A Pilot Interaction Analysis of Gut Microbiota and Peripheral Markers of Aging in Severe Psychiatric Disorders: A Role for Lachnoclostridium?

Excessive predominance of pathological species in the gut microbiota could increase the production of inflammatory mediators at the gut level and, via modification of the gut-blood barrier, at the systemic level. This pro-inflammatory state could, in turn, increase biological aging that is generally proxied by telomere shortening. In this study, we present findings from a secondary interaction analysis of gut microbiota, aging, and inflammatory marker data from a cohort of patients with different diagnoses of severe mental disorders. We analyzed 15 controls, 35 patients with schizophrenia (SCZ), and 31 patients with major depressive disorder (MDD) recruited among those attending a community mental health center (50 males and 31 females, mean and median age 46.8 and 46.3 years, respectively). We performed 16S rRNA sequencing as well as measurement of telomere length via quantitative fluorescence in situ hybridization and high-sensitivity C-reactive protein. We applied statistical modeling with logistic regression to test for interaction between gut microbiota and these markers. Our results showed statistically significant interactions between telomere length and gut microbiota pointing to the genus Lachnostridium, which remained significantly associated with a reduced likelihood of MDD even after adjustment for a series of covariates. Although exploratory, these findings show that specific gut microbiota signatures overexpressing Lachnoclostridium and interacting with biological aging could modulate the liability for MDD.

Three-dimensional nuclear architecture distinguishes thyroid cancer histotypes.

Molecular markers can serve as diagnostic tools to support pathological analysis in thyroid neoplasms. However, because the same markers can be observed in some benign thyroid lesions, additional approaches are necessary to differentiate thyroid tumor subtypes, prevent overtreatment and tailor specific clinical management. This applies particularly to the recently described variant of thyroid cancer referred to as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). This variant has an estimated prevalence of 4.4% to 9.1% of all papillary thyroid carcinomas worldwide. We studied 60 thyroid lesions: 20 classical papillary thyroid carcinoma (CPTC), 20 follicular variant of PTC (FVPTC) and 20 NIFTP. We examined morphological and molecular features to identify parameters that can differentiate NIFTP from the other PTC subtypes. When blindly investigating the nuclear architecture of thyroid neoplasms, we observed that NIFTP has significantly longer telomeres than CPTC and FVPTC. Super-resolved 3D-structured illumination microscopy demonstrated that NIFTP is heterogeneous and that its nuclei contain more densely packed DNA and smaller interchromatin spaces than CPTC and FVPTC, a pattern that resembles normal thyroid tissue. These data are consistent with the observed indolent biological behavior and favorable prognosis associated with NIFTP, which lacks BRAFV600E mutations. Of note, next-generation thyroid oncopanel sequencing was unable to distinguish the thyroid cancer histotypes in our study cohort. In summary, our data suggest that 3D nuclear architecture can be a powerful analytical tool to diagnose and guide clinical management of NIFTP.

Glutamine Starvation Affects Cell Cycle, Oxidative Homeostasis and Metabolism in Colorectal Cancer Cells.

Cancer cells adjust their metabolism to meet energy demands. In particular, glutamine addiction represents a distinctive feature of several types of tumors, including colorectal cancer. In this study, four colorectal cancer cell lines (Caco-2, HCT116, HT29 and SW480) were cultured with or without glutamine. The growth and proliferation rate, colony-forming capacity, apoptosis, cell cycle, redox homeostasis and metabolomic analysis were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test (MTT), flow cytometry, high-performance liquid chromatography and gas chromatography/mass spectrometry techniques. The results show that glutamine represents an important metabolite for cell growth and that its deprivation reduces the proliferation of colorectal cancer cells. Glutamine depletion induces cell death and cell cycle arrest in the GO/G1 phase by modulating energy metabolism, the amino acid content and antioxidant defenses. Moreover, the combined glutamine starvation with the glycolysis inhibitor 2-deoxy-D-glucose exerted a stronger cytotoxic effect. This study offers a strong rationale for targeting glutamine metabolism alone or in combination with glucose metabolism to achieve a therapeutic benefit in the treatment of colon cancer.

