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Os tumores do sistema nervoso central representam aproximadamente 2% de todos os tipos de cânceres. Embora a incidência dos tumores do SNC seja pequena, comparada com outras neoplasias, estes tumores estão entre as mais graves malignidades humanas, pois afetam o órgão responsável pela coordenação e integração de todas as atividades orgânicas. Os gliomas são os tumores mais comuns do SNC. Apesar do progresso marcante na caracterização da patogênese molecular dos gliomas, esses tumores permanecem incuráveis e, na maioria dos casos, refratários aos tratamentos, devido à sua heterogeneidade molecular. O aparecimento desses tumores ocorrem a partir do acúmulo de alterações genéticas nas células. Para entender o mecanismo molecular de formação e progressão tumoral é indispensável identificar os genes que acumulam essas alterações. Um polimorfismo de base única (SNP Single Nucleotide Polymorphism) é geralmente definido como uma substituição estável de apenas uma base na molécula de DNA com frequência maior que 1%, em pelo menos uma população Os SNPs são reconhecidos como importantes ferramentas na genética humana e médica e têm sido amplamente utilizados nos estudos de associação genética de várias doenças complexas, como por exemplo: distúrbios cardiovasculares, psiquiátricos e autoimunes, obesidade, osteoporose, diabetes e câncer Sendo assim, este trabalho teve como objetivo analisar polimorfismos entre populações caso e controle na intenção de identificar associações destes genótipos na suscetibilidade aos tumores. A técnica utilizada para a análise de polimorfismos foi de PCR-RFLP onde observamos diferenças nas distribuições genotípicas entre pacientes e controles nos SNPs EGF+61, GSTP-1Ile 105 Val, XRCC1 Arg 194 Trp, Pro 206 Pro, Arg 280 His, Arg 399 Gln, Gln 632 Gln, XRCC2 Arg 188 His, XRCC3 Thr 241 Met e XRCC4 G1394T, onde as variantes EGF G61, Trp194, Val105, Pro206, His280, Gln632, His188, Met241 e XRCC4 T1394 foram observados com maior freqüência entre os portadores de gliomas. Dessa forma, estas variantes podem ser fatores de susceptibilidade para o desenvolvimento dos tumores. / The Central nervous system tumors represent about 2% of all cancers. Although the incidence of CNS tumors is small compared with other cancers, these tumors are among the most serious human malignancies, because they affect the body responsible for coordination and integration of all organic activities. Gliomas are the most common tumors of the CNS. Despite remarkable progress in characterizing the molecular pathogenesis of gliomas, these tumors remain incurable and, in most cases, refractory to treatment, due to its molecular heterogeneity. The appearance of these tumors occurs from the accumulation of genetic changes in cells. To understand the molecular mechanism of tumor formation and progression is essential to identify genes that accumulate these changes. A single base polymorphism (SNP Single Nucleotide Polymorphism) is generally defined as a stable replacement of only one base in the DNA molecule often greater than 1% in at least one population SNPs are recognized as important tools in human genetics and medical and have been widely used in genetic association studies of various complex diseases, such as: cardiovascular, psychiatric and autoimmune diseases, obesity, osteoporosis, diabetes and cancer. Thereby, the objective of this study was to analyze the polymorphisms between cases and control the intention to identify associations of these genotypes in susceptibility to tumors. The technique used for the analysis of polymorphisms were PCR-RFLP where we observe differences in genotype between patients and controls in the EGF +61, GSTP-1 Ile105Val, XRCC1 Arg 194 Trp, Pro 206 Pro, Arg 280 His, Arg 399 Gln, Gln 632 Gln, XRCC2 Arg 188 His, XRCC3 Thr 241 Met and XRCC4 G1394T, where the variants EGF G61, Trp194, val105, Pro206, His280, Gln632, His188, Met241 and XRCC4 T1394 were observed more frequently among patients with gliomas. Thus, these variants can be important factors of susceptibility to the tumor development.

Gliomas are the most common human brain tumors and are divided into four stages by WHO classification scheme. Benign gliomas are defined as grades I (Pilocytic astrocytomas) and II (Astrocytomas), whereas grade III (Anaplastic Astrocytomas, AA) and grade IV (Glioblastoma Multiforme, GBM) are malignant. Although both grades III and IV are malignant, the prognoses for these tumors are quite different. The 2-year survival rate for grade III gliomas is 50%, and grade IV is < 20 %. Mechanisms of tumorigenesis are not exactly elucidated in brain tumor cells. The thesis is to study the role of p27 kip1 in human malignant brain tumors. The experimental methods include ribonuclease protection assay (RPA), western blotting, immunohistochemical staining and immunocytochemical staining. mRNAs of p130, p107, Rb, p53 and p27 kip1 in normal brain tissues and brain tumors were overexpressed in most case. The p27kip1 mRNA were expressed in all astrocytomas and GBM, and mRNA quantity of p27kip1 were more in brain tumors than in normal brain tissues. PI3K/Akt pathway regulates several cellular functions such as cell survival and cell proliferation. Active Akt can phosphorylate p27kip1 that may contribute cell cycle from G1 phase to S phase. Skp2 identifies phospho-p27kip1 and promotes p27kip1 degradation. We found p27kip1 overexpression and Akt activation in astrocytomas and GBM. The expression of p-Akt were found in 20 %, 87 % and 71 % in normal brain tissues, astrocytomas and GBM, respectively. Expression of p27kip1 and p-Akt has shown significant correlation in GBM (P = 0.0236). Overexpression of p27kip1 mRNA in brain tumors may be consequence of p-Akt and Skp2.

