Preoperative Assessment of TERT Promoter Mutation on Thyroid Core Needle Biopsies Supports Diagnosis of Malignancy and Addresses Surgical Strategy.

In the last decade, several molecular markers have been proposed to improve the diagnosis of thyroid nodules. Among these, mutations in the telomerase reverse transcriptase (TERT) promoter have been correlated to malignant tumors, characterized by highest recurrence and decreased patients' survival. This suggests an important role of TERT mutational analysis in the clinical diagnosis and management of thyroid cancer patients. The aim of the study was to demonstrate the adequacy of core needle biopsy (CNB) for the preoperative assessment of TERT mutational status, to reach a more accurate definition of malignancy and a more appropriate surgical planning. Indeed, CNB is gaining momentum for improving diagnosis of thyroid nodules deemed inconclusive by fine needle aspirate (FNA). The study included 50 patients submitted to CNB due to inconclusive FNA report. TERT mutational status was correlated with BRAF mutation, definitive histology, and post-operative TNM staging of the neoplasia. C228T mutation of the TERT promoter was reported in 10% of the papillary carcinomas (PTC) series. When compared with final histology, all cases harboring TERT mutation resulted as locally invasive PTCs. The prevalence of TERT mutated cases was 17.6% among locally advanced PTCs. TERT analysis on CNB allows the assessment of the pathological population on paraffin sections before DNA isolation, minimizing the risk of false negatives due to poor sampling that affects FNA, and gathering aggregate information about morphology and TERT mutational status. Data indicating a worse outcome of the tumor might be used to individualize treatment decision, surgical option, and follow-up design.

Immunohistochemistry for BRAF(V600E) antibody VE1 performed in core needle biopsy samples identifies mutated papillary thyroid cancers.

BRAF(V600E) is the most frequent genetic mutation in papillary thyroid cancer (PTC) and has been reported as an independent predictor of poor prognosis of these patients. Current guidelines do not recommend the use of BRAF(V600E) mutational analysis on cytologic specimens from fine needle aspiration due to several reasons. Recently, immunohistochemistry using VE1, a mouse anti-human BRAF(V600E) antibody, has been reported as a highly reliable technique in detecting BRAF-mutated thyroid and nonthyroid cancers. The aim of this study was to test the reliability of VE1 immunohistochemistry on microhistologic samples from core needle biopsy (CNB) in identifying BRAF-mutated PTC. A series of 30 nodules (size ranging from 7 to 22 mm) from 30 patients who underwent surgery following CNB were included in the study. All these lesions had had inconclusive cytology. In all cases, both VE1 and BRAF(V600E) genotypes were evaluated. After surgery, final histology demonstrated 21 cancers and 9 benign lesions. CNB correctly diagnosed 20/20 PTC and 5/5 adenomatous nodules. One follicular thyroid cancer and 4 benign lesions were assessed at CNB as uncertain follicular neoplasm. VE1 immunohistochemistry revealed 8 mutated PTC and 22 negative cases. A 100% agreement was found when positive and negative VE1 results were compared with BRAF mutational status. These data are the first demonstration that VE1 immunohistochemistry performed on thyroid CNB samples perfectly matches with genetic analysis of BRAF status. Thus, VE1 antibody can be used on thyroid microhistologic specimens to detect BRAF(V600E)-mutated PTC before surgery.

Measuring calcitonin in washout of the needle in patients undergoing fine needle aspiration with suspicious medullary thyroid cancer.