Three-dimensional telomere profiles in papillary thyroid cancer variants: A pilot study.

Besides the two main histologic types of papillary thyroid carcinoma (PTC), the classical PTC (CL-PTC) and the follicular variant PTC (FV-PTC), several other variants are described. The encapsulated FV-PTC variant was recently reclassified as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) due to its similarities to benign lesions. Specific molecular signatures, however, are still unavailable. It is well known that improper DNA repair of dysfunctional telomeres may cause telomere-related genome instability. The mechanisms involved in the damaged telomere repair processing may lead to detrimental outcomes, altering the three-dimensional (3D) nuclear telomere and genome organization in cancer cells. This pilot study aimed to evaluate whether a specific 3D nuclear telomere architecture might characterize NIFTP, potentially distinguishing it from other PTC histologic variants. Our findings demonstrate that 3D telomere profiles of CL-PTC and FV-PTC were different from NIFTP and that NIFTP more closely resembles follicular thyroid adenoma (FTA). NIFTP has longer telomeres than CL-PTC and FV-PTC samples, and the telomere length of NIFTP overlaps with that of the FTA histotype. In contrast, there was no association between BRAF expression and telomere length in all tested samples. These preliminary findings reinforce the view that NIFTP is closer to non-malignant thyroid nodules and confirm that PTC features short telomeres.

Vitamin C Cytotoxicity and Its Effects in Redox Homeostasis and Energetic Metabolism in Papillary Thyroid Carcinoma Cell Lines.

High-dose of vitamin C (L-ascorbic acid, ascorbate) exhibits anti-tumoral effects, primarily mediated by pro-oxidant mechanisms. This cytotoxic effect is thought to affect the reciprocal crosstalk between redox balance and cell metabolism in different cancer types. Vitamin C also inhibits the growth of papillary thyroid carcinoma (PTC) cells, although the metabolic and redox effects remain to be fully understood. To shed light on these aspects, PTC-derived cell lines harboring the most common genetic alterations characterizing this tumor were used. Cell viability, apoptosis, and the metabolome were explored by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test (MTT), flow cytometry, and UHPLC/MS. Changes were observed in redox homeostasis, with increased reactive oxygen species (ROS) level and perturbation in antioxidants and electron carriers, leading to cell death by both apoptosis and necrosis. The oxidative stress contributed to the metabolic alterations in both glycolysis and TCA cycle. Our results confirm the pro-oxidant effect of vitamin C as relevant in triggering the cytotoxicity in PTC cells and suggest that inhibition of glycolysis and alteration of TCA cycle via NAD+ depletion can play an important role in this mechanism of PTC cancer cell death.

Telomere attrition and inflammatory load in severe psychiatric disorders and in response to psychotropic medications.

Individuals with severe psychiatric disorders have a reduced life expectancy compared to the general population. At the biological level, patients with these disorders present features that suggest the involvement of accelerated aging, such as increased circulating inflammatory markers and shorter telomere length (TL). To date, the role of the interplay between inflammation and telomere dynamics in the pathophysiology of severe psychiatric disorders has been scarcely investigated. In this study we measured T-lymphocytes TL with quantitative fluorescent in situ hybridization (Q-FISH) and plasma levels of inflammatory markers in a cohort comprised of 40 patients with bipolar disorder (BD), 41 with schizophrenia (SZ), 37 with major depressive disorder (MDD), and 36 non-psychiatric controls (NPC). TL was shorter in SZ and in MDD compared to NPC, while it was longer in BD (model F6, 137 = 20.128, p = 8.73 × 10-17, effect of diagnosis, F3 = 31.870; p = 1.08 × 10-15). There was no effect of the different classes of psychotropic medications, while duration of treatment with mood stabilizers was associated with longer TL (Partial correlation controlled for age and BMI: correlation coefficient = 0.451; p = 0.001). Levels of high-sensitivity C-Reactive Protein (hsCRP) were higher in SZ compared to NPC (adjusted p = 0.027), and inversely correlated with TL in the whole sample (r = -0.180; p = 0.042). Compared to NPC, patients with treatment resistant (TR) SZ had shorter TL (p = 0.001), while patients with TR MDD had higher levels of tumor necrosis factor-α (TNFα) compared to NPC (p = 0.028) and to non-TR (p = 0.039). Comorbidity with cardio-metabolic disorders did not influence the observed differences in TL, hsCRP, and TNFα among the diagnostic groups. Our study suggests that patients with severe psychiatric disorders present reduced TL and increased inflammation.

