RESUMEN
Growth hormone (GH) signaling is essential for postnatal linear bone growth, but the relative importance of GHs actions on the liver and/or growth plate cartilage remains unclear. The importance of liver derived insulin like-growth factor-1 (IGF-1) for endochondral growth has recently been challenged. Here, we investigate linear growth in Suppressor of Cytokine Signaling-2 (SOCS2) knockout mice, which have enhanced growth despite normal systemic GH/IGF-1 levels. Wild-type embryonic ex vivo metatarsals failed to exhibit increased linear growth in response to GH, but displayed increased Socs2 transcript levels (P < 0.01). In the absence of SOCS2, GH treatment enhanced metatarsal linear growth over a 12 day period. Despite this increase, IGF-1 transcript and protein levels were not increased in response to GH. In accordance with these data, IGF-1 levels were unchanged in GH-challenged postnatal Socs2(-/-) conditioned medium despite metatarsals showing enhanced linear growth. Growth-plate Igf1 mRNA levels were not elevated in juvenile Socs2(-/-) mice. GH did however elevate IGF-binding protein 3 levels in conditioned medium from GH challenged metatarsals and this was more apparent in Socs2(-/-) metatarsals. GH did not enhance the growth of Socs2(-/-) metatarsals when the IGF receptor was inhibited, suggesting that IGF receptor mediated mechanisms are required. IGF-2 may be responsible as IGF-2 promoted metatarsal growth and Igf2 expression was elevated in Socs2(-/-) (but not WT) metatarsals in response to GH. These studies emphasise the critical importance of SOCS2 in regulating GHs ability to promote bone growth. Also, GH appears to act directly on the metatarsals of Socs2(-/-) mice, promoting growth via a mechanism that is independent of IGF-1.
Asunto(s)
Desarrollo Óseo/genética , Hormona del Crecimiento/metabolismo , Factor I del Crecimiento Similar a la Insulina/genética , Proteínas Supresoras de la Señalización de Citocinas/genética , Animales , Desarrollo Óseo/efectos de los fármacos , Regulación del Desarrollo de la Expresión Génica , Hormona del Crecimiento/administración & dosificación , Factor II del Crecimiento Similar a la Insulina/biosíntesis , Huesos Metatarsianos/crecimiento & desarrollo , Huesos Metatarsianos/metabolismo , Ratones , Ratones NoqueadosRESUMEN
BACKGROUND: Hypofractionation is now becoming the standard of care in breast irradiation. The aim of this study was to assess the toxicities and outcomes in patients with breast cancer treated with hypofractionated radiotherapy (HFRT). METHODS: Patients with localized breast cancer who received adjuvant HFRT between 2013 and 2015 with a minimum follow-up of 6 months following radiation were included in this prospective study. Late toxicities were assessed using CTCAE v 4 and included chest/breast pain, limb pain, limb edema, skin pigmentation, skin fibrosis, and shoulder movement restriction. Outcomes assessed included locoregional control, disease-free survival, and overall survival. Statistical analysis was done using Microsoft Excel and SPSS v22. RESULTS: A total of 81 patients fulfilled the inclusion criteria, of which 19 patients had died during follow-up. Regional nodal irradiation was done in 63 (77.8%) patients using the same hypofractionated schedule of 40 Gy in 15 fractions. Late toxicities were assessed for 62 patients. The median follow-up following the course of hypofractionated radiation was 45 months (range 14 - 65 months). Late toxicities were assessed for 62 patients. Grade 1/2 chest/breast pain, limb pain, limb edema, skin pigmentation, skin fibrosis, and shoulder movement restriction were seen in 11%, 12%, 7%, 6%, 8%, and 11% of cases, respectively. Distant recurrences were seen in 8% of cases, and there were no locoregional recurrences. Five-year overall survival was 76.5%. CONCLUSION: HFRT to whole breast or chest wall and the regional nodal areas was well-tolerated with acceptable rates of late toxicities on follow-up.
Asunto(s)
Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/radioterapia , Hipofraccionamiento de la Dosis de Radiación , Traumatismos por Radiación/mortalidad , Traumatismos por Radiación/patología , Radioterapia Adyuvante/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Traumatismos por Radiación/etiología , Radioterapia Adyuvante/efectos adversos , Estudios Retrospectivos , Tasa de Supervivencia , Adulto JovenRESUMEN
The muscular dystrophy X-linked (mdx) mouse is commonly used as a mouse model of Duchenne muscular dystrophy (DMD). Its phenotype is, however, mild, and other mouse models have been explored. The mdx:Cmah-/- mouse carries a human-like mutation in the Cmah gene and has a severe muscle phenotype, but its growth and bone development are unknown. In this study, we compared male mdx, mdx:Utrn+/-, mdx:Cmah-/- and wild-type (WT) mice at 3, 5 and 7â weeks of age to determine the suitability of the mdx:Cmah-/- mouse as a model for assessing growth and skeletal development in DMD. The mdx:Cmah-/- mice were lighter than WT mice at 3 weeks, but heavier at 7â weeks, and showed an increased growth rate at 5â weeks. Cortical bone fraction as assessed by micro-computed tomography was greater in both mdx and mdx:Cmah-/- mice versus WT mice at 7â weeks. Tissue mineral density was also higher in mdx:Cmah-/- mice at 3 and 7 weeks. Gene profiling of mdx:Cmah-/- bone identified increased expression of Igf1, Igf1r and Vegfa Both the mdx and mdx:Cmah-/- mice showed an increased proportion of regulated bone marrow adipose tissue (BMAT) but a reduction in constitutive BMAT. The mdx:Cmah-/- mice show evidence of catch-up growth and more rapid bone development. This pattern does not mimic the typical DMD growth trajectory and therefore the utility of the mdx:Cmah-/- mouse for studying growth and skeletal development in DMD is limited. Further studies of this model may, however, shed light on the phenomenon of catch-up growth.This article has an associated First Person interview with the first author of the paper.
