44 research outputs found
âIch bin eine MĂ€rchenerzĂ€hlerin. So wurde ich geboren.â
Ist Tonke Dragt die groĂe Neuerin der europĂ€ischen Kinder- und Jugendliteratur? Diese sicherlich provokante Frage nimmt der Sammelband in den Fokus, der auf die Tagung â'Ich bin eine MĂ€rchenerzĂ€hlerin. So wurde ich geboren'. Tonke Dragts Jugendromane â uÌbersehene Klassiker?", die im September 2019 an der UniversitĂ€t Siegen in Kooperation mit Helma van Lierop-Debrauwer stattgefunden hat, zurĂŒckgeht
Upstream ORF affects MYCN translation depending on exon 1b alternative splicing
<p>Abstract</p> <p>Background</p> <p>The <it>MYCN </it>gene is transcribed into two major mRNAs: one full-length (<it>MYCN) </it>and one exon 1b-spliced (<it>MYCN</it><sup>Î1<it>b</it></sup>) mRNA. But nothing is known about their respective ability to translate the MYCN protein.</p> <p>Methods</p> <p>Plasmids were prepared to enable translation from the upstream (uORF) and major ORF of the two <it>MYCN </it>transcripts. Translation was studied after transfection in neuroblastoma SH-EP cell line. Impact of the upstream AUG on translation was evaluated after directed mutagenesis. Functional study with the two <it>MYCN </it>mRNAs was conducted by a cell viability assay. Existence of a new protein encoded by the <it>MYCN</it><sup>Î1<it>b </it></sup>uORF was explored by designing a rabbit polyclonal antibody against a specific epitope of this protein.</p> <p>Results</p> <p>Both are translated, but higher levels of protein were seen with <it>MYCN</it><sup>Î1<it>b </it></sup>mRNA. An upstream ORF was shown to have positive cis-regulatory activity on translation from <it>MYCN </it>but not from <it>MYCN</it><sup>Î1<it>b </it></sup>mRNA. In transfected SH-EP neuroblastoma cells, high MYCN dosage obtained with <it>MYCN</it><sup>Î1<it>b </it></sup>mRNA translation induces an antiapoptotic effect after serum deprivation that was not observed with low MYCN expression obtained with <it>MYCN </it>mRNA. Here, we showed that MYCNOT: <it>MYCN </it>Overlap Transcript, a new protein of unknown function is translated from the upstream AUG of <it>MYCN</it><sup>Î1<it>b </it></sup>mRNA.</p> <p>Conclusions</p> <p>Existence of upstream ORF in <it>MYCN </it>transcripts leads to a new level of MYCN regulation. The resulting MYCN dosage has a weak but significant anti-apoptotic activity after intrinsic apoptosis induction.</p
Optimisation of a targeted therapy by combining with a immunotherapy : phase 1 clinical trial of the co-administration of Imatinib and interleukin-2
Chef de file des inhibiteurs de tyrosines kinase, lâImatinib Mesylate (IM) a rĂ©volutionnĂ© la prise en charge de la leucĂ©mie myĂ©loĂŻde chronique et des tumeurs stromales gastro-intestiales. En plus de son action directe sur les cellules tumorales, une partie de lâefficacitĂ© thĂ©rapeutique de lâIM a Ă©tĂ© attribuĂ©e Ă son aptitude Ă moduler la rĂ©ponse immunitaire. Cette propriĂ©tĂ© soulĂšve la possibilitĂ© que les rĂ©sultats cliniques de lâIM pourraient ĂȘtre amĂ©liorĂ©s en le combinant efficacement Ă une immunothĂ©rapie. A cet effet, nous avons montrĂ© dans un modĂšle prĂ©clinique que lâinterleukine-2 (IL-2) â adjuvant des cellules NK â augmente lâefficacitĂ© de lâIM. Nous avons Ă©galement dĂ©montrĂ© une efficacitĂ© supĂ©rieure de lâIM en association au cyclophosphamide (CTX) du fait de lâinhibition des lymphocytes T rĂ©gulateurs. Nous avons donc entrepris un essai clinique de phase 1 associant lâIM, lâIL-2 et le CTX chez des patients ayant une tumeur solide mĂ©tastatique ou localement avancĂ©e. Les objectifs de cet essai sont (i) de dĂ©terminer la dose maximale tolĂ©rĂ©e dâIL-2 associĂ©e Ă lâIM et au CTX ; (ii) dâĂ©tudier les paramĂštres pharmacocinĂ©tiques de lâassociation ; (iii) dâĂ©valuer lâefficacitĂ© de lâassociation et (iv) son effet sur les effecteurs de lâimmunitĂ©. Au total, 17 patients ont Ă©tĂ© inclus dans cette Ă©tude. La DMT dâIL-2 associĂ©e Ă la dose fixe de 400 mg dâIM correspond Ă 6 MUI/j. A ce niveau de dose, tous les patients ont prĂ©sentĂ© au moins un effet indĂ©sirable imputable au traitement : principalement fiĂšvre et frissons, augmentation des enzymes hĂ©patiques, asthĂ©nie et nausĂ©e mais sans que ne soit observĂ©e de toxicitĂ© limitante. LâĂ©tude des paramĂštres pharmacocinĂ©tiques rĂ©vĂšle une augmentation