RESUMEN
WDR5 is a highly-conserved nuclear protein that performs multiple scaffolding functions in the context of chromatin. WDR5 is also a promising target for pharmacological inhibition in cancer, with small molecule inhibitors of an arginine-binding pocket of WDR5 (the 'WIN' site) showing efficacy against a range of cancer cell lines in vitro. Efforts to understand WDR5, or establish the mechanism of action of WIN site inhibitors, however, are stymied by its many functions in the nucleus, and a lack of knowledge of the conserved gene networks-if any-that are under its control. Here, we have performed comparative genomic analyses to identify the conserved sites of WDR5 binding to chromatin, and the conserved genes regulated by WDR5, across a diverse panel of cancer cell lines. We show that a specific cohort of protein synthesis genes (PSGs) are invariantly bound by WDR5, demonstrate that the WIN site anchors WDR5 to chromatin at these sites, and establish that PSGs are bona fide, acute, and persistent targets of WIN site blockade. Together, these data reveal that WDR5 plays a predominant transcriptional role in biomass accumulation and provide further evidence that WIN site inhibitors act to repress gene networks linked to protein synthesis homeostasis.
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Regulación de la Expresión Génica , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Biosíntesis de Proteínas/genética , Secuencia de Bases , Sitios de Unión/genética , Línea Celular , Cromatina/metabolismo , Secuencia Conservada/genética , Femenino , Humanos , Masculino , Unión Proteica , Transcripción Genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Ewing sarcomas are rare mesenchymal-derived bone and soft tissue tumors in children. Afflicted children with distant metastases have poor survival despite aggressive therapeutics. Epithelial-to-mesenchymal transition in epithelial carcinomas is associated with loss of E-cadherin and resistance to apoptosis. ML327 is a novel small molecule that we have previously shown to reverse epithelial-to-mesenchymal transition features in both epithelial and neural crest-derived cancers. Herein, we sought to evaluate the effects of ML327 on mesenchymal-derived Ewing sarcoma cells, hypothesizing that ML327 initiates growth arrest and sensitizes to TNF-related apoptosis-inducing ligand. ML327 induced protein expression changes, increased E-cadherin and decreased vimentin, consistent with partial induction of mesenchymal-to-epithelial transition in multiple Ewing Sarcoma cell lines (SK-N-MC, TC71, and ES-5838). Induction of epithelial features was associated with apoptosis, as demonstrated by PARP and Caspase 3 cleavage by immunoblotting. Cell cycle analysis validated these findings by marked induction of the subG0 cell population. In vitro combination treatment with TRAIL demonstrated additive induction of apoptotic markers. Taken together, these findings establish a rationale for further in vivo trials of ML327 in cells of mesenchymal origin both alone and in combination with TRAIL.
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Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Isoxazoles/farmacología , Células Madre Mesenquimatosas/efectos de los fármacos , Niacinamida/análogos & derivados , Bibliotecas de Moléculas Pequeñas/farmacología , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Antígenos CD , Antineoplásicos/química , Cadherinas/genética , Cadherinas/metabolismo , Caspasa 3/genética , Caspasa 3/metabolismo , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Sinergismo Farmacológico , Transición Epitelial-Mesenquimal/efectos de los fármacos , Regulación de la Expresión Génica , Humanos , Isoxazoles/química , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/patología , Niacinamida/química , Niacinamida/farmacología , Poli(ADP-Ribosa) Polimerasas/genética , Poli(ADP-Ribosa) Polimerasas/metabolismo , Sarcoma de Ewing/genética , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/patología , Transducción de Señal , Bibliotecas de Moléculas Pequeñas/química , Vimentina/genética , Vimentina/metabolismoRESUMEN
Neuroblastoma arises from the neural crest, the precursor cells of the sympathoadrenal axis, and differentiation status is a key prognostic factor used for clinical risk group stratification and treatment strategies. Neuroblastoma tumor-initiating cells have been successfully isolated from patient tumor samples and bone marrow using sphere culture, which is well established to promote growth of neural crest stem cells. However, accurate quantification of sphere-forming frequency of commonly used neuroblastoma cell lines has not been reported. Here, we show that MYCN-amplified neuroblastoma cell lines form spheres more frequently than non-MYCN-amplified cell lines. We also show that sphere formation is directly sensitive to cellular differentiation status. 13-cis-retinoic acid is a clinically used differentiating agent that induces a neuronal phenotype in neuroblastoma cells. Induced differentiation nearly completely blocked sphere formation. Furthermore, sphere formation was specifically FGF-responsive and did not respond to increasing doses of EGF. Taken together, these data suggest that sphere formation is an accurate method of quantifying the stemness phenotype in neuroblastoma.