Made available in DSpace on 2014-06-11T19:23:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-02Bitstream added on 2014-06-13T20:29:59Z : No. of bitstreams: 1 cavalcante_sp_me_botfm.pdf: 252896 bytes, checksum: 04649d19f170ae42a833e1b00765902d (MD5) / Fundação Pio Xii - Barretos / Avaliar a densidade microvascular (DMV) em astrocitomas de baixo grau (ABG), astrocitomas anaplásicos (AA) e glioblastoma multiforme (GBM) por imuno-histoquímica, correlacionando com índices de captação pela SPECT com SESTAMIBI (MIBI). Estudo transversal com coleta retrospectiva que avaliou 48 pacientes, com faixa etária de 20 a 73 anos, com o diagnóstico de tumores cerebrais ditos ABG (somente os difusos), AA e GBM admitidos no Hospital de Câncer da Fundação Pio XII de Barretos. As SPECT-MIBI foram classificadas como alteradas ou normais inicialmente pela análise visual. Também foram analisadas de forma semiquantitativa através do desenho de regiões de interesse (RI) com a obtenção de um índice para correlacionar com os parâmetros da DMV. Esta foi determinada com o emprego de anticorpo anti-CD34. Os GBM, AA e ABG representaram 50%, 16,7% e 33,3% da amostra, respectivamente. Treze exames foram visualmente normais, e 35 considerados alterados. A DMV média teve diferença significativa entre os AA e ABG (p=0,040), mas não entre as SPECT-MIBI normais e alteradas. Os índices de contagem média obtidos através da análise semiquantitativa das SPECT-MIBI não apresentaram correlação com a DMV. Entre os GBM não foi encontrada nenhuma significância, exceto pela maior probabilidade de encontrar-se exames alterados neste tipo histológico. A DMV demonstrou relação com o grau histológico entre os AA e ABG, mas os índices de captação das SPECT-MIBI não apresentaram correlação com a DMV. / To evaluate the microvascular density (MVD) in low-grade astrocytomas (LGA), anaplastic astrocytomas (AA) and glioblastoma multiforme (GBM) by immunohistochemistry technique using anti-CD34, correlated with SPECT-MIBI uptake parameters. This is a cross-sectional study with retrospective assessment data which evaluated 48 subjects, ages ranging from 20 to 73 years, all with diagnosis of brain tumors known as LGA (only diffuse type), AA and GBM who were admitted to the Hospital de Cancer da Fundação Pio XII de Barretos. The SPECT-MIBI images were initially classified as normal or altered by visual analysis. Then they were also considered for semiquantitative analysis through drawing of anatomical regions of interest (ROI) resulting in an index to correlate with the MVD parameters. DMV was determined with the use of monoclonal antibody anti-CD34. GBM, AA and LGA represented 50%, 16.7% and 33.3% of the sample, respectively. Thirteen images were visually normal, while 35 were considered abnormal. There were significant differences in MVD between AA and LGA (p = 0.04), but not between the normal and abnormal SPECT-MIBI. The mean counts obtained by semiquantitative analysis from SPECT-MIBI showed no correlation with MVD. Among GBM subjects it was not seen any significance, except for being most likely to find this histological test as abnormal. MVD had relationship with the histological grade between AA and LGA, but there was no correlation with SPECT-MIBI.

