MARCELLO DELANO BRONSTEIN
Projetos de Pesquisa
Unidades Organizacionais
LIM/25 - Laboratório de Endocrinologia Celular e Molecular, Hospital das Clínicas, Faculdade de Medicina
16 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 16
- Cabergoline and prolactinomas: lack of association between DRD2 polymorphisms and response to treatment(2017) BUENO, C. B. F.; TRARBACH, E. B.; BRONSTEIN, M. D.; GLEZER, A.Background About 80% of prolactinomas respond to dopamine agonists (DA) with hormonal normalization and tumor shrinkage. Mechanisms of DA resistance include reduction of dopamine receptor subtype 2 (DRD2) expression, short and long isoform ratio and post-receptor mechanisms. It was suggested that polymorphisms in the gene encoding dopamine receptor subtype 2 gene (DRD2) could be associated with variable effectiveness of cabergoline (CAB). Objective To assess the influence of DRD2 polymorphisms in responsiveness of CAB treatment in patients with prolactinoma. Study design and patients Cross-sectional retrospective case-control study analyzing the frequency of five DRD2 polymorphisms in 148 patients with prolactinoma and 349 healthy subjects. The association of genetic variants and clinical characteristics with CAB responsiveness was performed in 118 patients (mean age at diagnosis 29 years; range 11-61 years) with hormonal evaluation. Patients with prolactin (PRL) normalization were considered as responders. Results No association in genotypes and allele proportions was found comparing patients and controls. On pharmacogenetic study, 118 patients on CAB were included and 20% were non-responders. No association was found between clinical characteristics (gender, age, PRL level and tumor size at diagnosis) and polymorphisms of DRD2 with CAB responsiveness. Otherwise, there was association between polymorphisms rs1076560 (allele A) and rs1800497 (allele T) and the presence of macroadenomas. Conclusion No correlation was found between DRD2 polymorphisms and CAB responsiveness in patients with prolactinoma. More data are necessary in order to assess the influence of DRD2 genotyping on DA treatment response.
- Influence of growth hormone receptor (GHR) exon 3 and-202A/C IGFBP-3 genetic polymorphisms on clinical and biochemical features and therapeutic outcome of patients with acromegaly(2015) JALLAD, Raquel S.; TRARBACH, Ericka B.; DUARTE, Felipe H.; JORGE, Alexander A. L.; BRONSTEIN, Marcello D.The association of GHR-exon 3 and -202 A/C IGFBP3 polymorphisms with clinical presentation, biochemical measurements and response to therapies in acromegaly have been suggested. To evaluate the presence of these polymorphisms in acromegaly and their influence on clinical and laboratorial characteristics of patients at diagnosis and after treatment in a large cohort of acromegalic patients. This is a cross-sectional study developed in a single tertiary reference center. Clinical data were obtained from the medical records of 186 acromegalic patients (116 women, age range 21-88 years). GH and IGF1 levels and GHR-exon 3 and -202 A/C IGFBP3 polymorphisms were evaluated in the same hospital. At diagnosis, serum GH concentrations were lower in patients with GHR-d3 genotype than those with GHR-fl, whereas an association of lower IGFBP3 levels with d3 allele was observed only after neurosurgical or medical treatments. However, these associations were not confirmed in posterior statistical analysis. Our results suggest that GHR-exon 3 and -202 A/C IGFBP3 polymorphisms did not show any consistent association on clinical and laboratorial features of acromegalic patients even after treatment.
- SOCS2 polymorphisms are not associated with clinical and biochemical phenotypes in acromegalic patients(2017) TRARBACH, Ericka B.; JORGE, Alexander A.; DUARTE, Felipe H.; BRONSTEIN, Marcello D.; JALLAD, Raquel S.Purpose Suppressor of cytokine signaling 2 (SOCS2) is a STAT5b-regulated gene and one of its functions is to influence growth and development through negative regulatory effects on GH/IGF-1 pathway. So, we evaluate the potential influence of SOCS2 single nucleotide polymorphisms (SNPs) on clinical and laboratorial characteristics of a large cohort of Brazilian patients with acromegaly. Methods Four SOCS2 SNPs (rs3782415, rs3816997, rs3825199 and rs11107116) were selected and genotyped by real-time PCR using specific Taqman probe assays. A total of 186 patients (116 women, age range 26-88 years) were evaluated. Results No association of SOCS2 genotypes was observed with none of the following clinical and laboratorial characteristics: age, sex, body mass index, comorbidities, basal GH, oral glucose tolerance test GH nadir, IGF-I, ULNRIGF-I. Conclusion Despite of the key role of SOCS2 in the regulation of GH receptor signaling, we did not find any significant association between SOCS2 polymorphisms and acromegaly.