Differences in telomere length between patients with bipolar disorder and controls are influenced by lithium treatment.

Aim: To assess the role of lithium treatment in the relationship between bipolar disorder (BD) and leukocyte telomere length (LTL). Materials & methods: We compared LTL between 131 patients with BD, with or without a history of lithium treatment, and 336 controls. We tested the association between genetically determined LTL and BD in two large genome-wide association datasets. Results: Patients with BD with a history lithium treatment showed longer LTL compared with never-treated patients (p = 0.015), and similar LTL compared with controls. Patients never treated with lithium showed shorter LTL compared with controls (p = 0.029). Mendelian randomization analysis showed no association between BD and genetically determined LTL. Conclusion: Our data support previous findings showing that long-term lithium treatment might protect against telomere shortening.

A multidisciplinary approach to mental illness: do inflammation, telomere length and microbiota form a loop? A protocol for a cross-sectional study on the complex relationship between inflammation, telomere length, gut microbiota and psychiatric disorders.

INTRODUCTION: Severe psychiatric disorders are typically associated with a significant reduction in life expectancy compared with the general population. Among the different hypotheses formulated to explain this observation, accelerated ageing has been increasingly recognised as the main culprit. At the same time, telomere shortening is becoming widely accepted as a proxy molecular marker of ageing. The present study aims to fill a gap in the literature by better defining the complex interaction/s between inflammation, age-related comorbidities, telomere shortening and gut microbiota in psychiatric disorders. METHODS AND ANALYSIS: A cross-sectional study is proposed, recruiting 40 patients for each of three different diagnostic categories (bipolar disorder, schizophrenia and major depressive disorder) treated at the Section of Psychiatry and at the Unit of Clinical Pharmacology of the University Hospital Agency of Cagliari (Italy), compared with 40 age-matched and sex-matched non-psychiatric controls. Each group includes individuals suffering, or not, from age-related comorbidities, to account for the impact of these medical conditions on the biological make-up of recruited patients. The inflammatory state, microbiota composition and telomere length (TL) are assessed. ETHICS AND DISSEMINATION: The study protocol was approved by the Ethics Committee of the University Hospital Agency of Cagliari (PG/2018/11693, 5 September 2018). The study is conducted in accordance with the principles of good clinical practice and the Declaration of Helsinki, and in compliance with the relevant Italian national legislation. Written, informed consent is obtained from all participants. Participation in the study is on a voluntary basis only. Patients will be part of the dissemination phase of the study results, during which a local conference will be organised and families of patients will also be involved. Moreover, findings will be published in one or more research papers and presented at national and international conferences, in posters or oral communications.

Crosstalk between Metabolic Alterations and Altered Redox Balance in PTC-Derived Cell Lines.

Background: Thyroid cancer is the most common endocrine malignancy, with papillary thyroid carcinoma (PTC) being the most common (85⁻90%) among all the different types of thyroid carcinomas. Cancer cells show metabolic alterations and, due to their rapid proliferation, an accumulation of reactive oxygen species, playing a fundamental role in cancer development and progression. Currently, the crosstalk among thyrocytes metabolism, redox balance and oncogenic mutations remain poorly characterized. The aim of this study was to investigate the interplay among metabolic alterations, redox homeostasis and oncogenic mutations in PTC-derived cells. Methods: Metabolic and redox profile, glutamate-cysteine ligase, glutaminase-1 and metabolic transporters were evaluated in PTC-derived cell lines with distinguished genetic background (TPC-1, K1 and B-CPAP), as well as in an immortalized thyroid cell line (Nthy-ori3-1) selected as control. Results: PTC-derived cells, particularly B-CPAP cells, harboring BRAF, TP53 and human telomerase reverse transcriptase (hTERT) mutation, displayed an increase of metabolites and transporters involved in energetic pathways. Furthermore, all PTC-derived cells showed altered redox homeostasis, as reported by the decreased antioxidant ratios, as well as the increased levels of intracellular oxidant species. Conclusion: Our findings confirmed the pivotal role of the metabolism and redox state regulation in the PTC biology. Particularly, the most perturbed metabolic phenotypes were found in B-CPAP cells, which are characterized by the most aggressive genetic background.

