Construction and validation of a novel tumor necrosis factor‐related apoptosis‐inducing ligand mutant MuR5S4‐TR

Abstract Aim Tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) can selectively kill tumor cells but has no significant effect on normal cells. However, the use of TRAIL is limited for resistance by more than 50% of the tumor cell lines. It's very important to develop a more efficient form of TRAIL for cancer treatment. Methods The N ‐terminal in soluble fragments (114–281aa) of TRAIL was redesigned to construct a novel TRAIL mutant‐MuR5S4‐TR. The Cell Counting Kit‐8 method to explore the antitumor effects. The potential mechanisms were also explored. Results Novel TRAIL mutant with cell‐penetrating peptides (CPP) like and Second mitochondria‐derived activator of caspases (Smac) like structure‐MuR5S4‐TR was successfully constructed. The prokaryotic expression system was successfully built, and the MuR5S4‐TR was purified and reconfirmed by western blot. MuR5S4‐TR could enhance the antitumor effects of TRAIL in most of the cancer cell lines significantly, NCI‐H460 lung cancer cell line, for instance. After MuR5S4‐TR treatment, the expressions of death receptor 4 (DR4), DR5, Caspase‐8, and cleaved Caspase‐3 were remarkably increased, however, there was no significant difference in X‐linked inhibitor of apoptosis expression. Conclusion We constructed a novel TRAIL mutant with CPP‐like and Smac‐like structure‐MuR5S4‐TR. The MuR5S4‐TR showed significantly stronger antitumor effects than TRAIL in many tumor cell lines. The MuR5S4‐TR showed strong antitumor effects both in vitro and in vivo. This preliminary study implies that MuR5S4‐TR may be a more efficient form of TRAIL for cancer therapy.