Os tumores do sistema nervoso central representam aproximadamente 2% de todos os tipos de cânceres. Embora a incidência dos tumores do SNC seja pequena, comparada com outras neoplasias, estes tumores estão entre as mais graves malignidades humanas, pois afetam o órgão responsável pela coordenação e integração de todas as atividades orgânicas. Os gliomas são os tumores mais comuns do SNC. Apesar do progresso marcante na caracterização da patogênese molecular dos gliomas, esses tumores permanecem incuráveis e, na maioria dos casos, refratários aos tratamentos, devido à sua heterogeneidade molecular. O aparecimento desses tumores ocorrem a partir do acúmulo de alterações genéticas nas células. Para entender o mecanismo molecular de formação e progressão tumoral é indispensável identificar os genes que acumulam essas alterações. Um polimorfismo de base única (SNP Single Nucleotide Polymorphism) é geralmente definido como uma substituição estável de apenas uma base na molécula de DNA com frequência maior que 1%, em pelo menos uma população Os SNPs são reconhecidos como importantes ferramentas na genética humana e médica e têm sido amplamente utilizados nos estudos de associação genética de várias doenças complexas, como por exemplo: distúrbios cardiovasculares, psiquiátricos e autoimunes, obesidade, osteoporose, diabetes e câncer Sendo assim, este trabalho teve como objetivo analisar polimorfismos entre populações caso e controle na intenção de identificar associações destes genótipos na suscetibilidade aos tumores. A técnica utilizada para a análise de polimorfismos foi de PCR-RFLP onde observamos diferenças nas distribuições genotípicas entre pacientes e controles nos SNPs EGF+61, GSTP-1Ile 105 Val, XRCC1 Arg 194 Trp, Pro 206 Pro, Arg 280 His, Arg 399 Gln, Gln 632 Gln, XRCC2 Arg 188 His, XRCC3 Thr 241 Met e XRCC4 G1394T, onde as variantes EGF G61, Trp194, Val105, Pro206, His280, Gln632, His188, Met241 e XRCC4 T1394 foram observados com maior freqüência entre os portadores de gliomas. Dessa forma, estas variantes podem ser fatores de susceptibilidade para o desenvolvimento dos tumores. / The Central nervous system tumors represent about 2% of all cancers. Although the incidence of CNS tumors is small compared with other cancers, these tumors are among the most serious human malignancies, because they affect the body responsible for coordination and integration of all organic activities. Gliomas are the most common tumors of the CNS. Despite remarkable progress in characterizing the molecular pathogenesis of gliomas, these tumors remain incurable and, in most cases, refractory to treatment, due to its molecular heterogeneity. The appearance of these tumors occurs from the accumulation of genetic changes in cells. To understand the molecular mechanism of tumor formation and progression is essential to identify genes that accumulate these changes. A single base polymorphism (SNP Single Nucleotide Polymorphism) is generally defined as a stable replacement of only one base in the DNA molecule often greater than 1% in at least one population SNPs are recognized as important tools in human genetics and medical and have been widely used in genetic association studies of various complex diseases, such as: cardiovascular, psychiatric and autoimmune diseases, obesity, osteoporosis, diabetes and cancer. Thereby, the objective of this study was to analyze the polymorphisms between cases and control the intention to identify associations of these genotypes in susceptibility to tumors. The technique used for the analysis of polymorphisms were PCR-RFLP where we observe differences in genotype between patients and controls in the EGF +61, GSTP-1 Ile105Val, XRCC1 Arg 194 Trp, Pro 206 Pro, Arg 280 His, Arg 399 Gln, Gln 632 Gln, XRCC2 Arg 188 His, XRCC3 Thr 241 Met and XRCC4 G1394T, where the variants EGF G61, Trp194, val105, Pro206, His280, Gln632, His188, Met241 and XRCC4 T1394 were observed more frequently among patients with gliomas. Thus, these variants can be important factors of susceptibility to the tumor development.

