Kerry Rhoden | Università di Bologna (original) (raw)

Papers by Kerry Rhoden

Research paper thumbnail of YFP-H148Q/I152L the yellow fluorescent protein variant Cell-based imaging of sodium iodide symporter activity

Research paper thumbnail of BRAFV600E mutation and expression of proangiogenic molecular markers in papillary thyroid carcinomas

European Journal of Endocrinology, 2011

ObjectiveTyrosine kinase inhibitors (TKIs) are evaluated for treatment of radioiodine refractory ... more ObjectiveTyrosine kinase inhibitors (TKIs) are evaluated for treatment of radioiodine refractory thyroid cancer. Their effects in this setting are based on blockade of proangiogenic signaling mediated by receptors for vascular endothelial growth factors (VEGFs) and platelet-derived growth factors (PDGF). Most TKIs also block other cancer-relevant kinases, such as B-type Raf kinase (BRAF), which are constitutively activated in approximately half of papillary thyroid carcinomas (PTCs), but the impact of these effects is not clear.DesignThe aim of our study was to investigate the impact of BRAFV600E on proangiogenic gene expression and microvascular features of PTCs.MethodsmRNA levels for VEGFA, VEGF receptors, and coreceptors (VEGFRs 1, 2, and 3, neuropilin-1), and PDGF receptor β (PDGFRβ or PDGFRB) were measured with real-time PCR in BRAFV600E (n=55) and wild-type BRAF (BRAF-wt; n=35) PTCs. VEGF and VEGFR protein expression and microvessel densities (MVD) and lymphatic vessel densiti...

Research paper thumbnail of Real-time quantitative RT-PCR identifies distinct c-RET, RET/PTC1 and RET/PTC3 expression patterns in papillary thyroid carcinoma

Laboratory Investigation, 2004

RET/PTC1 and RET/PTC3 are the markers for papillary thyroid carcinoma. Their reported prevalence ... more RET/PTC1 and RET/PTC3 are the markers for papillary thyroid carcinoma. Their reported prevalence varies broadly. Nonrearranged c-RET has also been detected in a variable proportion of papillary carcinomas. The published data suggest that a wide range in expression levels may contribute to the different frequency of c-RET and, particularly, of RET/PTC detection. However, quantitative expression analysis has never been systematically carried out. We have analyzed by real-time RT-PCR 25 papillary carcinoma and 12 normal thyroid samples for RET/PTC1, RET/PTC3 and for RET exons 10-11 and 12-13, which are adjacent to the rearrangement site. The variability in mRNA levels was marked and four carcinoma groups were identified: one lacking RET/ PTC rearrangement with balanced RET exon levels similar to those of the normal samples (7/25 cases, 28%), the second (6/25 cases, 24%) with balanced RET expression and very low levels of RET/PTC1, the third with unbalanced RET exons 10-11 and 12-13 expression, high RET/PTC1 levels but no RET/PTC3 (7/25 cases, 28%), and the fourth with unbalanced RET expression, high RET/PTC1 levels and low levels of RET/PTC3 (5/25 cases, 20%). Papillary carcinomas with high RET/PTC1 expression showed an association trend for large tumor size (P ¼ 0.063). Our results indicate that the variability in c-RET and RET/PTC mRNA levels contributes to the apparent inconsistencies in their reported detection rates and should be taken into account not only for diagnostic purposes but also to better understand the role of c-RET activation in thyroid tumorigenesis.

Research paper thumbnail of BRAF Mutation Predicts a Poorer Clinical Prognosis for Papillary Thyroid Cancer

The Journal of Clinical Endocrinology & Metabolism, 2005

Context: Use of BRAF mutation in papillary thyroid cancer (PTC) has the potential to improve risk... more Context: Use of BRAF mutation in papillary thyroid cancer (PTC) has the potential to improve risk stratification of this cancer. Objective: The objective of the study was to investigate the prognostic value of BRAF mutation in patients with PTC. Design, Setting, and Subjects: In a multicenter study of 219 PTC patients, data on their clinicopathological characteristics and clinical courses between 1990 and 2004 were retrospectively collected, and their tumor BRAF mutation status was determined. Associations of BRAF mutation with initial tumor characteristics and subsequent recurrence were analyzed. Main Outcome Measure: Relationships between the BRAF mutation status and clinicopathological outcomes, including recurrence, were measured. Results: We found a significant association between BRAF mutation and extrathyroidal invasion (P < 0.001), lymph node metastasis (P < 0.001), and advanced tumor stage III/IV (P = 0.007) at initial surgery. This association remained significant on...

Research paper thumbnail of RET/Papillary Thyroid Cancer Rearrangement in Nonneoplastic Thyrocytes: Follicular Cells of Hashimoto’s Thyroiditis Share Low-Level Recombination Events with a Subset of Papillary Carcinoma

The Journal of Clinical Endocrinology & Metabolism, 2006

Context: RET/papillary thyroid cancer (PTC) is a marker for papillary thyroid carcinoma, but its ... more Context: RET/papillary thyroid cancer (PTC) is a marker for papillary thyroid carcinoma, but its specificity has been questioned because of the disputed identification of RET/PTC in Hashimoto's thyroiditis (HT), oncocytic tumors, and other thyroid lesions. Objective: The objective of this study was to determine 1) whether RET/PTC occurs in nonneoplastic follicular cells of HT, and 2) its recombination rate in thyroid tumors. Design/Patients: Forty-three samples from 31 cases of HT were examined using interphase fluorescence in situ hybridization (FISH) with RET probes spanning the breakpoint region; real-time RT-PCR to quantify RET/PTC1, RET/PTC3, and c-RET transcripts; and RT-PCR after laser capture microdissection to enrich samples for follicular cells. The results were compared with those similarly obtained in 34 papillary carcinomas, eight thyroid oncocytic tumors, and 21 normal thyroids. Results: Normal samples showed no RET rearrangement. Sixtyeight percent (15 of 22) of HT were positive by FISH; in all thyroiditis, signals were localized to rare nonneoplastic follicular cells; low-level RET/PTC was identified in 17% (five of 29) of thyroiditis cases by real-time RT-PCR and in an additional six of 11 real-time negative cases after increasing sensitivity with laser capture microdissection. Low RET/PTC1 levels were detected in 26% (nine of 34) of papillary carcinomas with an expression pattern and proportion of FISHpositive cells similar to those of the thyroiditis. Forty-seven percent (16 of 34) of papillary carcinomas and one oncocytic carcinoma expressed high RET/PTC1 mRNA levels. Conclusions: Low-level RET/PTC recombination occurs in nonneoplastic follicular cells in HT and in a subset of papillary thyroid carcinomas. RET/PTC expression variability should be taken into account for the molecular diagnosis of thyroid lesions. Overlapping molecular mechanisms may govern early stages of tumor development and inflammation in the thyroid.

