Sebastiano Filetti | Università degli Studi "La Sapienza" di Roma (original) (raw)
Papers by Sebastiano Filetti
Journal of the Endocrine Society, 2017
Oncology reports, 2018
Anaplastic thyroid carcinoma (ATC) represents the most lethal thyroid cancer sub-type, currently ... more Anaplastic thyroid carcinoma (ATC) represents the most lethal thyroid cancer sub-type, currently unresponsive to standard treatments. Recently, bromodomain and extra-terminal (BET) proteins have emerged as attractive therapeutic targets in several diseases, including cancer. In different cancer models, the anti-neoplastic activity of BET inhibitors such as JQ1, I-BET762 and I-BET151 have already been established, due to both direct and indirect effects. miRNAs are 20-22 nucleotide transcriptional regulators which play important roles in proliferation, differentiation and apoptosis. Hitherto, the relationship between JQ1 and miRNAs has not been explored. The goal of this study was to delineate JQ1-associated miRNA regulation in ATC cells. Two ATC-derived cell lines (SW1736 and 8505c) were treated with either 5 µM JQ1 or vehicle for 48 or 72 h. A non-tumorigenic thyroid cell line (Nthy-ori 3-1) was used as a control. miRNome analysis displayed a JQ1-related dysregulation of several mi...
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...
Hyperfunctioning thyroid nodules are characterized by the presence of spontaneous somatic mutatio... more Hyperfunctioning thyroid nodules are characterized by the presence of spontaneous somatic mutations responsible for constitutive activation of the cAMP pathway. However, alterations affecting other elements of the cAMP signaling system may counteract the effects of the mutations. In this study, the expression of the adenylyl cyclase (AC) types III and VI was investigated by Western blot in 18 hyperfunctioning thyroid nodules; in 12 samples, we also assessed the presence of TSH receptor (TSHR) or gsp mutations and levels of AC VI and III mRNA. We found that the expression of nodular AC VI (but not AC III) was significantly lower (85.1% of normal, P=0.014) than the expression of both adenylyl cycles types of perinodular tissue from the same patients. Slightly, but not significant differences were detected in nodules with or without mutations and AC protein levels generally showed correlation with the levels of the transcripts detected by RT-PCR. In addition, AC III and AC VI expression levels within a given nodule were characterized by a significant positive correlation. These findings indicate that a diminished expression of AC type VI may be part of the mechanisms occurring in the hyperfunctioning nodules, independently of the presence of TSHR or gsp mutations, which influence the resulting phenotype.
Thyroid, 2003
Ten years after the first description of activating mutations in the thyroid stimulating hormone ... more Ten years after the first description of activating mutations in the thyroid stimulating hormone receptor (TSHR) gene in sporadic autonomous hyperfunctioning thyroid adenomas, there is general agreement in assigning a major pathogenic role of this genetic abnormality, acting via the constitutive activation of the cAMP pathway, in both the growth and functional characteristic of these tumours. From the beginning, however, the pathophysiological and clinical relevance of somatic TSHR mutations has been debated and some arguments still exist against a fully causative role of these mutations and the practical value of detecting these mutations for the diagnosis, treatment and prognosis of thyroid hot nodules. Some major issues will be examined herein, including (a) the frequency of TSHR alterations in various reports showing that the genetic abnormality underlying the pathogenesis of a substantial subset of thyroid tumours has yet to be identified; (b) the limitations of the present experimental models, which suggest greater caution in the interpretation of in vitro results; (c) the still unresolved question of absence of genotype-phenotype correlation. Clarification of these issues may hopefully provide new and useful tools for improving the clinical management of this disease.
The Journal of Clinical Endocrinology Metabolism, Jul 2, 2013
Nat Rev Endocrinol, 2009
Clinical investigation of enlarged, local lymph nodes after surgery for papillary thyroid carcino... more Clinical investigation of enlarged, local lymph nodes after surgery for papillary thyroid carcinoma is problematic. Use of the fine-needle aspiration thyroglobulin assay could help to identify patients whose disease has progressed to lymph-node metastasis.
