RESUMO
The insulin-like growth factor-I receptor (IGF-IR) is a ubiquitous multifunctional tyrosine kinase that has an important role in normal cell growth and development. However, abnormal stimulation of IGF-IR signaling has been implicated in the development of different types of tumors. The strong antiapoptotic activity of IGF-IR has been recognized as critical in IGF-I-dependent tumorigenesis, however, the impact of other IGF-IR functions, such as regulation of cell-cell and cell-matrix adhesion are also increasingly acknowledged. Here, on the model of breast cancer cells, we discuss how IGF-IR-dependent regulation of intercellular adhesion may affect cell survival, resistance to antiestrogens, and invasion.
Assuntos
Fenômenos Fisiológicos Celulares , Receptor IGF Tipo 1/fisiologia , Animais , Neoplasias da Mama/patologia , Neoplasias da Mama/fisiopatologia , Caderinas/fisiologia , Adesão Celular/fisiologia , Progressão da Doença , Feminino , Humanos , Neoplasias/patologia , Neoplasias/fisiopatologiaRESUMO
High consumption of soybean products, such as phytoestrogens, has been hypothesized to contribute to a reduced incidence of prostate cancer in Southeast Asian people, although there have been inconsistent results among studies. Human LNCaP cells, extensively used as a model for androgen-dependent prostate tumor, express the androgen receptor (AR) mutant T877A promiscuously transactivated by estrogens and other ligands, which may further facilitate cancer progression. Here, for the first time to our knowledge, we demonstrate that genistein and quercetin, two phytoestrogens abundantly present in soybeans, activate either the AR mutant T877A in LNCaP or in transfected Chinese hamster ovary cells. This observation is supported by their capability to induce AR accumulation in the nuclear compartment of LNCaP together with mRNA down-regulation of the androgen target genes AR and PAP, and PSA up-regulation. Of interest, at concentrations eliciting transcriptional activity, both genistein and quercetin stimulate LNCaP cell growth, whereas at high levels, they become cytotoxic independently of AR expression, as ascertained in steroid receptor-negative Hela cells. The results of our study provide evidence that phytoestrogens may regulate several signaling processes in LNCaP cells; however, further studies are needed to assess their potential capability to restrain prostate tumor progression.
Assuntos
Genisteína/farmacologia , Quercetina/farmacologia , Receptores Androgênicos/fisiologia , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Células CHO , Divisão Celular/efeitos dos fármacos , Cricetinae , Relação Dose-Resposta a Droga , Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Masculino , Antígeno Prostático Específico/genética , Neoplasias da Próstata/patologia , RNA Mensageiro , Receptores Androgênicos/genética , Células Tumorais Cultivadas , Regulação para Cima/efeitos dos fármacosRESUMO
Se realiza un estudio prospectivo en 52 pacientes con prolapso genital de grado variable para observar la incidencia de infección urinaria.Se analizan antecedentes importante que están en relación con el prolapso genitalasí como la presencia o no de incontinencia urinaria de esfuerzo;igualmente se hacen estudios comparativos en cuanto la forma de toma de la muestra de orina (chorro y cateterismo). Hacemos incapié sobre la relación existente entre la edad, pariedad, grado de prolapso, presencia o no de incontinencia urinaria de esfuerzoe infección urinaria; esta ultima determinada por urocultivo