Research paper thumbnail of Cell-based imaging of sodium iodide symporter activity with the yellow fluorescent protein variant YFP-H148Q/I152L

American Journal of Physiology-Cell Physiology, 2006

The sodium iodide symporter (NIS) mediates iodide (I−) transport in the thyroid gland and other t... more The sodium iodide symporter (NIS) mediates iodide (I−) transport in the thyroid gland and other tissues and is of increasing importance as a therapeutic target and nuclear imaging reporter. NIS activity in vitro is currently measured with radiotracers and electrophysiological techniques. We report on the development of a novel live cell imaging assay of NIS activity using the I−-sensitive and genetically encodable yellow fluorescent protein (YFP) variant YFP-H148Q/I152L. In FRTL-5 thyrocytes stably expressing YFP-H148Q/I152L, I− induced a rapid and reversible decrease in cellular fluorescence characterized by 1) high affinity for extracellular I− (35 μM), 2) inhibition by the NIS inhibitor perchlorate, 3) extracellular Na+ dependence, and 4) TSH dependence, suggesting that fluorescence changes are due to I− influx via NIS. Individual cells within a population of FRTL-5 cells exhibited a 3.5-fold variation in the rate of NIS-mediated I− influx, illustrating the utility of YFP-H148Q/I...

Research paper thumbnail of Perfluorooctane sulfonic acid, a persistent organic pollutant, inhibits iodide accumulation by thyroid follicular cells in vitro

Molecular and Cellular Endocrinology

Research paper thumbnail of miR-196B-5P and miR-200B-3P Are Differentially Expressed in Medulloblastomas of Adults and Children

Diagnostics

Medulloblastoma is a highly aggressive brain tumor that typically affects children, while in adul... more Medulloblastoma is a highly aggressive brain tumor that typically affects children, while in adults it represents ~1% of all brain tumors. Little is known about microRNA expression profile of the rare adult medulloblastoma. The main aim of this study was to identify peculiar differences in microRNA expression between childhood and adult medulloblastoma. Medulloblastomas were profiled for microRNA expression using the Exiqon Human miRNome panel (I + II) analyzing 752 microRNAs in a training set of six adult and six childhood cases. Then, the most differentially expressed microRNAs were validated in a total of 21 adult and 19 childhood cases. Eight microRNAs (miR-196b-5p, miR-183-5p, miR-200b-3p, miR-196a-5p, miR-193a-3p, miR-29c-3p, miR-33b-5p, and miR-200a-3p) were differentially expressed in medulloblastoma of adults and children. Analysis of the validation set confirmed that miR-196b-5p and miR-200b-3p were significantly overexpressed in medulloblastoma of adults as compared with ...

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

Cancers

BRAF exon 15 mutations are the most common molecular alterations found in papillary thyroid carci... more 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—Only in tissue surrounding BRAF p.V600E mutated PTCs...

Research paper thumbnail of Does the Site of Origin of the Microcarcinoma with Respect to the Thyroid Surface Matter? A Multicenter Pathologic and Clinical Study for Risk Stratification

Cancers

It is unclear whether the site of origin of papillary thyroid microcarcinoma (mPTC) with respect ... more It is unclear whether the site of origin of papillary thyroid microcarcinoma (mPTC) with respect to the thyroid surface has an influence on clinicopathologic parameters. The objectives of the study were to: (i) Accurately measure the mPTC distance from the thyroid surface; (ii) analyze whether this distance correlates with relevant clinicopathologic parameters; and (iii) investigate the impact of the site of origin of the mPTC on risk stratification. Clinicopathologic features and BRAF mutational status were analyzed and correlated with the site of origin of the mPTC in a multicenter cohort of 298 mPTCs from six Italian medical institutions. Tumors arise at a median distance of 3.5 mm below the surface of the thyroid gland. Statistical analysis identified four distinct clusters. Group A, mPTC: size ≥ 5 mm and distance of the edge of the tumor from the thyroid capsule = 0 mm; group B, mPTC: size ≥ 5 mm and distance of the edge of the tumor from the thyroid capsule > 0 mm; group C,...

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

Histopathology

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and t... more 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.

Research paper thumbnail of Mutant MYO1F alters the mitochondrial network and induces tumor proliferation in thyroid cancer

International journal of cancer, Jan 19, 2018

Familial aggregation is a significant risk factor for the development of thyroid cancer and famil... more Familial aggregation is a significant risk factor for the development of thyroid cancer and familial non-medullary thyroid cancer (FNMTC) accounts for 5-7% of all NMTC. Whole exome sequencing analysis in the family affected by FNMTC with oncocytic features where our group previously identified a predisposing locus on chromosome 19p13.2, revealed a novel heterozygous mutation (c.400G > A, NM_012335; p.Gly134Ser) in exon 5 of MYO1F, mapping to the linkage locus. In the thyroid FRTL-5 cell model stably expressing the mutant MYO1F p.Gly134Ser protein, we observed an altered mitochondrial network, with increased mitochondrial mass and a significant increase in both intracellular and extracellular reactive oxygen species, compared to cells expressing the wild-type (wt) protein or carrying the empty vector. The mutation conferred a significant advantage in colony formation, invasion and anchorage-independent growth. These data were corroborated by in vivo studies in zebrafish, since we ...

