The novel fusion protein sTRAIL-TMTP1 exhibits a targeted inhibition of primary tumors and metastases.

UNLABELLED: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively kill tumor cells and enhance therapy in vivo. However, concerns regarding its considerable liver toxicity limit its use in humans as a cancer therapy. Tumor molecular targeted peptide 1 (TMTP1) has previously been reported by our laboratory to target primary tumors and metastatic foci. Here, we report a novel recombinant fusion protein, sTRAIL-TMTP1, which not only induced apoptosis in cancer cells in vitro but also inhibited tumor growth and metastases in vivo. Moreover, sTRAIL-TMTP1 impacted tumor angiogenesis. The biodistribution results demonstrated that sTRAIL-TMTP1 accumulation peaked 6 h after injection and persisted for 24 h in the tumor, while faint sTRAIL-TMTP1 accumulation was detected in normal organs in tumor-bearing mice. Thus, combining sTRAIL with TMTP1 resulted in high anti-tumor activity and low toxicity. In conclusion, the novel fusion protein sTRAIL-TMTP1 was successfully developed in our laboratory and was observed to induce apoptosis both in primary and metastatic cancer, which may lead to the development of novel, targeted anticancer agents. KEY MESSAGE: Construction, purification, and characterization of the novel recombinant fusion protein, sTRAIL-TMTP1. sTRAIL-TMTP1 not only induce apoptosis in cancer cells but inhibit tumor growth and metastasis. sTRAIL-TMTP1 showed an impact on caspase activity and tumor angiogenesis. sTRAIL-TMTP1's accumulate in tumor with little accumulation in normal organs.