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Técnicas de Cultivo Celular por Lotes/métodos , Diferenciación Celular , Reprogramación Celular , Células Madre Neoplásicas/patología , Neuroblastoma/patología , Esferoides Celulares/patología , Línea Celular Tumoral , HumanosRESUMEN
BACKGROUND: Under normoxic conditions, cancer cells use aerobic glycolysis as opposed to glucose oxidation for energy production; this altered metabolism correlates with poor outcomes in neuroblastoma. Hypoxia-inducible factor-1 alpha (HIF-1α) and pyruvate dehydrogenase kinase 4 (PDK4) regulate aerobic glycolysis, while pyruvate dehydrogenase phosphatase 2 (PDP2) promotes glucose oxidation. Here, we sought to determine whether gastrin-releasing peptide receptor (GRP-R) signaling regulates glucose metabolism. PROCEDURE: Neuroblastoma cell lines, BE(2)-C and SK-N-AS, were used. PCR microararay for glucose metabolism was performed on GRP-R silenced cells. Target protein expression was validated using Western blotting and VEGF ELISA. Cobalt chloride (CoCl2 ) was used to induce chemical hypoxia. Efficacy of targeting PDK regulation in neuroblastoma was assessed using dichloroacetate (DCA) by conducting cell viability assays and Western blotting for apoptotic markers. RESULTS: Silencing GRP-R decreased HIF-1α expression and blocked VEGF expression and secretion in both normoxic and CoCl2 induced hypoxia. PCR array analysis identified that GRP-R silencing reduced PDK4 and increased PDP2 mRNA expression. These findings were validated by Western blotting. CoCl2 induced hypoxia increased VEGF secretion, HIF-1α, and PDK4 expression. PDK4 silencing decreased HIF-1α expression and VEGF expression and secretion. DCA treatment decreased BE(2)-C and SK-N-AS proliferation while promoting cell death. GRP-R silencing and DCA treatment synergistically halted BE(2)-C proliferation. CONCLUSIONS: We report that GRP-R regulates glucose metabolism in neuroblastoma by modulating HIF-1α, PDK4 and PDP2. PDK4 regulates glucose metabolism, in part, via regulation of HIF-1α. Synergistic consequences of GRP-R inhibition and DCA treatment may suggest a novel therapeutic strategy for the treatment of aggressive neuroblastoma.