Research paper thumbnail of RETmutation and increased angiogenesis in medullary thyroid carcinomas

Endocrine-Related Cancer, 2016

Advanced medullary thyroid cancers (MTCs) are now being treated with drugs that inhibit receptor ... more 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. Com...

Research paper thumbnail of Seronegative celiac disease: Shedding light on an obscure clinical entity

Digestive and Liver Disease, 2016

Although serological tests are useful for identifying celiac disease, it is well established that... more Although serological tests are useful for identifying celiac disease, it is well established that a minority of celiacs are seronegative. To define the prevalence and features of seronegative compared to seropositive celiac disease, and to establish whether celiac disease is a common cause of seronegative villous atrophy. Starting from 810 celiac disease diagnoses, seronegative patients were retrospectively characterized for clinical, histological and laboratory findings. Of the 810 patients, fourteen fulfilled the diagnostic criteria for seronegative celiac disease based on antibody negativity, villous atrophy, HLA-DQ2/-DQ8 positivity and clinical/histological improvement after gluten free diet. Compared to seropositive, seronegative celiac disease showed a significantly higher median age at diagnosis and a higher prevalence of classical phenotype (i.e., malabsorption), autoimmune disorders and severe villous atrophy. The most frequent diagnosis in the 31 cases with seronegative flat mucosa was celiac disease (45%), whereas other diagnoses were Giardiasis (20%), common variable immunodeficiency (16%) and autoimmune enteropathy (10%). Although rare seronegative celiac disease can be regarded as the most frequent cause of seronegative villous atrophy being characterized by a high median age at diagnosis; a close association with malabsorption and flat mucosa; and a high prevalence of autoimmune disorders.

Research paper thumbnail of Stimulation of the Na+-K+ Pump in Cultured Guinea Pig Airway Smooth Muscle Cells by Serotonin

Journal of Pharmacology and Experimental Therapeutics, Apr 1, 2000

The effect of 5-hydroxytryptamine (5-HT) or serotonin on Na(+)-K(+) pump activity of airway smoot... more The effect of 5-hydroxytryptamine (5-HT) or serotonin on Na(+)-K(+) pump activity of airway smooth muscle was investigated by measuring (86)Rb(+) uptake in cultured guinea pig tracheal smooth muscle cells. (86)Rb(+) uptake consisted of three distinct components, one sensitive to ouabain, one to bumetanide, and one insensitive to either inhibitor. 5-HT induced a concentration-dependent increase in ouabain-sensitive (86)Rb(+) uptake (EC(50) = 21 nM) but had no effect on bumetanide-sensitive uptake, suggesting that it stimulates the Na(+)-K(+) pump but not the Na(+)-K(+)-Cl(-) cotransporter. Ouabain-sensitive uptake also was stimulated by the 5-HT(2A/2C) agonists 2,5-dimethoxy-4-iodoamphetamine and alpha-methyl-5-HT, but not by the 5-HT(1) agonist 5-carboxamidotryptamine, the 5-HT(1A/1B/2C) agonist 1-(3-chlorophenyl)piperazine, or the 5-HT(3) agonist 1-(3-chlorophenyl)biguanide. 5-HT-stimulated (86)Rb(+) uptake was inhibited by the 5-HT(2A) antagonists ketanserin and spiperone, but not by the 5-HT(1A) antagonist NAN 190 or the 5-HT(3) antagonist Y25310. 5-HT-stimulated (86)Rb(+) uptake was inhibited by reducing extracellular Na(+) concentration and by the Na(+)-H(+) exchange inhibitors dimethylamiloride and 5-(N-methyl-N-isobutyl)-amiloride. These observations suggest that 5-HT stimulates the Na(+)-K(+) pump of airway smooth muscle via 5-HT(2A) receptors by a mechanism dependent on Na(+) influx, possibly through the Na(+)-H(+) exchanger. Because stimulation of the Na(+)-K(+) pump produces hyperpolarization, this may represent a negative-feedback mechanism that opposes contraction in response to 5-HT.

Research paper thumbnail of Potentiation of nonadrenergic neural relaxation in guinea pig airways by a cyclic cAMP phosphodiesterase inhibitor

Journal of Pharmacology and Experimental Therapeutics, 1990

We have studied the effect of phosphodiesterase inhibitors on relaxation of guinea pig tracheal s... more We have studied the effect of phosphodiesterase inhibitors on relaxation of guinea pig tracheal smooth muscle in an attempt to elucidate the role of cyclic nucleotides in relaxation to stimulation of inhibitory nonadrenergic noncholinergic (i-NANC) nerves. SK&amp;F 94120 (1-10 microM) potentiated relaxation induced by isoproterenol, vasoactive intestinal peptide (VIP) and electrical field stimulation (EFS) in the presence of atropine and propranolol but had no effect on relaxation induced by sodium nitroprusside. Zaprinast (3-30 microM) potentiated relaxation induced by sodium nitroprusside but not by isoproterenol or VIP. A small potentiation of relaxation to EFS was induced by 30 microM zaprinast but not by lower concentrations. Tetrodotoxin attenuated relaxations induced by EFS suggesting that they are at least partly neurogenic in origin. SK&amp;F 94120 and zaprinast had no effect of tetrodotoxin-resistant relaxation to EFS. The guanylate cyclase inhibitor had no effect on EFS-induced relaxation. These findings suggest that cyclic AMP may mediate relaxation of guinea pig tracheal smooth muscle in response to stimulation of i-NANC nerves, and are in agreement with the view that VIP may be the neurotransmitter released by i-NANC nerves in this tissue.

