Identifizierung neuer Entwicklungsgene der Maus durch Genfallen in embryonalen Stammzellen

Ein zur Identifizierung neuer entwicklungsrelevanter Gene angewandtes Verfahren stellt die zufällige Mutagenese des Genoms eines Modellorganismus dar. Eine Möglichkeit hierfür stellt die Gene-trap Methode dar, bei der GT-Konstrukte in embryonale Stammzellen (ES) der Maus eingebracht werden. Dies erlaubt die Selektion erfolgreicher Integrationsereignisse in vitro und den einfachen Nachweis der Expression des getroffenen Gens. Aus diesen Zellen können nachfolgend mutante Tiere hergestellt werden, in denen eine in vivo Analyse des Phänotyps der Mutation möglich ist. Im Rahmen dieser Arbeit wurden Gene-trap Zellinien durch Elektroporation von ES-Zellen und nachfolgender Selektion hergestellt. Um interessante Integrationen anzureichern, wurden Zellinien ausgewählt, die eine Aktivierung des Reporters während der Differenzierung oder nach Behandlung mit bekannten Signalfaktoren wie Retinsäure oder BMP2 zeigten. Es konnten so neun unbekannte und sechs bekannte Transkripte identifiziert werden, von denen GTXVI-168 in vitro charakterisiert wurde. Diese trägt eine Integration in einem bislang unbekannten, für eine RhoGAP-Domäne kodierenden Gen. Desweiteren wurden drei Mauslinien untersucht, die aufgrund der Expression der getroffenen Gene interessant erschienen. Für alle drei Linien wurde die Integration des Gene-trap Vektors charakterisiert. Das in der Mauslinie GTIII6 getroffene Gen kodiert für ein neues PX (phox-Homologie)-Domäne Protein. Die Mauslinie 2A-53 betrifft das Pafaha1b/Lis1 (Lissencephaly) Gen und die Mauslinie GTXVI-44 trägt eine Insertion im NFkappaB1 Gen. Eine Analyse der Phänotypen zeigte eine hohe Sterblichkeit der GTXVI-44 Mäuse, die vermutlich durch eine erhöhte Anfälligkeit für Infektionen und Entzündungen der Organe verursacht wird. 2A-53 homozygote Männchen sind steril und zeigen eine Arretierung der Differenzierung der Spermatozyten, während homozygote Weibchen fertil sind.Random mutagenesis of the genome of animal models represents a valuable approach for the identification of genes that play a role in development. In the gene-trap method insertional mutagenesis is performed by introducing reporter and selector genes into the genome of mouse embryonic stem (ES) cells. This enables the selection in vitro of ES-clones carrying interesting integrations as well as the analysis of the expression patterns of the mutated genes in growing and differenting cells. Moreover transgenic mice can be generated from these mutant cell lines in order to study the phenotypes derived from the gene disruptions. In this work gene-trap cell lines were generated by electroporation of gene-trap vectors into mouse ES cells. After selection of clones carrying integrations several gene-trap lines were elected for further studies according to either the expression pattern of the reporter gene during the in vitro differentiation or to its response upon exposure to RA or BMP2. Six of the isolated sequences were identical to known genes whereas nine represented novel genes. The gene-trap line GTXVI-168 containing a gene-trap insertion in a novel gene coding for a RhoGAP protein was analyzed in detail. In addition, three mutant mouse lines carrying a gene-trap insertion were characterized. All three lines displayed an interesting reporter gene expression pattern during early stages of development. The gene trapped in GTIII-6 mice coded for a new PX (phox)-domain protein. 2A-53 mice carried an insertion in the Lis1(lissencephaly)/Pafah1b gene and the mouse line GTXVI-44 contained a disruption in the NF-kappaB1 locus. Phenotypic abnormalities resulting from the insertional mutagenesis were observed in 2A-53 and GTXVI-44 mutants. GTXVI-44 homozygous mutants developed an inflammatory phenotype and showed a decreased survival rate. 2A-53 homozygous males were steril due to impaired spermatogenesis

The role of heart rate on the associations between body composition and heart rate variability in children with overweight/obesity : the ActiveBrains project