Yeung, Tak Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 181-197). / Abstracts in English and Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.iv / Acknowledgements --- p.vi / List of Publications --- p.vii / Presentation --- p.vii / List of Abbreviations --- p.viii / Abbreviations in Figures --- p.xiii / Abbreviations in Symbols --- p.xiv / List of Cell Lines Used in this Study --- p.xv / Table of Contents --- p.xvi / List of Figures --- p.xxv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Cellular Redox State and Cancer Biology --- p.1 / Chapter 1.2 --- Reactive Oxygen Species (ROS) --- p.1 / Chapter 1.3 --- Regulation of Cellular Redox State by Intrinsic and Extrinsic Antioxidant Systems --- p.5 / Chapter 1.3.1 --- Intrinsic Antioxidant System --- p.6 / Chapter 1.3.2 --- Extrinsic Antioxidant System --- p.8 / Chapter 1.4 --- Glutathione --- p.9 / Chapter 1.4.1 --- General Information of Glutathione --- p.9 / Chapter 1.4.2 --- Functions of Glutathione --- p.12 / Chapter 1.4.2.1 --- As an Antioxidant and Free Radical Scavenger --- p.12 / Chapter 1.4.2.2 --- As a Detoxifier --- p.13 / Chapter 1.4.2.3 --- As a Regulator of Cell Signaling --- p.14 / Chapter 1.4.3 --- Synthesis of Glutathione --- p.15 / Chapter 1.4.4 --- Catabolism of Glutathione --- p.15 / Chapter 1.4.5 --- Transport and Uptake of Glutathione --- p.16 / Chapter 1.4.6 --- Glutathione in Cancer Biology --- p.18 / Chapter 1.4.6.1 --- "Role of Glutathione in the Regulation of Carcinogenesis, Growth and Apoptosis of Cancer Cells" --- p.18 / Chapter 1.4.6.1.1 --- Role of Glutathione in Carcinogenesis --- p.18 / Chapter 1.4.6.1.2 --- Role of Glutathione in the Growth of Cancer Cells --- p.20 / Chapter 1.4.6.1.3 --- Role of Glutathione in Apoptosis of Cancer Cells --- p.21 / Chapter 1.4.6.2 --- Role of Glutathione in the Regulation of Metastasis --- p.23 / Chapter 1.4.6.3 --- Role of Glutathione in Cancer Resistance and Therapy --- p.24 / Chapter 1.4.6.3.1 --- Role of Glutathione in Cancer Resistance --- p.24 / Chapter 1.4.6.3.2 --- Role of Glutathione in Cancer Therapy --- p.24 / Chapter 1.5 --- Aims of the Present Study --- p.25 / Chapter Chapter 2 --- In Vitro Study of Bαicαlein and Baicalin on Glutathione Depletion --- p.28 / Chapter 2.1 --- Introduction --- p.28 / Chapter 2.1.1 --- Scutellaria bαicαlensis Georgi --- p.28 / Chapter 2.1.1.1 --- General Clinical Applications to Treat or Prevent Diseases --- p.28 / Chapter 2.1.1.2 --- As an Antioxidant and Free Radical Scavenger --- p.29 / Chapter 2.1.1.3 --- Long History for Treatment of Cancers with the Obscure Mechanism --- p.30 / Chapter 2.1.1.4 --- Major Components --- p.31 / Chapter 2.1.2 --- Baicalein and Baicalin --- p.32 / Chapter 2.1.2.1 --- General Clinical Applications to Treat or Prevent Diseases --- p.32 / Chapter 2.1.2.2 --- As an Antioxidant and Free Radical Scavenger --- p.33 / Chapter 2.1.3 --- Hypothesis: Baicalein and Baicalin Induce Cancer Cell Death Via Glutathione Depletion --- p.35 / Chapter 2.2 --- Materials and Methods --- p.36 / Chapter 2.2.1 --- Chemicals --- p.36 / Chapter 2.2.2 --- Buffers and Solutions --- p.36 / Chapter 2.2.3 --- Animals --- p.37 / Chapter 2.2.4 --- Preparation of Rat Brain Microsomes --- p.37 / Chapter 2.2.5 --- Glutathione Depletion Assay In Vitro and Thiol Depletion Assay in Rat Brain Microsomes --- p.38 / Chapter 2.2.6 --- Statistical Analysis --- p.39 / Chapter 2.3 --- Results --- p.40 / Chapter 2.3.1 --- Effects of Baicalein and Baicalin on Sulfhydryl Contents of Glutathione --- p.42 / Chapter 2.3.2 --- Effects of Baicalein and Baicalin on Sulfhydryl Contents of Rat Brain Microsomes --- p.42 / Chapter 2.4 --- Discussion --- p.44 / Chapter Chapter 3 --- Effects of Baicalein and Baicalin on Proliferation of Different Human Cancer and Normal Cells --- p.45 / Chapter 3.1 --- Introduction-Importance of Developing A Novel Compound Inducing Cancer Cells to Cell Death with the Least Side Effects on Normal Cells --- p.45 / Chapter 3.2 --- Materials and Methods --- p.46 / Chapter 3.2.1 --- Instruments --- p.46 / Chapter 3.2.2 --- Chemicals and Cell Culture Reagents --- p.46 / Chapter 3.2.3 --- Buffers --- p.46 / Chapter 3.2.4 --- Cell Lines --- p.47 / Chapter 3.2.5 --- Cell Culture --- p.48 / Chapter 3.2.6 --- Determination of Cell Proliferation by MTT Assay --- p.49 / Chapter 3.3 --- Results --- p.51 / Chapter 3.3.1 --- Anti-Proliferative Effects of Baicalein and Baicalin on Different Cancer Cell Lines --- p.51 / Chapter 3.3.2 --- Effects of Baicalein on Different Normal Cell Lines --- p.56 / Chapter 3.4 --- Discussion --- p.58 / Chapter 3.4.1 --- Anti-Proliferative Effects of Baicalein and Baicalin on Different Cancer Cell Lines --- p.58 / Chapter 3.4.2 --- Effects of Baicalein on Cell Proliferation on Different Human Normal Cell Lines --- p.60 / Chapter Chapter 4 --- Glutathione-Depleting Effects of Baicalein on Cell Proliferation of Different Cell Lines --- p.61 / Chapter 4.1 --- Introduction-Brain Tumors --- p.61 / Chapter 4.1.1 --- Types and Classifications of Brain Tumors --- p.61 / Chapter 4.1.2 --- "Incidence Time, Patient Survival Time and Rate for" --- p.65 / Chapter 4.1.3 --- Symptoms and Diagnostic Methods for Brain Tumors --- p.66 / Chapter 4.1.4 --- "Treatments, Side Effects and Difficulties of Treatments for