MicroRNAs Act as Decoy Molecules To Restore Granulocytic Maturation of Differentiation-Arrested BCR/ABL+ Myeloid Precursors.
Notice bibliographique
Résumé
Abstract Altered microRNA (miR) expression contributes to aberrant post-transcriptional regulation of gene expression in different type of cancers; however, their role in the pathogenesis and progression of chronic myelogenous leukemia (CML) from chronic phase (CML-CP) to blast crisis (CML-BC) is still largely unknown. Microarray analysis of miR expression reveals that a discrete number of miRs are significantly upregulated (∼ 6.7% of the total 505 miRs present on the chip; 34 miRs) or downregulated (∼2.8% of the miRs present on the chip; 14 miRs) in an imatinib-sensitive manner in CML-BCCD34+ compared to CML-CPCD34+ progenitors and in BCR/ABL-expressing hematopoietic cell lines compared to untransformed parental cells. Among them, we focused our attention on miR-223, miR-15a/16-1 and miR-328, a microRNA with no currently known function, because of their importance in myelopoiesis, potential role as tumor suppressors and sequence homology with the 5’UTR of CEBPA mRNA, respectively. In 32D-BCR/ABL and K562 cells, Northern blot and TaqMan RT-PCR analyses revealed that expression of miR-223, miR-328, miR-15a and miR-16-1 was markedly suppressed (50–75% inhibition) by p210-BCR/ABL kinase activity and that imatinib treatment (1mM; 24h) restored the expression of these miRs to levels similar to those detected in non-transformed 32Dcl3 cells. Interestingly, sequence analysis of both miR-223 and miR-328 revealed homology with the hnRNP E2-binding site contained in the CEBPA uORF/spacer mRNA, a known target of the negative regulator of myeloid differentiation hnRNP E2. Accordingly, REMSA and UV-crosslinking experiments showed that synthetic miR-223 and to a greater extent miR-328 bind efficiently to recombinant hnRNP E2 protein and compete for its binding to an oligoribonucleotide containing the CEBPA uORF/spacer region, which is required for hnRNP E2-mediated translational inhibition of CEBPA in CML-BCCD34+ progenitors. Furthermore, both miR-223 and miR-328 bind endogenous hnRNP E2 from lysates of BCR/ABL-expressing but not parental cells, and from lysates of parental 32Dcl3 myeloid precursors ectopically expressing a Flag-tagged hnRNP E2 protein, suggesting that miR-223 and miR-328 may act as decoy molecules that interfere with the translation-inhibitory activity of hnRNP E2. Indeed, ectopic expression of miR-223 restored G-CSF-driven granulocytic maturation of differentiation-arrested 32D-BCR/ABL cells and restored C/EBPα expression, whereas it did not have any effect on cytokine-independent growth and clonogenic potential. Consistent with its ability to bind hnRNP E2, miR-328 also rescued C/EBPα expression and differentiation of cytokine-independent BCR/ABL-expressing myeloid precursor 32Dcl3 cells. By contrast, BCR/ABL-dependent colony formation was markedly reduced by overexpression of miR-15a and miR-16-1 (65–75% inhibition, P<0.001) and slightly decreased (40–50% inhibition, P<0.01) by ectopic miR-328 expression. Altogether, these data not only reinforce the importance of BCR/ABL-dependent post-transcriptional regulation of gene expression during CML disease progression but also suggest a new function for microRNAs as functional regulators of RNA binding proteins involved in the control of malignant cell growth, survival and differentiation.
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) | 0,002 | 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 ».