Research paper thumbnail of Features and Progression of Potential Celiac Disease in Adults

Clinical Gastroenterology and Hepatology, 2015

Individuals with potential celiac disease have serologic and genetic markers of the disease with ... more Individuals with potential celiac disease have serologic and genetic markers of the disease with little or no damage to the small intestinal mucosa. We performed a prospective study to learn more about disease progression in these people. We collected data from 77 adults (59 female; median age, 33 years) diagnosed with potential celiac disease (based on serology and HLA type) at Bologna University, in Italy, from 2004 through 2013. The subjects had normal or slight inflammation of the small intestinal mucosa. Clinical, laboratory, and histologic parameters were evaluated at diagnosis and during a 3-year follow-up period. Sixty-one patients (46 female; median age, 36 years) showed intestinal and extra-intestinal symptoms, whereas the remaining 16 (13 female; median age, 21 years) were completely asymptomatic at diagnosis. All subjects tested positive for immunoglobulin (Ig)A endomysial antibody and tissue transglutaminase antibody, except for 1 patient with IgA deficiency; 95% of patients were carriers of HLA-DQ2. Duodenal biopsies from 26% patients had a Marsh score of 0 and 74% had a Marsh score of 1. A higher proportion of symptomatic patients had autoimmune disorders (36%) and antinuclear antibodies (41%) than asymptomatic patients (5% and 12.5%, respectively), and symptomatic patients were of older age at diagnosis (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.05). Gluten withdrawal led to a significant clinical improvement in all 61 symptomatic patients. The 16 asymptomatic patients continued on gluten-containing diets and only 1 developed mucosal flattening; levels of anti-endoymsial and tissue transglutaminase antibodies fluctuated in 5 of these patients or became undetectable. In a 3 year study of adults with potential celiac disease, we found most to have symptoms, but these improved upon gluten withdrawal. Conversely, we do not recommend a gluten-free diet for asymptomatic adults with potential celiac disease, since they do not tend to develop villous atrophy.

Research paper thumbnail of BRAF V600E and risk stratification of thyroid microcarcinoma: a multicenter pathological and clinical study

Modern Pathology, 2015

Studies from single institutions have analyzed BRAF in papillary microcarcinomas, sometimes with ... more Studies from single institutions have analyzed BRAF in papillary microcarcinomas, sometimes with contradictory results. Most of them have provided limited integration of histological and clinical data. To obtain a comprehensive picture of BRAF V600E-mutated microcarcinomas and to evaluate the role of BRAF testing in risk stratification we performed a retrospective multicenter analysis integrating microscopical, pathological, and clinical information. Three hundred and sixty-five samples from 300 patients treated at six medical institutions covering different geographical regions of Italy were analyzed with central review of all cases. BRAF V600E statistical analysis was conducted on 298 microcarcinomas from 264 patients after exclusion of those that did not meet the required criteria. BRAF V600E was identified in 145/298 tumors (49%) including the following subtypes: 35/37 (95%, Po0.0001) tall cell and 72/114 (64%, Po0.0001) classic; conversely 94/129 follicular variant papillary microcarcinomas (73%, Po0.0001) were BRAF wild type. BRAF V600E-mutated microcarcinomas were characterized by markedly infiltrative contours (Po0.0001) with elongated strings of neoplastic cells departing from the tumor, and by intraglandular tumor spread (Po0.0001), typically within 5 mm of the tumor border. Multivariate analysis correlated BRAF V600E with specific microscopic features (nuclear grooves, optically clear nuclei, tall cells within the tumor, and tumor fibrosis), aggressive growth pattern (infiltrative tumor border, extension into extrathyroidal tissues, and intraglandular tumor spread), higher American Thyroid Association recurrence risk group, and non-incidental tumor discovery. The following showed the strongest link to BRAF V600E: tall cell subtype, many neoplastic cells with nuclear grooves or with optically clear nuclei, infiltrative growth, intraglandular tumor spread, and a tumor discovery that was non-incidental. BRAF V600E-mutated microcarcinomas represent a distinct biological subtype. The mutation is associated with conventional clinico-pathological features considered to be adverse prognostic factors for papillary microcarcinoma, for which it could be regarded as a surrogate marker. BRAF analysis may be useful to identify tumors (BRAF wild type) that have negligible clinical risk.

Research paper thumbnail of Expression of HMGI-C and HMGI(Y) in ordinary lipoma and atypical lipomatous tumors: immunohistochemical reactivity correlates with karyotypic alterations

The American journal of pathology, 1997

The high mobility group proteins (HMGs) are a class of low molecular weight, nonhistone, nuclear ... more The high mobility group proteins (HMGs) are a class of low molecular weight, nonhistone, nuclear proteins that bind DNA and function as transcription cofactors. This class includes the HMGI family members HMGI-C and HMGI(Y). Both are not significantly expressed in differentiated adult tissues, including fat, but their expression is induced in proliferating and transformed cells. Their involvement in the development of lipomatous tumors has been recently demonstrated for HMGI-C, which is encoded by a gene located at 12q15, the chromosomal segment often rearranged in ordinary lipomas. The same chromosomal segment is consistently amplified in the ring and giant marker chromosomes of atypical lipomatous tumors (ALTs), a term used to designate tumors previously labeled as well differentiated liposarcomas or atypical lipomas. The involvement of HMGI(Y) is strongly suspected as the gene coding for HMGI(Y) is located at 6p21, a chromosomal segment rearranged in a subset of ordinary lipomas....

Research paper thumbnail of Endothelium-dependent relaxation of human pulmonary arteries

The American journal of physiology, 1987

Although endothelial cell (EC)-dependent relaxation has been described in most mammals, there hav... more Although endothelial cell (EC)-dependent relaxation has been described in most mammals, there have been no detailed reports of its existence in humans. Consequently, we evaluated human pulmonary artery segments taken from uninvolved regions of resected lung from 11 patients. EC removal did not significantly alter relaxation to vasoactive intestinal peptide (VIP). However, relaxation to acetylcholine (ACh) was observed only in segments with EC. Preincubation with either 1 microM propranolol or 10 microM indomethacin failed to block relaxation, but the addition of either 30 microM quinacrine hydrochloride or 100 microM nordihydroguaiaretic acid prevented it entirely. EC-dependent relaxation to ATP was also demonstrated. These data demonstrate that EC-dependent relaxation occurs in human pulmonary arteries. Neither beta-adrenergic pathways nor prostaglandin intermediaries are utilized. An oxidized breakdown product of arachidonic or some other fatty acid from EC phospholipid appears to...