Asunto(s)
Desarrollo Óseo , Huesos/patología , Utrofina/metabolismo , Adiposidad , Animales , Fenómenos Biomecánicos , Médula Ósea/patología , Huesos/diagnóstico por imagen , Hueso Esponjoso/diagnóstico por imagen , Hueso Esponjoso/patología , Hueso Esponjoso/fisiopatología , Hueso Cortical/diagnóstico por imagen , Hueso Cortical/patología , Hueso Cortical/fisiopatología , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Placa de Crecimiento/diagnóstico por imagen , Placa de Crecimiento/patología , Placa de Crecimiento/fisiopatología , Fuerza de la Mano , Inflamación/patología , Factor I del Crecimiento Similar a la Insulina/metabolismo , Ratones Endogámicos C57BL , Ratones Endogámicos mdx , Músculo Esquelético/diagnóstico por imagen , Músculo Esquelético/patología , Músculo Esquelético/fisiopatología , Distrofia Muscular de Duchenne/diagnóstico por imagen , Distrofia Muscular de Duchenne/patología , Distrofia Muscular de Duchenne/fisiopatología , Fenotipo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Tibia/diagnóstico por imagen , Tibia/patología , Tibia/fisiopatología , Microtomografía por Rayos XRESUMEN
Cellular cross-talk between ubiquitination and other posttranslational modifications contributes to the regulation of numerous processes. One example is ADP-ribosylation of the carboxyl terminus of ubiquitin by the E3 DTX3L/ADP-ribosyltransferase PARP9 heterodimer, but the mechanism remains elusive. Here, we show that independently of PARP9, the conserved carboxyl-terminal RING and DTC (Deltex carboxyl-terminal) domains of DTX3L and other human Deltex proteins (DTX1 to DTX4) catalyze ADP-ribosylation of ubiquitin's Gly76 Structural studies reveal a hitherto unknown function of the DTC domain in binding NAD+ Deltex RING domain recruits E2 thioesterified with ubiquitin and juxtaposes it with NAD+ bound to the DTC domain to facilitate ADP-ribosylation of ubiquitin. This ubiquitin modification prevents its activation but is reversed by the linkage nonspecific deubiquitinases. Our study provides mechanistic insights into ADP-ribosylation of ubiquitin by Deltex E3s and will enable future studies directed at understanding the increasingly complex network of ubiquitin cross-talk.
Asunto(s)
Ubiquitina-Proteína Ligasas , Ubiquitina , ADP-Ribosilación , Humanos , NAD/metabolismo , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , UbiquitinaciónRESUMEN
Phosphorylation of MDM2 by ATM upon DNA damage is an important mechanism for deregulating MDM2, thereby leading to p53 activation. ATM phosphorylates multiple residues near the RING domain of MDM2, but the underlying molecular basis for deregulation remains elusive. Here we show that Ser429 phosphorylation selectively enhances the ubiquitin ligase activity of MDM2 homodimer but not MDM2-MDMX heterodimer. A crystal structure of phospho-Ser429 (pS429)-MDM2 bound to E2-ubiquitin reveals a unique 310-helical feature present in MDM2 homodimer that allows pS429 to stabilize the closed E2-ubiquitin conformation and thereby enhancing ubiquitin transfer. In cells Ser429 phosphorylation increases MDM2 autoubiquitination and degradation upon DNA damage, whereas S429A substitution protects MDM2 from auto-degradation. Our results demonstrate that Ser429 phosphorylation serves as a switch to boost the activity of MDM2 homodimer and promote its self-destruction to enable rapid p53 stabilization and resolve a long-standing controversy surrounding MDM2 auto-degradation in response to DNA damage.