Background: Heart rate variability (HRV) is negatively associated with body mass index and adiposity in several populations. However, less information is available about this association in children with overweight and obesity, especially severe/morbid obesity, taking into consideration the dependence of HRV on heart rate (HR). Objectives: (1) to examine associations between body composition measures and HRV, (2) to study differences in HRV between children with overweight and severe/morbid obesity; and (3) to test whether relationships and differences tested in objectives 1 and 2, respectively are explained by the dependency of HRV on HR. Methods: A total of 107 children with overweight/obesity (58% boys, 10.03 +/- 1.13 years) participated in this study. Body composition measures were evaluated by Dual-energy X-ray absorptiometry (DXA). HRV parameters were measured with Polar RS800CXR (R). Results: Body composition measures were negatively associated with HRV indicators of parasympathetic activity (beta values ranging from -0.207 to -0.307, all p 0.05). Conclusion: All associations between adiposity/obesity and HRV could be explained by HR, suggesting a key confounding role of HR in HRV studies in children with weight disturbances

Feasibility and outcomes after dose reduction of immunochemotherapy in young adults with Burkitt lymphoma and leukemia: results of the BURKIMAB14 trial

High dose -intensive or infusional intermediate -dose immunochemotherapy is highly effective treatment for Burkitt lymphoma irrespective of human immunodeficiency virus (HIV) infection. However, toxicities of these regimens are relevant, especially in older adults and elderly patients. The prospective multicenter BURKIMAB14 trial included four to six blocks of immunochemotherapy according to stage (localized: 1 and 2 non -bulky; advanced: 2 bulky, 3, 4) and age, with dose reduction in patients >55 years old. Dose -intensity of chemotherapy was reduced in patients 55 years old had a significantly higher treatment -related mortality despite dose reduction of chemotherapy. With a median follow-up of 3.61 years the 4 -year OS probability was 73% (range, 63-81%). Age (55 years) and stage (localized vs. advanced) had prognostic significance. No significant differences in OS were observed in HIV -positive versus HIV -negative patients. The results of BURKIMAB14 are similar to those of other dose -intensive immunochemotherapy trials. Age >55 years and advanced stage, but not HIV infection, were associated with poor survival. Dose reduction of chemotherapy in young adults in CMR is safe and does not impact outcomes (clinicaltrials gov. Identifier: NCT05049473)

A pediatric regimen for adolescents and young adults with Philadelphia chromosome‐negative acute lymphoblastic leukemia: Results of the ALLRE08 PETHEMA trial

Background: Pediatric-based or -inspired trials have improved the prognosis of adolescents and young adults (AYA) with Philadelphia chromosome-negative (Ph-neg) acute lymphoblastic leukemia (ALL). Methods: This study reports the results of treatment of the ALLRE08 trial, a full pediatric trial for AYA aged 15-30 years with standard-risk (SR) ALL. Results: From 2008 to 2018, 89 patients (38 adolescents [15-18 years] and 51 young adults [YA, 19-30 years], median age: 20 [15-29] years) were enrolled in the ALLRE08 trial. The complete response (CR) was 95%. Twenty-two patients were transferred to a high-risk (HR) protocol because of poor marrow response on day 14 (n = 20) or high-level of end-induction minimal residual response (MRD ≥ 0.25%, n = 2). Cumulative incidence of relapse (CIR) at 5 years was 35% (95%CI: 23%-47%), with significant differences between adolescents and YA: 13% (4%-28%) vs 52% (34%-67%), P = .012. No treatment-related mortality was observed in 66/66 patients following the ALLRE08 trial vs 3/23 patients moved to a HR trial. The estimated 5-year overall survival (OS) was 74% (95%CI: 63%-85%), with significantly higher rates for adolescents vs YA: 87% (95%CI: 74%-100%) vs 63% (46%-80%), P = .021. Although CIR or OS were lower in patients who were transferred to a HR trial, the differences were not statistically significant (CIR: 34% [21%-47%] vs 37% [14%-61%]; OS: 78% [66%-90%] vs 61% [31%;91%]). Conclusion: A full pediatric trial is feasible and effective for AYA with Ph-neg, SR-ALL, with better results for adolescents than for YA. Outcome of patients with poor early response rescued with a HR trial was not significantly inferior

A pediatric regimen for adolescents and young adults with Philadelphia chromosome-negative acute lymphoblastic leukemia : Results of the ALLRE08 PETHEMA trial

