The Cytotoxicity Study Of Monoclonal Antibodies Specific For TRAIL Receptors On Human Renal Cell Carcinoma, In Vitro And In Vivo

ObjectiveTo study the cytotoxicity of monoclonal antibodies specific for tumor necrosis factor (TNF) - related apoptosis - inducing ligand (TRAIL) receptors to human renal cell carcinoma cells.MethodsMTT assay was used to evaluate the cytotoxicity of TRAIL - R1, R2 monoclonal antibody ( ETR1, ETR2). Flow cytometry was used to detect the expression of TRAIL - R1, R2. Fluorescence staining and Annexin V were used to detect apoptosis, and colorimetric analysis was used to study caspase activities. Two in vivo experiments using nude mouse xenograft model engrafted with primary RCC cells were carried out to confirm the anticancer activity of ETR2.ResultsETR2 effectively induced apoptotic cell death in 10 of 11 cell cultures, including two human RCC cell lines and nine freshly derived RCC cell cultures. In contrast, ETR1 was effective in only one fresh RCC cell culture. The greater impact of ETR2 on cell death was most likely due to the different cell - surface expression of the two TRAIL receptors, namely that TRAIL - R2 but not TRAIL - Rl is frequently expressed in most of the RCC cells tested. The activity of caspase - 9, - 8, - 6, and - 3 was increased with ETR1 or ETR2 - induced...