Brain Tumors" --- p.67 / Chapter 4.1.5 --- Glutathione Levels in Brain Normal and Cancer Cells --- p.69 / Chapter 4.2 --- Materials and Methods --- p.70 / Chapter 4.2.1 --- Instruments --- p.70 / Chapter 4.2.2 --- Chemicals --- p.70 / Chapter 4.2.3 --- Buffers --- p.70 / Chapter 4.2.4 --- Determination of Cell Proliferation by MTT Assay --- p.70 / Chapter 4.2.5 --- Determination of Intracellular Glutathione Depletion by Fluorescent Dye CMAC --- p.71 / Chapter 4.2.6 --- Determination of Cellular Reduced Glutathione Levels by DTNB-Coupled Glutathione Reductase Recycling Assay --- p.73 / Chapter 4.3 --- Results --- p.75 / Chapter 4.3.1 --- Effects of Baicalein on Intracellular GSH Levels and Cell Proliferation for Different Cell Lines --- p.75 / Chapter 4.3.2 --- Basal Intracellular Glutathione in Different Cell Lines --- p.81 / Chapter 4.4 --- Discussion --- p.84 / Chapter 4.4.1 --- Intracellular Glutathione Depletion and Cell Death Induction Effects of Baicalein on Different Cell Lines --- p.84 / Chapter 4.4.2 --- Relationship between Basal Glutathione Levels and Drug Susceptibilities --- p.85 / Chapter Chapter 5 --- Effects of Baicalein on Apoptosis and Caspase Pathways --- p.88 / Chapter 5.1 --- Introduction-Modes of Cell Death --- p.88 / Chapter 5.1.1 --- Necrosis --- p.88 / Chapter 5.1.2 --- Apoptosis --- p.89 / Chapter 5.2 --- Materials and Methods --- p.92 / Chapter 5.2.1 --- Chemicals --- p.92 / Chapter 5.2.2 --- Buffers --- p.92 / Chapter 5.2.3 --- Determination of Change of Mitochondrial Membrane Potential by JC-1 --- p.93 / Chapter 5.2.4 --- Determination of Apoptosis by Annexin V-Propidium Iodide Staining --- p.94 / Chapter 5.2.5 --- Determination of Cell Cycle Arrest by Propidium Iodide Staining --- p.95 / Chapter 5.2.6 --- "Determination of Caspase-3, -8 and -9 Activities by Fluorescent-Labeled Peptides" --- p.96 / Chapter 5.2.7 --- Determination of DNA Fragmentation --- p.97 / Chapter 5.2.8 --- Terminal Deoxynucleotidyl Transferase Mediated dUTP End Labeling (TUNEL) Assay --- p.99 / Chapter 5.2.9 --- Flow Cytometry --- p.101 / Chapter 5.3 --- Results --- p.102 / Chapter 5.3.1 --- Effects of Baicalein on Mitochondrial Membrane Potential by JC-1 Staining --- p.102 / Chapter 5.3.2 --- Effects of Baicalein on Apoptosis and Necrosis by Annexin V-Propidium Iodide Staining --- p.104 / Chapter 5.3.3 --- Effects of Baicalein on Cell Cycle Arrest by Propidium Iodide Staining --- p.108 / Chapter 5.3.4 --- "Effects of Baicalein on Caspase-3, -8 and -9 Activities" --- p.110 / Chapter 5.3.5 --- Effeets of Baiealein on DNA Fragmentation --- p.115 / Chapter 5.3.6 --- Effects of Baicalein on TUNEL Assay --- p.117 / Chapter 5.4 --- Discussion --- p.120 / Chapter Chapter 6 --- Pro-Oxidant Role of Baicalein on Reactive Oxygen Species Generation --- p.122 / Chapter 6.1 --- Introduction --- p.122 / Chapter 6.2 --- Materials and Methods --- p.122 / Chapter 6.2.1 --- Chemicals --- p.122 / Chapter 6.2.2 --- Determination of Cellular Reactive Oxygen Species Generation by Fluorescent Dye cDCFDA --- p.123 / Chapter 6.2.3 --- Determination of Mitochondrial Reactive Oxygen Species Generation by Fluorescent Dye Rhl23 --- p.124 / Chapter 6.3 --- Results --- p.125 / Chapter 6.3.1 --- Effects of Baicalein on Cellular ROS Generation by Fluorescent Dye cDCFDA --- p.125 / Chapter 6.3.2 --- Effects of Baicalein on Mitochondrial ROS Generation by Fluorescent Dye Rhl23 --- p.129 / Chapter 6.4 --- Discussion --- p.132 / Chapter Chapter 7 --- The Anticancer Mechanistic Study of Baicalein --- p.133 / Chapter 7.1 --- Introduction --- p.133 / Chapter 7.2 --- Materials and Methods --- p.134 / Chapter 7.2.1 --- Chemicals --- p.134 / Chapter 7.2.2 --- Reversibility of Baicalein-Induced GSH Depletion and Cell Death by Different Antioxidant Treatments --- p.134 / Chapter 7.2.3 --- Reversibility of Baicalein-Induced Cellular ROS Generation --- p.136 / Chapter 7.2.4 --- Reversibility of Baicalein-Induced Apoptosis by Co-Treatment of Different Antioxidants and Caspase Inhibitors --- p.137 / Chapter 7.2.5 --- "Reversibility of Baicalein-Induced Caspase-3, -8 and -9 Activation by Co-Treatment of Different Antioxidants" --- p.138 / Chapter 7.3 --- Results --- p.139 / Chapter 7.3.1 --- Reversibility of Baicalein-Induced GSH Depletion and Cell Death by Different Antioxidant Treatments --- p.139 / Chapter 7.3.1.1 --- Pre-treatments --- p.139 / Chapter 7.3.1.2 --- Co-treatments --- p.141 / Chapter 7.3.1.3 --- Post-treatments --- p.144 / Chapter 7.3.2 --- Reversibility of Baicalein-Induced Cellular ROS Generation by Co-Treatment of Different Antioxidants --- p.147 / Chapter 7.3.3 --- Reversibility of Baicalein-Induced Apoptosis by Co-Treatment of