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Regulación Neoplásica de la Expresión Génica , Glucólisis , Proteínas de Neoplasias/biosíntesis , Neuroblastoma/metabolismo , Receptores de Bombesina/biosíntesis , Antimutagênicos/farmacología , Hipoxia de la Célula/efectos de los fármacos , Hipoxia de la Célula/genética , Línea Celular Tumoral , Cobalto/farmacología , Perfilación de la Expresión Génica , Silenciador del Gen , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/biosíntesis , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Proteínas de Neoplasias/genética , Neuroblastoma/genética , Neuroblastoma/patología , Análisis de Secuencia por Matrices de Oligonucleótidos , Proteínas Serina-Treonina Quinasas/biosíntesis , Proteínas Serina-Treonina Quinasas/genética , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora , Receptores de Bombesina/genética , Factor A de Crecimiento Endotelial Vascular/biosíntesis , Factor A de Crecimiento Endotelial Vascular/genéticaRESUMEN
BACKGROUND: Endovascular aortic repair has revolutionized the management of traumatic blunt aortic injury (BAI). However, debate continues about the extent of injury requiring endovascular repair, particularly with regard to minimal aortic injury. Therefore, we conducted a retrospective observational analysis of our experience with these patients. METHODS: We retrospectively reviewed all BAI presenting to an academic level I trauma center over a 10-year period (2000-2010). Images were reviewed by a radiologist and graded according to Society for Vascular Surgery guidelines (grade I-IV). Demographics, injury severity, and outcomes were recorded. RESULTS: We identified 204 patients with BAI of the thoracic or abdominal aorta. Of these, 155 were deemed operative injuries at presentation, had grade III-IV injuries or aortic dissection, and were excluded from this analysis. The remaining 49 patients had 50 grade I-II injuries. We managed 46 grade I injuries (intimal tear or flap, 95%), and four grade II injuries (intramural hematoma, 5%) nonoperatively. Of these, 41 patients had follow-up imaging at a mean of 86 days postinjury and constitute our study cohort. Mean age was 41 years, and mean length of stay was 14 days. The majority (48 of 50, 96%) were thoracic aortic injuries and the remaining two (4%) were abdominal. On follow-up imaging, 23 of 43 (55%) had complete resolution of injury, 17 (40%) had no change in aortic injury, and two (5%) had progression of injury. Of the two patients with progression, one progressed from grade I to grade II and the other progressed from grade I to grade III (pseudoaneurysm). Mean time to progression was 16 days. Neither of the patients with injury progression required operative intervention or died during follow-up. CONCLUSIONS: Injury progression in grade I-II BAI is rare (~5%) and did not cause death in our study cohort. Given that progression to grade III injury is possible, follow-up with repeat aortic imaging is reasonable.
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Aorta Abdominal/lesiones , Aorta Torácica/lesiones , Fármacos Cardiovasculares/uso terapéutico , Lesiones del Sistema Vascular/terapia , Heridas no Penetrantes/terapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Aneurisma Falso/etiología , Aneurisma Falso/terapia , Aorta Abdominal/efectos de los fármacos , Aorta Abdominal/cirugía , Aorta Torácica/efectos de los fármacos , Aorta Torácica/cirugía , Aneurisma de la Aorta/etiología , Aneurisma de la Aorta/terapia , Aortografía/métodos , Progresión de la Enfermedad , Procedimientos Endovasculares , Femenino , Humanos , Puntaje de Gravedad del Traumatismo , Tiempo de Internación , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Tomografía Computarizada Espiral , Centros Traumatológicos , Resultado del Tratamiento , Lesiones del Sistema Vascular/diagnóstico , Lesiones del Sistema Vascular/mortalidad , Heridas no Penetrantes/diagnóstico , Heridas no Penetrantes/mortalidad , Adulto JovenRESUMEN
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the pediatric and adolescent population, with 350 new cases diagnosed each year. While they can develop anywhere in the body, the genitourinary tract is the second most common primary location for an RMS to develop. Overall survival has improved through the increased use of protocols and multidisciplinary approaches. However, the guidelines for management continue to change as systemic and radiation therapeutics advance. Given the relative rarity of this disease compared to other non-solid childhood malignancies, healthcare providers not directly managing RMS may not be familiar with their presentation and updated management. This review aims to provide foundational knowledge of the management of RMSs with an emphasis on specific management paradigms for those arising from the genitourinary tract. The genitourinary tract is the second most common location for an RMS to develop but varies greatly in symptomology and survival depending on the organ of origin. As the clinical understanding of these tumors advances, treatment paradigms have evolved. Herein, we describe the breadth of presentations for genitourinary RMSs with diagnostic and treatment management considerations, incorporating the most recently available guidelines and societal consensus recommendations.
