• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Doctoral Thesis
DOI
10.11606/T.5.2011.tde-26052011-115043
Document
Author
Full name
Carlos Afonso Clara
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2011
Supervisor
Committee
Rosemberg, Sergio (President)
Bacchi, Carlos Eduardo
Scapulatempo Neto, Cristovam
Stávale, João Norberto
Taricco, Mario Augusto
Title in Portuguese
Estudo das expressões imunoistoquímicas dos marcadores HIF-1, VEGF e PDGF-C correlacionados com a angiogênese e o prognóstico em glioblastomas
Keywords in Portuguese
Angiogênese patológica
Glioblastoma
Hipóxia
Imunoistoquímica
Sobrevida
Abstract in Portuguese
O glioblastoma multiforme (GBM) é o tumor mais agressivo do Sistema Nervoso Central (SNC) e caracteriza-se por um alto poder angiogênico que está diretamente relacionado com a capacidade invasiva e inversamente com o prognóstico. A angiogênese contribui para a malignidade por prover a oxigenação e o suprimento nutricional necessários para o crescimento e invasão do tumor. O GBM prolifera sob um ambiente de hipóxia e o fator induzido por hipóxia (HIF-1) apresenta um papel fundamental na ativação da transcrição de genes alvo que favorecem a angiogênese e evitam a morte celular. O fator de crescimento do endotélio vascular (VEGF) e o fator de crescimento derivado da plaqueta C (PDGF-C) são agentes de grande interesse na angiogênese tumoral e que podem ser modulados pelo HIF-1. Foi realizado tissue microarray(TMA) de 208 casos de GBM e estudados pelo método de imunoistoquímica os marcadores HIF-1, VEGF e PDGFC. Os resultados foram correlacionados com a angiogênese avaliada através da densidade microvascular (DMV) pelo CD34, CD105, VEGF e PDGF-C, com a proliferação celular endotelial através da marcação nuclear pelo KI-67 e também com a sobrevida. A expressão tumoral do HIF-1 foi observada em 184 casos (88,5%), a do VEGF em 131 (63%) e a do PDGF-C em 160 (77%). As DMVs medianas pelo CD34, PDGF-C, VEGF e CD105 foram, respectivamente, 20, 16, 5 e 6. Os GBMs com marcação positiva pelo HIF-1 tiveram uma DMV mediana pelo CD34 de 30, enquanto que nos negativos a DMV mediana foi 14 (p<0,001). A expressão tumoral positiva pelo HIF-1 teve correlação com a marcação tumoral pelo VEGF e PDGF-C (p<0,001). Houve também uma correlação entre a marcação do VEGF e do PDGF-C tanto no tumor (p=0,001) como na célula endotelial (p<0,001). A expressão do VEGF no tumor teve correlação com a sua expressão no vaso (p<0,001). Células endoteliais marcadas pelo PDGF-C e pelo VEGF também foram marcadas pelo CD105 e seus núcleos pelo KI-67 confirmando seu padrão neoangiogênico e proliferativo. A marcação nuclear das células tumorais pelo VEGF teve impacto na sobrevida (p=0,002), bem como as marcações nucleares pelo HIF-1 e VEGF (p=0,005). Em conclusão, este estudo mostrou que a expressão do HIF-1 está associada com as expressões do VEGF e do PDGF-C e que houve uma correlação desses marcadores com a angiogênese no GBM.
Title in English
Study of immunohistochemical expressions on the HIF-1, VEGF and PDGF-C markers, correlated to angiogenesis and to glioblastoma prognosis
Keywords in English
Angiogenesis
Glioblastoma
Hypoxia
Immunohistochemistry
Survival
Abstract in English
Glioblastoma multiforme (GBM) is the most aggressive tumour of the central nervous system (CNS) and is characterized by a high angiogenic power that is directly related to the invasiveness and inversely to the prognosis. Angiogenesis contributes to malignancy by providing the necessary oxygenation and nutritional supplement for the tumour's growth and invasion. GBM proliferates under a hypoxia environment and the hypoxia-inducible factor (HIF-1) plays a key role on the transcription of essential genes which promote angiogenesis and prevent cellular death. The vascular endothelial growth factor (VEGF) and the platelet-derived growth factor C (PDGF-C) are agents of great interest on tumour angiogenesis and may be modulated by the HIF-1. Tissue micro-array (TMA) was conducted on 208 cases of GBM and the HIF-1, VEGF and PDGF-C markers were studied under immunohistochemistry method. The results were correlated with angiogenesis assessed by micro-vessel density (MVD) for CD34, CD105, VEGF and PDGF-C, with endothelial cell proliferation by nuclear staining for KI-67, and also with survival. The tumour expression by HIF-1 was observed in 184 cases (88.5%), by VEGF in 131 (63%) and by PDGF-C in 160 (77%). The median MVD for CD34, PDGF-C, VEGF and CD105 was respectively 20, 16, 5 and 6.The GBMs which stained positive for HIF-1 showed a median MVD of 30 for CD34, whereas in negative ones, median MVD was 14 (p <0.001). The positive tumour expression for HIF-1 was correlated with tumour markings for VEGF and PDGF-C (p <0.001). There was also a correlation between the markings for VEGF and PDGF-C in both the tumour (p = 0.001) and endothelial cell (p <0.001). VEGF expression in the tumour was correlated with its expression in the blood vessel (p <0.001). Endothelial cells marked for the PDGF-C and VEGF were also marked for CD105 and their nuclei for KI-67 confirming its neoangiogenic and proliferative pattern. The nuclear staining on tumour cells for VEGF had an impact on survival (p = 0.002), as well as the cases with nuclear staining for HIF-1 and VEGF (p = 0.005). In conclusion, this study showed that HIF-1 expression is associated with VEGF and PDGF-C and correlated with angiogenesis on GBM.
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
CarlosAfonsoClara.pdf (6.21 Mbytes)
Publishing Date
2011-05-26
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
Centro de Informática de São Carlos
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2021. All rights reserved.