Cellular IAP proteins and LUBAC differentially regulate necrosome-associated RIP1 ubiquitination.

Necroptosis is a caspase-independent regulated type of cell death that relies on receptor-interacting protein kinases RIP1 (receptor-interacting protein kinases 1) and RIP3. Tumor necrosis factor-α (TNFα)-stimulated assembly of the TNFR1 (TNF receptor 1)-associated signaling complex leads to the recruitment of RIP1, whose ubiquitination is mediated by the cellular inhibitors of apoptosis (c-IAPs). Translocation of RIP1 to the cytoplasm and association of RIP1 with the necrosome is believed to correlate with deubiquitination of RIP1. However, we found that RIP1 is ubiquitinated with K63 and linear polyubiquitin chains during TNFα, IAP antagonist BV6 and caspase inhibitor zVAD-fmk-induced necroptotic signaling. Furthermore, ubiquitinated RIP1 is associated with the necrosome, and RIP1 ubiquitination in the necrosome coincides with RIP3 phosphorylation. Both cellular IAPs and LUBAC (linear ubiquitin chain assembly complex) modulate RIP1 ubiquitination in IAP antagonist-treated necrotic cells, but they use different mechanisms. c-IAP1 regulates RIP1 recruitment to the necrosome without directly affecting RIP1 ubiquitination, whereas HOIP and HOIL1 mediate linear ubiquitination of RIP1 in the necrosome, but are not essential for necrosome formation. Knockdown of the E3 ligase c-IAP1 decreased RIP1 ubiquitination, necrosome assembly and necroptosis induced by TNFα, BV6 and zVAD-fmk. c-IAP1 deficiency likely decreases necroptotic cell death through the activation of the noncanonical NF-κB pathway and consequent c-IAP2 upregulation. The ability to upregulate c-IAP2 could determine whether c-IAP1 absence will have a positive or negative impact on TNFα-induced necroptotic cell death and necrosome formation. Collectively, these results reveal unexpected complexity of the roles of IAP proteins, IAP antagonists and LUBAC in the regulation of necrosome assembly.

The inhibitor of apoptosis (IAP) proteins are critical regulators of signaling pathways and targets for anti-cancer therapy.

Cell death regulation is vital for maintenance of homeostasis and proper development of multicellular organisms. Inhibitor of apoptosis (IAP) proteins are implicated in multiple ways in cell death regulation, ranging from inhibition of apoptosis and necrosis to the regulation of cell cycle and inflammation. Due to their prominent ability to control cell death and elevated expression in a variety of cancer cell types, IAP proteins are attractive targets for the development of novel anti-cancer treatments. The most widely used strategy for targeting IAP proteins is based on mimicking the natural IAP antagonist, SMAC/DIABLO. IAP antagonists are currently being tested in humans and they were designed for anti-cancer therapy but they could potentially also be considered for treatments of the immune system disorders. In this manuscript we will review the functional roles of IAP proteins, specifically of c-IAP1, c-IAP2, ML-IAP and XIAP, and evaluate IAP targeting strategies for disease treatments. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later".

Efectividad y seguridad de 5-azacitidina en tres pacientes con síndrome mielodisplásico / Effectiveness and safety of 5-azacitidine in three patients with myelodysplastic syndromes

Objetivo Evaluar la efectividad y seguridad del tratamiento con 5-azacitidina en síndrome mielodisplásico. Métodos Revisión de historias clínicas de pacientes que recibieron 5-azacitidina 75mg/m2 subcutánea durante 7 días, cada 28 días en 12 ciclos. Se valoró la respuesta objetiva, mejoría clínica y tiempo hasta la progresión de la enfermedad. Se recogieron las reacciones adversas descritas en la historia clínica. Resultados Seis pacientes fueron candidatos a tratamiento con 5-azacitidina. Tres casos fueron evaluables tras el período considerado. La mayoría permanecieron en respuesta parcial o mejor al finalizar el estudio, dejando de precisar transfusiones. En una paciente se retrasó la progresión a leucemia.Conclusiones5-Azacitidina podría considerarse un fármaco relativamente efectivo y seguro, pudiendo haber contribuido al control de citopenias periféricas, a mejorar la calidad de vida y a retrasar la progresión a leucemia. Serían necesarios estudios con mayor número de pacientes que corroborasen estos resultados (AU)

Objective To assess the effectiveness and safety of using 5-azacitidine to treat myelodysplastic syndromes. Methods Review of medical records of patients who received 5-azacitidine 75mg/m2 subcutaneously for during 7 days every 28 days in twelve cycles as compassionate use. We evaluated the objective response, clinical improvement and time to disease progression. We recorded adverse reactions described in the medical history. Results Six patients were candidates for treatment with 5-azacitidine. Three cases were evaluated over the study period. Most remained in partial response or better after the study, and no longer needed transfusions. In one patient, the treatment appeared to delay progression to leukaemia.Conclusions5-Azacitidine might be considered an effective and relatively safe drug, and may have contributed to controlling peripheral cytopenias, improving the quality of life and delaying progression to leukaemia. Additional studies with more patients are needed to support these results (AU)

[Effectiveness and safety of 5-azacitidine in three patients with myelodysplastic syndromes]. / Efectividad y seguridad de 5-azacitidina en tres pacientes con síndrome mielodisplásico.