RESUMEN
The lost expression of α-catenin has been found in cancers, and reinstalling α-catenin inhibits tumor growth. Here we hypothesized that the α-N-catenin, a homologous member of α-catenin and neural-specific expressed, functions as a novel tumor suppressor in neural crest-derived tumor, neuroblastoma. We correlated CTNNA2 (encodes α-N-catenin) expression to neuroblastoma disease relapse-free survival probability using publicly accessible human neuroblastoma datasets in R2 platform. The result showed that it negatively correlated to relapse-free survival probability significantly in patients with neuroblastoma with non-MYCN amplified tumor. Conversely, overexpressing CTNNA2 suppressed the neuroblastoma cell proliferation as measuring by the clonogenesis, inhibited anchorage-independent growth with soft agar colony formation assay. Forced expression of CTNNA2 decreased cell migration and invasion. Further, overexpression of CTNNA2 reduced the secretion of angiogenic factor IL-8 and HUVEC tubule formation. Our results show, for the first time, that α-N-catenin is a tumor suppressor in neuroblastoma cells. These findings were further corroborated with in vivo tumor xenograft study, in which α-N-catenin inhibited tumor growth and reduced tumor blood vessel formation. Interestingly, this is only observed in SK-N-AS xenografts lacking MYCN expression, and not in BE(2)-C xenografts with MYCN amplification. Mechanistically, α-N-catenin attenuated NF-κB responsive genes by inhibiting NF-κB transcriptional activity. In conclusion, these data demonstrate that α-N-catenin is a tumor suppressor in non-MYCN-amplified neuroblastomas and it inhibits NF-κB signaling pathway to suppress tumor growth in human neuroblastomas. Therefore, restoring the expression of α-N-catenin can be a novel therapeutic approach for neuroblastoma patients who have the deletion of CTNNA2 and lack of MYCN amplification.
RESUMEN
BACKGROUND/AIM: Sirtuins (SIRTs) play crucial roles in various signaling pathways that modulate differentiation and proliferation. We sought to elucidate the role of SIRTs in differentiation and proliferation of human neuroblastoma (NB). MATERIALS AND METHODS: NB cells were treated with nicotinamide (NAM), a non-specific SIRT inhibitor, SIRT-targeted short hairpin RNAs, and retinoic acid to assess cell growth and differentiation. RESULTS: SIRTs are involved in proliferation and differentiation using NAM in BE(2)-C cells. Specifically, SIRT6 knockdown in BE(2)-C cells reduced cell proliferation, induced neurite extension, corresponding with induction of p21CIP1 expression and G1 cell-cycle arrest. These effects were rescued by forced re-overexpression of SIRT6. SIRT6 expression was reduced in differentiated human NB sections, and RA-induced differentiation in BE(2)-C cells. CONCLUSION: SIRTs have important oncogenic properties in NB beyond its established functions in aging and genome stability. SIRT6 may represent a novel target for developing future therapeutics for the treatment of aggressive NBs.
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Diferenciación Celular/efectos de los fármacos , Neuroblastoma/tratamiento farmacológico , Neuroblastoma/metabolismo , Sirtuinas/antagonistas & inhibidores , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Técnicas de Silenciamiento del Gen , Humanos , Neuroblastoma/patología , Niacinamida/farmacología , ARN Interferente Pequeño/farmacología , Sirtuinas/genética , Tretinoina/administración & dosificación , Tretinoina/farmacologíaRESUMEN
BACKGROUND: The MYC family of proteins promotes neuroblastoma tumorigenesis at least in part through the induction of aerobic glycolysis by promoting the transcription of key glycolytic enzymes, such as LDHA. FX11 is a selective inhibitor of LDHA that has demonstrated preclinical efficacy in adult cancers. Herein, we hypothesized that FX11 would inhibit aerobic glycolysis and block growth of neuroblastoma cells. METHODS: We surveyed 3 MYCN-single copy and 5 MYCN-amplified neuroblastoma cell lines to correlate C-MYC/N-MYC protein levels with LDHA expression. Cell viability was measured with FX11 using a tetrazolium-based assay. Cell cycle analysis using propidium iodide with flow cytometry was performed to evaluate for growth arrest. Immunoblotting demonstrated PARP and Caspase 3 cleavage as evidence of apoptosis. RESULTS: LDHA is frequently expressed in both MYCN--amplified and MYCN-single copy cell lines. N-MYC and C-MYC protein levels did not correlate with LDHA protein expression. FX11 inhibits aerobic glycolysis and growth in three MYCN-amplified and one MYCN-single copy neuroblastoma cell lines. FX11 induces modest G1 cell cycle arrest with selective induction of apoptosis. CONCLUSION: Small molecule LDHA inhibition is capable of blocking aerobic glycolysis and growth of neuroblastoma cell lines in vitro and merits further in vivo evaluation of its preclinical efficacy in neuroblastomas.