Journal of Atherosclerosis and Thrombosis, Jun 30, 2010
Type 2 diabetes increases the risk for cardiovascular disease, and 3-hydroxy-3-methylglutaryl coe... more Type 2 diabetes increases the risk for cardiovascular disease, and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) reduce cardiovascular events in these patients. The benefits of statin therapy cannot be explained only by the lipid-lowering effect. The aim of this study was to test the effect of atorvastatin therapy on CD36 scavenger receptor expression, nuclear factor-kappaB (NFkappaB) levels and markers of inflammation (C-reactive protein, CRP, Tumor Necrosis Factor-alpha, TNF-alpha) in circulating monocytes from diabetic patients. Twenty-two type 2 diabetic patients were treated for 8 weeks with atorvastatin (20 mg/day). At baseline and after treatment a blood sample was collected for measurement of glucose, lipid profile (total cholesterol, HDL, LDL cholesterol, triglycerides), glycated hemoglobin (HbA1c), CRP and for isolation of monocytes. Atorvastatin decreased total (p<0.0001) and LDL (p<0.01), and incresased HDL choles-terol (p<0.02). CD36 surface protein expression (anti-CD36 fluorescein isothiocyanate-FITC) was reduced in circulating monocytes after atorvastatin therapy (p<0.02) while immunoblot analysis showed reduced nuclear and increased cytoplasm NFkappaB levels (p<0.05). Finally, TNFalpha production in lipopolysaccharide-activated monocytes from patients treated with atorvastatin was reduced (p<0.05). These results suggest that atorvastatin therapy, beside lowering serum cholesterol levels, could exert anti-atherogenic and anti-inflammatory effects in type 2 diabetic patients.
Journal of Biological Chemistry
The presence of 50 mM nicotinamide together with 100 milliunits/ml of TSH in the incubation mediu... more The presence of 50 mM nicotinamide together with 100 milliunits/ml of TSH in the incubation medium prevented the decline in human thyroid cell cAMP from maximum, stimulated levels (15-30 min) that occurs when the cells are exposed to TSH alone. Nicotinamide in the absence of TSH did not increase thyroid cell cAMP content. TSH desensitization, and its prevention by nicotinamide, occurred in the presence or absence of 3-isobutyl-methylxanthine. 1-Methyl nicotinamide and N'-methyl nicotinamide similarly prevented TSH desensitization. Recovery from TSH desensitization was prolonged and incomplete after 72 h. The presence of 50 mM nicotinamide hastened recovery from desensitization. Desensitization of the cAMP response to 10(6) M prostaglandin E1 and 1 mM adenosine was unaffected by nicotinamide. Other inhibitors of poly(ADP-ribose) polymerase activity, 5-bromouridine, 5-bromo-2'-deoxyuridine, and thymidine (all at 50 mM) completely or partially prevented TSH desensitization. Pyridoxine (50 mM) similarly prevented this phenomenon. As with dog thyroid cells, 10(-4) M cycloheximide blocked TSH desensitization. The combination of 10(-4) M cycloheximide and 50 mM nicotinamide had a synergistic effect in augmenting the thyroid cell cAMP response to TSH stimulation.
Journal of Biological Chemistry
Oncogene
A series of 14 thyroid carcinomas, characterized for their basal adenyl cyclase activity (ACA), w... more A series of 14 thyroid carcinomas, characterized for their basal adenyl cyclase activity (ACA), was examined for the presence of activating point mutations in the TSH receptor (TSHR) gene. Sequencing of the carboxyl-part of this gene revealed the presence of a somatic and heterozygotic point mutation in codon 623 in three out of six tumors showing a constitutively enhanced ACA and a poor response to TSH stimulation. The mutation determines the substitution of a serine for an alanine in the third intracellular loop of the receptor, in a region critical for signal transduction. One tumor bearing a TSHR mutation presented also a N-ras point mutation. Both mutations were detected also in a lung metastasis of this tumor. Our data represent the first report of alterations in the TSHR gene in thyroid malign neoplasia. TSHR mutations may indeed participate, as well as the G alpha s protein (gsp oncogene), in the oncogenesis of some differentiated thyroid carcinomas presenting increased basal levels of cAMP and a poor response to TSH.
Forum (Genoa, Italy)
Human thyroid tumours represent an example of the interplay of genetic and non genetic carcinogen... more Human thyroid tumours represent an example of the interplay of genetic and non genetic carcinogenesis. Recently, genetic abnormalities in the elements of the Thyrotropin receptor (TSH-R) dependent cAMP regulatory cascade have been found to be involved both in benign and malignant thyroid tumours. The presence of activating mutations has been demonstrated in the TSH-R gene as well as in the Gs alpha protein gene in thyroid toxic adenoma resulting in the constitutive activation of the cAMP pathway and it has been hypothesised that these genetic alterations may play a causative role in the disease. However, recent observations suggest more caution in accepting such a hypothesis. The presence of activating TSH-R mutations has also been demonstrated in differentiated thyroid carcinomas. At present, the percentage of such a modification is low, unless referred to selected series of tumours. Activating mutations of the TSH-R gene have been detected in a group of differentiated carcinomas with high basal adenylyl cyclase activity, and in a few cases of hyperfunctioning thyroid carcinoma. However, the role of the TSH-R-related cAMP pathway alterations in thyroid transformation remains to be elucidated. In this review, the role of TSH-R gene alterations in benign and malignant thyroid neoplasia is examined.
