484 research outputs found

    Teaching an old dog new tricks : activity-on-target interferon to treat T-cell acute lymphoblastic leukemia

    Get PDF
    Background Type 1 interferon (IFN) has a long history in the treatment of cancer, including hematological malignancies. The anti-cancer effects induced by IFN result from a combination of 1) direct cancer cell growth inhibition by cell cycle arrest, apoptosis, or differentiation and 2) the activation of the immune system involving antigen presentation by Clec9A+ dendritic cells and priming of cytotoxic CD8+ T-cells. However, IFN therapy experienced variable and unpredictable success in the clinic. Its clinical application is severely impeded by a complex pattern of adverse side-effects, due to the multifaceted activity pattern of IFN. Therefore, safe exploitation of the anti-cancer potential of IFN requires strategies to direct their activity to selected target cells, avoiding systemic toxicity. Aims Safe exploitation of the anti-cancer potential of IFN requires strategies to direct their activity to selected target cells, avoiding systemic toxicity. Methods To improve the therapeutic index of IFN, we have developed AcTaferons (Activity-on-Target Interferon), optimized (mutant) immunocytokines. Mutated IFNa2Q124R, with a strongly reduced affinity for its receptor complex, was fused to single domain antibodies targeting cell-specific domains, which selectively restores the AcTaferon (AFN) activity in a cell-type specific manner. As such, CD8-AFN and Clec9A-AFN were generated which selectively target either CD8+ T(-ALL) cells or Clec9A+ dendritic cells. Results Using CD8- and CD8+ mouse T-ALL cell lines, we evaluated the direct and indirect anti-leukemic effects of our novel AFNs, in vitro and in vivo upon transplantation in immunocompromised and immunocompetent syngeneic hosts. A significant reduction in the leukemic burden was observed. These anti-cancer effects of AFN were similar as observed for the wildtype IFN, but in a cell-type specific manner and with drastically reduced adverse side-effects. Monotherapy was even sufficient to completely cure a proportion of leukemic mice, which highlights the strong anti-leukemic power of these optimized immunocytokines. Strinkingly only the direct effect CD8-AFN on in vivo CD8+ T-ALL was synergistic with asparaginase treatment. No synergism was observed between asparaginase and the indirect immune-mediated Clec9A-AFN anti-leukemic effect. Conclusion In conclusion, we have developed novel optimized immunocytokines as an off-the-shelve targeted immunotherapy for T-ALL

    Improved survival for adolescents and young adults with Hodgkin lymphoma and continued high survival for children in the Netherlands:a population-based study during 1990-2015

    Get PDF
    Population-based studies that assess long-term patterns of incidence, major aspects of treatment and survival are virtually lacking for Hodgkin lymphoma (HL) at a younger age. This study assessed the progress made for young patients with HL (<25 years at diagnosis) in the Netherlands during 1990–2015. Patient and tumour characteristics were extracted from the population-based Netherlands Cancer Registry. Time trends in incidence and mortality rates were evaluated with average annual percentage change (AAPC) analyses. Stage at diagnosis, initial treatments and site of treatment were studied in relation to observed overall survival (OS). A total of 2619 patients with HL were diagnosed between 1990 and 2015. Incidence rates increased for 18–24-year-old patients (AAPC + 1%, P = 0·01) only. Treatment regimens changed into less radiotherapy and more ‘chemotherapy only’, different for age group and stage. Patients aged 15–17 years were increasingly treated at a paediatric oncology centre. The 5-year OS for children was already high in the early 1990s (93%). For patients aged 15–17 and 18–24 years the 5-year OS improved from 84% and 90% in 1990–1994 to 96% and 97% in 2010–2015, respectively. Survival for patients aged 15–17 years was not affected by site of treatment. Our present data demonstrate that significant progress in HL treatment has been made in the Netherlands since 1990

    MAPK-ERK is a central pathway in T-cell acute lymphoblastic leukemia that drives steroid resistance

    Full text link
    (Patho-)physiological activation of the IL7-receptor (IL7R) signaling contributes to steroid resistance in pediatric T-cell acute lymphoblastic leukemia (T-ALL). Here, we show that activating IL7R pathway mutations and physiological IL7R signaling activate MAPK-ERK signaling, which provokes steroid resistance by phosphorylation of BIM. By mass spectrometry, we demonstrate that phosphorylated BIM is impaired in binding to BCL2, BCLXL and MCL1, shifting the apoptotic balance toward survival. Treatment with MEK inhibitors abolishes this inactivating phosphorylation of BIM and restores its interaction with anti-apoptotic BCL2-protein family members. Importantly, the MEK inhibitor selumetinib synergizes with steroids in both IL7-dependent and IL7-independent steroid resistant pediatric T-ALL PDX samples. Despite the anti-MAPK-ERK activity of ruxolitinib in IL7-induced signaling and JAK1 mutant cells, ruxolitinib only synergizes with steroid treatment in IL7-dependent steroid resistant PDX samples but not in IL7-independent steroid resistant PDX samples. Our study highlights the central role for MAPK-ERK signaling in steroid resistance in T-ALL patients, and demonstrates the broader application of MEK inhibitors over ruxolitinib to resensitize steroid-resistant T-ALL cells. These findings strongly support the enrollment of T-ALL patients in the current phase I/II SeluDex trial (NCT03705507) and contributes to the optimization and stratification of newly designed T-ALL treatment regimens

