RESUMEN
Multiple myeloma (MM) is an incurable malignancy with an unmet need for innovative treatment options. Histone deacetylase inhibitors (HDACi) are a new class of anticancer agent that have demonstrated activity in hematological malignancies. Here, we investigated the efficacy and safety of HDACi (vorinostat, panobinostat, romidepsin) and novel combination therapies using in vitro human MM cell lines and in vivo preclinical screening utilizing syngeneic transplanted Vk*MYC MM. HDACi were combined with ABT-737, which targets the intrinsic apoptosis pathway, recombinant human tumour necrosis factor-related apoptosis-inducing ligand (rhTRAIL/MD5-1), that activates the extrinsic apoptosis pathway or the DNA methyl transferase inhibitor 5-azacytidine. We demonstrate that in vitro cell line-based studies provide some insight into drug activity and combination therapies that synergistically kill MM cells; however, they do not always predict in vivo preclinical efficacy or toxicity. Importantly, utilizing transplanted Vk*MYC MM, we report that panobinostat and 5-azacytidine synergize to prolong the survival of tumor-bearing mice. In contrast, combined HDACi/rhTRAIL-based strategies, while efficacious, demonstrated on-target dose-limiting toxicities that precluded prolonged treatment. Taken together, our studies provide evidence that the transplanted Vk*MYC model of MM is a useful screening tool for anti-MM drugs and should aid in the prioritization of novel drug testing in the clinic.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Azacitidina/uso terapéutico , Compuestos de Bifenilo/uso terapéutico , Inhibidores de Histona Desacetilasas/uso terapéutico , Mieloma Múltiple/tratamiento farmacológico , Nitrofenoles/uso terapéutico , Sulfonamidas/uso terapéutico , Ligando Inductor de Apoptosis Relacionado con TNF/uso terapéutico , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Apoptosis/efectos de los fármacos , Azacitidina/farmacología , Compuestos de Bifenilo/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Ácidos Hidroxámicos/farmacología , Ácidos Hidroxámicos/uso terapéutico , Indoles/farmacología , Indoles/uso terapéutico , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mieloma Múltiple/metabolismo , Mieloma Múltiple/patología , Nitrofenoles/farmacología , Panobinostat , Piperazinas/farmacología , Piperazinas/uso terapéutico , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Receptores de Muerte Celular/metabolismo , Proteínas Recombinantes , Sulfonamidas/farmacología , Ligando Inductor de Apoptosis Relacionado con TNF/farmacologíaAsunto(s)
Compuestos de Bifenilo/farmacología , Inhibidores de Histona Desacetilasas/farmacología , Ácidos Hidroxámicos/farmacología , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/patología , Nitrofenoles/farmacología , Sulfonamidas/farmacología , Adulto , Anciano , Anciano de 80 o más Años , Sinergismo Farmacológico , Femenino , Humanos , Técnicas In Vitro , Indoles , Masculino , Persona de Mediana Edad , Panobinostat , Piperazinas/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Células Tumorales Cultivadas , VorinostatRESUMEN
Higher concentrations of Ca in the diet may decrease phytate-phosphorus hydrolysis because of chelation of Ca with the phytin molecule. In experiment 1, drakes were fed 0.74, 0.85, 0.95, or 1.11% Ca (analyzed) from 7 to 18 d of age (6 birds/cage, 8 cages/diet). Intestinal mucosa was collected at 18 d of age from birds fed 0.74 and 1.11% Ca for determination of intestinal phytase activity. In experiment 1, 17 d BW gain and feed consumption exhibited a quadratic response to increasing concentrations of Ca and were found to be maximal for ducks fed the 0.95% Ca diet. Toe ash percentage (18 d) had a quadratic response to increasing concentrations of Ca with a maximal response for birds fed the 0.85% Ca diet. Increasing dietary Ca did not affect P retention from 15 to 17 d of age or intestinal phytase activity and brush border vesicle Ca concentration. A positive correlation was found between the Vmax and the Ca concentration within the vesicles (r = 0.59, P < 0.02), suggesting that the vesicle Ca concentration did not negatively affect the kinetics of the phytase assay. In experiment 2, drakes were fed 0.6, 0.8, 1.0, or 1.2% Ca (formulated) with 826 or 8,260 ICU/kg of vitamin D3 from 0 to 13 d of age. There was no response to increasing concentrations of Ca for performance characteristics or bone ash measurements.