Journal of Clinical Endocrinology & Metabolism
The Journal of nuclear biology and medicine
Recenti progressi in medicina
Cardiovascular disease is the leading cause of death in the industrialized world. Being multiple ... more Cardiovascular disease is the leading cause of death in the industrialized world. Being multiple risk factors for atherosclerosis it emerged the concept of global cardiovascular risk assessment. Furthermore, risk factors clustered together. The metabolic syndrome, as the confluence of risk factors of metabolic origin, is associated with cardiovascular disease and type 2 diabetes. A clinical diagnosis of metabolic syndrome allows to identify individuals at high risk of developing cardiovascular disease and type 2 diabetes and it affects therapeutic strategies for primary prevention. Although changes in lifestyle are fundamental to treat all the risk factors, pharmacologic interventions targeting the single component of the syndrome also play an important role. Increasingly, an alternative strategy is available and attractive: the introduction of therapies targeting multiple risk factors simultaneously through a combination of 2 or more drugs into a single capsule.
Hormone and metabolic research. Supplement series
Molecular Endocrinology
Five overlapping cDNA clones representing the entire mRNA for human thyroid peroxidase (TPO) have... more Five overlapping cDNA clones representing the entire mRNA for human thyroid peroxidase (TPO) have been isolated from a human Graves' thyroid cDNA library. The cDNA sequence has been determined. Human TPO cDNA contains 3060 bases from the start of transcription to the beginning of the poly (A) tail at the 3'-end. The derived amino acid sequence of human TPO consists of 933 amino acids with a mol wt of 102,937. The derived amino acid sequence contains five potential glycosylation sites (Asn-X-Ser/Thr), a probable transmembrane signal peptide sequence at the amino terminus, and a hydrophobic putative membrane-spanning region beginning 85 amino acid residues from the carboxyl terminal end. Comparison of the human TPO amino acid sequence to that of pig TPO shows strong homology extending from the amino terminus to within 44 amino acid residues of the carboxyl-terminus.
Diabetologie und Stoffwechsel, 2010
The Journal of nuclear biology and medicine
Journal of the Endocrine Society, 2017
Oncology reports, 2018
Anaplastic thyroid carcinoma (ATC) represents the most lethal thyroid cancer sub-type, currently ... more Anaplastic thyroid carcinoma (ATC) represents the most lethal thyroid cancer sub-type, currently unresponsive to standard treatments. Recently, bromodomain and extra-terminal (BET) proteins have emerged as attractive therapeutic targets in several diseases, including cancer. In different cancer models, the anti-neoplastic activity of BET inhibitors such as JQ1, I-BET762 and I-BET151 have already been established, due to both direct and indirect effects. miRNAs are 20-22 nucleotide transcriptional regulators which play important roles in proliferation, differentiation and apoptosis. Hitherto, the relationship between JQ1 and miRNAs has not been explored. The goal of this study was to delineate JQ1-associated miRNA regulation in ATC cells. Two ATC-derived cell lines (SW1736 and 8505c) were treated with either 5 µM JQ1 or vehicle for 48 or 72 h. A non-tumorigenic thyroid cell line (Nthy-ori 3-1) was used as a control. miRNome analysis displayed a JQ1-related dysregulation of several mi...
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...
Hyperfunctioning thyroid nodules are characterized by the presence of spontaneous somatic mutatio... more Hyperfunctioning thyroid nodules are characterized by the presence of spontaneous somatic mutations responsible for constitutive activation of the cAMP pathway. However, alterations affecting other elements of the cAMP signaling system may counteract the effects of the mutations. In this study, the expression of the adenylyl cyclase (AC) types III and VI was investigated by Western blot in 18 hyperfunctioning thyroid nodules; in 12 samples, we also assessed the presence of TSH receptor (TSHR) or gsp mutations and levels of AC VI and III mRNA. We found that the expression of nodular AC VI (but not AC III) was significantly lower (85.1% of normal, P=0.014) than the expression of both adenylyl cycles types of perinodular tissue from the same patients. Slightly, but not significant differences were detected in nodules with or without mutations and AC protein levels generally showed correlation with the levels of the transcripts detected by RT-PCR. In addition, AC III and AC VI expression levels within a given nodule were characterized by a significant positive correlation. These findings indicate that a diminished expression of AC type VI may be part of the mechanisms occurring in the hyperfunctioning nodules, independently of the presence of TSHR or gsp mutations, which influence the resulting phenotype.
