Genotypic Representation of Myelodysplastic/Myeloproliferative Neoplasms in Nrg, Nrg-3GS and Srg-W41 Mice with Transgenic Expression of Human Cytokines
Notice bibliographique
Résumé
Abstract Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are complex clonal hematopoietic stem cell malignancies with overlapping dysplastic and proliferative features. Genomic analyses have charted the somatic mutation spectrum of MDS/MPN and revealed a major role for epigenetic dysregulation in their pathogenesis. No disease-modifying therapies are currently available, as progress has been hampered by a lack of genetically faithful in vivo model systems suitable for the preclinical development of new strategies. Yoshimi et al (Blood. 2017;130:397-407) recently showed that patients' chronic myelomonocytic leukemia (CMML) and juvenile myelomonocytic leukemia (JMML) cells transplanted into NOD/SCID-IL2Rγ-/-mice expressing human IL3, GM-CSF and SCF transgenes (NSG-3GS mice) produced xenografts that had mutations characteristic of the input cells. Since we had demonstrated a superior level of chimerism achieved from transplants of normal human CD34+cord blood cells in SirpaNOD/Rag1-/-/IL2rγc-/-/W41/41mice with c-KIT deficiency (with an otherwise mixed NOD-C57Bl/6 background - SRG-W41 mice) compared to conventional NSG or NRG hosts (Miller et al. Exp Hematol. 2017;48:41-49), it was of interest to explore their use as hosts of samples from patients with MDS/MPN: CMML, atypical chronic myeloid leukemia (aCML) and secondary acute myeloid leukemia (sAML) progressed from CMML or aCML. Heparinized blood or bone marrow samples were obtained from patients treated at Huntsman Cancer Institute after informed consent. Diagnoses included CMML (n=5), aCML (n=2), and sAML (n=2). Unseparated cells were shipped by overnight courier to Vancouver and CD34+cells isolated on the same day were injected intravenously into sub-lethally irradiated female NRG mice or SRG-W41 mice, or in some cases the same sex and strains also carrying the human 3GS transgenes (NRG-3GS or SRG-W41-3GS mice) in accordance with British Columbia Cancer Agency institutional guidelines. Occasionally when mice were not immediately available, or large numbers of cells were available, cells were viably cryopreserved and transplanted later after thawing. Mice were observed for up to 36 weeks after xenotransplantation with .05 to 1.1x106 human CD34+cells. Engraftment of human CD45+cells in xenografts was evaluated by immunophenotyping, and a median of 90% human chimerism (range: 1% - 95%) was achieved at the time of bone marrow harvest from xenografts. Variant allele frequencies (VAF) were determined in genomic DNA extracted from both the patient samples (CD34+cells) and matching fluorescence-activated cells (FACS)-sorted human CD45+cells (hCD45+cells) purified from xenografts (1-5 xenografts per patient sample). DNA samples were subjected to PCR amplification with extension primers and analyzed using a MALDI-TOF mass spectrometer (MassArray, Agena Bioscience, San Diego, CA). Each mutation call was assigned by the software based on the molecular weight of the extended primer. Analysis of hCD45+cells from eight xenograft samples so far demonstrated a strong correlation of VAF between the patient samples and hCD45+cells from xenografts, in both SRG-W41-3GS (R2=0.94, p<0.01) and NRG-3GS (R2=0.97, p<0.01) models (Figure 1). This tight correlation of VAF was illustrated in hCD45+cells from xenografts transplanted with CMML, aCML or sAML cells. The majority of mutations detected were those in epigenetic regulator genes, such as ASXL1, EZH2 and TET2. No significant difference in VAF was observed between CD34+and CD34- compartments within the hCD45+cells. Additional samples, including specimens from patients with the related myeloproliferative neoplasm, chronic neutrophilic leukemia (CNL) are being analyzed and will be presented. These findings demonstrate the utility of SRG-W41-3GS as well as NRG-3GS as receptive hosts of primary human MDS/MPN cells with genetic evidence of their growth in these mice closely recapitulating the mutational profiles of the transplanted cells. These new strains may facilitate the development of functional screening and pre-clinical testing of novel therapeutic strategies for a range of human MDS/MPN and related myeloid disorders. Disclosures Deininger: Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Blueprint: Consultancy.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».