significative de lâexposition systĂ©mique Ă lâIM en fin de cycle et qui semble ĂȘtre imputable Ă lâIL-2. La pharmacocinĂ©tique de lâIL-2 nâest par contre pas modifiĂ©e par lâadministration concomitante dâIM. Sur le plan des effecteurs de lâimmunitĂ©, lâassociation IM, IL-2 et CTX diminue le taux de lymphocytes B, lymphocytes T (LT) CD4+ et LT CD8+ mais active les cellules NK puisquâon observe une augmentation des marqueurs CD56bright, HLA-DR et TRAIL. De maniĂšre intĂ©ressante, la sous-population de cellules NK HLA-DR+ possĂšde des capacitĂ©s de dĂ©granulation plus importante aprĂšs exposition Ă cette association et son expansion est associĂ©e Ă une meilleure survie. Cette association pourrait donc sâavĂ©rer particuliĂšrement intĂ©ressante dans le traitement de tumeurs sensibles dâune part Ă lâIM et dâautre part Ă la lyse par les cellules NK. Les GIST Ă©tant particuliĂšrement sensibles Ă lâIM, nous avons Ă©tudiĂ© lâinfiltrat tumoral prĂ©sent au niveau de ses tumeurs. Nous avons ainsi pu mettre en Ă©vidence le rĂŽle pronostique de lâinfiltrat en LT et NK sur la survie sans progression des GIST. En vue dâune Ă©tude de phase 2, les GIST apparaissent donc ĂȘtre un modĂšle tumoral particuliĂšrement pertinent pour Ă©valuer les bĂ©nĂ©fices de lâassociation IM, IL-2 et CTX.Imatinib mesylate (IM) was the first tyrosine kinase inhibitor to be successfully used in clinical practice and its introduction has revolutionized the management of chronic myeloid leukemia and gastrointestinal stromal tumors. In addition to its direct effects on malignant cells, IM appears to exert immunological off-target effects that contribute to its anticancer effects. Thus, combining IM with immunotherapy might improve patientsâ clinical outcome. Indeed, IM combined to Interleukin-2 (IL-2) - a cytokine that enhances natural killer (NK) cells functions - improved antitumor responses in preclinical models. We also observed synergistic effects of cyclophosphamide (CTX) and IM as a result of the inhibition of regulatory T lymphocytes. Based on the promising results of these preclinical studies, we developed a phase 1 clinical trial which combines metronomic CTX, IM and escalating doses of IL-2 in patients affected by refractory solid tumors. The goals of this study were (i) to determine the maximum tolerated dose of IL-2 combined with IM and CTX ; (ii) to study the pharmacokinetics of IM and IL-2 ; (iii) to evaluate clinical efficacy of the combined therapy and (iv) effects of the association on immune parameters. A total of 17 patients were enrolled in the study. The maximum tolerated dose of IL-2 combined with IM, given at a constant dose of 400 mg was determined to be 6 MIU/day. At this dose level, all patients experienced at least one treatment-related adverse event: fevers and chills, transaminase elevation, fatigue and nausea but no dose-limiting toxicities were observed. Pharmacokinetic studies revealed that the co-administration of IL-2 increases the systemic exposure of patients to IM. In contrast, the pharmacokinetics of IL-2 was not modified by IM. The combined therapy markedly reduced the absolute numbers of B lymphocytes, CD4+ T cells and CD8+ T cells in a IL-2 dose-dependant manner. The NK cell compartment was activated, exhibiting a significant upregulation of CD56bright, HLA-DR and TRAIL. Interinstingly, the abundance of HLA-DR+ NK cells after one course of combined therapy positively correlated with both progression free- and overall survival. Thus, it could be of interest to evaluate this immunotherapeutic regimen in a tumor model sensitive to IM and to lysis by NK cells and evaluate whether the adjunction of IL-2 can boost the efficacy of IM. GIST are particularly sensitive to IM, thus we performed a retrospective study of the immune infiltrates and their prognostic value in these tumors. We found that both LT and NK cell infiltrates were independent prognostic factors for progression-free survival. For a phase 2 clinical trial, gastrointestinal stromal tumors appear to be a particularly relevant to evaluate the benefits of the association IM, IL-2 and CTX
Optimisation dâune stratĂ©gie thĂ©rapeutique antitumorale conventionnelle par association Ă une immunothĂ©rapie : etude de phase I combinant lâImatinib Ă lâInterleukine-2