Thyroid, 2003
Ten years after the first description of activating mutations in the thyroid stimulating hormone ... more Ten years after the first description of activating mutations in the thyroid stimulating hormone receptor (TSHR) gene in sporadic autonomous hyperfunctioning thyroid adenomas, there is general agreement in assigning a major pathogenic role of this genetic abnormality, acting via the constitutive activation of the cAMP pathway, in both the growth and functional characteristic of these tumours. From the beginning, however, the pathophysiological and clinical relevance of somatic TSHR mutations has been debated and some arguments still exist against a fully causative role of these mutations and the practical value of detecting these mutations for the diagnosis, treatment and prognosis of thyroid hot nodules. Some major issues will be examined herein, including (a) the frequency of TSHR alterations in various reports showing that the genetic abnormality underlying the pathogenesis of a substantial subset of thyroid tumours has yet to be identified; (b) the limitations of the present experimental models, which suggest greater caution in the interpretation of in vitro results; (c) the still unresolved question of absence of genotype-phenotype correlation. Clarification of these issues may hopefully provide new and useful tools for improving the clinical management of this disease.
The Journal of Clinical Endocrinology Metabolism, Jul 2, 2013
Nat Rev Endocrinol, 2009
Clinical investigation of enlarged, local lymph nodes after surgery for papillary thyroid carcino... more Clinical investigation of enlarged, local lymph nodes after surgery for papillary thyroid carcinoma is problematic. Use of the fine-needle aspiration thyroglobulin assay could help to identify patients whose disease has progressed to lymph-node metastasis.
Journal of Atherosclerosis and Thrombosis, Jun 30, 2010
Type 2 diabetes increases the risk for cardiovascular disease, and 3-hydroxy-3-methylglutaryl coe... more Type 2 diabetes increases the risk for cardiovascular disease, and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) reduce cardiovascular events in these patients. The benefits of statin therapy cannot be explained only by the lipid-lowering effect. The aim of this study was to test the effect of atorvastatin therapy on CD36 scavenger receptor expression, nuclear factor-kappaB (NFkappaB) levels and markers of inflammation (C-reactive protein, CRP, Tumor Necrosis Factor-alpha, TNF-alpha) in circulating monocytes from diabetic patients. Twenty-two type 2 diabetic patients were treated for 8 weeks with atorvastatin (20 mg/day). At baseline and after treatment a blood sample was collected for measurement of glucose, lipid profile (total cholesterol, HDL, LDL cholesterol, triglycerides), glycated hemoglobin (HbA1c), CRP and for isolation of monocytes. Atorvastatin decreased total (p<0.0001) and LDL (p<0.01), and incresased HDL choles-terol (p<0.02). CD36 surface protein expression (anti-CD36 fluorescein isothiocyanate-FITC) was reduced in circulating monocytes after atorvastatin therapy (p<0.02) while immunoblot analysis showed reduced nuclear and increased cytoplasm NFkappaB levels (p<0.05). Finally, TNFalpha production in lipopolysaccharide-activated monocytes from patients treated with atorvastatin was reduced (p<0.05). These results suggest that atorvastatin therapy, beside lowering serum cholesterol levels, could exert anti-atherogenic and anti-inflammatory effects in type 2 diabetic patients.
Journal of Biological Chemistry
The presence of 50 mM nicotinamide together with 100 milliunits/ml of TSH in the incubation mediu... more The presence of 50 mM nicotinamide together with 100 milliunits/ml of TSH in the incubation medium prevented the decline in human thyroid cell cAMP from maximum, stimulated levels (15-30 min) that occurs when the cells are exposed to TSH alone. Nicotinamide in the absence of TSH did not increase thyroid cell cAMP content. TSH desensitization, and its prevention by nicotinamide, occurred in the presence or absence of 3-isobutyl-methylxanthine. 1-Methyl nicotinamide and N'-methyl nicotinamide similarly prevented TSH desensitization. Recovery from TSH desensitization was prolonged and incomplete after 72 h. The presence of 50 mM nicotinamide hastened recovery from desensitization. Desensitization of the cAMP response to 10(6) M prostaglandin E1 and 1 mM adenosine was unaffected by nicotinamide. Other inhibitors of poly(ADP-ribose) polymerase activity, 5-bromouridine, 5-bromo-2'-deoxyuridine, and thymidine (all at 50 mM) completely or partially prevented TSH desensitization. Pyridoxine (50 mM) similarly prevented this phenomenon. As with dog thyroid cells, 10(-4) M cycloheximide blocked TSH desensitization. The combination of 10(-4) M cycloheximide and 50 mM nicotinamide had a synergistic effect in augmenting the thyroid cell cAMP response to TSH stimulation.
