Objective: To investigate the correlation between sensitivity to tumor necrosis factor-related apoptosis inducing ligand (TRAIL) and expression level of death receptor 5 (DR5) on tumor cell surface.
Methods: Anti-DR5 mAb was used to detect expression level of DR5 on surface of tumor cells by flow cytometry. Sensitivity to apoptosis induced by TRAIL was determined by TRAIL apoptosis kit. The correlation between expression level of DR5 and sensitivity to TRAIL was analyzed.
Results: The expression of DR5 on surface of tumor cells was approximately 97.9% in U937 cells, 95.1% in Jurkat cells, 93.8% in SW480 cells, 86.2% in HCT116 cells, 64.2% in HL-60 cells, 46.6% in HeLa cells and 13.1% in K562 cells, respectively. The apoptosis rate induced by TRAIL was 72.6% in U937 cells, 85.2% in Jurkat cells, 78.6% in SW480 cells, 70.2% in HCT116 cells, 60.1% in HL-60 cells, 45.4% in HeLa cells and 12.3% in K562 cells, respectively. There was a significant positive correlation between the expression level of DR5 with TRAIL-inducing apoptosis (r = 0.997, P < 0.001).
Conclusion: TRAIL-inducing apoptosis is related to the expression level of DR5 on surface of tumor cells. The results confirm the importance of DR5 expression for induction of apoptosis by TRAIL.