LUCIANA PINTO BRITO
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
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- PROP1 and CTNNB1 expression in adamantinomatous craniopharyngiomas with or without beta-catenin mutations(2011) CANI, Carolina M. G.; MATUSHITA, Hamilton; CARVALHO, Luciani R. S.; SOARES, Ibere C.; BRITO, Luciana P.; ALMEIDA, Madson Q.; MENDONCA, Berenice B.INTRODUCTION: Activating mutations in exon 3 of the beta-catenin gene are involved in the pathogenesis of adamantinomatous craniopharyngiomas. Recently, the interaction between beta-catenin and PROP1 has been shown to be responsible for pituitary cell lineage determination. We hypothesized that dysregulated PROP1 expression could also be involved in the pathogenesis of craniopharyngiomas. OBJECTIVES: To determine whether dysregulated gene expression was responsible for tumor pathogenesis in adamantinomatous craniopharyngiomas, the beta-catenin gene was screened for mutations, and the expression of the beta-catenin gene and PROP1 was evaluated. METHODS: The beta-catenin gene was amplified and sequenced from 14 samples of adamantinomatous craniopharyngiomas. PROP1 and beta-catenin gene expression was assessed by real-time RT-PCR from 12 samples, and beta-catenin immunohistochemistry was performed on 11 samples. RESULTS: Mutations in the beta-catenin gene were identified in 64% of the adamantinomatous craniopharyngiomas samples. Evidence of beta-catenin gene overexpression was found in 71% of the tumors with beta-catenin mutations and in 40% of the tumors without mutations, and beta-catenin immunohistochemistry revealed a nuclear staining pattern for each of the analyzed samples. PROP1 expression was undetectable in all of the tumor samples. CONCLUSION: We found evidence of beta-catenin gene overexpression in the majority of adamantinomatous craniopharyngiomas, and we also detected a nuclear beta-catenin staining pattern regardless of the presence of a beta-catenin gene mutation. These results suggest that WNT signaling activation plays an important role in the pathogenesis of adamantinomatous craniopharyngiomas. Additionally, this study was the first to evaluate PROP1 expression in adamantinomatous craniopharyngiomas, and the absence of PROP1 expression indicates that this gene is not involved in the pathogenesis of this tumor, at least in this cohort.
- Intra-individual Variability of Serum Aldosterone and Implications for Primary Aldosteronism Screening(2023) MACIEL, Ana Alice W.; FREITAS, Thais C.; FAGUNDES, Gustavo F. C.; PETENUCI, Janaina; VILELA, Leticia A. P.; BRITO, Luciana P.; GOLDBAUM, Tatiana S.; ZERBINI, Maria Claudia N.; LEDESMA, Felipe L.; TANNO, Fabio Y.; SROUGI, Victor; CHAMBO, Jose L.; PEREIRA, Maria Adelaide A.; COELHO, Fernando M. A.; CAVALCANTE, Aline C. B. S.; CARNEVALE, Francisco C.; PILAN, Bruna; PIO-ABREU, Andrea; V, Joao Silveira; CONSOLIM-COLOMBO, Fernanda M.; BORTOLOTTO, Luiz A.; LATRONICO, Ana Claudia; V, Maria Candida B. Fragoso; DRAGER, Luciano F.; MENDONCA, Berenice B.; ALMEIDA, Madson Q.Context Primary aldosteronism (PA) screening relies on an elevated aldosterone to renin ratio with a minimum aldosterone level, which varies from 10 to 15 ng/dL (277-415.5 pmol/L) using immunoassay. Objective To evaluate intra-individual coefficient of variation (CV) of aldosterone and aldosterone to direct renin concentration ratio (A/DRC) and its impact on PA screening. Methods A total of 671 aldosterone and DRC measurements were performed by the same chemiluminescence assays in a large cohort of 216 patients with confirmed PA and at least 2 screenings. Results The median intra-individual CV of aldosterone and A/DRC was 26.8% and 26.7%. Almost 40% of the patients had at least one aldosterone level <15 ng/dL, 19.9% had at least 2 aldosterone levels <15 ng/dL, and 16.2% had mean aldosterone levels <15 ng/dL. A lower cutoff of 10 ng/dL was associated with false negative rates for PA screening of 14.3% for a single aldosterone measurement, 4.6% for 2 aldosterone measurements, and only 2.3% for mean aldosterone levels. Considering the minimum aldosterone, true positive rate of aldosterone thresholds was 85.7% for 10 ng/dL and 61.6% for 15 ng/dL. An A/DRC >2 ng/dL/mu IU/mL had a true positive rate for PA diagnosis of 94.4% and 98.4% when based on 1 or 2 assessments, respectively. CV of aldosterone and A/DRC were not affected by sex, use of interfering antihypertensive medications, PA lateralization, hypokalemia, age, and number of hormone measurements. Conclusion Aldosterone concentrations had a high CV in PA patients, which results in an elevated rate of false negatives in a single screening for PA. Therefore, PA screening should be based on at least 2 screenings with concomitant aldosterone and renin measurements.