Calcitonin measurement in washout of the needle after aspiration (WO-Ct) has been rarely evaluated. Here we analyzed the role of WO-Ct in a series of subjects who underwent fine needle aspiration (FNA) with suspicious medullary thyroid cancer (MTC). Twenty-one patients referred following elevated serum calcitonin (S-Ct) or suspicious MTC by cytology. All patients underwent re-evaluation of S-Ct, FNA, and measurement of WO-Ct. S-Ct and WO-Ct were assessed by chemiluminescence assay (IMMULITE 2000, Diagnostic Products Corporation, USA). S-Ct showed elevated value in six subjects (mean 368.8 ± 373.9 pg/ml), of which three cases were cytologically classified as Class 5. WO-Ct obtained in this group (304.0 ± 309.3 pg/ml) was no different from S-Ct. After surgery MTC was confirmed in all patients. In the other 15 patients MTC was excluded by cytology or histology. Two subjects had moderately skewed S-Ct with nonmedullary histology. In the remaining 13 patients S-Ct resulted normal (6.2 ± 5.6 pg/ml) and WO-Ct low (2.9 ± 2.2 pg/ml). Significant (two-tailed P < 0.05, r(2) = 0.27, 95% confidence interval = 0.017-0.81) correlation was found between S-Ct and WO-Ct in nonmedullary patients but not in MTC patients. This study showed that WO-Ct can play a role in diagnosing primary and metastatic MTC. The procedure is easy, cost effective, and should be used in patients undergoing FNA with elevated S-Ct. Further studies and guidelines for the method are needed to use this technique in clinical routine. Until this any institute should use itself cut-off.

Phenotypic changes of the thyrocyte membrane in papillary thyroid carcinoma. A three-dimensional study.

Aim of the study was to assess the presence of structural changes in the complex carbohydrate chains of thyroid epithelia undergoing neoplastic transformation. We investigated thyroid cells from neoplastic lesions using a panel of lectins with specific affinity for distinct carbohydrate residues. Sixty samples of thyroid tissue, including normal, hyperplastic and neoplastic lesions were obtained from surgical specimens and blindly evaluated with lectin stains. Confocal microscopy was used to obtain three-dimensional (3-D) images of the samples with a positive reaction. Wheat germ agglutinin (WGA) was consistently positive on the apical membrane of papillary thyroid carcinomas (PTC), was weakly expressed in follicular carcinomas (FC) and resulted negative in normal thyrocytes and in benign conditions. The 3-D microscopy model showed that the WGA staining pattern in light microscopy corresponds to a continuous layer on the luminal surface of both papillary and tubular structures of PTC cells. The other lectins under evaluation did not provide any significant result. In conclusion, in PTC the apical border of thyrocytes showed a strong, specific and consistent staining with WGA. These findings may be related to a modified interaction of thyroglobulin molecule with thyroid cell membrane and with the expression of molecules that are involved in the process of tumorigenesis and tumor progression.

Angiotensin-converting enzyme inhibition modulates high-glucose-induced extracellular matrix changes in mouse glomerular epithelial cells.

BACKGROUND/AIM: Extracellular matrix alterations are involved in the pathogenesis of diabetic nephropathy. We evaluated the effects of high glucose concentrations and inhibition of angiotensin-converting enzyme on the laminin and fibronectin production by glomerular epithelial cells. METHODS: Glomerular epithelial cells were cultured in 5 and 30 mmol/l glucose, with and without enalaprilat (0.3 mmol/l). Laminin and fibronectin were measured (35S-methionine, immunoprecipitation), and their mRNA expression was evaluated (RT-PCR). RESULTS: The laminin concentration was higher in the cells than in the medium, where an increase of its content was observed under high-glucose conditions (p < 0.01). Fibronectin, found only in the medium, was not modified by the high glucose concentration. Following enalaprilat administration, the laminin concentration was decreased under high-glucose conditions, both in the cell and in the medium (p < 0.001), whereas the fibronectin concentration was increased under high-glucose conditions (p < 0.001). The mRNA expression of laminin and fibronectin under high-glucose conditions only slightly increased. Enalaprilat decreased the fibronectin mRNA synthesis dramatically (>50%, p < 0.0001) under high-glucose conditions. CONCLUSIONS: Enalaprilat normalizes the abnormal, high-glucose-induced concentration of laminin, while it decreases the fibronectin synthesis. The improvement of the renal function in diabetic patients treated with angiotensin-converting enzyme inhibitors may, in part, be due to a modulator effect on extracellular matrix content and composition.