Research paper thumbnail of YFP-H148Q/I152L the yellow fluorescent protein variant Cell-based imaging of sodium iodide symporter activity

Research paper thumbnail of BRAFV600E mutation and expression of proangiogenic molecular markers in papillary thyroid carcinomas

European Journal of Endocrinology, 2011

ObjectiveTyrosine kinase inhibitors (TKIs) are evaluated for treatment of radioiodine refractory ... more ObjectiveTyrosine kinase inhibitors (TKIs) are evaluated for treatment of radioiodine refractory thyroid cancer. Their effects in this setting are based on blockade of proangiogenic signaling mediated by receptors for vascular endothelial growth factors (VEGFs) and platelet-derived growth factors (PDGF). Most TKIs also block other cancer-relevant kinases, such as B-type Raf kinase (BRAF), which are constitutively activated in approximately half of papillary thyroid carcinomas (PTCs), but the impact of these effects is not clear.DesignThe aim of our study was to investigate the impact of BRAFV600E on proangiogenic gene expression and microvascular features of PTCs.MethodsmRNA levels for VEGFA, VEGF receptors, and coreceptors (VEGFRs 1, 2, and 3, neuropilin-1), and PDGF receptor β (PDGFRβ or PDGFRB) were measured with real-time PCR in BRAFV600E (n=55) and wild-type BRAF (BRAF-wt; n=35) PTCs. VEGF and VEGFR protein expression and microvessel densities (MVD) and lymphatic vessel densiti...

Research paper thumbnail of Real-time quantitative RT-PCR identifies distinct c-RET, RET/PTC1 and RET/PTC3 expression patterns in papillary thyroid carcinoma

Laboratory Investigation, 2004

RET/PTC1 and RET/PTC3 are the markers for papillary thyroid carcinoma. Their reported prevalence ... more RET/PTC1 and RET/PTC3 are the markers for papillary thyroid carcinoma. Their reported prevalence varies broadly. Nonrearranged c-RET has also been detected in a variable proportion of papillary carcinomas. The published data suggest that a wide range in expression levels may contribute to the different frequency of c-RET and, particularly, of RET/PTC detection. However, quantitative expression analysis has never been systematically carried out. We have analyzed by real-time RT-PCR 25 papillary carcinoma and 12 normal thyroid samples for RET/PTC1, RET/PTC3 and for RET exons 10-11 and 12-13, which are adjacent to the rearrangement site. The variability in mRNA levels was marked and four carcinoma groups were identified: one lacking RET/ PTC rearrangement with balanced RET exon levels similar to those of the normal samples (7/25 cases, 28%), the second (6/25 cases, 24%) with balanced RET expression and very low levels of RET/PTC1, the third with unbalanced RET exons 10-11 and 12-13 expression, high RET/PTC1 levels but no RET/PTC3 (7/25 cases, 28%), and the fourth with unbalanced RET expression, high RET/PTC1 levels and low levels of RET/PTC3 (5/25 cases, 20%). Papillary carcinomas with high RET/PTC1 expression showed an association trend for large tumor size (P ¼ 0.063). Our results indicate that the variability in c-RET and RET/PTC mRNA levels contributes to the apparent inconsistencies in their reported detection rates and should be taken into account not only for diagnostic purposes but also to better understand the role of c-RET activation in thyroid tumorigenesis.

Research paper thumbnail of BRAF Mutation Predicts a Poorer Clinical Prognosis for Papillary Thyroid Cancer

The Journal of Clinical Endocrinology & Metabolism, 2005

Context: Use of BRAF mutation in papillary thyroid cancer (PTC) has the potential to improve risk... more Context: Use of BRAF mutation in papillary thyroid cancer (PTC) has the potential to improve risk stratification of this cancer. Objective: The objective of the study was to investigate the prognostic value of BRAF mutation in patients with PTC. Design, Setting, and Subjects: In a multicenter study of 219 PTC patients, data on their clinicopathological characteristics and clinical courses between 1990 and 2004 were retrospectively collected, and their tumor BRAF mutation status was determined. Associations of BRAF mutation with initial tumor characteristics and subsequent recurrence were analyzed. Main Outcome Measure: Relationships between the BRAF mutation status and clinicopathological outcomes, including recurrence, were measured. Results: We found a significant association between BRAF mutation and extrathyroidal invasion (P < 0.001), lymph node metastasis (P < 0.001), and advanced tumor stage III/IV (P = 0.007) at initial surgery. This association remained significant on...

Research paper thumbnail of RET/Papillary Thyroid Cancer Rearrangement in Nonneoplastic Thyrocytes: Follicular Cells of Hashimoto’s Thyroiditis Share Low-Level Recombination Events with a Subset of Papillary Carcinoma

The Journal of Clinical Endocrinology & Metabolism, 2006

Context: RET/papillary thyroid cancer (PTC) is a marker for papillary thyroid carcinoma, but its ... more Context: RET/papillary thyroid cancer (PTC) is a marker for papillary thyroid carcinoma, but its specificity has been questioned because of the disputed identification of RET/PTC in Hashimoto's thyroiditis (HT), oncocytic tumors, and other thyroid lesions. Objective: The objective of this study was to determine 1) whether RET/PTC occurs in nonneoplastic follicular cells of HT, and 2) its recombination rate in thyroid tumors. Design/Patients: Forty-three samples from 31 cases of HT were examined using interphase fluorescence in situ hybridization (FISH) with RET probes spanning the breakpoint region; real-time RT-PCR to quantify RET/PTC1, RET/PTC3, and c-RET transcripts; and RT-PCR after laser capture microdissection to enrich samples for follicular cells. The results were compared with those similarly obtained in 34 papillary carcinomas, eight thyroid oncocytic tumors, and 21 normal thyroids. Results: Normal samples showed no RET rearrangement. Sixtyeight percent (15 of 22) of HT were positive by FISH; in all thyroiditis, signals were localized to rare nonneoplastic follicular cells; low-level RET/PTC was identified in 17% (five of 29) of thyroiditis cases by real-time RT-PCR and in an additional six of 11 real-time negative cases after increasing sensitivity with laser capture microdissection. Low RET/PTC1 levels were detected in 26% (nine of 34) of papillary carcinomas with an expression pattern and proportion of FISHpositive cells similar to those of the thyroiditis. Forty-seven percent (16 of 34) of papillary carcinomas and one oncocytic carcinoma expressed high RET/PTC1 mRNA levels. Conclusions: Low-level RET/PTC recombination occurs in nonneoplastic follicular cells in HT and in a subset of papillary thyroid carcinomas. RET/PTC expression variability should be taken into account for the molecular diagnosis of thyroid lesions. Overlapping molecular mechanisms may govern early stages of tumor development and inflammation in the thyroid.

