RESUMEN
The indisputable role of epigenetics in cancer and the fact that epigenetic alterations can be reversed have favoured development of epigenetic drugs. In this study, we design and synthesize potent novel, selective and reversible chemical probes that simultaneously inhibit the G9a and DNMTs methyltransferase activity. In vitro treatment of haematological neoplasia (acute myeloid leukaemia-AML, acute lymphoblastic leukaemia-ALL and diffuse large B-cell lymphoma-DLBCL) with the lead compound CM-272, inhibits cell proliferation and promotes apoptosis, inducing interferon-stimulated genes and immunogenic cell death. CM-272 significantly prolongs survival of AML, ALL and DLBCL xenogeneic models. Our results represent the discovery of first-in-class dual inhibitors of G9a/DNMTs and establish this chemical series as a promising therapeutic tool for unmet needs in haematological tumours.
Asunto(s)
Antineoplásicos/farmacología , Metilasas de Modificación del ADN/antagonistas & inhibidores , Diseño de Fármacos , Inhibidores Enzimáticos/farmacología , Neoplasias Hematológicas/tratamiento farmacológico , N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , Animales , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Apoptosis/genética , Apoptosis/inmunología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Cristalografía por Rayos X , Metilasas de Modificación del ADN/química , Metilasas de Modificación del ADN/genética , Metilasas de Modificación del ADN/metabolismo , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/uso terapéutico , Epigénesis Genética/efectos de los fármacos , Femenino , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/inmunología , Neoplasias Hematológicas/mortalidad , Antígenos de Histocompatibilidad/química , Antígenos de Histocompatibilidad/genética , Antígenos de Histocompatibilidad/metabolismo , N-Metiltransferasa de Histona-Lisina/química , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Interferones/inmunología , Interferones/metabolismo , Ratones , Ratones Endogámicos BALB C , Microsomas Hepáticos , Simulación del Acoplamiento Molecular , Análisis de Supervivencia , Resultado del Tratamiento , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Analogues of the cationic antimicrobial peptide gramicidin S (GS), cyclo(Val-Orn-Leu-D-Phe-Pro)2, with d-Phe residues replaced by different (restricted mobility, mostly) surrogates have been synthesized and used in SAR studies against several pathogenic bacteria. While all D-Phe substitutions are shown by NMR to preserve the overall beta-sheet conformation, they entail subtle structural alterations that lead to significant modifications in biological activity. In particular, the analogue incorporating D-Tic (1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) shows a modest but significant increase in therapeutic index, mostly due to a sharp decrease in hemolytic effect. The fact that NMR data show a shortened distance between the D-Tic aromatic ring and the Orn delta-amino group may help explain the improved antibiotic profile of this analogue.
Asunto(s)
Gramicidina/análogos & derivados , Gramicidina/uso terapéutico , Fenilalanina/análogos & derivados , Acinetobacter baumannii/efectos de los fármacos , Sustitución de Aminoácidos , Animales , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Hemolíticos/farmacología , Listeria monocytogenes/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Resonancia Magnética Nuclear Biomolecular , Fenilalanina/química , Estructura Secundaria de Proteína , Ovinos , Staphylococcus aureus/efectos de los fármacos , Relación Estructura-Actividad , Tetrahidroisoquinolinas/químicaRESUMEN
The structure of alpha-hemoglobin stabilizing protein (AHSP), a molecular chaperone for free alpha-hemoglobin, has been determined using NMR spectroscopy. The protein native state shows conformational heterogeneity attributable to the isomerization of the peptide bond preceding a conserved proline residue. The two equally populated cis and trans forms both adopt an elongated antiparallel three alpha-helix bundle fold but display major differences in the loop between the first two helices and at the C terminus of helix 3. Proline to alanine single point mutation of the residue Pro-30 prevents the cis/trans isomerization. The structure of the P30A mutant is similar to the structure of the trans form of AHSP in the loop 1 region. Both the wild-type AHSP and the P30A mutant bind to alpha-hemoglobin, and the wild-type conformational heterogeneity is quenched upon complex formation, suggesting that just one conformation is the active form. Changes in chemical shift observed upon complex formation identify a binding interface comprising the C terminus of helix 1, the loop 1, and the N terminus of helix 2, with the exposed residues Phe-47 and Tyr-51 being attractive targets for molecular recognition. The characteristics of this interface suggest that AHSP binds at the intradimer alpha1beta1 interface in tetrameric HbA.