Asunto(s)
Peso Corporal/efectos de los fármacos , Calcio de la Dieta/farmacología , Calcio/metabolismo , Colecalciferol/farmacología , Patos/metabolismo , Fósforo/metabolismo , 6-Fitasa/metabolismo , Alimentación Animal , Animales , Huesos/efectos de los fármacos , Huesos/metabolismo , Relación Dosis-Respuesta a Droga , Intestino Delgado/enzimología , MasculinoRESUMEN
Copper is often added to broiler diets at prophylactic concentrations as an antimicrobial despite purported chelation with and reduced utilization of phytin phosphorus. Therefore, male chicks were fed 0, 62.5, 125, 250, or 375 ppm Cu from Cu sulfate in combination with 600 phytase units (FTU)/kg phytase from 9 to 22 d of age (6 cages/diet, 8 birds/cage). Nonphytate phosphorus (NPP) and Ca were formulated to 0.2 and 0.7% of the diet, respectively. Three additional control diets were formulated to contain 0.27, 0.34, and 0.40% NPP, each with 0.7% Ca. Birds fed increasing concentrations of Cu with 600 FTU phytase/kg had linear reductions in performance characteristics (P < or = 0.05). Birds fed increasing concentrations of Cu with 600 FTU phytase/kg had linear increases in toe ash percentage (P < or = 0.027), but tibia ash percentage was not affected (P > 0.05). Birds fed increasing Cu concentrations with 600 FTU phytase/kg had linear reductions in apparent P retention as a percentage of total P (P < or = 0.0005). Supplementation with increasing concentrations of Cu to a diet containing 600 FTU phytase/kg resulted in decreases in 21 d BW, BW gain, feed consumption, feed conversion, tibia and toe ash weights, and apparent P retention as a percentage of total P. In this experiment, Cu supplementation did not reduce the efficacy of phytase (i.e., improvement in apparent P retention with phytase supplementation) but did decrease apparent P retention, BW gain, feed consumption, feed conversion, and tibia ash and toe ash weights.
Asunto(s)
6-Fitasa/administración & dosificación , Pollos/fisiología , Cobre/administración & dosificación , Dieta , Fósforo Dietético/metabolismo , Aumento de Peso , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Calcificación Fisiológica , Sulfato de Cobre/administración & dosificación , Relación Dosis-Respuesta a Droga , Ingestión de Alimentos , Masculino , Minerales/análisis , Fósforo Dietético/administración & dosificaciónRESUMEN
Copper sulfate is often added to broiler and laying hen diets at prophylactic dosages due to its antimicrobial and growth promoting effects despite reduced P digestibility, whereas P use from other Cu sources is unknown. Therefore, male broiler chicks were fed diets containing 0 or 250 ppm Cu from Cu sulfate (Cu SUL), Cu citrate (Cu CIT), Cu lysinate (Cu LYS), or CuCl from 9 to 22 d of age (8 cages/diet, 6 birds/cage) to determine the effect of each Cu source on performance characteristics, bone mineralization, and P retention. Body weight gain was not different among treatments (P > 0.05). Supplementation with 250 ppm Cu from Cu LYS resulted in chicks having greater toe and tibia ash weights as compared with chicks fed Cu SUL (P < or = 0.05) but was not significantly different from those of birds fed Cu CL, Cu CIT, and 0 ppm Cu diets. Supplementation with Cu LYS resulted in birds with greater toe ash percentage as compared with birds fed Cu CIT, Cu SUL, and the 0 ppm Cu diets (P < or = 0.05) but was not significantly different than those of birds fed the CuCl diet. Birds fed the Cu LYS diet had greater tibia ash percentage as compared with birds fed Cu SUL and 0 ppm Cu diets (P < or = 0.05) but were not significantly different than birds fed the Cu CL or Cu CIT diet. Supplementation with 250 ppm Cu SUL or Cu CIT reduced apparent P retention by 0.029 and 0.053 percentage-units of the diet, respectively (P < or = 0.05) as compared with the 0 ppm diet; whereas the apparent P retention when 250 ppm Cu LYS or Cu CL was fed was not different from the 0 ppm Cu diet (P > 0.05). Feeding of different Cu sources in a subsequent experiment had no influence on P retention in laying hens (P > 0.05). In conclusion, supplementation with 250 ppm Cu from Cu CIT or Cu SUL resulted in decreased apparent P retention. Supplementation with 250 ppm Cu CL or Cu LYS, however, improved apparent P retentions as compared with Cu CIT or Cu SUL.
Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales , Pollos/fisiología , Cobre/administración & dosificación , Dieta , Fósforo Dietético/farmacocinética , Envejecimiento , Animales , Calcificación Fisiológica , Citratos/administración & dosificación , Sulfato de Cobre/administración & dosificación , Suplementos Dietéticos , Lisina/administración & dosificación , Oviposición , Aumento de PesoRESUMEN
A three-dimensional solution structure for the self-complementary dodecanucleotide [d-(GCCTGATCAGGC)]2 has been determined by distance geometry with further refinements being performed after back-calculation of the NOESY spectrum. This DNA dodecamer contains the hexamer [d(TGATCA)]2 recognized and cut by the restriction endonuclease BclI, and its structure was determined in hopes of obtaining a better understanding of the sequence-specific interactions which occur between proteins and DNA. Preliminary examination of the structure indicates the structure is underwound with respect to idealized B-form DNA though some of the local structural parameters (glycosyl torsion angle and pseudorotation angle) suggest a B-family type of structure is present. This research demonstrates the requirements (resonance assignments, interproton distance measurements, distance geometry calculations, and NOESY spectra back-calculation) to generate experimentally self-consistent solution structures for short DNA sequences.