- Association between KISS1 rs5780218 promoter polymorphism and onset of growth hormone secreting pituitary adenoma(2019) AMORIM, Paulo V. G. H.; GRANDE, Isabella P. P.; BATISTA, Rafael L.; SILVEIRA, Leticia F. G.; FREIRE, Ane Caroline T. B.; BRONSTEIN, Marcello D.; JALLAD, Raquel S.; TRARBACH, Ericka B.Objectives. - This study analyzed the KISS1 c.-145delA (rs5780218) promoter polymorphism in a cohort of patients with growth hormone secreting pituitary adenoma (somatotropinoma) and controls, to investigate its role in the incidence of acromegaly and to assess patient/tumor characteristics. Material and methods rs5780218 allelic and genotypic distributions were compared between 49 somatotropinoma patients and 167 healthy controls. rs5780218 was also assessed in relation to patient characteristics and tumor aggressiveness, as characterized by tumor invasion and resistance to conventional therapy. The relationship between KISS1 mRNA expression and the rs5780218 genotype was also assessed in available pituitary tumor samples. Results. - The homozygous -/- variant genotype was associated with high rates of somatotropinoma (P < 0.01), but not with tumor invasiveness, patient characteristics or hormonal remission. KISS1 mRNA expression was much lower in somatotropinomas carrying the deleted allele than in homozygous wild type AA. Conclusions. - In this pilot study, the rs5780218 promoter polymorphism was evaluated in pituitary adenoma, and showed a possible association with the incidence of somatotropinoma but not with tumor progression.
- Differential gene expression of sirtuins between somatotropinomas and nonfunctioning pituitary adenomas(2018) GRANDE, Isabella P. P.; AMORIM, Paulo V. G. H.; FREIRE, Ane Caroline The B.; JALLAD, Raquel S.; MUSOLINO, Nina R.; CESCATO, Valter A.; SILVA, Gilberto O. da; BRONSTEIN, Marcello D.; TRARBACH, Ericka B.Sirtuins 1-7 (SIRT) are a highly conserved family of histone deacetylases involved in the regulation of longevity that have a considerable impact in transcription, DNA repair regulation, telomeric stability, cell senescence and apoptosis. In the present study, SIRT1-7 mRNA levels were evaluated in 37 somatotropinomas and 31 nonfunctioning pituitary adenomas (NFPAs) using qPCR and relation to tumor size, invasiveness and Ki-67 proliferative index was made. Overexpression of SIRT1 was observed in 86.5% of somatotropinomas versus 41.9% of NFPAs (P < 0.01). SIRT3 was more underexpressed in NFPAs than somatotropinomas (77.4 and 40.5%, respectively, P < 0.01) as well as SIRT4 and SIRT7. Despite the lack of association between sirtuins and invasiveness or Ki-67 index, SIRT1 and SIRT3 expressions were related to tumor size. Mean of the largest diameter was smaller in adenomas with SIRT1 overexpression than with normal expression (P < 0.01) and SIRT3 underexpression was associated with larger tumors (P < 0.01). In conclusion, a pronounced difference in sirtuins expression was identified between pituitary adenomas, suggesting that these genes are potential markers of pituitary adenomas and could be employed in the characterization of somatotropinomas and NFPAs. The role of sirtuins in pathogenesis of pituitary tumors merits further investigation and possibly will provide new molecular insight about their progression.
