Elevated Expression of Mir-130a in t(8,21) AML Reinforces the Aberrant Molecular Program of AML1-ETO
Notice bibliographique
Résumé
Background: Deregulation of self-renewal and differentiation programs are central to the pathogenesis of hematologic malignancies. MicroRNAs (miRNAs) represent a large class of post-transcriptional regulators that mediate repression of multiple target mRNAs and are frequently deregulated in acute myeloid leukemia (AML). From our previous in vivo miRNA enforced expression screen in human hematopoietic stem and progenitor cells (HSPC), we identified miR-130a as a regulator of self-renewal and lineage specification. Enforced expression of miR-130a in human cord blood (CB) derived HSPC caused an expansion of HSC, block in erythroid differentiation and abnormal myelopoiesis in xenografts. Thus, we examined miR-130a expression in AML and found miR-130a to be specifically upregulated in t(8,21) AML. The translocation t(8,21) is one of the most common karyotypic abnormalities in AML, accounting up to 10% of all AML cases. The consequence of this translocation is a fusion of AML1 and ETO genes, resulting in a formation of the AML1-ETO (AE) oncofusion protein, which acts as a dominant repressor of the wild type AML1/RUNX1. The ETO moiety mediates the recruitment of the nuclear corepressor (NCoR) and histone deacetylases (HDAC1-3) to block RUNX1 target gene expression. This prevents myeloid maturation, apoptosis and promotes leukemogenesis. Here we investigated the molecular mechanism of miR-130a in t(8,21) AML and how it contributes to the leukemogenesis of this AML subtype. Results: Using the TCGA dataset and our PMCC patient cohort, we identified miR-130a to be upregulated in t(8,21) AML and high miR-130a expression was associated with worse patient overall survival. To interrogate the functional significance of elevated miR-130a in t(8,21) AML, we performed knock-down (KD) experiments in the Kasumi-1 cell line, which represents a well characterized model system for t(8,21) AML. Notably, KD of miR-130a induced a significant reduction in the CD34+ cell population and an increase in differentiated CD11b+CD15+ and pro-apoptotic annexin V+ cells. We next examined the impact of miR-130a KD in CD34+ blasts from primary t(8,21) AML patient samples. In line with our findings in the Kasumi-1 cells, miR-130a KD decreased the proportion of CD34+ cells and increased the proportion of differentiated CD11b+CD15+ blasts. To investigate the effect of miR-130a KD on leukemic engraftment in vivo, we transduced CD34+ blasts from 2 patient samples and transplanted them into NSG-GF mice. miR-130a KD decreased leukemic engraftment and the proportion of transduced cells, corroborating the functional significance of high miR-130a expression in t(8,21) AML. To investigate the mechanistic action of miR-130a, we performed label-free semi-quantitative proteomics in human CB derived HSPC to uncover miR-130a targets. Surprisingly, we found the beta subunit of RUNX1, CBFb, and Transducin Beta Like 1 X-Linked Receptor 1, TBL1XR1, to be among the most repressed targets. TBL1XR1 is a component of the nuclear receptor corepressor (NCoR) complex and is involved in NCoR degradation. Thus, we performed western and immunoprecipitations (IP) assays in Flag-AE Kasumi-1 cells following miR-130a KD to examine changes in the expression of proteins associated with the AE complex. We observed increased expression of CBFβ, TBL1XR1 and CEBPA with miR-130a KD. Notably, miR-130a KD resulted in a dramatic decrease of NCoR protein levels. IP of Flag-AE showed decreased association of CBFβ and NCoR with AE, despite unaltered protein levels of AE. To investigate changes in binding occupancy of Flag-AE after miR-130a KD, we performed Cleavage Under the Targets and Release Using Nuclease (CUT&RUN) assay. Surprisingly, we observed 2-fold gain of AE sites in miR-130a KD sample compared to control. De novo motif enrichment analysis showed loss of motives for ETS and HOX transcription factors known to associate with AE following miR-130a KD. Genomic distribution of the peaks revealed a dramatic shift of AE peaks away from the promoter region to introns in miR-130a KD. Pathway enrichment analysis of the unique peaks gained in miR-130a KD showed stress responses and organelle disassembly, in line with the differentiation phenotype observed with miR-130a KD. Collectively, we uncovered a novel mechanism by which miR-130a reinforces the aberrant AE molecular program by controlling the composition and binding of the AE complex. Disclosures Dick: Bristol-Myers Squibb/Celgene: Research Funding.
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 | 0,000 | 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 | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 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 ».