Cisplatin sensitizes human hepatocellular carcinoma cells, but not hepatocytes and mesenchymal stem cells, to TRAIL within a therapeutic window partially depending on the upregulation of DR5.

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family of cytokines and has been shown to induce cell apoptosis in many types of tumors, but not in normal cells. This tumor-selective property has made TRAIL a promising approach for the development of cancer therapy. However, hepatocellular carcinoma (HCC) cells display a striking resistance to TRAIL. Although some chemotherapeutic agents can overcome this resistance, safety issues remain a concern because the combination of these agents and TRAIL has been reported to induce toxicity in normal hepatocytes. In this study, we examined whether cisplatin could reverse TRAIL resistance in HCC cells with different p53 status and evaluated the toxicity of combination TRAIL and cisplatin to normal hepatocytes and mesenchymal stem cells (MSCs). We observed that cisplatin could efficiently sensitize HCC cells, but not hepatocytes and MSCs to TRAIL-induced apoptosis within a wide therapeutic window. The apoptosis of HCC cells only partially depended on the upregulation of DR5 and the status of p53. In addition, we provide favorable evidence supporting the feasibility of the combination of chemotherapy and MSCs transduced with TRAIL.