levels of NEDD8 and RBX1 affect CRL activity. Inhibition of CRL activity, by either NEDD8/RBX1 silencing or pevonedistat treatment of cells resulted in induction of apoptosis that could be partially rescued by siRNA-based silencing of p27. Differential expression of both p27 and NEDD8 was confirmed in a second cohort of SI-NET using immunohistochemistry. Collectively, these findings suggest a role for CRLs and the ubiquitin proteasome system in suppression of p27 in SI-NET, and inhibition of neddylation as a putative therapeutic strategy in SI-NET

Потребительский экстремизм как правовое явление

Материалы XIII Междунар. науч. конф. студентов, магистрантов, аспирантов и молодых ученых, Гомель, 21–22 мая 2020 г

The Value of Histological Algorithms to Predict the Malignancy Potential of Pheochromocytomas and Abdominal Paragangliomas—A Meta-Analysis and Systematic Review of the Literature

Pheochromocytomas (PCCs) and abdominal paragangliomas (PGLs), collectively abbreviated PPGLs, are neuroendocrine tumors of the adrenal medulla and paraganglia, respectively. These tumors exhibit malignant potential but seldom display evidence of metastatic spread, the latter being the only widely accepted evidence of malignancy. To counter this, pre-defined histological algorithms have been suggested to stratify the risk of malignancy: Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) and the Grading system for Adrenal Pheochromocytoma and Paraganglioma (GAPP). The PASS algorithm was originally intended for PCCs whereas the GAPP model is proposed for stratification of both PCCs and PGLs. In parallel, advances in terms of coupling overtly malignant PPGLs to the underlying molecular genetics have been made, but there is yet no combined risk stratification model based on histology and the overall mutational profile of the tumor. In this review, we systematically meta-analyzed previously reported cohorts using the PASS and GAPP algorithms and acknowledge a &#8220;rule-out&#8222; way of approaching these stratification models rather than a classical &#8220;rule-in&#8222; strategy. Moreover, the current genetic panorama regarding possible molecular adjunct markers for PPGL malignancy is reviewed. A combined histological and genetic approach will be needed to fully elucidate the malignant potential of these tumors

Metastatic Neuroendocrine Neoplasms of Unknown Primary: Clues from Pathology Workup

Neuroendocrine neoplasms (NENs) are diverse tumors arising in various anatomical locations and may therefore cause a variety of symptoms leading to their discovery. However, there are instances in which a NEN first presents clinically as a metastatic deposit, while the associated primary tumor is not easily identified using conventional imaging techniques because of small primary tumor sizes. In this setting (which is referred to as a &ldquo;NEN of unknown primary&rdquo;; NEN-UP), a tissue biopsy is often procured to allow the surgical pathologist to diagnose the metastatic lesion. If indeed a metastatic NEN-UP is found, several clues can be obtained from morphological assessment and immunohistochemical staining patterns that individually or in concert may help identify the primary tumor site. Herein, histological and auxiliary analyses of value in this context are discussed in order to aid the pathologist when encountering these lesions in clinical practice

Papillary thyroid carcinoma with pleomorphic tumor giant cells in a pregnant woman – a case report

Abstract Background Papillary thyroid carcinoma with pleomorphic tumor giant cells (PTC-PC) is characterized by the occurrence of bizarre, pleomorphic cells within a small area of a conventional PTC. The histologic distinction between PTC-PC and PTC’s with a focal anaplastic thyroid cancer (ATC) component (denoted in the 2004 WHO classification as “papillary thyroid carcinoma with spindle and giant cell carcinoma”, PTC-SGC) is debated, however the prognosis is thought to be different (excellent for PTC-PC, poor for PTC-SGC). Therefore, this diagnostic challenge is significant for any endocrine pathologist to recognize. Herein, we report the histological and clinical workup of a PTC-PC case, with particular focus on the molecular analyses that facilitated the establishment of the final diagnosis. Case presentation The patient was a pregnant, 28-year-old female presenting with a 30 mm conventional PTC, with focal areas with undifferentiated cells exhibiting exaggerated nuclear pleomorphism. No foci of extrathyroidal extension, angioinvasion or lymph node engagement were seen. Immunohistochemical analyses revealed the pleomorphic cells exhibiting retained differentiation. Molecular genetic analyses demonstrated a codon V600 missense mutation of the BRAF gene, but no TP53 or TERT promoter mutations. The absence of an aggressive phenotype in addition to the lack of mutations in two major ATC-related genes led to the diagnosis of a PTC-PC. Postoperative MRI showed no evidence of metastatic disease. Radioiodine ablation was performed seven months post-operatively, and a SPECT-CT imaging did not show signs of residual tissue. She is well and without signs of disease 16 months post-operatively. Conclusions PTC-PC is a differential diagnosis to PTC-SGC that mandates careful considerations. Taken together with previous publications, PTC-PC seems to be histologically similar to PTC-SGC, but clinically distinct. Even so, the distinction is not easily made given the different therapeutic consequences for each individual patient. This is the first report that includes molecular genetics to aid in finalizing the diagnosis. Exclusion of mutations in TP53 and the TERT promoter could be considered as an adjunct tool when assessing papillary thyroid cancer with focal pleomorphism