Combatiendo el metabolismo de las células cancerosas mediante la activación de SIRT3 y el ejercicio físico / Combating tumor cells through SIRT3 activation and exercise

One of the main features of cancer is the high rate of cell proliferation and growth. To do this, cancer cells need to redirect their metabolism mainly towards anaerobic glycolysis and an increased mitochondrial glutamine energy metabolism. Sirtuins are cellular proteins with regulatory functions on metabolic pathways, genomic stability, apoptosis, longevity, inflammation, energy metabolism and oxidative stress. Sirtuins have emerged recently as a potential therapeutic option to treat several chronic diseases including cancer. This review summarizes the tumor suppressor function of Sirtuin 3 (SIRT3), highlighting its repressor effect on glycolytic metabolism, promoting mitochondrial metabolism and oxidative stress reduction. SIRT3 activation by exercise is particularly described since it may represent a potent tool for several types of cancer treatment.

Downregulation of TGF-ß1 suppressed proliferation and increased chemosensitivity of ovarian cancer cells by promoting BRCA1/Smad3 signaling

BACKGROUND: Studies have demonstrated that transforming growth factor beta-1 (TGF-ß1) exhibits oncogenic activity in different types of cancer, including ovarian cancer (OC). However, its regulatory mechanism in OC and whether TGF-ß1 is involved in chemosensitivity regulation remains unclear. Thus, the aim of this study was to investigate the role of TGF-ß1 in OC. METHODS: The OC cell line SKOV3 was employed, and TGF-ß1 overexpression or knockdown vectors were constructed. The cell proliferation of SKOV3 was evaluated with the cell counting kit (CCK8) kit after treatment with different concentrations of cis-platinum. Western blot and protein immunoprecipitation were employed to detect changes in BRCA1 and Smad3 expression and their interactions. Tumor growth in nude mice was evaluated. RESULTS: The results showed that TGF-ß1 knockdown increased chemosensitivity by promoting BRCA1 expression and Smad3 phosphorylation. In vivo studies showed that TGF-ß1 knockdown significantly inhibited the growth of tumors, also by upregulating BRCA1 expression and Smad3 phosphorylation. CONCLUSION: Taken together, our results suggest that TGF-ß1 knockdown inhibits tumor growth and increases chemosensitivity by promotion of BRCA1/Smad3 signaling.

The perceptions of medical researchers on qualitative methodologies / Percepción de los investigadores médicos en metodologías cualitativas / Percepção de pesquisadores médicos sobre metodologias qualitativas

We aimed to verify doctor's perception of the qualitative research method, via a qualitative study of interviews with questions on the academic profile of doctors and on the methodology. We interviewed 42 professionals, of which 18 had experience with the qualitative method and 24 with the quantitative method. The results showed that knowledge on the qualitative method was virtually nil among "quantitative researchers", who did not value qualitative research, although some of those realized that it would be important to be more accepting in clinical practice. Others only considered the method as subsidiary to quantitative. The majority considered qualitative methods as lacking academic structure, taking too long to conduct empirical studies, and being difficult to publish. All of them criticized the misuse of the method, and the "quantitatives" pointed out the problem of being unable to reproduce. We concluded that widening the use of the qualitative method by doctors requires investment from the beginning of the academic career and participation in qualitative research projects.

El objetivo es verificar la percepción de médicos sobre el método de investigación cualitativa. Se trata de un estudio cualitativo por medio de entrevistas con preguntas sobre el perfil de los médicos y sobre el método. Entrevistamos a 42 profesionales, 18 con experiencia en el método cualitativo y 24 con el cuantitativo. Los resultados mostraron que el conocimiento sobre lo cualitativo es casi nulo entre los "cuantitativistas", que no valoran la investigación cualitativa, aunque algunos se dan cuenta de que sería importante tener un enfoque más amplio en la práctica clínica. Otros la ven como subsidiaria a lo cuantitativo. Sus dificultades para utilizar ese abordaje son: falta de formación, cantidad de tiempo que exigen y problemas de publicación. Todos han criticado el mal uso del método. Los "cuantitativistas" han destacado como fragilidad, la no reproductibilidad. Llegamos a la conclusión de que para ampliar el uso de los abordajes cualitativos entre los médicos es importante invertir en su formación desde el inicio del curso y la participación en proyectos de investigación cualitativa.

Objetivamos verificar a percepção de médicos sobre o método qualitativo de pesquisa. Estudo qualitativo por meio de entrevistas com questões sobre o perfil acadêmico do médico e perguntas abertas a respeito do método. Entrevistamos 42 profissionais, sendo 18 com experiência no método qualitativo e 24 com o quantitativo. Os resultados evidenciaram que o conhecimento sobre o qualitativo é quase nulo entre os pesquisadores "quantitativistas", os quais não valorizam a pesquisa qualitativa, embora alguns percebam que seria importante ter uma postura mais compreensiva na prática clínica. Outros só a veem como subsidiária ao quantitativo. As principais dificuldades da maioria são: falta de formação, tempo longo despendido nos estudos empíricos e dificuldade de publicação. Todos os entrevistados criticaram o mau uso do método, e os "quantitativistas" ressaltaram, como problema, sua não reprodutibilidade. Concluímos que ampliar o uso do método qualitativo por médicos exige investimento na formação desde o início da graduação e participação em projetos de pesquisa qualitativa.

Caveolae and caveolae-like membrane domains in cellular signaling and disease: identification of downstream targets for the tumor suppressor protein caveolin-1

Caveolae are small, flask-shaped invaginations of the plasma membrane present on a large number of mammalian cells. Recent results obtained with knock-out mice for the gene caveolin-1 demonstrate that expression of caveolin-1 protein is essential for caveolae formation in vivo. Caveolae are implicated in a wide variety of cellular events including transcytosis, cholesterol trafficking and as cellular centers important in coordinating signalling events. Caveolae share this role and the property of detergent insolubility with plasma membrane assemblies rich in glycosphingolipids and cholesterol, often called lipid rafts, but preferably referred to here as caveolae-like membrane domains. Due to such widespread presence and usage in cellular function, caveolae and related domains are implicated in human diseases, including cancer. In particular, the protein caveolin-1 is suggested to function as a tumor suppressor protein. Evidence demonstrating such a role for caveolin-1 in human colon carcinoma cells will be discussed together with data from microarray experiments seeking to identify caveolin-1 target genes responsible for such behavior