A High Throughput Screen Identified Cyproheptadine That Decreases D-Type Cyclins, Arrests Cells in the G1 Phase, and Induces Apoptosis in Multiple Myeloma and Leukemia Cells.
Notice bibliographique
Résumé
Abstract Cyclin Ds are key regulators of the cell cycle that are frequently over-expressed in multiple myeloma and leukemia and act to promote the phosphorylation of Rb, thereby facilitating the transition from G1 to S phase. Over-expression of cyclin Ds increases cell proliferation and chemoresistance. In contrast, reducing cyclin Ds levels directly or indirectly through G1 arrest can decrease cellular proliferation and induce apoptosis. To identify novel pharmaceutical inhibitors of cyclin D transactivation, we screened the LOPAC and Prestwick libraries of drugs and natural compounds (n = 2400) using NIH 3T3 cells stably expressing the Cyclin D2 promoter-driving a luciferase reporter gene. From this library screen and subsequent validation experiments we identified Cyproheptadine as a novel inhibitor of Cyclin D2 transactivation. Cyproheptadine has been used previously for the treatment of atopic dermatitis and anorexia, but its ability to inhibit cyclin D expression has not previously been reported. By immunoblotting, Cyproheptadine decreased expression of cyclin D1, D2 and D3 proteins in human myeloma and leukemia cell lines at low micromolar concentrations. Consistent with effects on the cyclin Ds, Cyproheptadine arrested cells in the G1 phase at concentrations associated with reduction in cyclin D expression. Decreased cyclin D expression and G1 arrest can induce apoptosis, so we tested the effects of Cyproheptadine on cell viability. Myeloma and leukemia cell lines were treated with increasing concentrations of Cyproheptadine and viability was measured by the MTS assay. Cyproheptadine reduced the viability of 7/10 myeloma and 7/8 AML cells lines with an IC50 ranging from 10–25μM. In contrast, it was less toxic to HeLa or NIH3T3 cells with IC20 > 50 μM. Cyproheptadine also reduced the viability of primary myeloma (8/8) and AML patient samples (7/9) with an IC50 <25 μM, but was less toxic to normal hematopoietic cells (IC20 > 50 μM). In a MDAY-D2 mouse model of leukemia, treatment with Cyproheptadine (50mg/kg/d) abolished formation of malignant leukemic ascites without untoward toxicity. Cyproheptadine-induced cell death was associated with reductions in mitochondrial membrane potential. Furthermore, reductions of pro-caspases -3 and -9 were observed prior to the reduction in pro-caspase-8, indicating that Cyproheptadine activates the mitochondrial pathway of caspase activation. Cyproheptadine is a known H1 histamine and serotonin receptor inhibitor, but pre-incubation with histamine, serotonin, or a combination of histamine and serotonin did not abrogate Cyproheptadine-induced cell death. Moreover, the structurally related H1 receptor inhibitor loratadine did not decrease cyclin D expression or reduce cell viability. Therefore, the pro-apoptotic activity of Cyproheptadine is not due to a competitive inhibition of the H1 and/or serotonin receptors, suggesting that Cyproheptadine has additional targets. In summary, Cyproheptadine arrests cells in G1, reduces cyclin D expression, and induces apoptosis via the mitochondrial pathway of caspase activation. Given the prior safety and toxicity record of Cyproheptadine, this drug could be rapidly advanced into clinical trial for the treatment of hematologic malignancies.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| 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) | 0,000 | 0,000 |
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 tête enseignante, 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 ».