Research paper thumbnail of Cell-based imaging of sodium iodide symporter activity with the yellow fluorescent protein variant YFP-H148Q/I152L

American Journal of Physiology-Cell Physiology, 2006

The sodium iodide symporter (NIS) mediates iodide (I−) transport in the thyroid gland and other t... more The sodium iodide symporter (NIS) mediates iodide (I−) transport in the thyroid gland and other tissues and is of increasing importance as a therapeutic target and nuclear imaging reporter. NIS activity in vitro is currently measured with radiotracers and electrophysiological techniques. We report on the development of a novel live cell imaging assay of NIS activity using the I−-sensitive and genetically encodable yellow fluorescent protein (YFP) variant YFP-H148Q/I152L. In FRTL-5 thyrocytes stably expressing YFP-H148Q/I152L, I− induced a rapid and reversible decrease in cellular fluorescence characterized by 1) high affinity for extracellular I− (35 μM), 2) inhibition by the NIS inhibitor perchlorate, 3) extracellular Na+ dependence, and 4) TSH dependence, suggesting that fluorescence changes are due to I− influx via NIS. Individual cells within a population of FRTL-5 cells exhibited a 3.5-fold variation in the rate of NIS-mediated I− influx, illustrating the utility of YFP-H148Q/I...

Research paper thumbnail of Perfluorooctane sulfonic acid, a persistent organic pollutant, inhibits iodide accumulation by thyroid follicular cells in vitro

Molecular and Cellular Endocrinology

Research paper thumbnail of miR-196B-5P and miR-200B-3P Are Differentially Expressed in Medulloblastomas of Adults and Children

Diagnostics

Medulloblastoma is a highly aggressive brain tumor that typically affects children, while in adul... more Medulloblastoma is a highly aggressive brain tumor that typically affects children, while in adults it represents ~1% of all brain tumors. Little is known about microRNA expression profile of the rare adult medulloblastoma. The main aim of this study was to identify peculiar differences in microRNA expression between childhood and adult medulloblastoma. Medulloblastomas were profiled for microRNA expression using the Exiqon Human miRNome panel (I + II) analyzing 752 microRNAs in a training set of six adult and six childhood cases. Then, the most differentially expressed microRNAs were validated in a total of 21 adult and 19 childhood cases. Eight microRNAs (miR-196b-5p, miR-183-5p, miR-200b-3p, miR-196a-5p, miR-193a-3p, miR-29c-3p, miR-33b-5p, and miR-200a-3p) were differentially expressed in medulloblastoma of adults and children. Analysis of the validation set confirmed that miR-196b-5p and miR-200b-3p were significantly overexpressed in medulloblastoma of adults as compared with ...

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

Cancers

BRAF exon 15 mutations are the most common molecular alterations found in papillary thyroid carci... more 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—Only in tissue surrounding BRAF p.V600E mutated PTCs...

Research paper thumbnail of Does the Site of Origin of the Microcarcinoma with Respect to the Thyroid Surface Matter? A Multicenter Pathologic and Clinical Study for Risk Stratification

Cancers

It is unclear whether the site of origin of papillary thyroid microcarcinoma (mPTC) with respect ... more It is unclear whether the site of origin of papillary thyroid microcarcinoma (mPTC) with respect to the thyroid surface has an influence on clinicopathologic parameters. The objectives of the study were to: (i) Accurately measure the mPTC distance from the thyroid surface; (ii) analyze whether this distance correlates with relevant clinicopathologic parameters; and (iii) investigate the impact of the site of origin of the mPTC on risk stratification. Clinicopathologic features and BRAF mutational status were analyzed and correlated with the site of origin of the mPTC in a multicenter cohort of 298 mPTCs from six Italian medical institutions. Tumors arise at a median distance of 3.5 mm below the surface of the thyroid gland. Statistical analysis identified four distinct clusters. Group A, mPTC: size ≥ 5 mm and distance of the edge of the tumor from the thyroid capsule = 0 mm; group B, mPTC: size ≥ 5 mm and distance of the edge of the tumor from the thyroid capsule > 0 mm; group C,...

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

Histopathology

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and t... more 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.

Research paper thumbnail of Mutant MYO1F alters the mitochondrial network and induces tumor proliferation in thyroid cancer

International journal of cancer, Jan 19, 2018

Familial aggregation is a significant risk factor for the development of thyroid cancer and famil... more Familial aggregation is a significant risk factor for the development of thyroid cancer and familial non-medullary thyroid cancer (FNMTC) accounts for 5-7% of all NMTC. Whole exome sequencing analysis in the family affected by FNMTC with oncocytic features where our group previously identified a predisposing locus on chromosome 19p13.2, revealed a novel heterozygous mutation (c.400G > A, NM_012335; p.Gly134Ser) in exon 5 of MYO1F, mapping to the linkage locus. In the thyroid FRTL-5 cell model stably expressing the mutant MYO1F p.Gly134Ser protein, we observed an altered mitochondrial network, with increased mitochondrial mass and a significant increase in both intracellular and extracellular reactive oxygen species, compared to cells expressing the wild-type (wt) protein or carrying the empty vector. The mutation conferred a significant advantage in colony formation, invasion and anchorage-independent growth. These data were corroborated by in vivo studies in zebrafish, since we ...