- The role of fibroblast growth factor receptor 4 overexpression and gene amplification as prognostic markers in pediatric and adult adrenocortical tumors(2012) BRITO, Luciana Pinto; RIBEIRO, Tamaya Castro; ALMEIDA, Madson Q.; JORGE, Alexander Augusto de Lima; SOARES, Ibere Cauduro; LATRONICO, Ana Claudia; MENDONCA, Berenice Bilharinho; FRAGOSO, Maria Candida Barisson Villares; LERARIO, Antonio Marcondes
- Increased expression of ACTH (MC2R) and androgen (AR) receptors in giant bilateral myelolipomas from patients with congenital adrenal hyperplasia(2014) ALMEIDA, Madson Q.; KAUPERT, Laura C.; BRITO, Luciana P.; LERARIO, Antonio M.; MARIANI, Beatriz M. P.; RIBEIRO, Marta; MONTE, Osmar; DENES, Francisco T.; MENDONCA, Berenice B.; BACHEGA, Tania A. S. S.Background: Although chronic adrenocorticotropic hormone (ACTH) and androgen hyperstimulation are assumed to be involved in the pathogenesis of adrenal myelolipomas associated with poor-compliance patients with congenital adrenal hyperplasia (CAH), the expression of their receptors has not yet been demonstrated in these tumors so far. Methods: We analyzed Melanocortin 2 receptor (MC2R), Androgen Receptor (AR), Leptin (LEP), and Steroidogenic factor 1 (SF1) expression using real-time qRT-PCR in two giant bilateral adrenal myelolipomas from two untreated simple virilizing CAH cases and in two sporadic adrenal myelolipomas. In addition, the X-chromosome inactivation pattern and CAG repeat numbers in AR exon 1 gene were evaluated in the 4 cases. Results: The MC2R gene was overexpressed in myelolipomas from 3 out of 4 patients. AR overexpression was detected in 2 tumors: a giant bilateral myelolipoma in a CAH patient and a sporadic case. Simultaneous overexpression of AR and MC2R genes was found in two of the cases. Interestingly, the bilateral giant myelolipoma associated with CAH that had high androgen and ACTH levels but lacked MC2R and AR overexpression presented a significantly shorter AR allele compared with other tumors. In addition, X-chromosome inactivation pattern analysis showed a polyclonal origin in all tumors, suggesting a stimulatory effect as the trigger for tumor development. Conclusion: These findings are the first evidence for MC2R or AR overexpression in giant bilateral myelolipomas from poor-compliance CAH patients.
- Efficacy of Oral Furosemide Test for Primary Aldosteronism Diagnosis(2023) FREITAS, Thais C.; MACIEL, Ana Alice W.; FAGUNDES, Gustavo F. C.; PETENUCI, Janaina; SANTANA, Lucas S.; GUIMARAES, Augusto G.; FREITAS-CASTRO, Felipe; SROUGI, Victor; TANNO, Fabio Y.; CHAMBO, Jose L.; PEREIRA, Maria Adelaide A.; BRITO, Luciana P.; PIO-ABREU, Andrea; BORTOLOTTO, Luiz A.; LATRONICO, Ana Claudia; V, Maria Candida B. Fragoso; DRAGER, Luciano F.; MENDONCA, Berenice B.; ALMEIDA, Madson Q.Context: Confirmatory tests represent a fundamental step in primary aldosteronism (PA) diagnosis, but they are laborious and often require a hospital environment due to the risks involved.Objective: To evaluate the efficacy of oral furosemide as a new confirmatory test for PA diagnosis.Methods: We prospectively evaluated the diagnostic performance of 80 mg of oral furosemide in 64 patients with PA and 22 with primary hypertension (controls). Direct renin concentration (DRC) was measured before, and 2 hours and 3 hours after the oral furosemide. In addition, the oral furosemide test was compared with 2 other confirmatory tests: the furosemide upright test (FUT) and saline infusion test (SIT) or captopril challenge test (CCT) in all patients with PA.Results: The cut-off of 7.6 mu U/mL for DRC at 2 hours after oral furosemide had a sensitivity of 92%, specificity of 82%, and accuracy of 90% for PA diagnosis. In 5 out of 6 controls with low-renin hypertension, which might represent a PA spectrum, renin remained suppressed. Excluding these 6 controls with low-renin hypertension, the DRC cut-off of 10 mu U/mL at 2 hours after oral furosemide had a sensitivity of 95.3%, specificity of 93.7% and accuracy of 95% for PA diagnosis. DRC after 3 hours of oral furosemide did not improve diagnostic performance. Using the cut-off of 10 mu U/mL, the oral furosemide test and the FUT were concordant in 62 out of 64 (97%) patients with PA. Only 4 out of 64 cases with PA (6.4%) ended the oral furosemide test with potassium <3.5 mEq/L. Hypotension was not evidenced in any patient with PA during the test.Conclusion: The oral furosemide test was safe, well-tolerated and represents an effective strategy for PA investigation.