RESUMEN
The tumor suppressor Adenomatous polyposis coli (APC) is a negative regulator of Wnt signaling and functions in cytoskeletal organization. Disruption of human APC in colonic epithelia initiates benign polyps that progress to carcinoma following additional mutations. The early events of polyposis are poorly understood, as is the role of canonical Wnt signaling in normal epithelial architecture and morphogenesis. To determine the consequences of complete loss of APC in a model epithelium, we generated APC2 APC1 double null clones in the Drosophila wing imaginal disc. APC loss leads to segregation, apical constriction, and invagination that result from transcriptional activation of canonical Wnt signaling. Further, we show that Wnt-dependent changes in cell fate can be decoupled from Wnt-dependent changes in cell shape. Wnt activation is reported to upregulate DE-cadherin in wing discs, and elevated DE-cadherin is thought to promote apical constriction. We find that apical constriction and invagination of APC null tissue are independent of DE-cadherin elevation, but are dependent on Myosin II activity. Further, we show that disruption of Rho1 suppresses apical constriction and invagination in APC null cells. Our data suggest a novel link between canonical Wnt signaling and epithelial structure that requires activation of the Rho1 pathway and Myosin II.
Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriología , Miosina Tipo II/metabolismo , Transducción de Señal , Proteínas Wnt/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Proteína de la Poliposis Adenomatosa del Colon/genética , Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Animales , Proteínas de Drosophila/genética , Embrión no Mamífero/metabolismo , Genes APC , Miosina Tipo II/genética , Proteínas Wnt/genética , Proteínas de Unión al GTP rho/genéticaRESUMEN
UNLABELLED: Engaging in sexual intercourse early in life and without protection often leads to unplanned pregnancy and sexually transmitted diseases in teens. METHODS: A binary logistical regression analysis was used to identify the risk and protective factors associated with two preventive health behaviors: sexual abstinence and consistent condom use among 6,902 Central American teens receiving web-based adolescent health promotion education from 2004 to 2008. RESULTS: The average age was 15 years, with ages ranging between 10 and 20 years. Of these, 52% were girls and 48% boys. Personal competencies, social peer influences, and family factors were found to influence their sexual behavior patterns and were generally consistent with other studies worldwide. CONCLUSION: Information technology provides new avenues to assess individual health and provide individualized data collection in a confidential, sensitive, accessible, and engaging manner. Health promotion interventions must continue to address the development of personal knowledge, skills, and motivations to prevent and or reduce sexual risk-taking behaviors.