Asunto(s)
Daño del ADN , Proteínas Proto-Oncogénicas c-mdm2/química , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Dominios RING Finger , Secuencia de Aminoácidos , Línea Celular Tumoral , Humanos , Modelos Moleculares , Fosforilación , Fosfoserina/metabolismo , Unión Proteica , Multimerización de Proteína , Relación Estructura-Actividad , Ubiquitina/metabolismoRESUMEN
Malignant gonadal germ cell tumors, referred to as germ cell cancers (GCC), occur with increased frequency in individuals who have specific types of differences (disorders) of sex development (DSD). Recent population-based studies have identified new environmental and genetic risk factors that have led to a 'genvironment' hypothesis, which may potentially be helpful in risk assessment in DSD-related GCC. In DSD, the malignancy risk is highly heterogeneous, but recent studies allow now to discriminate between high- and low-risk conditions. Gonadal biopsy is in some cases the best procedure of choice to assess the risk, and with the availability of immunohistochemical biomarkers [OCT3/4 (POU5F1), TSPY, SOX9, FOXL2 and KITLG (SCF)], a reliable classification of GCC and its precursors can be made. The opportunities in the field of virtual diagnostic pathology will be presented, having possibilities for rare diseases in general and DSD specifically. It is expected that the International DSD Registry will stimulate international collaborations, facilitating better diagnostic procedures as well as research.
Asunto(s)
Trastornos del Desarrollo Sexual/patología , Trastornos del Desarrollo Sexual/terapia , Gónadas/patología , Gónadas/embriología , Humanos , Guías de Práctica Clínica como Asunto , Factores de Riesgo , Diferenciación Sexual , TelemedicinaAsunto(s)
Ciliopatías/diagnóstico , Ciliopatías/genética , Dineínas Citoplasmáticas/genética , Anomalías del Sistema Digestivo/diagnóstico , Anomalías del Sistema Digestivo/genética , Mutación , Femenino , Estudios de Asociación Genética/métodos , Predisposición Genética a la Enfermedad , Humanos , Recién Nacido , FenotipoRESUMEN
BACKGROUND: A very large number of women in the reproductive age group consume cocaine, leading to grave concerns regarding the long term health of millions of children after in utero exposure. The results of controlled studies have been contradictory, leading to confusion, and, possible, misinformation and misperception of teratogenic risk. OBJECTIVE: To systematically review available data on pregnancy outcome when the mother consumed cocaine. METHODS: A meta-analysis of all epidemiologic studies based on a priori criteria was conducted. Comparisons of adverse events in subgroups of exposed vs. unexposed children were performed. Analyses were based on several exposure groups: mainly cocaine, cocaine plus polydrug, polydrug but no cocaine, and drug free. RESULTS: Thirty three studies met our inclusion criteria. For all end points of interest (rates of major malformations, low birth weight, prematurity, placental abruption, premature rupture of membrane [PROM], and mean birth weight, length and head circumference), cocaine-exposed infants had higher risks than children of women not exposed to any drug. However, most of these adverse effects were nullified when cocaine exposed children were compared to children exposed to polydrug but no cocaine. Only the risk of placental abruption and premature rupture of membranes were statistically associated with cocaine use itself. CONCLUSIONS: Many of the perinatal adverse effects commonly attributed to cocaine may be caused by the multiple confounders that can occur in a cocaine using mother. Only the risk for placental abruption and PROM could be statistically related to cocaine. For other adverse effects, additional studies will be needed to ensure adequate statistical power.
Asunto(s)
Anomalías Inducidas por Medicamentos/epidemiología , Trastornos Relacionados con Cocaína/epidemiología , Cocaína/efectos adversos , Feto/efectos de los fármacos , Complicaciones del Embarazo/epidemiología , Aborto Espontáneo/inducido químicamente , Aborto Espontáneo/epidemiología , Desprendimiento Prematuro de la Placenta/inducido químicamente , Desprendimiento Prematuro de la Placenta/epidemiología , Adulto , Femenino , Rotura Prematura de Membranas Fetales/inducido químicamente , Rotura Prematura de Membranas Fetales/epidemiología , Humanos , Recién Nacido de Bajo Peso , Recién Nacido , Recien Nacido Prematuro , MEDLINE , Embarazo , Complicaciones del Embarazo/inducido químicamente , Resultado del Embarazo , Factores de RiesgoRESUMEN
The Motherisk [corrected] Program, a teratogenic information service, conducts patient interviews over the telephone as well as in a clinic setting. In both instances, medical information and exposure history is obtained from the patient, including such items as pregnancy history, drug exposure, alcohol and smoking habits. It occurred on several occasions that the clinic interviewer remarked that the same patient had volunteered information to them, that differed from the information documented on the intake telephone form. The objective of the study was to establish the levels of agreement in the documentation, between these two forms of interviews. Two groups of 100 paired telephone and clinic forms were randomly selected from our data base, 1990-1991 and 1996-1997. These two groups were chosen to assess if there were any differences over a five year time period. Statistical calculations were performed using the Kappa statistic, a method that measures agreement. Kappa scores indicated high reproducibility for both pregnancy and smoking history, good reproducibility for medical history, marginal-good for exposures (although excellent agreement was found for the primary drug of concern) and marginal-good for alcohol information. Overall, agreement was superior in the 1990-1991 group. There were marked differences in consistency, between the information recorded on the telephone form and the clinic form, most specifically relating to secondary exposures and alcohol history. It suggests that a person to person interview yields a more complete medical history than a telephone interview.