Journal of Biological Chemistry
Oncogene
A series of 14 thyroid carcinomas, characterized for their basal adenyl cyclase activity (ACA), w... more A series of 14 thyroid carcinomas, characterized for their basal adenyl cyclase activity (ACA), was examined for the presence of activating point mutations in the TSH receptor (TSHR) gene. Sequencing of the carboxyl-part of this gene revealed the presence of a somatic and heterozygotic point mutation in codon 623 in three out of six tumors showing a constitutively enhanced ACA and a poor response to TSH stimulation. The mutation determines the substitution of a serine for an alanine in the third intracellular loop of the receptor, in a region critical for signal transduction. One tumor bearing a TSHR mutation presented also a N-ras point mutation. Both mutations were detected also in a lung metastasis of this tumor. Our data represent the first report of alterations in the TSHR gene in thyroid malign neoplasia. TSHR mutations may indeed participate, as well as the G alpha s protein (gsp oncogene), in the oncogenesis of some differentiated thyroid carcinomas presenting increased basal levels of cAMP and a poor response to TSH.
Forum (Genoa, Italy)
Human thyroid tumours represent an example of the interplay of genetic and non genetic carcinogen... more Human thyroid tumours represent an example of the interplay of genetic and non genetic carcinogenesis. Recently, genetic abnormalities in the elements of the Thyrotropin receptor (TSH-R) dependent cAMP regulatory cascade have been found to be involved both in benign and malignant thyroid tumours. The presence of activating mutations has been demonstrated in the TSH-R gene as well as in the Gs alpha protein gene in thyroid toxic adenoma resulting in the constitutive activation of the cAMP pathway and it has been hypothesised that these genetic alterations may play a causative role in the disease. However, recent observations suggest more caution in accepting such a hypothesis. The presence of activating TSH-R mutations has also been demonstrated in differentiated thyroid carcinomas. At present, the percentage of such a modification is low, unless referred to selected series of tumours. Activating mutations of the TSH-R gene have been detected in a group of differentiated carcinomas with high basal adenylyl cyclase activity, and in a few cases of hyperfunctioning thyroid carcinoma. However, the role of the TSH-R-related cAMP pathway alterations in thyroid transformation remains to be elucidated. In this review, the role of TSH-R gene alterations in benign and malignant thyroid neoplasia is examined.
Journal of Clinical Endocrinology & Metabolism
The Journal of nuclear biology and medicine
Recenti progressi in medicina
Cardiovascular disease is the leading cause of death in the industrialized world. Being multiple ... more Cardiovascular disease is the leading cause of death in the industrialized world. Being multiple risk factors for atherosclerosis it emerged the concept of global cardiovascular risk assessment. Furthermore, risk factors clustered together. The metabolic syndrome, as the confluence of risk factors of metabolic origin, is associated with cardiovascular disease and type 2 diabetes. A clinical diagnosis of metabolic syndrome allows to identify individuals at high risk of developing cardiovascular disease and type 2 diabetes and it affects therapeutic strategies for primary prevention. Although changes in lifestyle are fundamental to treat all the risk factors, pharmacologic interventions targeting the single component of the syndrome also play an important role. Increasingly, an alternative strategy is available and attractive: the introduction of therapies targeting multiple risk factors simultaneously through a combination of 2 or more drugs into a single capsule.
Hormone and metabolic research. Supplement series
Molecular Endocrinology
Five overlapping cDNA clones representing the entire mRNA for human thyroid peroxidase (TPO) have... more Five overlapping cDNA clones representing the entire mRNA for human thyroid peroxidase (TPO) have been isolated from a human Graves' thyroid cDNA library. The cDNA sequence has been determined. Human TPO cDNA contains 3060 bases from the start of transcription to the beginning of the poly (A) tail at the 3'-end. The derived amino acid sequence of human TPO consists of 933 amino acids with a mol wt of 102,937. The derived amino acid sequence contains five potential glycosylation sites (Asn-X-Ser/Thr), a probable transmembrane signal peptide sequence at the amino terminus, and a hydrophobic putative membrane-spanning region beginning 85 amino acid residues from the carboxyl terminal end. Comparison of the human TPO amino acid sequence to that of pig TPO shows strong homology extending from the amino terminus to within 44 amino acid residues of the carboxyl-terminus.
Diabetologie und Stoffwechsel, 2010
The Journal of nuclear biology and medicine