MADSON QUEIROZ DE ALMEIDA

(Fonte: Lattes)
Índice h a partir de 2011
24
Lattes
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Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina

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  • article 26 Citação(ões) na Scopus
    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.
  • article 9 Citação(ões) na Scopus
    Clinical and molecular aspects of a pediatric metachronous adrenocortical tumor
    (2011) LIMA, Lorena de Oliveira; LERARIO, Antonio Marcondes; ALENCAR, Guilherme Asmar; BRITO, Luciana Pinto; ALMEIDA, Madson Queiroz; DOMENICE, Sorahia; LATRONICO, Ana Claudia; MENDONCA, Berenice Bilharinho; FRAGOSO, Maria Candida Barrison Villares
    The occurrence of metachronous adrenocortical carcinoma has rarely been described. We report a case of a child with virilizing adrenocortical metachronous tumors that, despite several metastases, presented long-term survival (15 years). We analyzed in this tumor IGF2, IGF1R and FGFR4 gene expression, and evaluated the presence of p.R337H germline p53 mutation and somatic CTNNB1 mutation. IGF2 gene was over-expressed in both left (Weiss score 5) and right (Weiss 7) adrenocortical tumors. IGF1R expression levels were higher in the right adrenocortical tumor. FGFR4 over-expression was also detected in the right adrenocortical tumor. In addition, this patient harbors the germline p.R337H p53 mutation and loss of heterozygosity (LOH) was detected in the tumors. No somatic CTNNB1 mutations were found in both tumors. In conclusion, we demonstrated in this unusual case the over-expression of growth signaling pathways, which are molecular mechanisms previously related to adrenocortical tumorigenesis. Furthermore, the absence of somatic CTNNB1 mutations, which is a molecular marker of poor prognosis in adults, might be related to the long-term survival of this patient. Arq Bras Endocrinol Metab. 2011;55(1) 72-7