Characterizing the three-dimensional organization of telomeres in papillary thyroid carcinoma cells.

The relationship between the three-dimensional (3D) nuclear telomere architecture and specific genetic alterations in papillary thyroid carcinoma (PTC), in particular in cancer stem-like cells (CSLCs), has not yet been investigated. We isolated thyrospheres containing CSLCs from B-CPAP, K1, and TPC-1 PTC-derived cell lines, representative of tumors with different genetic backgrounds within the newly identified BRAFV600E -like PTC subgroup, and used immortalized normal human thyrocytes (Nthy-ori 3.1) as control. We performed quantitative fluorescence in situ hybridization, 3D imaging, and 3D telomere analysis using TeloView software to examine telomere dysfunction in both parental and thyrosphere cells. Among the 3D telomere profile, a wide heterogeneity was observed, except for telomere intensity. Our findings indicate that CSLCs of each cell line had longer telomeres than parental cells, according to telomere intensity values, which correlate with telomere length. Indeed, the thyrosphere cells had lower numbers of lower-intensity telomeres (≤5,000 arbitrary fluorescent units, a.u.), compared with parental cancer cells, as well as parental control cells, (p < 0.0001). The B-CPAP thyrospheres showed a decreased number of higher intensity telomeres (>17,000 a.u.) than K1 and TPC-1 cells, as well as control cells (p < 0.0001). By selecting PTC-derived cell lines with different genetic backgrounds characteristic of BRAFV600E -like PTC subgroups, we demonstrate that thyrosphere cells with BRAFV600E and TP53 mutations show shorter telomeres than those harboring RET/PTC or BRAFV600E and wild-type TP53. Hence, our data reveal a trend towards a decrease in telomere shortening in CSLCs, representing the early cancer-promoting subpopulation, as opposed to parental cells representing the tumor bulk cells.

Thyrospheres from B-CPAP Cell Line with BRAF and TERT Promoter Mutations have Different Functional and Molecular Features than Parental Cells.

Human thyroid cancer derived cell lines are widely used to study the mechanisms involved in thyroid carcinogenesis. However, there is limited availability of non-cross-contaminated cancer cell lines derived from papillary thyroid carcinoma (PTC), and the B-CPAP cell line is one of the few such lines. B-CPAP cells have been genetically and cytogenetically well-characterized, but details of their stemness features remain uncertain. Considering that this cell line is extensively used for in vitro studies on thyroid tumorigenesis, we broaden its functional and molecular profiles as well as the tumorigenic capacity. We used functional assays (sphere-forming capacity and efficiency), assessed self-renewal and propagation efficiency and tested in vivo tumorigenicity in Hsd:Athymic Nude-Foxn1nu mice. Expression of markers of stemness, differentiation, and epithelial-mesenchymal transition were estimated at RNA and protein levels in adherent parental cells and sphere-forming cells. Functional aspects and stemness features were compared with normal thyrocytes. Protein expression of xenograft tumors was evaluated by immunohistochemistry. B-CPAP sphere-forming cells were able to form thyrospheres theoretically indefinitely in an appropriate serum-free medium, reverting to the adherent parental cell phenotype when cultured in differentiation medium. Different expression of ALDH1-A1 and CD44 stemness markers and TTF-1 and CK19 differentiation markers allowed discrimination between isolated sphere-forming cells and adherent parental cells, indicating that sphere-forming cells retained stem-like features. In keeping with these observations, tumorigenicity assays confirmed that, relative to parental adherent cells, thyrospheres had enhanced capacity to initiate xenograft tumors. Thyrospheres from normal cell line retained very low functional capacity, as well as different stemness markers expression compared to tumor thyrospheres. Our findings may constitute a useful background to develop an in vitro model for assessing the origin and progression of papillary thyroid carcinoma bearing BRAFV600E and TERT promoter mutations.

