RESUMEN
TweakR is a TNF receptor family member, whose natural ligand is the multifunctional cytokine TWEAK. The growth inhibitory activity observed following TweakR stimulation in certain cancer cell lines and the overexpression of TweakR in many solid tumor types led to the development of enavatuzumab (PDL192), a humanized IgG1 monoclonal antibody to TweakR. The purpose of this study was to determine the mechanism of action of enavatuzumab's tumor growth inhibition and to provide insight into the biology behind TweakR as a cancer therapeutic target. A panel of 105 cancer lines was treated with enavatuzumab in vitro; and 29 cell lines of varying solid tumor backgrounds had >25% growth inhibition in response to the antibody. Treatment of sensitive cell lines with enavatuzumab resulted in the in vitro and in vivo (xenograft) activation of both classical (p50, p65) and non-classical (p52, RelB) NFκB pathways. Using NFκB DNA binding functional ELISAs and microarray analysis, we observed increased activation of NFκB subunits and NFκB-regulated genes in sensitive cells over that observed in resistant cell lines. Inhibiting NFκB subunits (p50, p65, RelB, p52) and upstream kinases (IKK1, IKK2) with siRNA and chemical inhibitors consistently blocked enavatuzumab's activity. Furthermore, enavatuzumab treatment resulted in NFκB-dependent reduction in cell division as seen by the activation of the cell cycle inhibitor p21 both in vitro and in vivo. The finding that NFκB drives the growth inhibitory activity of enavatuzumab suggests that targeting TweakR with enavatuzumab may represent a novel cancer treatment strategy.
RESUMEN
BACKGROUND: The high-throughput analysis of strontium and calcium in plasma, tissue and bone (femur) using inductively coupled plasma-MS is described. Method validation, the results and experience obtained during sample analysis are highlighted. RESULTS: The different matrices were destructed with concentrated nitric acid by heating at 60°C overnight. Using this approach it was possible to analyze large numbers of samples in parallel. CONCLUSION: Inductively coupled plasma-MS proved to be a highly sensitive, robust and efficient technique for the analysis of several different biological samples. A total of 6767 samples were analyzed, and the performance of the method was illustrated by the fact that only 0.2% of the samples had to be reanalyzed due to anomalous results and ISR for all matrices fulfilled the acceptance criteria.
Asunto(s)
Calcio/análisis , Espectrometría de Masas/métodos , Estroncio/análisis , Animales , Calcio/sangre , Descubrimiento de Drogas , Femenino , Fémur/química , Ensayos Analíticos de Alto Rendimiento/métodos , Leche/química , Ratas , Ratas Sprague-Dawley , Estroncio/sangre , Útero/químicaRESUMEN
RATIONALE: Lung adenocarcinoma histology and clinical outcome are heterogeneous and associated with tumor invasiveness. OBJECTIVES: We hypothesized that invasiveness is associated with a distinct molecular signature and that genes differentially expressed in tumor or adjacent stroma will identify cell surface signal transduction and matrix remodeling pathways associated with the acquisition of invasiveness in lung adenocarcinoma. MAIN RESULTS: Microarray analysis of microdissected noninvasive bronchioloalveolar carcinoma (BAC) and invasive adenocarcinoma and adenocarcinoma-mixed type with BAC features identified transcriptional profiles of lung adenocarcinoma invasiveness. Among the signature set that was lower in adenocarcinoma-mixed compared with BAC was the type II transforming growth factor beta (TGF-beta) receptor, suggesting downregulation of TGFbetaRII is an early event in lung adenocarcinoma metastasis. Immunostaining in independently acquired specimens demonstrated a correlation between TbetaRII expression and length of tumor invasion. Repression of TGFbetaRII in lung cancer cells increased tumor cell invasiveness and activated p38 mitogen-activated protein kinases. Microarray analysis of invasive cells identified potential downstream mediators of TGFbetaRII with differential expression in lung adenocarcinomas. CONCLUSIONS: The repression of type II TGF-beta receptor may act as a significant determinant of lung adenocarcinoma invasiveness, an early step in tumor progression toward metastasis.