- Transcriptome analysis showed a Differential signature between invasive and non-invasive corticotrophinomas(2017) ARAUJO, Leonardo Jose Tadeu de; LERARIO, Antonio Marcondes; CASTRO, Margaret de; MARTINS, Clarissa Silva; BRONSTEIN, Marcello Delano; MACHADO, Marcio Carlos; TRARBACH, Ericka Barbosa; FRAGOSO, Maria Candida Barisson VillaresACTH-dependent hypercortisolism caused by a pituitary adenoma [Cushing's disease (CD)] is the most common cause of endogenous Cushing's syndrome. CD is often associated with several morbidities, including hypertension, diabetes, osteoporosis/bone fractures, secondary infections, and increased cardiovascular mortality. While the majority (approximate to 80%) of the corticotrophinomas visible on pituitary magnetic resonance imaging are microadenomas (MICs, <10 mm of diameter), some tumors are macroadenomas (MACs, >= 10 mm) with increased growth potential and invasiveness, exceptionally exhibiting malignant demeanor. In addition, larger and invasive MACs are associated with a significant increased risk of local complications, such as hypopituitarism and visual defects. Given the clinical and molecular heterogeneity of corticotrophinomas, the aim of this study was to investigate the pattern of genetic differential expression between MIC and MAC, including the invasiveness grade as a criterion for categorizing these tumors. In this study, were included tumor samples from patients with clinical, laboratorial, radiological, and histopathological diagnosis of hypercortisolism due to an ACTH-producing pituitary adenoma. Differential gene expression was studied using an Affymetrix microarray platform in 12 corticotrophinomas, classified as non-invasive MIC (n = 4) and MAC (n = 5), and invasive MAC (n = 3), according to modified Hardy criteria. Somatic mutations in USP8 were also investigated, but none of the patients exhibited USP8 variants. Differential expression analysis demonstrated that non-invasive MIC and MAC have a similar genetic signature, while invasive MACs exhibited a differential expression profile. Among the genes differentially expressed, we highlighted CCND2, ZNF676, DAPK1, and TIMP2, and their differential expression was validated through quantitative real-time PCR in another cohort of 15 non-invasive and 3 invasive cortocotrophinomas. We also identified potential biological pathways associated with growth and invasiveness, TGF-beta and G protein signaling pathways, DNA damage response pathway, and pathways associated with focal adhesion. Our study revealed a differential pattern of genetic signature in a subgroup of MAC, supporting a genetic influence on corticotrophinomas in patients with CD.
- Survivin: A Potential Marker of Resistance to Somatostatin Receptor Ligands(2023) HERKENHOFF, Clarissa G. Borba; TRARBACH, Ericka B.; BATISTA, Rafael Loch; SOARES, Ibere Cauduro; FRASSETTO, Fernando Pereira; NASCIMENTO, Felipe Barjud Pereira do; GRANDE, Isabella Pacetti Pajaro; SILVA, Paula P. B.; DUARTE, Felipe H. G.; BRONSTEIN, Marcello D.; JALLAD, Raquel S.Context Invasive and somatostatin receptor ligand (SRL)-resistant pituitary tumors represent a challenge in the clinical practice of endocrinologists. Efforts have been made to elucidate reliable makers for both. Survivin and eukaryotic translation initiation factor-binding protein 1 (4EBP1) are upregulated in several cancers and involved in apoptosis and cell proliferation. Objective We explored the role of these markers in somatotropinomas. Methods Immunostains for survivin and 4EBP1, and also for somatostatin receptor type 2 (SSTR2), Ki-67, and cytokeratin 18, were analyzed in tissue microarrays containing 52 somatotropinoma samples. Tumor invasiveness was evaluated in all samples while drug resistance was evaluated in 34 patients who received SRL treatment. All these parameters were correlated with first-generation SRL (fg-SRL) responsiveness and tumor invasiveness. Results Low survivin expression (P = 0.04), hyperintense signal on T2 weighted image (T2WI) (P = 0.01), younger age (P = 0.01), sparsely granular adenomas (SGA) (P = 0.04), high postoperative growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels (P = 0.049 and P < 0.001, respectively), and large postoperative tumor size (P = 0.02) were associated with resistance to fg-SRL. Low survivin and SSTR2 expression and high 4EBP1 expression were associated with SGA (P = 0.04, P = 0.01, and P = 0.001, respectively). Younger age (P = 0.03), large tumor pre- and postoperative (P = 0.04 and P = 0.006, respectively), low SSTR2 expression (P = 0.03), and high baseline GH and IGF-1 (P = 0.01 and P = 0.02, respectively) were associated with tumor invasiveness. However, survivin, 4EBP1, Ki-67, and granulation patterns were not associated with tumor invasion. Conclusion This study suggests that low survivin expression is predictive of resistance to fg-SRL in somatotropinomas, but not of tumor invasiveness.