OBJECTIVE: To assess the effectiveness and safety of using 5-azacitidine to treat myelodysplastic syndromes. METHODS: Review of medical records of patients who received 5-azacitidine 75mg/m(2) subcutaneously for during 7 days every 28 days in twelve cycles as compassionate use. We evaluated the objective response, clinical improvement and time to disease progression. We recorded adverse reactions described in the medical history. RESULTS: Six patients were candidates for treatment with 5-azacitidine. Three cases were evaluated over the study period. Most remained in partial response or better after the study, and no longer needed transfusions. In one patient, the treatment appeared to delay progression to leukaemia. CONCLUSIONS: 5-Azacitidine might be considered an effective and relatively safe drug, and may have contributed to controlling peripheral cytopenias, improving the quality of life and delaying progression to leukaemia. Additional studies with more patients are needed to support these results.

Validación farmacéutica y detección de errores de prescripción de antineoplásicos en pacientes oncohematológicos / Pharmaceutical validation and error detection in the prescription of antineoplastics in oncohematological patients

Objetivo: Identificar los distintos tipos de error de prescripción de citostáticos en pacientes oncohematológicos adultos y pediátricos de nuestro hospital y proponer estrategias de mejora. Métodos: Estudio observacional longitudinal prospectivo en el que se validaron las prescripciones médicas de antineoplásicos procedentes de Hematología y Oncohematología Pediátrica durante 15 me ses. Se clasificaron los tipos de error atendiendo a la terminología y taxonomía publicadas por Otero et al en el documento "Errores de medicación: estandarización de la terminología y clasificación", recogiéndose 11 variables. Entre otros parámetros se determinaron: porcentaje de error global, por tipo de prescripción y servicios, así como de intervención farmacéutica y grado de aceptación. Resultados: Se detectaron un total de 92 errores correspondientes al 1,4% del total de prescripciones, y los de mayor frecuencia fueron: dosificación incorrecta (28,2%), duración incorrecta (21,7%) y volumen y/o vehículo inadecuados (16,3%). Además se detectó una orden de tratamiento de un paciente pediátrico alérgico al citostático prescrito. El 81,8% de órdenes con error se prescribieron de forma manual. En Hematología se obtuvo un 0,9% de error y en Oncohematología Pediátrica un 3,5%. Tanto el índice de intervención farmacéutica como su grado aceptación fueron del 100% (AU)

Objective: To identify the different types of cytostatic prescription errors in adult and paediatric oncohematological patients in our hospital and to propose strategies for improvement. Methods: Longitudinal, prospective, observational study in which prescriptions for antineoplastics from the haematology and paediatric oncohaematology departments were validated over a 15-monthperiod. The types of error were classified in accordance with the terminology and taxonomy published by Otero and cols in the document “Medication errors: standardisation of terminology and classification”. Eleven variables were recorded. Amongst other parameters, the following were determined: percentage of overall error, percentage of error in type of prescription, percentage of service error, percentage of pharmaceutical intervention and level of acceptance. Results: A total of 92 errors were recorded which corresponded to1.4% of the total prescriptions. The most significant errors were: incorrect dose (28.2%), incorrect duration (21.7%), incorrect volume and/or inadequate vehicle (16.3%), and in one case a prescription was made up where the patient was allergic to the specific cytostatic drug prescribed. 81.8% of prescription errors were made manually. In the haematology department a 0.9% error was recorded, as was a3.5% error in paediatric oncohaematology. Both the rate of pharmaceutical intervention and its level of acceptance were 100% (AU)

[Pharmaceutical validation and error detection in the prescription of antineoplastics in oncohematological patients]. / Validación farmacéutica y detección de errores de prescripción de antineoplásicos en pacientes oncohematológicos.

OBJECTIVE: To identify the different types of cytostatic prescription errors in adult and paediatric oncohematological patients in our hospital and to propose strategies for improvement. METHODS: Longitudinal, prospective, observational study in which prescriptions for antineoplastics from the haematology and paediatric oncohaematology departments were validated over a 15-month period. The types of error were classified in accordance with the terminology and taxonomy published by Otero and cols in the document "Medication errors: standardisation of terminology and classification". Eleven variables were recorded. Amongst other parameters, the following were determined: percentage of overall error, percentage of error in type of prescription, percentage of service error, percentage of pharmaceutical intervention and level of acceptance. RESULTS: A total of 92 errors were recorded which corresponded to 1.4% of the total prescriptions. The most significant errors were: incorrect dose (28.2%), incorrect duration (21.7%), incorrect volume and/or inadequate vehicle (16.3%), and in one case a prescription was made up where the patient was allergic to the specific cytostatic drug prescribed. 81.8% of prescription errors were made manually. In the haematology department a 0.9% error was recorded, as was a 3.5% error in paediatric oncohaematology. Both the rate of pharmaceutical intervention and its level of acceptance were 100%.