Different Antioxidants and Caspase Inhibitors --- p.152 / Chapter 7.3.4 --- Reversibility of Baicalein-Induced Caspase-3 Activation by Co-Treatment of Different Antioxidants --- p.156 / Chapter 7.3.5 --- Reversibility of Baicalein-Induced Caspase-8 and -9 Activation by Co-Treatment of Different Antioxidants --- p.160 / Chapter 7.4 --- Discussion --- p.164 / Chapter 7.4.1 --- Reversibility of Baicalein-Induced GSH Depletion and Cell Death --- p.164 / Chapter 7.4.2 --- "Reversibility of Baicalein-Induced ROS Generation," --- p.167 / Chapter 7.5 --- Concluding Remarks --- p.168 / Chapter Chapter 8 --- General Discussion --- p.169 / Chapter 8.1 --- Drug Delivery to Brain --- p.169 / Chapter 8.2 --- Protective Roles of Baicalein on Brain Cells --- p.170 / Chapter 8.2.1 --- Actions Against Oxidative Stress --- p.170 / Chapter 8.2.2 --- Actions Against Other Neurotoxic Damages --- p.171 / Chapter 8.2.3 --- Actions Against Neuronal Diseases --- p.172 / Chapter 8.3 --- Anticancer Roles of Baicalein on Astrocytoma --- p.173 / Chapter 8.4 --- Implications on the Dual Roles of Baicalein: Antioxidant and Pro-oxidant --- p.175 / Chapter 8.5 --- Future Perspectives --- p.175 / Chapter 8.5.1 --- Effects of Baicalein on Antioxidant System --- p.175 / Chapter 8.5.2 --- Effects of Baicalein on GSH Synthesis --- p.176 / Chapter 8.5.3 --- In Vivo Studies on Cytotoxic Effects of Baicalein --- p.177 / Chapter 8.5.4 --- In Vivo Studies on Anti-Tumor Effects and In Vitro Studies on Anti-Metastasis Effects of Baicalein --- p.178 / Reference List --- p.181

Orientador: Euclides Timóteo da Rocha / Banca: Marco Antonio Zanini / Banca: Cristovam Scapulatempo Neto / Resumo: Avaliar a densidade microvascular (DMV) em astrocitomas de baixo grau (ABG), astrocitomas anaplásicos (AA) e glioblastoma multiforme (GBM) por imuno-histoquímica, correlacionando com índices de captação pela SPECT com SESTAMIBI (MIBI). Estudo transversal com coleta retrospectiva que avaliou 48 pacientes, com faixa etária de 20 a 73 anos, com o diagnóstico de tumores cerebrais ditos ABG (somente os difusos), AA e GBM admitidos no Hospital de Câncer da Fundação Pio XII de Barretos. As SPECT-MIBI foram classificadas como alteradas ou normais inicialmente pela análise visual. Também foram analisadas de forma semiquantitativa através do desenho de regiões de interesse (RI) com a obtenção de um índice para correlacionar com os parâmetros da DMV. Esta foi determinada com o emprego de anticorpo anti-CD34. Os GBM, AA e ABG representaram 50%, 16,7% e 33,3% da amostra, respectivamente. Treze exames foram visualmente normais, e 35 considerados alterados. A DMV média teve diferença significativa entre os AA e ABG (p=0,040), mas não entre as SPECT-MIBI normais e alteradas. Os índices de contagem média obtidos através da análise semiquantitativa das SPECT-MIBI não apresentaram correlação com a DMV. Entre os GBM não foi encontrada nenhuma significância, exceto pela maior probabilidade de encontrar-se exames alterados neste tipo histológico. A DMV demonstrou relação com o grau histológico entre os AA e ABG, mas os índices de captação das SPECT-MIBI não apresentaram correlação com a DMV / Abstract: To evaluate the microvascular density (MVD) in low-grade astrocytomas (LGA), anaplastic astrocytomas (AA) and glioblastoma multiforme (GBM) by immunohistochemistry technique using anti-CD34, correlated with SPECT-MIBI uptake parameters. This is a cross-sectional study with retrospective assessment data which evaluated 48 subjects, ages ranging from 20 to 73 years, all with diagnosis of brain tumors known as LGA (only diffuse type), AA and GBM who were admitted to the Hospital de Cancer da Fundação Pio XII de Barretos. The SPECT-MIBI images were initially classified as normal or altered by visual analysis. Then they were also considered for semiquantitative analysis through drawing of anatomical regions of interest (ROI) resulting in an index to correlate with the MVD parameters. DMV was determined with the use of monoclonal antibody anti-CD34. GBM, AA and LGA represented 50%, 16.7% and 33.3% of the sample, respectively. Thirteen images were visually normal, while 35 were considered abnormal. There were significant differences in MVD between AA and LGA (p = 0.04), but not between the normal and abnormal SPECT-MIBI. The mean counts obtained by semiquantitative analysis from SPECT-MIBI showed no correlation with MVD. Among GBM subjects it was not seen any significance, except for being most likely to find this histological test as abnormal. MVD had relationship with the histological grade between AA and LGA, but there was no correlation with SPECT-MIBI / Mestre

No description available.

