RESUMEN
Arf GTPase-activating proteins (Arf GAPs) control the activity of ADP-ribosylation factors (Arfs) by inducing GTP hydrolysis and participate in a diverse array of cellular functions both through mechanisms that are dependent on and independent of their Arf GAP activity. A number of these functions hinge on the remodeling of actin filaments. Accordingly, some of the effects exerted by Arf GAPs involve proteins known to engage in regulation of the actin dynamics and architecture, such as Rho family proteins and nonmuscle myosin 2. Circular dorsal ruffles (CDRs), podosomes, invadopodia, lamellipodia, stress fibers and focal adhesions are among the actin-based structures regulated by Arf GAPs. Arf GAPs are thus important actors in broad functions like adhesion and motility, as well as the specialized functions of bone resorption, neurite outgrowth, and pathogen internalization by immune cells. Arf GAPs, with their multiple protein-protein interactions, membrane-binding domains and sites for post-translational modification, are good candidates for linking the changes in actin to the membrane. The findings discussed depict a family of proteins with a critical role in regulating actin dynamics to enable proper cell function.
Asunto(s)
Factores de Ribosilacion-ADP/metabolismo , Citoesqueleto de Actina/metabolismo , Proteínas Activadoras de GTPasa/metabolismo , Factores de Ribosilacion-ADP/química , Citoesqueleto de Actina/química , Actinas/química , Actinas/metabolismo , Animales , Apoptosis , Movimiento Celular , Adhesiones Focales , Proteínas Activadoras de GTPasa/química , Proteínas Activadoras de GTPasa/genética , Interacciones Huésped-Patógeno , Humanos , Familia de Multigenes , Proyección Neuronal , Neuronas/metabolismo , Podosomas/metabolismo , Unión Proteica , Seudópodos/metabolismo , Relación Estructura-Actividad , Proteínas de Unión al GTP rho/genética , Proteínas de Unión al GTP rho/metabolismoRESUMEN
Esophageal squamous cell carcinomas (ESCCs) harbor recurrent chromosome 3q amplifications that target the transcription factor SOX2. Beyond its role as an oncogene in ESCC, SOX2 acts in development of the squamous esophagus and maintenance of adult esophageal precursor cells. To compare Sox2 activity in normal and malignant tissue, we developed engineered murine esophageal organoids spanning normal esophagus to Sox2-induced squamous cell carcinoma and mapped Sox2 binding and the epigenetic and transcriptional landscape with evolution from normal to cancer. While oncogenic Sox2 largely maintains actions observed in normal tissue, Sox2 overexpression with p53 and p16 inactivation promotes chromatin remodeling and evolution of the Sox2 cistrome. With Klf5, oncogenic Sox2 acquires new binding sites and enhances activity of oncogenes such as Stat3. Moreover, oncogenic Sox2 activates endogenous retroviruses, inducing expression of double-stranded RNA and dependence on the RNA editing enzyme ADAR1. These data reveal SOX2 functions in ESCC, defining targetable vulnerabilities.
Asunto(s)
Adenosina Desaminasa/metabolismo , Epigenoma , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas de Esófago/genética , Proteínas de Unión al ARN/metabolismo , Factores de Transcripción SOXB1/metabolismo , Regiones no Traducidas 3'/genética , Animales , Secuencia de Bases , Carcinogénesis/genética , Línea Celular Tumoral , Transformación Celular Neoplásica/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Retrovirus Endógenos/genética , Elementos de Facilitación Genéticos/genética , Regulación Neoplásica de la Expresión Génica , Genoma Humano , Humanos , Interferones/metabolismo , Intrones/genética , Factores de Transcripción de Tipo Kruppel/genética , Ratones , Organoides/patología , Unión Proteica , ARN Bicatenario/metabolismo , Factores de Transcripción SOXB1/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
BACKGROUND: Systemic lupus erythematosus (SLE or lupus) is an autoimmune multisystem disease. While a complete understanding of lupus' origins, mechanisms, and progression is not yet available, a number of studies have demonstrated correlations between disease prevalence and severity, gender, and race. There have been few population based studies in the United States. OBJECTIVES: To assess temporal changes in demographics and hospital mortality of patients with lupus in Washington State from 2003 to 2011. STUDY DESIGN: This study used data from the Healthcare Cost and Utilization Project (HCUP), a patient information database, and data from the Washington State census to study a group of patients in the state. Lupus hospitalizations were defined as any hospitalization with an ICD-9-CM diagnosis code for systemic lupus erythematosus. Regression analysis was used to assess the effect of calendar time on demographics and hospital outcomes. RESULTS: There were a total of 18,905 patients in this study with a diagnostic code for lupus. The mean age of the group was 51.5 years (95% CI: 50.6-52.3) in 2003 and 51.3 years (95% CI: 50.6-52.0) in 2011. The population was 88.6% female. Blacks were 2.8 times more likely to have a lupus hospitalization than whites when compared to the Washington population. While hospital mortality decreased during this eight year period (3.12% in 2003 to 1.28% in 2011, p=0.001) hospital length of stay remained statistically unchanged at an average of 4.9 days during that eight year period. We found a significant decrease in annual hospital mortality over the study period [odds ratio(OR): 0.92 per year, 95% CI 0.88-0.96, P<0.001]. Hospital mortality was higher in males (2.6% male death to 1.8% female death). CONCLUSIONS: In this large group of hospitalized lupus patients in Washington, hospital length of stay remained relatively stable over time but hospital mortality decreased by over 50% over the eight year study period.