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Glucólisis/efectos de los fármacos , Naftalenos/farmacología , Neuroblastoma/metabolismo , Neuroblastoma/patología , Apoptosis/efectos de los fármacos , Técnicas de Cultivo de Célula , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Proteína Proto-Oncogénica N-Myc/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismoRESUMEN
Although currently available data are variable, it appears that the incidence of surgical necrotizing enterocolitis (NEC) has not decreased significantly over the past decade. Pneumoperitoneum and clinical deterioration despite maximal medical therapy remain the most common indications for operative treatment. Robust studies linking outcomes with specific indications for operation are lacking. Promising biomarkers for severe NEC include fecal calprotectin and S100A12; serum fatty acid-binding protein; and urine biomarkers. Recent advances in ultrasonography make this imaging modality more useful in identifying surgical NEC and near-infrared spectroscopy (NIRS) is being actively studied. Another fairly recent finding is that regionalization of care for infants with NEC likely improves outcomes. The neurodevelopmental outcomes after surgical treatment are known to be poor. A randomized trial near completion will provide robust data regarding neurodevelopmental outcomes after laparotomy versus drainage as the initial operative treatment for severe NEC.
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Drenaje , Enterocolitis Necrotizante/cirugía , Enterostomía , Enfermedades del Prematuro/cirugía , Laparotomía , Biomarcadores/metabolismo , Enterocolitis Necrotizante/fisiopatología , Proteínas de Unión a Ácidos Grasos/metabolismo , Heces , Humanos , Recien Nacido Extremadamente Prematuro , Recién Nacido , Enfermedades del Prematuro/fisiopatología , Recién Nacido de muy Bajo Peso , Complejo de Antígeno L1 de Leucocito/metabolismo , Selección de Paciente , Valor Predictivo de las Pruebas , Proteína S100A12/metabolismo , Resultado del TratamientoRESUMEN
Epithelial cancers (carcinomas) comprise the top four causes of cancer-related deaths in the United States. While overall survival has been steadily improving, therapy-resistant disease continues to present a major therapeutic challenge. Carcinomas often exploit the normal developmental program, epithelial-to-mesenchymal transition (EMT), to gain a mesenchymal phenotype associated with increased invasiveness and resistance to apoptosis. We have previously shown that an isoxazole-based small molecule, ML327, partially reverses TGF-ß-induced EMT in an immortalized mouse mammary epithelial cell line. Herein, we demonstrate that ML327 reverses much of the EMT gene expression program in cultured carcinoma cell lines. The reversal of EMT sensitizes these cancer cells to the apoptosis-inducing ligand TRAIL. This sensitization is independent of E-cadherin expression and rather relies on the downregulation of a major anti-apoptotic protein, cFLIPS. Loss of cFLIPS is sufficient to overcome resistance to TRAIL and exogenous overexpression of cFLIPS restores resistance to TRAIL-induced apoptosis despite EMT reversal with ML327. In summary, we have utilized an isoxazole-based small molecule that partially reverses EMT in carcinoma cells to demonstrate that cFLIPS critically regulates the apoptosis resistance phenotype associated with EMT.
