RESUMEN
A series of pyridoxine hydroxamic acid analog bearing a 5-aryl-spacers were synthesized. Evaluation of these novel HIV integrase complex inhibitors revealed compounds with high potency against wild-type HIV virus.
Asunto(s)
Inhibidores de Integrasa VIH/química , Integrasa de VIH/química , VIH-1/fisiología , Ácidos Hidroxámicos/química , Animales , Dominio Catalítico , Femenino , Integrasa de VIH/metabolismo , Inhibidores de Integrasa VIH/síntesis química , Inhibidores de Integrasa VIH/farmacocinética , Semivida , Humanos , Ácidos Hidroxámicos/síntesis química , Ácidos Hidroxámicos/farmacocinética , Concentración 50 Inhibidora , Piridoxina/química , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Replicación Viral/efectos de los fármacosRESUMEN
In an effort to develop new agents and molecular targets for the treatment of cancer, aspargine-glycine-arginine (NGR)-targeted liposomal doxorubicin (TVT-DOX) is being studied. The NGR peptide on the surface of liposomal doxorubicin (DOX) targets an aminopeptidase N (CD13) isoform, specific to the tumor neovasculature, making it a promising strategy. To further understand the molecular mechanisms of action, we investigated cell binding, kinetics of internalization as well as cytotoxicity of TVT-DOX in vitro. We demonstrate the specific binding of TVT-DOX to CD13-expressing endothelial [human umbilical vein endothelial cells (HUVEC) and Kaposi sarcoma-derived endothelial cells (SLK)] and tumor (fibrosarcoma, HT-1080) cells in vitro. Following binding, the drug was shown to internalize through the endosomal pathway, eventually leading to the localization of doxorubicin in cell nuclei. TVT-DOX showed selective toxicity toward CD13-expressing HUVEC, sparing the CD13-negative colon-cancer cells, HT-29. Additionally, the nontargeted counterpart of TVT-DOX, Caelyx, was less cytotoxic to the CD13-positive HUVECs demonstrating the advantages of NGR targeting in vitro. The antitumor activity of TVT-DOX was tested in nude mice bearing human prostate-cancer xenografts (PC3). A significant growth inhibition (up to 60%) of PC3 tumors in vivo was observed. Reduction of tumor vasculature following treatment with TVT-DOX was also apparent. We further compared the efficacies of TVT-DOX and free doxorubicin in the DOX-resistant colon-cancer model, HCT-116, and observed the more pronounced antitumor effects of the TVT-DOX formulation over free DOX. The potential utility of TVT-DOX in a variety of vascularized solid tumors is promising.
Asunto(s)
Antineoplásicos/administración & dosificación , Antineoplásicos/farmacocinética , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacocinética , Oligopéptidos/metabolismo , Animales , Antineoplásicos/farmacología , Transporte Biológico , Antígenos CD13/metabolismo , Línea Celular Tumoral , Neoplasias del Colon , Doxorrubicina/farmacología , Resistencia a Antineoplásicos , Endocitosis , Endosomas/metabolismo , Humanos , Técnicas In Vitro , Liposomas , Masculino , Ratones , Ratones Desnudos , Neoplasias de la Próstata , Unión ProteicaRESUMEN
Human PSP94 (prostate secretory protein of 94 amino acids) is a major protein synthesized by the prostate gland and secreted in large quantities in seminal fluid. Previous studies have suggested a potential biomedical utility of PSP94 in applications such as diagnosis/prognosis and in treatment of human prostate cancer (PCa). This study was designed to produce a recombinant human PSP94 (rPSP94) to evaluate its clinical and functional role in PCa. We cloned PSP94 cDNA and successfully expressed an active recombinant protein in yeast using Pichia pastoris expression system. A simple purification strategy was established that incorporated combination of membrane ultrafiltration (Pellicon tangential-flow system) and anion exchange chromatography using DE52 resin. The method minimized the technical level of expertise for the production of high quality functional protein. The purified rPSP94 (>98% purity) showed a single band with SDS-PAGE analysis and a peak with a molecular mass (M(r)) of 11,495 kDa using MALDI TOF mass spectrometry (MS). The in vitro competitive binding assays indicated high functional similarity of the rPSP94 with that of its native counterpart. Furthermore, in vivo administration of rPSP94 caused a significant growth inhibition of hormone refractory Mat LyLu tumors in Dunning rat model. Taken together, our data provides evidence for high suitability of the purified rPSP94 for evaluation of its potential diagnostic and therapeutic role in PCa and as a valuable analytical reference standard for clinical studies.
Asunto(s)
Proteínas de Secreción Prostática/genética , Proteínas de Secreción Prostática/uso terapéutico , Animales , Antineoplásicos/uso terapéutico , Cromatografía por Intercambio Iónico , Clonación Molecular , Humanos , Masculino , Pichia/metabolismo , Neoplasias de la Próstata/tratamiento farmacológico , Proteínas de Secreción Prostática/aislamiento & purificación , Ratas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/uso terapéutico , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Solid tumors often display sites of necrosis near regions of angiogenesis in vivo. As tumor cell necrosis would result in the release of nucleosomes into the extracellular environment, we explored the potential role of nucleosomes in the promotion of angiogenesis. Data indicate that nucleosomes acted similar to heparin and bound to several heparin-binding, proangiogenic factors [i.e., fibroblast growth factor (FGF)-1, FGF-2, vascular endothelial growth factor, and transforming growth factor-beta1]. Nucleosomes modestly enhanced FGF-2 growth of human umbilical vein endothelial cells when grown in restricted media as well as increased human umbilical vein endothelial cell migration and primitive blood vessel tube formation in vitro. On s.c. injection in mice, nucleosomes aided FGF-2 in promoting angiogenesis. These results suggest that nucleosomes released from dying tumor cells aid in the formation of blood vessels and may provide a novel means by which tumor cells increase angiogenesis.