    The significance of PTEN and AKT aberrations in pediatric T-cell acute lymphoblastic leukemia

    Get PDF
    textabstractBackground PI3K/AKT pathway mutations are found in T-cell acute lymphoblastic leukemia, but their overall impact and associations with other genetic aberrations is unknown. PTEN mutations have been proposed as secondary mutations that follow NOTCH1-activating mutations and cause cellular resistance to γ-secretase inhibitors. Design and Methods The impact of PTEN, PI3K and AKT aberrations was studied in a genetically well-characterized pediatric T-cell leukemia patient cohort (n=146) treated on DCOG or COALL protocols. Results PTEN and AKT E17K aberrations were detected in 13% and 2% of patients, respectively. Defective PTEN-splicing was identified in incidental cases. Patients without PTEN protein but lacking exon-, splice-, promoter mutations or promoter hypermethylation were present. PTEN/AKTmutations were especially abundant in TAL- or LMO-rearranged leukemia but nearly absent in TLX3-rearranged patients (P=0.03), the opposite to that observed for NOTCH1- activating mutations. Most PTEN/AKT mutant patients either lacked NOTCH1-activating mutations (P=0.006) or had weak NOTCH1-activating mutations (P=0.011), and consequently expressed low intracellular NOTCH1, cMYC and MUSASHI levels. T-cell leukemia patients without PTEN/AKT and NOTCH1-activating mutations fared well, with a cumulative incidence of relapse of only 8% versus 35% for PTEN/AKT and/or NOTCH1-activated patients (P=0.005). Conclusions PI3K/AKT pathway aberrations are present in 18% of pediatric T-cell acute lymphoblastic leukemia patients. Absence of strong NOTCH1-activating mutations in these cases may explain cellular insensitivity to γ-secretase inhibitors

    Improved survival for adolescents and young adults with Hodgkin lymphoma and continued high survival for children in the Netherlands: a population-based study during 1990–2015

    Get PDF
    Population-based studies that assess long-term patterns of incidence, major aspects of treatment and survival are virtually lacking for Hodgkin lymphoma (HL) at a younger age. This study assessed the progress made for young patients with HL (<25 years at diagnosis) in the Netherlands during 1990–2015. Patient and tumour characteristics were extracted from the population-based Netherlands Cancer Registry. Time trends in incidence and mortality rates were evaluated with average annual percentage change (AAPC) analyses. Stage at diagnosis, i

    The significance of PTEN and AKT aberrations in pediatric T-cell acute lymphoblastic leukemia

    Get PDF
    Background PI3K/AKT pathway mutations are found in T-cell acute lymphoblastic leukemia, but their overall impact and associations with other genetic aberrations is unknown. PTEN mutations have been proposed as secondary mutations that follow NOTCH1-activating mutations and cause cellular resistance to γ-secretase inhibitors. Design and Methods The impact of PTEN, PI3K and AKT aberrations was studied in a genetically well-characterized pediatric T-cell leukemia patient cohort (n=146) treated on DCOG or COALL protocols. Results PTEN and AKT E17K aberrations were detected in 13% and 2% of patients, respectively. Defective PTEN-splicing was identified in incidental cases. Patients without PTEN protein but lacking exon-, splice-, promoter mutations or promoter hypermethylation were present. PTEN/AKTmutations were especially abundant in TAL- or LMO-rearranged leukemia but nearly absent in TLX3-rearranged patients (P=0.03), the opposite to that observed for NOTCH1- activating mutations. Most PTEN/AKT mutant patients either lacked NOTCH1-activating mutations (P=0.006) or had weak NOTCH1-activating mutations (P=0.011), and consequently expressed low intracellular NOTCH1, cMYC and MUSASHI levels. T-cell leukemia patients without PTEN/AKT and NOTCH1-activating mutations fared well, with a cumulative incidence of relapse of only 8% versus 35% for PTEN/AKT and/or NOTCH1-activated patients (P=0.005). Conclusions PI3K/AKT pathway aberrations are present in 18% of pediatric T-cell acute lymphoblastic leukemia patients. Absence of strong NOTCH1-activating mutations in these cases may explain cellular insensitivity to γ-secretase inhibitors

    Műszerügyi és Méréstechnikai Közlemények

    Get PDF
    UNIDO Workshop a Műszerügyi és Méréstechnikai Szolgálatnál Újszerű lehetőségek a Kutatófilm és Videotechnikai Főosztályon Műszerkölcsönzés Császár László: Üzemeltetési és szerviztapasztalataink (3.) A GOULD gyártmányú digitális oszcilloszkópok Új irányok a műszer- és méréstechnikában Radnai Rudolf: Gyakorlati tanácsok számítógépes mérőrendszerek üzembehelyezéséhez és üzemeltetéséhez Kőfalvi Jenő: Mikrovezetékes analitika az integrált áramkörök mintájára Szaktanácsadás Kőfalvi Jenő: Válogatás az Országos Műszernyilvántartás nagyértékű műszerújdonságaiból Külföldi műszerújdonságok. Összeállította: Csont Tamás - Fekete Gábor - Kőfalvi Jenő Könyvismertetés. Összeállította: Radnai Rudolf - Kőfalvi Jenő Műszerkölcsönzés Görgényi László: A kölcsönműszerpark szaporulata Szolgálatunk életébő

    Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

    Get PDF
    The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points
    corecore