RESUMEN
Neuroblastomas are the most common extracranial solid tumors in children and arise from the embryonic neural crest. MYCN-amplification is a feature of â¼30% of neuroblastoma tumors and portends a poor prognosis. Neural crest precursors undergo epithelial-to-mesenchymal transition (EMT) to gain migratory potential and populate the sympathoadrenal axis. Neuroblastomas are posited to arise due to a blockade of neural crest differentiation. We have recently reported effects of a novel MET inducing compound ML327 (N-(3-(2-hydroxynicotinamido) propyl)-5-phenylisoxazole-3-carboxamide) in colon cancer cells. Herein, we hypothesized that forced epithelial differentiation using ML327 would promote neuroblastoma differentiation. In this study, we demonstrate that ML327 in neuroblastoma cells induces a gene signature consistent with both epithelial and neuronal differentiation features with adaptation of an elongated phenotype. These features accompany induction of cell death and G1 cell cycle arrest with blockage of anchorage-independent growth and neurosphere formation. Furthermore, pretreatment with ML327 results in persistent defects in proliferative potential and tumor-initiating capacity, validating the pro-differentiating effects of our compound. Intriguingly, we have identified destabilization of MYC signaling as an early and consistent feature of ML327 treatment that is observed in both MYCN-amplified and MYCN-single copy neuroblastoma cell lines. Moreover, ML327 blocked MYCN mRNA levels and tumor progression in established MYCN-amplified xenografts. As such, ML327 may have potential efficacy, alone or in conjunction with existing therapeutic strategies against neuroblastoma. Future identification of the specific intracellular target of ML327 may inform future drug discovery efforts and enhance our understanding of MYC regulation.
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Approximately two-thirds of patients with neuroblastoma are found to have metastatic disease at time of diagnosis with frequent skeletal, lymph node, central nervous system, and liver involvement. Using a serial in vivo splenic injection model, we have isolated an aggressive subclone (BE(2)-C/LM2) from MYCN-amplified neuroblastomas that demonstrate an enhanced propensity to develop metastatic liver lesions. BE(2)-C/LM2 subclone cells demonstrate increased adherent, soft agar colony and tumorsphere growth in vitro. Components of the tumor microenvironment regulate cancer progression, via networks of cytokines and growth factors. Cytokine array analysis identified increased TIMP-1 in the plasma of mice injected with BE(2)-C/LM2 subclone cells, leading us to hypothesize that TIMP-1 may play a role in our observed prometastatic phenotype. Immunoblotting and ELISA demonstrated enhanced endogenous TIMP-1 expression in our isolated neuroblastoma subclone. Silencing endogenous TIMP-1 successfully blocked in vitro proliferation, soft agar colony formation and tumorsphere formation by BE(2)-C/LM2 cells. Stable RNA interference of endogenous TIMP-1 failed to reverse the prometastatic phenotype of our BE(2)-C/LM2 subclone in our liver metastasis model, suggesting that endogenous TIMP-1 levels may not be an essential component of this in vivo behavior. Notably, tissue microarray analysis and Kaplan-Meier by gene expression demonstrates that elevated TIMP-1 expression is correlated with increased disease relapse and mortality in patients with neuroblastoma. Taken together, our study identifies TIMP-1 as a novel soluble factor that is associated with a prometastatic phenotype in our in vivo model and adverse outcomes in patients with neuroblastoma.
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We report that the ability to absorb water vapor from the air in larvae of the American dog tick, Dermacentor variabilis, changes depending upon moisture conditions where the eggs develop. When development occurs at lower relative humidities, resultant larvae can replenish water stores, maintain water balance, and survive at relative humidities as low as 75-85% RH, a range that agrees with previously published values for the critical equilibrium humidity or CEH. In contrast, exposure to high relative humidity conditions during development elevates the CEH to 93-97% RH. These larvae can survive only at relative humidities that are close to saturation, as 93% RH is a dehydrating atmosphere. For these larvae, absorption at 97% RH can be prevented by blocking the mouthparts with wax, indicating that an upward shift has occurred in the moisture threshold where the active mechanism for water vapor absorption operates. Based on transfer experiments between low and high relative humidities, the CEH of larvae is determined by the relative humidity experienced by the mother rather than the moisture conditions encountered by eggs after they are laid. The fact that no changes in body water content, dehydration tolerance limit and water loss rate were observed implies that adjustments to the CEH conferred by the mother have the adaptive significance of enabling larvae to maintain water balance by limiting the range of hydrating atmospheres.
