RECK-Mediated Inhibition of Glioma Migration and Invasion

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Glioma cordoide do terceiro ventrículo: descrição de um novo caso

O glioma cordoide é um tumor cerebral raro, recentemente descrito, localizado na região do terceiro ventrículo e com características histológicas, imuno-histoquímicas e ultraestruturais peculiares. Este estudo ilustra um caso de glioma cordoide do terceiro ventrículo em uma paciente de 59 anos de idade.

DO GLIOMA-CELLS EXPRESS CYTOKERATIN

There have been several recent reports of cytokeratin immunoreactivity in glial cells and tumors. We wanted to further test these tissues for cytokeratin immunoreactivity, and to determine whether antibody positivity corresponded to true cytokeratin expression. In the first set of experiments, a series of 10 formalin-fixed, frozen sections of glial tissue were employed; positive immunostaining with a cocktail of monoclonal anti-cytokeratin antibodies was seen only when a pepsin predigestion step was included in the immunostaining procedure. In the second set of experiments, 30 cases of malignant glioma fixed in both methacarn and formalin fixation were employed. Using a panel of three different anti-cytokeratin monoclonal antibodies (35 beta H11, 34 beta E12, CAM5.2), no positive immunostaining was observed in any of the methacarn-fixed tissues; positive immunostaining in the corresponding formalin-fixed tissue was frequently found, but only using the antibodies (35 beta H11, 34 beta E12) requiring enzyme predigestion. In the third set of experiments, immunoblots were performed on cytoskeletal extracts of human gliomas; no bands corresponding to known cytokeratins were observed in any cases. It is concluded that glial tissues and tumors do not, in fact, truly express cytokeratins, despite the fact that it is possible to obtain positive immunostaining of glial tumors and tissues using certain anti-cytokeratin antibodies under certain laboratory conditions.

Downregulation of the RECK-tumor and metastasis suppressor gene in glioma invasiveness

Invasive behavior is the pathological hallmark of malignant gliomas, being responsible for the failure of surgery, radiation, and chemotherapy. Matrix metalloproteinases (MMPs) are essential for proper ECM remodeling and invasion. The tumor and metastasis suppressor RECK protein regulates at least three members of the MMPs family: MMP-2, MMP-9, and MT1-MMP. In order to mimic the in vivo invasion process, A172 and T98G, respectively, non-invasive and invasive human glioblastoma cell lines, were cultured onto uncoated (control) or type I collagen gel-coated surface, and maintained for up to 7 days to allow establishment of the invasive process. We show that the collagen substrate causes decreased growth rates and morphological alterations correlated with the invasive phenotype. Electronic transmission microscopy of T98G cells revealed membrane invaginations resembling podosomes, which are typically found in cells in the process of crossing tissue boundaries, since they constitute sites of ECM degradation. Real time PCR revealed higher RECK mRNA expression in A172 cells, when compared to T98G cells and, also, in samples obtained from cultures where the invasive process was fully established. Interestingly, the collagen substrate increases RECK expression in A172 cells and the same tendency is displayed by T98G cells. MMPs-2 and -9 displayed higher levels of expression and activity in T98G cells, and their activities are also upregulated by collagen. Therefore, we suggest that: (1) RECK down regulation is critical for the invasiveness process displayed by T98G cells; (2) type 1 collagen could be employed to modulate RECK expression in glioblastoma cell lines. Since a positive correlation between RECK expression and patients survival has been noted in several types of tumors, our results may contribute to elucidate the complex mechanisms of malignant gliomas invasiveness.

Cloning of glucocorticoid-regulated genes in C6/ST1 rat glioma phenotypic reversion

The C6 rat glioma cell line is responsive to glucocorticoid hormones. C6 variants that are hyper-responsive (ST1) and resistant (P7) to hormone treatment have been derived previously. Glucocorticoid treatment of ST1 cells leads to complete reversion of the transformed phenotype and loss of tumorigenic potential. Production of C type retrovirus particles is also induced by glucocorticoids in ST1 cells. Cloning of the genes regulated by glucocorticoids in this cell system was used here as a strategy to uncover the gene products involved in the transformed-to-normal phenotypic change. Construction of a cDNA library from glucocorticoid-treated ST1 cells and screening by differential hybridization resulted in the isolation of three cellular sequences that code for rat metallothioneins (C27 and C41) and α1-acid glycoprotein (C36). Northern blot analysis revealed that expression of these genes was dramatically induced by hydrocortisone in ST1 but not in P7 cells. Viral genomic RNA was used to isolate and characterize retrovirus-related sequences that could also be responsible for the phenotypic reversion phenomenon.

Pesquisa em educação ambiental: a atividade de campo em teses e dissertações

Pós-graduação em Educação - IBRC

A dimensão valorativa da educação ambiental na formação continuada de professores apresentada em teses e dissertações brasileiras

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A ética ambiental na produção teórica (dissertações e teses) em educação ambiental no Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Os projetos de Educação Ambiental desenvolvidos nas escolas brasileiras: análise de diissertações e teses

Pós-graduação em Educação - IBRC

Análise da produção acadêmica constante no banco de teses da Capes segundo o assunto educação de surdos (2005-2009)

Pós-graduação em Educação Escolar - FCLAR

Compreensões elaboradas pelo campo da educação ambiental sobre o tema mudanças climáticas: análise de dissertações e teses brasileiras

Pós-graduação em Educação - IBRC

A representação do ato de ensinar: continuidades e rupturas da concepção de ensino na pedagogia tradicional, na psicologia histórico-cultural e na pedagogia histórico-crítica : uma análise a partir das teses e dissertações no Portal da CAPES

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

As práticas das professoras alfabetizadoras como objeto de investigação: teses e dissertações de programas de pós-graduação em educação do estado de São Paulo (1980 a 2005)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O uso de jogos no ensino e aprendizagem de Matemática nos anos iniciais do Ensino Fundamental: levantamento de teses e dissertações

Pós-graduação em Educação - FCT

Dissertações e teses da pós-graduação em educação na Unesp-Campus de Marília: um estudo das citações e cocitações (2004 a 2009)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)