RESUMEN
T-cell lymphomas (TCL) are aggressive lymphomas usually treated with CHOP (cyclophsophamide, doxorubicin, vincristine, prednisolone)-like regimens upfront. Recent data suggest that TCL are driven by epigenetic defects, potentially rendering them sensitive to epigenetic therapies. We explored the therapeutic merits of a combined epigenetic platform using histone deacetylase inhibitors (HDACIs) and DNA methyltransferase inhibitors (DNMT) in in vitro and in vivo models of TCL. The 50% inhibitory concentration (IC50 ) values revealed romidepsin was the most potent HDACI, with an IC50 in the low nanomolar range. The combination with a hypomethylating agent produced synergy across all cell lines, which was confirmed in cytotoxicity and apoptosis assays. An in vivo xenograft study demonstrated inhibition of tumour growth in the combination cohort compared to the single agent. Gene expression array and global methylation profiling revealed differentially expressed genes and modulated pathways for each of the single treatment conditions and the combination. Most of the effects induced by the single agent treatment were maintained in the combination group. In total, 944 unique genes were modulated by the combination treatment, supporting the hypothesis of molecular synergism. These data suggest combinations of hypomethylating agents and HDACIs are synergistic in models of TCL, which is supported at the molecular level.
RESUMEN
The kinesin spindle protein (KSP) is a mitotic protein essential for cell cycle control and motility. SB-743921 (hereafter SB-921) is an inhibitor that selectively targets the ATP-binding domain of the KSP. The preclinical activity of SB-921 was evaluated in models of diffuse large B-cell lymphoma (DLBCL). The cytotoxicity of SB-921 was evaluated in a series of germinal center (GC-DLBCL) and post-germinal center (ABC-DLBCL) DLBCL cell lines and a murine lymphoma xenograft model. GC-DLBCL lines generally demonstrated greater sensitivity to SB-921. IC50 values ranged between 1 nM and 900 nM for GC-DLBCL compared to 1 nM to 10 µM for ABC lines. SB-921 demonstrated marked activity in a xenograft model of Ly-1 (GC-DLBCL). While SB-921 was relatively more active in GC derived cell lines, ABC-derived lines still underwent apoptosis at higher concentrations. These results demonstrate that SB-921 inhibits proliferation and induces apoptosis in both GC-DLBCL and ABC-DLBCL.
Asunto(s)
Antineoplásicos/farmacología , Benzamidas/farmacología , Cromonas/farmacología , Cinesinas/antagonistas & inhibidores , Cinesinas/metabolismo , Linfoma de Células B Grandes Difuso/metabolismo , Linfoma de Células B Grandes Difuso/patología , Animales , Biomarcadores , Ciclo Celular/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Humanos , Concentración 50 Inhibidora , Cinesinas/genética , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Ratones , Mitosis/genética , Ensayos Antitumor por Modelo de XenoinjertoAsunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Farmacéuticos , Gestión de Riesgos , Aprobación de Drogas , Etiquetado de Medicamentos , Drogas en Investigación , Humanos , Administración del Tratamiento Farmacológico , Educación del Paciente como Asunto , Vigilancia de Productos Comercializados , Medición de RiesgoRESUMEN
Plasmablastic lymphoma (PBL) is an aggressive lymphoma classified by the World Health Organization as a subtype of diffuse large B-cell lymphoma that shares many morphologic and immunophenotypic features with multiple myeloma. It is extremely rare in immunocompetent patients. Because of the small number of patients reported, this rare lymphoma remains a poorly characterized and understood entity with presently no standard recommendations regarding the optimal treatment. Herein, we report a dramatic clinical response coupled with tumor lysis syndrome to a bortezomib-based treatment in an HIV-negative patient with refractory plasmablastic lymphoma.