Research paper thumbnail of RETmutation and increased angiogenesis in medullary thyroid carcinomas

Endocrine-Related Cancer, 2016

Advanced medullary thyroid cancers (MTCs) are now being treated with drugs that inhibit receptor ... more 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. Com...

Research paper thumbnail of Seronegative celiac disease: Shedding light on an obscure clinical entity

Digestive and Liver Disease, 2016

Although serological tests are useful for identifying celiac disease, it is well established that... more Although serological tests are useful for identifying celiac disease, it is well established that a minority of celiacs are seronegative. To define the prevalence and features of seronegative compared to seropositive celiac disease, and to establish whether celiac disease is a common cause of seronegative villous atrophy. Starting from 810 celiac disease diagnoses, seronegative patients were retrospectively characterized for clinical, histological and laboratory findings. Of the 810 patients, fourteen fulfilled the diagnostic criteria for seronegative celiac disease based on antibody negativity, villous atrophy, HLA-DQ2/-DQ8 positivity and clinical/histological improvement after gluten free diet. Compared to seropositive, seronegative celiac disease showed a significantly higher median age at diagnosis and a higher prevalence of classical phenotype (i.e., malabsorption), autoimmune disorders and severe villous atrophy. The most frequent diagnosis in the 31 cases with seronegative flat mucosa was celiac disease (45%), whereas other diagnoses were Giardiasis (20%), common variable immunodeficiency (16%) and autoimmune enteropathy (10%). Although rare seronegative celiac disease can be regarded as the most frequent cause of seronegative villous atrophy being characterized by a high median age at diagnosis; a close association with malabsorption and flat mucosa; and a high prevalence of autoimmune disorders.

Research paper thumbnail of Stimulation of the Na+-K+ Pump in Cultured Guinea Pig Airway Smooth Muscle Cells by Serotonin

Journal of Pharmacology and Experimental Therapeutics, Apr 1, 2000

The effect of 5-hydroxytryptamine (5-HT) or serotonin on Na(+)-K(+) pump activity of airway smoot... more The effect of 5-hydroxytryptamine (5-HT) or serotonin on Na(+)-K(+) pump activity of airway smooth muscle was investigated by measuring (86)Rb(+) uptake in cultured guinea pig tracheal smooth muscle cells. (86)Rb(+) uptake consisted of three distinct components, one sensitive to ouabain, one to bumetanide, and one insensitive to either inhibitor. 5-HT induced a concentration-dependent increase in ouabain-sensitive (86)Rb(+) uptake (EC(50) = 21 nM) but had no effect on bumetanide-sensitive uptake, suggesting that it stimulates the Na(+)-K(+) pump but not the Na(+)-K(+)-Cl(-) cotransporter. Ouabain-sensitive uptake also was stimulated by the 5-HT(2A/2C) agonists 2,5-dimethoxy-4-iodoamphetamine and alpha-methyl-5-HT, but not by the 5-HT(1) agonist 5-carboxamidotryptamine, the 5-HT(1A/1B/2C) agonist 1-(3-chlorophenyl)piperazine, or the 5-HT(3) agonist 1-(3-chlorophenyl)biguanide. 5-HT-stimulated (86)Rb(+) uptake was inhibited by the 5-HT(2A) antagonists ketanserin and spiperone, but not by the 5-HT(1A) antagonist NAN 190 or the 5-HT(3) antagonist Y25310. 5-HT-stimulated (86)Rb(+) uptake was inhibited by reducing extracellular Na(+) concentration and by the Na(+)-H(+) exchange inhibitors dimethylamiloride and 5-(N-methyl-N-isobutyl)-amiloride. These observations suggest that 5-HT stimulates the Na(+)-K(+) pump of airway smooth muscle via 5-HT(2A) receptors by a mechanism dependent on Na(+) influx, possibly through the Na(+)-H(+) exchanger. Because stimulation of the Na(+)-K(+) pump produces hyperpolarization, this may represent a negative-feedback mechanism that opposes contraction in response to 5-HT.

Research paper thumbnail of Potentiation of nonadrenergic neural relaxation in guinea pig airways by a cyclic cAMP phosphodiesterase inhibitor

Journal of Pharmacology and Experimental Therapeutics, 1990

We have studied the effect of phosphodiesterase inhibitors on relaxation of guinea pig tracheal s... more We have studied the effect of phosphodiesterase inhibitors on relaxation of guinea pig tracheal smooth muscle in an attempt to elucidate the role of cyclic nucleotides in relaxation to stimulation of inhibitory nonadrenergic noncholinergic (i-NANC) nerves. SK&amp;F 94120 (1-10 microM) potentiated relaxation induced by isoproterenol, vasoactive intestinal peptide (VIP) and electrical field stimulation (EFS) in the presence of atropine and propranolol but had no effect on relaxation induced by sodium nitroprusside. Zaprinast (3-30 microM) potentiated relaxation induced by sodium nitroprusside but not by isoproterenol or VIP. A small potentiation of relaxation to EFS was induced by 30 microM zaprinast but not by lower concentrations. Tetrodotoxin attenuated relaxations induced by EFS suggesting that they are at least partly neurogenic in origin. SK&amp;F 94120 and zaprinast had no effect of tetrodotoxin-resistant relaxation to EFS. The guanylate cyclase inhibitor had no effect on EFS-induced relaxation. These findings suggest that cyclic AMP may mediate relaxation of guinea pig tracheal smooth muscle in response to stimulation of i-NANC nerves, and are in agreement with the view that VIP may be the neurotransmitter released by i-NANC nerves in this tissue.