Altres ajuts: Supported in part by grants from Fundació La Caixa and CIBERONC (JMHR and AO).Pediatric-based or -inspired trials have improved the prognosis of adolescents and young adults (AYA) with Philadelphia chromosome-negative (Ph-neg) acute lymphoblastic leukemia (ALL). This study reports the results of treatment of the ALLRE08 trial, a full pediatric trial for AYA aged 15-30 years with standard-risk (SR) ALL. From 2008 to 2018, 89 patients (38 adolescents [15-18 years] and 51 young adults [YA, 19-30 years], median age: 20 [15-29] years) were enrolled in the ALLRE08 trial. The complete response (CR) was 95%. Twenty-two patients were transferred to a high-risk (HR) protocol because of poor marrow response on day 14 (n = 20) or high-level of end-induction minimal residual response (MRD ≥ 0.25%, n = 2). Cumulative incidence of relapse (CIR) at 5 years was 35% (95%CI: 23%-47%), with significant differences between adolescents and YA: 13% (4%-28%) vs 52% (34%-67%), P = .012. No treatment-related mortality was observed in 66/66 patients following the ALLRE08 trial vs 3/23 patients moved to a HR trial. The estimated 5-year overall survival (OS) was 74% (95%CI: 63%-85%), with significantly higher rates for adolescents vs YA: 87% (95%CI: 74%-100%) vs 63% (46%-80%), P = .021. Although CIR or OS were lower in patients who were transferred to a HR trial, the differences were not statistically significant (CIR: 34% [21%-47%] vs 37% [14%-61%]; OS: 78% [66%-90%] vs 61% [31%;91%]). A full pediatric trial is feasible and effective for AYA with Ph-neg, SR-ALL, with better results for adolescents than for YA. Outcome of patients with poor early response rescued with a HR trial was not significantly inferior. A full pediatric trial is feasible and effective for adolescent and young adults with acute lymphoblastic leukemia, with better results for adolescents than for young adults. The outcome of patients showing poor early response was not significantly inferior than that observed for good responders after being transferred to a high-risk trial

Adverse prognostic impact of complex karyotype (≥3 cytogenetic alterations) in adult T-cell acute lymphoblastic leukemia (T-ALL)

© 2021 The Author(s).The potential prognostic value of conventional karyotyping in adult T-cell acute lymphoblastic leukemia (T-ALL) remains an open question. We hypothesized that a modified cytogenetic classification, based on the number and type of cytogenetic abnormalities, would allow the identification of high-risk adult T-ALL patients. Complex karyotype defined by the presence of ≥3 cytogenetic alterations identified T-ALL patients with poor prognosis in this study. Karyotypes with ≥3 abnormalities accounted for 16 % (22/139) of all evaluable karyotypes, corresponding to the largest poor prognosis cytogenetic subgroup of T-ALL identified so far. Patients carrying karyotypes with ≥3 cytogenetic alterations showed a significantly inferior response to therapy, and a poor outcome in terms of event-free survival (EFS), overall survival (OS) and cumulative incidence of relapse (CIR), independently of other baseline characteristics and the end-induction minimal residual disease (MRD) level. Additional molecular analyses of patients carrying ≥3 cytogenetic alterations showed a unique molecular profile that could contribute to understand the underlying molecular mechanisms of resistance and to evaluate novel targeted therapies (e.g. IL7R directed) with potential impact on outcome of adult T-ALL patients.This project was supported by the AECC (GC16173697BIGA); ISCIII (PI19/01828) co-funded by ERDF/ESF "A way to make Europe"/ "Investing in your future", CERCA/Generalitat de Catalunya SGR 2017 288 (GRC)/ “La Caixa” P. Barba was supported by the Instituto de Salud Carlos III FIS16/01433 and PERIS 2018-2020 from Generalitat de Catalunya (BDNS357800)

Outcomes and prognostic factors of adults with refractory or relapsed T-cell acute lymphoblastic leukemia included in measurable residual disease-oriented trials