conferenceObject Screening of AIP (aryl hydrocarbon receptor-interacting protein) Gene Mutations in Patients with Sporadic Pituitary Gigantism(2014) FOLTRAN, Renata Kikuchi; TRARBACH, Ericka Barbosa; DUARTE, Felipe H. G.; JALLAD, Raquel S.; BRONSTEIN, Marcello D.- Impaired Bone Microarchitecture in Premenopausal Women With Acromegaly: The Possible Role of Wnt Signaling(2021) SILVA, Paula P. B.; PEREIRA, Rosa M. R.; TAKAYAMA, Liliam; BORBA, Clarissa G.; DUARTE, Felipe H.; TRARBACH, Ericka B.; MARTIN, Regina Matsunaga; BRONSTEIN, Marcello D.; TRITOS, Nicholas A.; JALLAD, Raquel S.Context: Acromegaly can impair bone integrity, increasing the risk of vertebral fractures (VFs). Objective: To evaluate the impact of isolated GH/IGF-I hypersecretion on bone turnover markers, Wnt inhibitors, bone mineral density (BMD), microarchitecture, bone strength and vertebral fractures in female patients with acromegaly (Acro), compared with healthy control group (HC). Design, setting, and patients: Cross-sectional study including 83 premenopausal women without any pituitary deficiency:18 acromegaly in remission (AcroR), 12 in group with active acromegaly (AcroA), and 53 HC. Serum procollagen type 1 N-terminal propeptide, beta-carboxy-terminal crosslinked telopeptide of type 1 collagen, osteocalcin, sclerostin, and DKK1 were measured in blood samples. dual-energy X-ray absorptiometry, high-resolution peripheral quantitative computed tomography (HR-pQCT) and vertebral fractures evaluation were also assessed simultaneously. Main outcome and results: AcroA showed significantly lower sclerostin and higher DKK1 compared with HC. On HR-pQCT of tibia and radius, Acro showed impairment of trabecular (area and trabecular number), increased cortical porosity, and increased cortical area and cortical thickness compared with HC. The only significant correlation found with HR-pQCT parameters was a positive correlation between cortical porosity and serum DKK1 (R= 0.45, P= 0.044). Mild VFs were present in approximately 30% of patients. Conclusions: Eugonadal women with acromegaly without any pituitary deficiency showed increased cortical BMD, impairment of trabecular bone microstructure, and increased VF. Sclerostin was not correlated with any HR-pQCT parameters; however, DKK1 was correlated with cortical porosity in tibia (P= 0.027). Additional studies are needed to clarify the role of Wnt inhibitors on bone microarchitecture impairment in acromegaly.
- Filamin A and DRD2 expression in corticotrophinomas(2019) SICKLER, Thais; TRARBACH, Ericka Barbosa; FRASSETTO, Fernando Pereira; DETTONI, Juliano Bertollo; ALVES, Venancio Avancini Ferreira; FRAGOSO, Maria Candida Barisson Villares; MACHADO, Marcio Carlos; CARDOSO, Ellison Fernando; BRONSTEIN, Marcello Delano; GLEZER, AndreaPurposeFilamin A (FLNA) expression is related to dopamine receptor type 2 (DRD2) expression in prolactinomas. Nevertheless, in corticotrophinomas, there are few studies about DRD2 expression and no data on FLNA. Therefore, we evaluated FLNA and DRD2 expression in corticotrophinomas and their association with tumor characteristics.MethodsDRD2 and FLNA expression by immunohistochemistry, using H-score, based on the percentage of positive cells in a continuous scale of 0-300, were evaluated in 23 corticotrophinomas samples from patients submitted to neurosurgery. In six patients, treatment with cabergoline was indicated after non curative surgery.ResultsTwenty-two patients were female and one male. Regarding tumor size, 10 were micro and 12 were macroadenomas. DRD2 expression was found in 89% of cases and did not correlate with FLNA expression. Moreover, the response to cabergoline, observed in 33% of the cases, did not correlate with DRD2 nor FLNA expression. FLNA expression was not associated with clinical and tumor characteristics, except for sphenoid sinus invasion.ConclusionsIn our cohort of corticotrophinomas, DRD2 expression was not associated with FLNA expression nor to the response to CAB. Nonetheless, FLNA expression could be related to tumor invasiveness.