Research paper thumbnail of Features and Progression of Potential Celiac Disease in Adults

Clinical Gastroenterology and Hepatology, 2015

Individuals with potential celiac disease have serologic and genetic markers of the disease with ... more Individuals with potential celiac disease have serologic and genetic markers of the disease with little or no damage to the small intestinal mucosa. We performed a prospective study to learn more about disease progression in these people. We collected data from 77 adults (59 female; median age, 33 years) diagnosed with potential celiac disease (based on serology and HLA type) at Bologna University, in Italy, from 2004 through 2013. The subjects had normal or slight inflammation of the small intestinal mucosa. Clinical, laboratory, and histologic parameters were evaluated at diagnosis and during a 3-year follow-up period. Sixty-one patients (46 female; median age, 36 years) showed intestinal and extra-intestinal symptoms, whereas the remaining 16 (13 female; median age, 21 years) were completely asymptomatic at diagnosis. All subjects tested positive for immunoglobulin (Ig)A endomysial antibody and tissue transglutaminase antibody, except for 1 patient with IgA deficiency; 95% of patients were carriers of HLA-DQ2. Duodenal biopsies from 26% patients had a Marsh score of 0 and 74% had a Marsh score of 1. A higher proportion of symptomatic patients had autoimmune disorders (36%) and antinuclear antibodies (41%) than asymptomatic patients (5% and 12.5%, respectively), and symptomatic patients were of older age at diagnosis (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.05). Gluten withdrawal led to a significant clinical improvement in all 61 symptomatic patients. The 16 asymptomatic patients continued on gluten-containing diets and only 1 developed mucosal flattening; levels of anti-endoymsial and tissue transglutaminase antibodies fluctuated in 5 of these patients or became undetectable. In a 3 year study of adults with potential celiac disease, we found most to have symptoms, but these improved upon gluten withdrawal. Conversely, we do not recommend a gluten-free diet for asymptomatic adults with potential celiac disease, since they do not tend to develop villous atrophy.

Research paper thumbnail of BRAF V600E and risk stratification of thyroid microcarcinoma: a multicenter pathological and clinical study

Modern Pathology, 2015

Studies from single institutions have analyzed BRAF in papillary microcarcinomas, sometimes with ... more Studies from single institutions have analyzed BRAF in papillary microcarcinomas, sometimes with contradictory results. Most of them have provided limited integration of histological and clinical data. To obtain a comprehensive picture of BRAF V600E-mutated microcarcinomas and to evaluate the role of BRAF testing in risk stratification we performed a retrospective multicenter analysis integrating microscopical, pathological, and clinical information. Three hundred and sixty-five samples from 300 patients treated at six medical institutions covering different geographical regions of Italy were analyzed with central review of all cases. BRAF V600E statistical analysis was conducted on 298 microcarcinomas from 264 patients after exclusion of those that did not meet the required criteria. BRAF V600E was identified in 145/298 tumors (49%) including the following subtypes: 35/37 (95%, Po0.0001) tall cell and 72/114 (64%, Po0.0001) classic; conversely 94/129 follicular variant papillary microcarcinomas (73%, Po0.0001) were BRAF wild type. BRAF V600E-mutated microcarcinomas were characterized by markedly infiltrative contours (Po0.0001) with elongated strings of neoplastic cells departing from the tumor, and by intraglandular tumor spread (Po0.0001), typically within 5 mm of the tumor border. Multivariate analysis correlated BRAF V600E with specific microscopic features (nuclear grooves, optically clear nuclei, tall cells within the tumor, and tumor fibrosis), aggressive growth pattern (infiltrative tumor border, extension into extrathyroidal tissues, and intraglandular tumor spread), higher American Thyroid Association recurrence risk group, and non-incidental tumor discovery. The following showed the strongest link to BRAF V600E: tall cell subtype, many neoplastic cells with nuclear grooves or with optically clear nuclei, infiltrative growth, intraglandular tumor spread, and a tumor discovery that was non-incidental. BRAF V600E-mutated microcarcinomas represent a distinct biological subtype. The mutation is associated with conventional clinico-pathological features considered to be adverse prognostic factors for papillary microcarcinoma, for which it could be regarded as a surrogate marker. BRAF analysis may be useful to identify tumors (BRAF wild type) that have negligible clinical risk.

Research paper thumbnail of Expression of HMGI-C and HMGI(Y) in ordinary lipoma and atypical lipomatous tumors: immunohistochemical reactivity correlates with karyotypic alterations

The American journal of pathology, 1997

The high mobility group proteins (HMGs) are a class of low molecular weight, nonhistone, nuclear ... more The high mobility group proteins (HMGs) are a class of low molecular weight, nonhistone, nuclear proteins that bind DNA and function as transcription cofactors. This class includes the HMGI family members HMGI-C and HMGI(Y). Both are not significantly expressed in differentiated adult tissues, including fat, but their expression is induced in proliferating and transformed cells. Their involvement in the development of lipomatous tumors has been recently demonstrated for HMGI-C, which is encoded by a gene located at 12q15, the chromosomal segment often rearranged in ordinary lipomas. The same chromosomal segment is consistently amplified in the ring and giant marker chromosomes of atypical lipomatous tumors (ALTs), a term used to designate tumors previously labeled as well differentiated liposarcomas or atypical lipomas. The involvement of HMGI(Y) is strongly suspected as the gene coding for HMGI(Y) is located at 6p21, a chromosomal segment rearranged in a subset of ordinary lipomas....

Research paper thumbnail of Endothelium-dependent relaxation of human pulmonary arteries

The American journal of physiology, 1987

Although endothelial cell (EC)-dependent relaxation has been described in most mammals, there hav... more Although endothelial cell (EC)-dependent relaxation has been described in most mammals, there have been no detailed reports of its existence in humans. Consequently, we evaluated human pulmonary artery segments taken from uninvolved regions of resected lung from 11 patients. EC removal did not significantly alter relaxation to vasoactive intestinal peptide (VIP). However, relaxation to acetylcholine (ACh) was observed only in segments with EC. Preincubation with either 1 microM propranolol or 10 microM indomethacin failed to block relaxation, but the addition of either 30 microM quinacrine hydrochloride or 100 microM nordihydroguaiaretic acid prevented it entirely. EC-dependent relaxation to ATP was also demonstrated. These data demonstrate that EC-dependent relaxation occurs in human pulmonary arteries. Neither beta-adrenergic pathways nor prostaglandin intermediaries are utilized. An oxidized breakdown product of arachidonic or some other fatty acid from EC phospholipid appears to...