Imatinib mesylate (IM) was the first tyrosine kinase inhibitor to be successfully used in clinical practice and its introduction has revolutionized the management of chronic myeloid leukemia and gastrointestinal stromal tumors. In addition to its direct effects on malignant cells, IM appears to exert immunological off-target effects that contribute to its anticancer effects. Thus, combining IM with immunotherapy might improve patientsâ clinical outcome. Indeed, IM combined to Interleukin-2 (IL-2) - a cytokine that enhances natural killer (NK) cells functions - improved antitumor responses in preclinical models. We also observed synergistic effects of cyclophosphamide (CTX) and IM as a result of the inhibition of regulatory T lymphocytes. Based on the promising results of these preclinical studies, we developed a phase 1 clinical trial which combines metronomic CTX, IM and escalating doses of IL-2 in patients affected by refractory solid tumors. The goals of this study were (i) to determine the maximum tolerated dose of IL-2 combined with IM and CTX ; (ii) to study the pharmacokinetics of IM and IL-2 ; (iii) to evaluate clinical efficacy of the combined therapy and (iv) effects of the association on immune parameters. A total of 17 patients were enrolled in the study. The maximum tolerated dose of IL-2 combined with IM, given at a constant dose of 400 mg was determined to be 6 MIU/day. At this dose level, all patients experienced at least one treatment-related adverse event: fevers and chills, transaminase elevation, fatigue and nausea but no dose-limiting toxicities were observed. Pharmacokinetic studies revealed that the co-administration of IL-2 increases the systemic exposure of patients to IM. In contrast, the pharmacokinetics of IL-2 was not modified by IM. The combined therapy markedly reduced the absolute numbers of B lymphocytes, CD4+ T cells and CD8+ T cells in a IL-2 dose-dependant manner. The NK cell compartment was activated, exhibiting a significant upregulation of CD56bright, HLA-DR and TRAIL. Interinstingly, the abundance of HLA-DR+ NK cells after one course of combined therapy positively correlated with both progression free- and overall survival. Thus, it could be of interest to evaluate this immunotherapeutic regimen in a tumor model sensitive to IM and to lysis by NK cells and evaluate whether the adjunction of IL-2 can boost the efficacy of IM. GIST are particularly sensitive to IM, thus we performed a retrospective study of the immune infiltrates and their prognostic value in these tumors. We found that both LT and NK cell infiltrates were independent prognostic factors for progression-free survival. For a phase 2 clinical trial, gastrointestinal stromal tumors appear to be a particularly relevant to evaluate the benefits of the association IM, IL-2 and CTX.Chef de file des inhibiteurs de tyrosines kinase, lâImatinib Mesylate (IM) a rĂ©volutionnĂ© la prise en charge de la leucĂ©mie myĂ©loĂŻde chronique et des tumeurs stromales gastro-intestiales. En plus de son action directe sur les cellules tumorales, une partie de lâefficacitĂ© thĂ©rapeutique de lâIM a Ă©tĂ© attribuĂ©e Ă son aptitude Ă moduler la rĂ©ponse immunitaire. Cette propriĂ©tĂ© soulĂšve la possibilitĂ© que les rĂ©sultats cliniques de lâIM pourraient ĂȘtre amĂ©liorĂ©s en le combinant efficacement Ă une immunothĂ©rapie. A cet effet, nous avons montrĂ© dans un modĂšle prĂ©clinique que lâinterleukine-2 (IL-2) â adjuvant des cellules NK â augmente lâefficacitĂ© de lâIM. Nous avons Ă©galement dĂ©montrĂ© une efficacitĂ© supĂ©rieure de lâIM en association au cyclophosphamide (CTX) du fait de lâinhibition des lymphocytes T rĂ©gulateurs. Nous avons donc entrepris un essai clinique de phase 1 associant lâIM, lâIL-2 et le CTX chez des patients ayant une tumeur solide mĂ©tastatique ou localement avancĂ©e. Les objectifs de cet essai sont (i) de dĂ©terminer la dose maximale tolĂ©rĂ©e dâIL-2 associĂ©e Ă lâIM et au CTX ; (ii) dâĂ©tudier les paramĂštres pharmacocinĂ©tiques de lâassociation ; (iii) dâĂ©valuer lâefficacitĂ© de lâassociation et (iv) son effet sur les effecteurs de lâimmunitĂ©. Au total, 17 patients ont Ă©tĂ© inclus dans cette Ă©tude. La DMT dâIL-2 associĂ©e Ă la dose fixe de 400 mg dâIM correspond Ă 6 MUI/j. A ce niveau de dose, tous les patients ont prĂ©sentĂ© au moins un effet