Effects of TNF secreting HEK cells on B lymphocytes' apoptosis in human chronic lymphocytic leukemias.

BACKGROUND Tumor necrosis factor (TNF) related apoptosis-inducing ligand (TRAIL) is an antitumor candidate in cancer therapy. This study focused on effects of TRAIL, as a proapototic ligand that causes apoptosis, in B-CELL chronic lymphocytic leukemia cells (B-CLL) . MATERIALS AND METHODS A population of HEK 293 cells was transducted by lentivirus that these achieved ability for producing the TRAIL protein and then HEK 293 cells transducted were placed in the vicinity of CLL cells. After 24 hours of co-culture, apoptosis of CLL cells was assessed by annexin V staining. RESULTS The amount of Apoptosis was examined separately in four groups: 293 HEK TRAIL (16.17±1.04%); 293 HEK GFP (2.7±0.57%); WT 293 HEK (2±2.6%); and CLL cells (0.01±0.01%). Among the groups studied, the maximum amount of apoptosis was in the group that the vector encoding TRAIL was transducted. In this group, the mean level of soluble TRAIL in the culture medium was 253 pg/ml; also flow cytometry analyzes showed that proapotosis in this group was 32.8±1.6%, which was higher than the other groups. CONCLUSIONS In this study, we have demonstrated that TNF secreted from HEK 293 cells are effective in death of CLL cells.