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Aclimatación/fisiología , Deshidratación , Ixodidae/fisiología , Pérdida Insensible de Agua/fisiología , Análisis de Varianza , Animales , Humedad , Ixodidae/crecimiento & desarrollo , Larva/crecimiento & desarrollo , Larva/fisiología , Óvulo/metabolismoRESUMEN
BACKGROUND/PURPOSE: Patients with hypoplastic left heart syndrome (HLHS) experience a higher risk for complications from gastroesophageal reflux, prompting frequent need for fundoplication. Patients between stage I and II palliation ("interstage") are at particularly high operative risk because of the parallel nature of their pulmonary and systemic blood flow. Laparoscopic approach for fundoplication is common for pediatric patients. However, its safety in interstage HLHS is relatively unknown. We examined the perioperative physiologic burden of a laparoscopic fundoplication in HLHS patients. METHODS: All patients who underwent open or laparoscopic fundoplication during the interstage period at our institution since 2006 were reviewed. Perioperative physiologic data, echocardiographic findings, survival, and complications were collected from the anesthetic record and patient chart. RESULTS: Nineteen patients with HLHS had laparoscopic fundoplication, 13 (68%) during the interstage period, compared to 64 performed by the open approach. Ten (77%) of 13 interstage patients had perioperative hemodynamic instability. Incidence of instability between open and laparoscopic groups was not different. One laparoscopic patient required ECMO support for shunt thrombosis. CONCLUSIONS: Despite a high incidence of hemodynamic instability, overall outcomes are consistent with those reported in the literature for this high-risk patient population. Laparoscopic approach for fundoplication during the interstage period appears to be a relatively safe option for these patients.
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Fundoplicación/métodos , Reflujo Gastroesofágico/cirugía , Síndrome del Corazón Izquierdo Hipoplásico/complicaciones , Laparoscopía/métodos , Femenino , Reflujo Gastroesofágico/complicaciones , Reflujo Gastroesofágico/fisiopatología , Hemodinámica , Humanos , Síndrome del Corazón Izquierdo Hipoplásico/mortalidad , Síndrome del Corazón Izquierdo Hipoplásico/fisiopatología , Lactante , Recién Nacido , Masculino , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
The capacity of ticks to transmit a fungus was examined by analyzing tick saliva, host tissue from feeding sites, and host blood for presence of Scopulariopsis brevicaulis (Sacc.) Bainier, an internal mycosymbiont of the American dog tick, Dermacentor variabilis (Say), and lone star tick, Amnblyomma americanum (L.). Although >85% of ticks were infected with S. brevicaulis, conidia presence was low (0-5% of samples) in microscopic observations and mycological culturing of saliva expressed from larvae, nymphs, and adults. Additionally, the recovery of S. brevicaulis from blood and tissue feeding sites from a rabbit where S. brevicaulis-positive adult ticks had attached and fed was not increased compared with control tissue where no feeding occurred, indicating that transmission does not occur by the blood-feeding route. Tick mouthparts were found to contain S. brevicaulis in addition to Penicillium glabrum (Wehmer) Westling, but these agents were sparse in isolations from the feeding sites, which makes it unlikely that ticks act frequently as a mechanical fungal vector.
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Dermacentor/microbiología , Ixodidae/microbiología , Hongos Mitospóricos , Micosis/transmisión , Animales , Dermacentor/anatomía & histología , Ixodidae/anatomía & histología , Hongos Mitospóricos/aislamiento & purificación , Conejos , Saliva/microbiología , OvinosRESUMEN
Moisture requirements were evaluated for female adults of spider beetles Mezium affine Boieldieu and Gibbium aequinoctiale Boieldieu to determine how they are differentially adapted for life in a dry environment. Features showing extreme desiccation resistance of M. affine were an impermeable cuticle wherein activation energies (43kJ/mol) were suppressed, daily water losses as little as 0.3%/day with an associated group effect, a low 64% water content and an impressive ability to survive nearly 3 months with no food and water. Behaviorally, the extended period of water stress and fasting was marked by long intervals of physical inactivity (quiescence), as though dead. These characteristics emphasizing water retention rather than gain are shared by G. aequinoctiale and reflect a typical xerophilic water balance profile. Water uptake was restricted to imbibing liquid, as evidenced by uptake of dye-stained droplets of free water and a critical equilibrium activity of 1.00a(v), where the inability to absorb water vapor from the air fails to equilibrate declining water levels (gain not equal to loss) except at saturation. Four-fold reduction in survival time within dry air and accelerated water loss rates with high activation energies for female adults of the closely related winged Prostephanus truncatus (Say) suggest that the enhanced water conservation of spider beetles is due, in part, to fusion of their elytra supplemented by entering into quiescence.