La malignité des astrocytomes est établie sur base de critères morphologiques définis au sein de la classification de l’Organisation Mondiale de la Santé (OMS). Ce système de gradation, qui s’échelonne de I à IV, constitue actuellement l’outil pronostique le plus fiable. Par facilité, les cliniciens regroupent les astrocytomes de grade I (astrocytomes pilocytiques) et les astrocytomes diffus de grade II sous le terme d’« Astrocytomes de bas-grade » par opposition aux astrocytomes de haut-grade, constitués des astrocytomes anaplasiques (grade III) et des glioblastomes (GBM ;grade IV). Cette terminologie conduit à des prises en charge cliniques inadéquates car elle englobe des tumeurs très différentes en terme d’agressivité :les astrocytomes de grade I, majoritairement non infiltrants, non évolutifs et indolents et les astrocytomes diffus de grade II, toujours infiltrants et évolutifs, progressant systématiquement en astrocytomes de haut-grade et entraînant le plus souvent le décès prématuré du patient. Bien que ces tumeurs soient définies par la classification de l’OMS comme des entités clinicopathologiques distinctes, peu de données sont disponibles dans la littérature pour expliquer leurs particularités biologiques et la pratique quotidienne montre que les différencier peut être difficile. <p><p>Le but des études entreprises au cours de ce travail de thèse est d’apporter une contribution à la compréhension des mécanismes de tumorigenèse qui différencient l’astrocytome de grade I des astrocytomes diffus (grade II-IV), de manière à identifier des voies biologiques qui permettraient, au moins en partie, d’expliquer ces différences de comportement. <p><p>Au cours de la première partie de ce travail, nous avons caractérisé les profils d’expression génomique des astrocytomes de grade I et de grade II, en comparant les données d’expression de gènes (évaluées par des technologies de micropuces d’ADN) de travaux publiés entre 2000 et 2005. L’expression des gènes identifiés a été validée par des analyses de RT-PCR quantitative sur une série indépendante d’astrocytomes de grade I, II et IV. Les fonctions biologiques des protéines codées par chacun de ces gènes ont fait l’objet de recherches bibliographiques détaillées afin de proposer un modèle permettant d’approcher les différences de comportement de ces tumeurs. Cette analyse nous a permis d’identifier TIMP4 (tissue inhibitor of metalloproteinases 4) et IGFBP2 (insulin-like growth factor binding protein 2) comme gènes candidats pour améliorer la caractérisation biologique et clinique des astrocytomes de grade I par rapport aux astrocytomes diffus. TIMP4 et IGFBP2 codent respectivement pour un inhibiteur endogène des métalloprotéinases matricielles (MMPs) et une protéine de liaison capable d’inhiber l’action des « insulin-like growth factors » (IGFs, dont IGFI et IGFII), des facteurs impliqués dans la croissance et la migration des astrocytes normaux et tumoraux. <p><p>Sur base de la surexpression de TIMP4 et d’IGFBP2 dans les astrocytomes de grade I, en comparaison aux astrocytomes diffus de grade II, nous avons posé l’hypothèse suivante :« L’absence d’agressivité des astrocytomes de grade I, en comparaison aux astrocytomes diffus (grade II-IV) pourrait en partie être liée à l’inhibition par TIMP-4 de la protéolyse des complexes IGFBP2-IGFII au sein de ces tumeurs ». Cette protéolyse, qui diminue l’affinité d’IGFBP2 pour IGFII, pourrait contribuer à libérer IGFII dans la matrice extracellulaire (MEC), favoriser la liaison d’IGFII à son récepteur IGF-IR et stimuler la croissance et la migration des cellules astrocytaires tumorales. Pour tester cette hypothèse, nous avons réalisé différentes analyses biochimiques afin i) de caractériser les actions protéolytiques de MMP-2, MMP-9 et MT1-MMP sur le complexe IGFBP2-IGFII, ii) d’identifier la libération d’IGFII lors du clivage de ce complexe, et iii) d’étudier l’action inhibitrice de TIMP-4. A l’aide d’un modèle cellulaire in vitro (lignée astrocytaire tumorale LN229), nous avons ensuite observé l’influence de la protéolyse du complexe IGFBP2-IGFII sur la croissance et la motilité cellulaire. Cette étude a montré :(1) la protéolyse du complexe IGFBP2-IGFII par MMP-9, (2) l’inhibition partielle de cette protéolyse par TIMP-4, (3) la libération d’IGFII résultant de cette protéolyse et (4) les effets stimulants de la libération d’IGFII sur la croissance et la motilité des cellules LN229. Cette étude souligne le rôle important de la protéolyse des complexes IGFBP2-IGFII dans l’agressivité des astrocytomes diffus. Elle confirme les effets stimulants propres d’IGFII, d’IGFBP2 et de MMP-9 sur la motilité et/ou la croissance des cellules astrocytaires tumorales. Enfin, elle identifie un rôle inhibiteur potentiel de TIMP-4 sur la protéolyse du complexe IGFBP2-IGFII, qui pourrait contribuer à expliquer le caractère plus indolent des astrocytomes de grade I en comparaison aux astrocytomes diffus.<p><p>\ / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished