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.

Leukocyte telomere length positively correlates with duration of lithium treatment in bipolar disorder patients.

Bipolar disorder (BD) has been suggested to be associated with accelerated aging and premature cell senescence. While findings on shorter telomeres in BD are controversial, a recent study showed that long-term lithium treatment correlates with longer telomeres in BD. In our study, we sought to investigate the correlation between leukocyte telomere length (LTL) and long-term lithium treatment in a sample of 200 BD patients characterized for lithium response. We also compared data from two different methods commonly used to measure telomere length, quantitative PCR (qPCR) and quantitative fluorescence in situ hybridization (Q-FISH). We also measured, for the first time, the effect of lithium in vitro on the expression of the telomerase gene in human-derived neural progenitor cells (NPCs). Our findings showed that LTL correlated negatively with age (p=0.0002) and was independent of sex, diagnosis, age at onset, suicidal behavior, number of mood episodes, response to lithium and use of other psychotropic medications. After correcting for age, LTL was positively correlated with lithium treatment duration in patients treated for more than two years (n=150, R=0.17, p=0.037). There was a significant correlation between data measured with qPCR and Q-FISH (p=0.012, R=0.826). Lithium treatment increased telomerase expression in NPCs, though this effect was not statistically significant. Our data support previous findings showing that long-term lithium treatment associates with longer telomeres in BD, though this effect appeared to be independent from clinical response to the treatment. Moreover, we suggested for the first time that lithium increases the expression of telomerase gene in human neural progenitor cells.

Optimizing detection of RET and PPARg rearrangements in thyroid neoplastic cells using a home-brew tetracolor probe.

BACKGROUND: Fluorescence in situ hybridization (FISH) to identify specific DNA target sequences in the nuclei of nondividing cells of numerous solid neoplasms has contributed to the introduction of molecular cytogenetics as a useful adjunct to cytology, leading recently to the "marriage" of the 2 disciplines. Numerous cancer molecular markers can now be investigated using different technical approaches, at both the gene and expression levels, in biopsies of various suspected cancers, including differentiated thyroid carcinoma. The limited amount of bioptic material is often insufficient to carry out multiple tests, and optimizing handling of the biopsy is desirable. METHODS: We have developed a home-brew tetracolor break-apart probe able to simultaneously identify the 2 most common genetic alterations in differentiated thyroid carcinoma: RET/PTC variants in papillary thyroid carcinoma and PAX8/PPARg fusion and variants in follicular thyroid carcinoma. RESULTS: The probe had 100% specificity, 99.5% sensitivity, and ≥ 3% cutoff. The probe was tested on RET/PTC and PAX8/PPARg RT-PCR positive controls, and feasibility was assessed in 368 thyroid nodule fine-needle aspirations (FNA). In the latter analysis, 24 FNAs had split RET signal, and 9 had split PPARg signal. FISH analysis of available surgically removed nodules confirmed the sensitivity of FISH in detecting abnormal clones and oligoclones. CONCLUSIONS: The home-brew tetracolor probe showed high feasibility, optimizing the use of the biological material in relation to the available molecular tests and maximizing the FISH experimental and slide-scoring times. This probe may be considered an alternative to RT-PCR when recovery and quality of RNA amplification from FNA are insufficient.

Assessing RET/PTC in thyroid nodule fine-needle aspirates: the FISH point of view.