Autoimmune markers and neurological complications in non-insulin-dependent diabetes mellitus.

To verify whether autoimmune markers related to nervous system structures and other autoimmunity indexes present in diabetes mellitus are associated with subclinical neuropathy, we examined 48 non-insulin-dependent diabetic patients with and without neuroelectrophysiological alterations. Nerve conduction velocity at the external sciatic-popliteal nerve, at the sural nerve, at the median and ulnar nerves level has been evaluated. Autoimmunity was investigated by evaluating glutamic acid decarboxylase (GAD-Ab), insulin (IAA), GM3, GD3 and GT1b gangliosides, pancreatic islet cell (IC-A) and anti-nervous-tissue autoantibody presence. Nerve conduction velocities were decreased in 72.9% of diabetic patients. Anti-insulin antibodies were detected in seven non-insulin created diabetic patients and in higher amount in subjects with (17.1%) than in those without (7.7%) asymptomatic neuropathy. Anti-GM3 antibodies were detected in four diabetic patients all of whom presented neurological complication. A significant correlation has been found between neurological damage and presence of anti-insulin antibodies (p<0.05). In the case of GM3 autoantibody, a similar result was obtained, but the data failed to reach statistical significance. Our data demonstrate that autoimmunity might play a role in the development of peripheral neuropathy.

High glucose modifies heparansulphate synthesis by mouse glomerular epithelial cells.

BACKGROUND: Alterations in proteoglycan metabolism are involved in the pathogenesis of diabetic nephropathy. The aim of this study is to evaluate the effects of high glucose on proteoglycan production and to find a reliable in vitro model for the study of diabetic nephropathy. METHODS: A clone of mouse glomerular epithelial cells was cultured in media containing elevated (30 mmol) and physiological (5 mmol) glucose, or iso-osmolar (30 mmol) mannitol concentrations. We evaluated the synthesis of 35SO4-labeled molecules and the amount of proteoglycans by Sepharose CL6B and DEAE-Sephacel chromatographies. RESULTS: A clear decrease (56%) in total cell-layer proteoglycan synthesis was induced by 30 mmol glucose, in comparison with normal glucose. A reduction of 25% in medium associated proteoglycan synthesis was observed in high glucose cultured cells. After Sepharose CL6B, in cells cultured in high glucose, cell layer heparansulphate proteoglycan-I (Kav 6B 0. 04) synthesis was reduced by about 81%, heparansulphate proteoglycan-II (Kav 6B 0.21) by about 87% and heparansulphate glycosaminoglycan (Kav 0.4-0.8) by about 91%, respectively. In mannitol-incubated cells the reductions observed were less evident and not significantly different from those in normal glucose. CONCLUSIONS: These results indicate that (1) glomerular epithelial cells play a central role in proteoglycan synthesis, (2) high glucose modifies the amount and influences the different species production of these macromolecules, while osmotic forces seem to be only partially involved in these effects, and (3) this cellular clone of glomerular epithelial cells can represent a reliable in vitro model for the study of the mechanisms involved in diabetic nephropathy.

Specific inhibitory effect of H1e histone somatic variant on in vitro DNA-methylation process.

H1e and H1c histone variants were purified from mouse L929 fibroblasts using a reverse phase HPLC, and their effect on in vitro DNA methylation was investigated, together with their ability to bind unmethylated or methylated CpG-rich 44bp oligonucleotides. In a "physiological" range of H1:DNA ratios only H1e, at variance from H1c, was found to cause a marked inhibition of in vitro enzymic DNA methylation. It was also shown that both variants have a similar affinity in binding a methylated CpG-rich oligonucleotide, but that the binding to the same oligonucleotide in the unmethylated form occurs preferentially with H1e rather than with H1c. H1e is therefore likely to be directly involved in maintaining CpG-rich sequences in the unmethylated state.