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Escarabajos/fisiología , Agua/metabolismo , Animales , Femenino , Privación de Alimentos/fisiología , Especificidad de la Especie , Factores de TiempoRESUMEN
BACKGROUND: MYCN amplification is a key molecular hallmark of high-risk neuroblastoma. Previously considered an "undruggable" target, MYCN transcription can be disrupted by inhibiting the bromodomain and the extraterminal (BET) domain family of proteins that regulates MYCN transcription epigenetically. JQ1 is a potent, small-molecule BET inhibitor that induces cell-cycle arrest and initiates apoptosis in neuroblastoma. Here, we sought to validate the antitumorigenic effects of JQ1 in neuroblastoma and to evaluate whether blocking N-myc expression with JQ1 promotes neural differentiation. METHODS: We determined the effects in vitro of JQ1 treatment on human neuroblastoma cell growth in both monolayer and sphere-forming conditions. Subcutaneous neuroblastoma xenografts were used for an in vivo study. Western blotting and immunohistochemistry were performed to evaluate the effects on neural differentiation and stem cell markers. RESULTS: JQ1 treatment blocked neuroblastoma cell growth in both monolayer and sphere-forming conditions; JQ1 also attenuated the growth of neuroblastoma xenograft in athymic nude mice. Neurofilament expression was enhanced with JQ1 treatment, indicating that JQ1 induces neuronal differentiation. Sphere forming conditions resulted in increased expression of multiple stem cell markers; these effects were reversed with JQ1 treatment. CONCLUSION: BET inhibition attenuates progression and promotes neural differentiation of neuroblastoma in vitro and in vivo in mice, providing insight into potential clinical applications of BET inhibitors in the treatment of patients with neuroblastoma.
Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Azepinas/farmacología , Neuroblastoma/tratamiento farmacológico , Neurogénesis/efectos de los fármacos , Triazoles/farmacología , Animales , Antineoplásicos/uso terapéutico , Azepinas/uso terapéutico , Biomarcadores de Tumor/metabolismo , Western Blotting , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Ratones , Ratones Desnudos , Proteína Proto-Oncogénica N-Myc , Neuroblastoma/genética , Neuroblastoma/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Oncogénicas/metabolismo , Distribución Aleatoria , Triazoles/uso terapéutico , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Reactive oxygen species (ROS) contribute to adult tumorigenesis; however, their roles in pediatric solid tumors are unknown. Here, we sought to define the steady-state ROS levels in neuroblastoma and to examine whether aggressive cellular behavior, which may predict treatment failure, is regulated by ROS. METHODS: Neuroblastoma sections were assessed for 4-hydroxynonenal (4-HNE), a marker of intracellular lipid peroxidation and a byproduct of increased levels of ROS. Human neuroblastoma cell lines, MYCN-amplified BE(2)-C and MYCN-nonamplified SK-N-SH, were examined in our study. Superoxide and hydroperoxide oxidation products were detected by staining for dihydroethidium (DHE) and 5, 6-carboxy-2', 7'-dichlorodihydrofluorescein diacetate (CDCFH2), using the oxidation-insensitive analog CDCF as a negative control. Cells were treated with N-acetylcysteine (NAC; 10 mmol/L) daily for 5 days and analyzed. RESULTS: Greater expression of 4-HNE was observed in undifferentiated tumor sections as compared with the more differentiated tumors. Interestingly, increased levels of ROS were detected in MYCN-amplified BE(2)-C cells. Moreover, gastrin-releasing peptide receptor-induced ROS production stimulated upregulation of the hypoxia inducible factor (HIF)-1α/vascular endothelial growth factor (VEGF) pathway and an increase in cell growth. Antioxidant NAC decreased HIF-1α/VEGF expression and inhibited BE(2)-C cell growth. CONCLUSION: We report a novel observation that shifting the redox balance toward greater ROS levels results in a more aggressive neuroblastoma phenotype. Our data suggest that ROS play a critical role in refractory neuroblastoma.