RET/PTC rearrangement and BRAF(V600E) mutation are the two prevalent molecular alterations associated with papillary thyroid carcinoma (PTC), and their identification is increasingly being used as an adjunct to cytology in diagnosing PTC. However, there are caveats associated with the use of the molecular approach in fine-needle aspiration (FNA), particularly for RET/PTC, that should be taken into consideration. It has been claimed that a clonal or sporadic presence of this abnormality in follicular cells can distinguish between malignant and benign nodules. Nevertheless, the most commonly used PCR-based techniques lack the capacity to quantify the number of abnormal cells. Because fluorescence in situ hybridization (FISH) is the most sensitive method for detecting gene rearrangement in a single cell, we compared results from FISH and conventional RT-PCR obtained in FNA of a large cohort of consecutive patients with suspicious nodules and investigated the feasibility of setting a FISH-FNA threshold capable of distinguishing non-clonal from clonal molecular events. For this purpose, a home brew break-apart probe, able to recognize the physical breakage of RET, was designed. While a ≥3% FISH signal for broken RET was sufficient to distinguish nodules with abnormal follicular cells, only samples with a ≥6.8% break-apart FISH signal also exhibited positive RT-PCR results. On histological analysis, all nodules meeting the ≥6.8% threshold proved to be malignant. These data corroborate the power of FISH when compared with RT-PCR in quantifying the presence of RET/PTC in FNA and validate the RT-PCR efficiency in detecting clonal RET/PTC alterations.

Simultaneous occurrence of PAX8-PPARg and RET-PTC3 rearrangements in a follicular variant of papillary thyroid carcinoma.

Specific genotype-phenotype correlations have been identified in conventional-type papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC). In contrast, the genetic alterations underlying the pathogenesis of the follicular variant of PTC (FV-PTC), which shares some clinicopathologic and molecular features with both PTC and FTC, remain to be clarified. This entity shows a PAX8-PPARg fusion gene (associated with FTC), more frequently than BRAF or RET-PTC alterations (associated with PTC). Herein, we report, for the first time, an FV-PTC with the simultaneous occurrence of both RET-PTC and PAX8-PPARg alterations. Neoplastic cells were of the wild type for BRAF and H,K,N-RAS, had an apparently normal karyotype by conventional cytogenetics, and had a balanced genome by array comparative genomic hybridization analysis. In fact, submicroscopic chromosome rearrangements producing RET-PTC3 and PAX8-PPARg chimeric genes were found by interphase fluorescence in situ hybridization. We demonstrated that these 2 genetic alterations coexisted in the same tumor and were confined to 2 different clones. Our findings indicate that molecular heterogeneity, although an uncommon phenomenon, may occur in thyroid carcinoma and demonstrate the coexistence in a case of FV-PTC not only of the histologic but also of the molecular features of both PTC (RET-PTC) and FTC (PAX8-PPARg).

Telomere abnormalities and chromosome fragility in patients affected by familial papillary thyroid cancer.

INTRODUCTION: Genomic instability has been proposed to play a role in cancer development and can occur through different mechanisms including telomere association and telomere loss. Studies carried out in our unit have demonstrated that familial papillary thyroid cancer (fPTC) patients display an imbalance, at the germinal level, in telomere-telomerase complex. AIM: We aimed to verify whether familial fPTC patients show an increased spontaneous chromosome fragility. METHODS: To this purpose, we compared telomeric fusions and associations as well as other chromosomal fragility features by conventional and molecular cytogenetic analyses, in phytohemagglutinin stimulated T-lymphocytes from fPTC patients, unaffected family members, sporadic papillary thyroid cancer patients, and healthy subjects. RESULTS: We demonstrate that fPTC patients have a significant increase in spontaneous telomeric associations and telomeric fusions compared with healthy subjects and sporadic cases in the frame of an otherwise common spontaneous chromosome fragility pattern. A quantitative fluorescence in situ hybridization analysis demonstrates that familial cases display a significant decrease in the telomeric peptide nucleic acid-fluorescence in situ hybridization signal intensity in the metaphase chromosome. Moreover, three copies of the hTERT gene were found only in familial cases, although the result was not statistically significant. CONCLUSIONS: These results contribute in defining familial thyroid cancer as a clinical entity characterized by an altered telomere stability, which may be associated with the predisposition to develop the familial form of thyroid cancer.

Centrosomal and mitotic abnormalities in cell lines derived from papillary thyroid cancer harboring specific gene alterations.