Despite high complete remission (CR) rates with frontline therapy, relapses are frequent in adults with T-cell acute lymphoblastic leukemia (T-ALL) with limited salvage options. We analyzed the outcomes and prognostic factors for CR to salvage therapy and overall survival (OS) of patients with R/R T-ALL included in two prospective measurable residual disease-oriented trials. Seventy-five patients (70 relapsed, 5 refractory) were identified. Relapses occurred in bone marrow, isolated or combined in 50 patients, and in the central nervous system (CNS; isolated or combined) in 20. Second CR was attained in 30/75 patients (40%). Treatment with FLAG-Ida and isolated CNS relapse were independently associated with a higher CR rate after first salvage therapy. The median OS was 6.2 (95% confidence interval [CI], 3.9–8.6) months, with a 4-year OS probability of 18% (95% CI, 9%–27%). No differences in survival were observed according to the treatment with hematopoietic stem cell transplantation in patients in CR after first salvage therapy. Multivariable analysis showed a ≥12-month interval between first CR and relapse, CR after first salvage therapy and isolated CNS relapse as favorable prognostic factors for OS with hazard ratios (HR) (95% CI) of 1.931 (1.109–3.362), 2.958 (1.640–5.334), and 2.976 (1.157–7.655), respectively. This study confirms the poor outcomes of adults with R/R T-ALL among whom FLAG-Ida was the best of the rescue therapies evaluated. Late relapse, CR after first rescue therapy and isolated CNS relapse showed prognostic impact on survival. More effective rescue therapies are needed in adults with R/R T-ALL.La Caixa" Foundation and ISCIII, Grant/ Award Number: PI19/01828; Generalitat de Catalunya (GRC), Grant/Award Number: 2017 SGR28

Chemotherapy or allogeneic transplantation in high-risk Philadelphia chromosome–negative adult lymphoblastic leukemia

The need for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in adults with Philadelphia chromosome–negative (Ph−) acute lymphoblastic leukemia (ALL) with high-risk (HR) features and adequate measurable residual disease (MRD) clearance remains unclear. The aim of the ALL-HR-11 trial was to evaluate the outcomes of HR Ph− adult ALL patients following chemotherapy or allo-HSCT administered based on end-induction and consolidation MRD levels. Patients aged 15 to 60 years with HR-ALL in complete response (CR) and MRD levels (centrally assessed by 8-color flow cytometry) <0.1% after induction and <0.01% after early consolidation were assigned to receive delayed consolidation and maintenance therapy up to 2 years in CR. The remaining patients were allocated to allo-HSCT. CR was attained in 315/348 patients (91%), with MRD <0.1% after induction in 220/289 patients (76%). By intention-to-treat, 218 patients were assigned to chemotherapy and 106 to allo-HSCT. The 5-year (±95% confidence interval) cumulative incidence of relapse (CIR), overall survival (OS), and event-free survival probabilities for the whole series were 43% ± 7%, 49% ± 7%, and 40% ± 6%, respectively, with CIR and OS rates of 45% ± 8% and 59% ± 9% for patients assigned to chemotherapy and of 40% ± 12% and 38% ± 11% for those assigned to allo-HSCT, respectively. Our results show that avoiding allo-HSCT does not hamper the outcomes of HR Ph− adult ALL patients up to 60 years with adequate MRD response after induction and consolidation. Better postremission alternative therapies are especially needed for patients with poor MRD clearance

Novel genes and sex differences in COVID-19 severity

[EN] Here, we describe the results of a genome-wide study conducted in 11 939 coronavirus disease 2019 (COVID-19) positive cases with an extensive clinical information that were recruited from 34 hospitals across Spain (SCOURGE consortium). In sex-disaggregated genome-wide association studies for COVID-19 hospitalization, genome-wide significance (P < 5 × 10−8) was crossed for variants in 3p21.31 and 21q22.11 loci only among males (P = 1.3 × 10−22 and P = 8.1 × 10−12, respectively), and for variants in 9q21.32 near TLE1 only among females (P = 4.4 × 10−8). In a second phase, results were combined with an independent Spanish cohort (1598 COVID-19 cases and 1068 population controls), revealing in the overall analysis two novel risk loci in 9p13.3 and 19q13.12, with fine-mapping prioritized variants functionally associated with AQP3 (P = 2.7 × 10−8) and ARHGAP33 (P = 1.3 × 10−8), respectively. The meta-analysis of both phases with four European studies stratified by sex from the Host Genetics Initiative (HGI) confirmed the association of the 3p21.31 and 21q22.11 loci predominantly in males and replicated a recently reported variant in 11p13 (ELF5, P = 4.1 × 10−8). Six of the COVID-19 HGI discovered loci were replicated and an HGI-based genetic risk score predicted the severity strata in SCOURGE. We also found more SNP-heritability and larger heritability differences by age (<60 or ≥60 years) among males than among females. Parallel genome-wide screening of inbreeding depression in SCOURGE also showed an effect of homozygosity in COVID-19 hospitalization and severity and this effect was stronger among older males. In summary, new candidate genes for COVID-19 severity and evidence supporting genetic disparities among sexes are provided.S

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types