Τα αστροκυττώματα αποτελούν τη συχνότερη ομάδα νεοπλασμάτων του κεντρικού νευρικού συστήματος. Συνιστούν μία ετερογενή ομάδα σε ότι αφορά τη βιολογική τους συμπεριφορά και την πρόγνωσή τους και παρά την πρόοδο που έχει σημειωθεί στην κατανόηση των παθογενετικών μηχανισμών τους, συνεχίζουν να αποτελούν μια από τις επιθετικότερες μορφές καρκίνου. Ένα από τα βασικότερα χαρακτηριστικά των αστροκυττωμάτων είναι η διηθητική τους ικανότητα δηλαδή η κυτταρική μετακίνηση (cell locomotion) και η αποδόμηση στοιχείων της εξωκυττάριας ουσίας (extracellular matrix degradation) που είναι απαραίτητη για να επιτευχθεί η διήθηση. Η ιδιότητα της κυτταρικής διήθησης καθιστά τα νεοπλάσματα αυτά ιδιαιτέρως καταστροφικά για το νευρικό ιστό και επιπλέον δυσχεραίνει τη θεραπεία τους. Τόσο η χειρουργική αντιμετώπιση όσο και η ακτινοθεραπεία καθίστανται μη επαρκείς για την ριζική αντιμετώπιση των όγκων αυτών. Η παρούσα μελέτη έχει ως σκοπό την μοριακή μελέτη του φαινομένου της κυτταρικής διήθησης και εντοπίζεται κυρίως στους μηχανισμούς διάσπασης της εξωκυττάριας ουσίας. Είναι γεγονός ότι τα τελευταία χρόνια μεγάλη ερευνητική προσπάθεια συντελείται προς την κατεύθυνση αυτή και πολλοί από τους μοριακούς μηχανισμούς που εμπλέκονται στη διαδικασία αποδόμησης της εξωκυττάριας ουσίας αρχίζουν να αποσαφηνίζονται. Όμως καθώς η έρευνα προχωρά όλο και περισσότερα δεδομένα αναδεικνύονται γεγονός που υποδηλώνει την πολυπλοκότητα του φαινομένου. Ένα σχετικά πρόσφατα ταυτοποιημένο μόριο η ογκοκατασταλτική πρωτείνη ING-4 (Inhibition of growth) πιστεύεται ότι είναι πιθανόν να εμπλέκεται στον έλεγχο της αποδόμησης στοιχείων της εξωκυττάριας ουσίας. Πρόσφατες μελέτες υποδεικνύουν τον ρυθμιστικό ρόλο του ING-4 στο μεταγραφικό παράγοντα NF-κB ο οποίος είναι γνωστό ότι αποτελεί κύριο ρυθμιστή της έκφρασης των ενζύμων διάσπασης της εξωκυττάριας ουσίας MMP-2, MMP-9 (matrix metalloproteases 2,9) και του ενεργοποιητή του πλασμινογόνου τύπου ουροκινάσης u-PA (urokinase-type plasminogen activator). Στη μελέτη αυτή γίνεται εκτίμηση των επιπέδων έκφρασης της πρωτείνης ING-4 της p65 υπομονάδας του NF-κB και των ενζύμων MMP-2, MMP-9 και του u-PA με τη χρήση της ανοσοιστοχημικής τεχνικής σε τομές παραφίνης ληφθείσες από 101 περιστατικά αστροκυττωμάτων του ανθρώπου όλων των βαθμίδων διαφοποίησης. Η γνώση του επιπέδου έκφρασης των μορίων αυτών στα αστροκυττώματα καθώς και η μεταξύ τους συσχέτιση αφενώς μεν θα συμβάλει στην κατανόηση των μηχανισμών που ελέγχουν την κυτταρική διήθηση, αφετέρου πιθανόν να αποτελέσει χρήσιμη γνώση για μελλοντικό σχεδιασμό θεραπειών περιορισμού του φαινομένου αυτού. / Inhibitor of growth 4 (ING-4) is a tumor suppressor gene that interacts with nuclear factorkappaB (NF-kB) and represses its transcriptional activity. Several lines of evidence suggest that the tumor suppressor gene ING-4, the transcription factor NF-kB and its target genes matrix metalloproteases MMP-2, MMP-9 and urokinase plasminogen activator (u-PA) are critically involved in tumor invasion. The aim of the present study was to investigate immunohistochemically the expression pattern of ING-4, NF-kB and the NF-kB downstream targets MMP-2, MMP-9 and u-PA in human astrocytomas from 101 patients. We found that ING-4 expression was significantly decreased in astrocytomas, and ING-4 loss was associated with tumor grade progression. Expression of p65, a NF-kB subunit, was significantly higher in grade IV than in grade III and grade I/II tumors, and a statistical significant negative correlation between expression of ING-4 and expression of nuclear p65 was noticed. MMP-9, MMP-2 and u-PA were overexpressed in human astrocytomas. Of note, astrocytomas of advanced histologic grades (grade III, IV) displayed significantly higher expression levels of these proteins compared to tumors of lower grades (grade I, II). Collectively, our data suggest an essential role for ING-4 in human astrocytoma development and progression possibly through regulation of the NF-kB-dependent expression of genes involved in tumor invasion.