BACKGROUND: Differentiated thyroid carcinoma offers a good model to investigate the possible correlation between specific gene mutations and chromosome instability. Papillary thyroid neoplasms are characterized by different mutually exclusive genetic alterations, some of which are associated with aneuploidy and aggressive phenotype. RESULTS: We investigated the centrosome status and mitotic abnormalities in three thyroid carcinoma-derived cell lines, each maintaining the specific, biologically relevant gene alteration harbored by the parental tumors: RET/PTC1 rearrangement in TPC1; heterozygous and homozygous BRAFV600E mutation in K1 and in B-CPAP, respectively. B-CPAP cells showed a statistically significant (P < 0.01) higher frequency of abnormal mitotic figures compared to TPC1 and K1 cells. CONCLUSIONS: Our data indicate that RET/PTC1 oncogenic activity is not related to mitotic chromosome impairment and missegregation whereas, based on the consistent difference in types/frequencies of centrosome and spindle abnormalities observed between K1 and B-CPAP cells, the hetero/homozygous allelic status of BRAFV600E mutation seems to be not irrelevant in respect to chromosomal instability development.

Deep fibrous histiocytoma with a clonal karyotypic alteration: molecular cytogenetic characterization of a t(16;17)(p13.3;q21.3).

Deep fibrous histiocytoma, a rare lesion occuring in deep soft tissues, has recently been formally characterized as a diagnostically distinguishable variant of the benign fibrous histiocytoma spectrum with distinct morphological features. Nevertheless, because of the small number of cases published, information on their clinical behavior, including propensity for local recurrence and metastasis, is quite limited, and no molecular genetic or cytogenetic data are available. We report a 46,XY,t(16;17)(p13.3;q21.3) karyotype in a deep fibrous histiocytoma. Fluorescence in situ hybridization using bacterial artificial chromosome (BAC) clones refined the translocation breakpoints within 119.9 kb at 16p13.3 and 214 kb at 17q21.3. Moreover, to ascertain whether they may be nonrandomly involved in changes in this rare tumor type, we designed two dual-color break-apart probes with BAC clones, mapping proximally and distally to the two breakpoints, to be tested in additional archival cases by interphase fluorescence in situ hybridization. No break-apart signals were observed in the six additional cases studied, indicating either that the translocation is sporadic or that it is rare in deep fibrous histiocytoma. In conclusion, our data show that chromosome aberrations may be found in deep fibrous histiocytoma and that, as with cutaneous lesions, they may have clonal, at present nonrecurrent, chromosome changes.

Trisomy 17 as a marker for a subset of noninvasive thyroid nodules with focal features of papillary carcinoma: cytogenetic and molecular analysis of 62 cases and correlation with histological findings.

CONTEXT: Differentiated carcinomas of the thyroid are divided into follicular thyroid carcinoma and papillary thyroid carcinoma (PTC), based on their propensity to invade and their cytological features [papillary carcinoma-type nuclear changes (PTC-NCs)]. PTC typically exhibits a diploid karyotype sometimes with inv10(q11.2q21.2), leading to rearranged RET gene. Follicular thyroid carcinomas are often aneuploid and may exhibit t(2;3)(q13;p25), resulting in PAX8-PPARgamma1 gene fusion. Isolated trisomy 17 has rarely been reported in thyroid lesions, and its significance is unknown. OBJECTIVE/DESIGN: Our objective was to determine whether isolated trisomy 17 corresponds to a specific histological or molecular thyroid tumor subset. Nine cases with isolated trisomy 17 were critically reviewed and investigated for RAS and BRAF mutations and for RET and PAX8-PPARgamma1 rearrangements. RESULTS: All nine cases were noninvasive, exhibited follicular growth pattern, and showed PTC-NCs focally defined within the nodule: four were PTCs follicular variant within larger tumors, and five were follicular-patterned nodules with incomplete cytological features of papillary carcinoma (variable proportion of cells with PTC-NCs scattered inside the lesion). RAS, BRAF V600E mutation, RET or PAX8-PPARgamma1 rearrangements were not identified. One case had BRAF K601E mutation. Only two of the 53 control cases showed focal PTC-NCs. CONCLUSIONS: Isolated trisomy 17 is associated with focal papillary carcinoma changes in follicular-patterned thyroid nodules and may be a marker for this subset of thyroid lesions that are often difficult to classify.