indĂ©sirable imputable au traitement : principalement fiĂšvre et frissons, augmentation des enzymes hĂ©patiques, asthĂ©nie et nausĂ©e mais sans que ne soit observĂ©e de toxicitĂ© limitante. LâĂ©tude des paramĂštres pharmacocinĂ©tiques rĂ©vĂšle une augmentation significative de lâexposition systĂ©mique Ă lâIM en fin de cycle et qui semble ĂȘtre imputable Ă lâIL-2. La pharmacocinĂ©tique de lâIL-2 nâest par contre pas modifiĂ©e par lâadministration concomitante dâIM. Sur le plan des effecteurs de lâimmunitĂ©, lâassociation IM, IL-2 et CTX diminue le taux de lymphocytes B, lymphocytes T (LT) CD4+ et LT CD8+ mais active les cellules NK puisquâon observe une augmentation des marqueurs CD56bright, HLA-DR et TRAIL. De maniĂšre intĂ©ressante, la sous-population de cellules NK HLA-DR+ possĂšde des capacitĂ©s de dĂ©granulation plus importante aprĂšs exposition Ă cette association et son expansion est associĂ©e Ă une meilleure survie. Cette association pourrait donc sâavĂ©rer particuliĂšrement intĂ©ressante dans le traitement de tumeurs sensibles dâune part Ă lâIM et dâautre part Ă la lyse par les cellules NK. Les GIST Ă©tant particuliĂšrement sensibles Ă lâIM, nous avons Ă©tudiĂ© lâinfiltrat tumoral prĂ©sent au niveau de ses tumeurs. Nous avons ainsi pu mettre en Ă©vidence le rĂŽle pronostique de lâinfiltrat en LT et NK sur la survie sans progression des GIST. En vue dâune Ă©tude de phase 2, les GIST apparaissent donc ĂȘtre un modĂšle tumoral particuliĂšrement pertinent pour Ă©valuer les bĂ©nĂ©fices de lâassociation IM, IL-2 et CTX
Clinical trials during pandemics and beyond: time for a more efficient pharmacological strategy
International audienceDuring the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, clinical trials on antiviral or symptomatic drugs have been conducted very rapidly even for drugs with a poor pharmacological rationale for efficacy on SARS-CoV-2. Despite lacking basic pharmacological information, most of these clinical trials were also extremely redundant. Applying simple rules, (such as identifying a mechanistic rationale, confirming the ability to reach exposure targets at therapeutic dosage and ensuring tests show drug efficacy in appropriate in vitro and animal models before entering clinical trials) might have saved considerable amounts of time and money, and might have avoided useless research. Moreover, combining these simple rules with the implementation of a relevant policy at both an international and a national level, by limiting studies with a poor methodological/scientific approach and aggregating studies with similar design into single clinical trials, is potentially a far more-efficient strategy
Publication by association: how the COVID-19 pandemic has shown relationships between authors and editorial board members in the field of infectious diseases
International audienceDuring the COVID-19 pandemic, the rush to scientific and political judgements on the merits of hydroxychloroquine was fuelled by dubious papers which may have been published because the authors were not independent from the practices of the journals in which they appeared. This example leads us to consider a new type of illegitimate publishing entity, âself-promotion journalsâ which could be deployed to serve the instrumentalisation of productivity-based metrics, with a ripple effect on decisions about promotion, tenure and grant funding, but also on the quality of manuscripts that are disseminated to the medical community and form the foundation of evidence-based medicine
Publication by association: the Covid-19 pandemic reveals relationships between authors and editors
During the COVID-19 pandemic, the rush to scientific and political judgments on the merits of hydroxychloroquine was fuelled by dubious papers which may have been published because the authors were not independent from the practices of the journals in which they appeared. This example leads us to consider a new type of illegitimate publishing entity, âself-promotion journalsâ which could be deployed to serve the instrumentalisation of productivity-based metrics, with a ripple effect on decisions about promotion, tenure, and grant funding
Meta-analysis of phase I dose-finding studies: Application for protein kinase inhibitors developed in oncology
International audienc