Obtaining a Multi-Target Fusion Protein Based on the Antitumor Cytokine Trail-DRS-B

The cytokine TRAIL is distinguished by its remarkable ability to preferentially induce apoptosis in transformed but not normal cells. Clinical trials of the recombinant extracellular domain of TRAIL and other first-generation DR4 and DRS death receptor agonists have shown very limited antitumor activity in patients. To enhance the antitumor effect, in this work we developed a multitarget recombinant fusion protein SRH-DRS-B-p48 based on the DRS-selective variant of the cytokine TRAIL-DRS-B for simultaneously effect on tumor cells (DR5-B-mediated apoptosis) and the tumor microenvironment, in particular, to suppress angiogenesis. For this purpose, a recombinant SRH-DRS-B-p48 fusion protein with antagonistic synthetic peptides (SRH and p48) to the VEGFR2 and FGFR1 receptors was modeled and produced. Interaction analysis of molecular trajectories in molecular dynamics showed that the SRH and p48 peptides form non-specific temporary contacts with the DRS-B domain. Using enzyme-linked immunosorbent assay, we showed that SRH-DRS-B-p48 was similar to DRS-B in its affinity for the death receptor DRS, and showed high affinity for VEGFR2 and FGFR1 with a dissociation constant in the nanomolar range. SRH-DRS-B-p48 killed tumor cells of various origin more effectively than DRS-B, and effectively destroyed tumor-like structures in 3D cell models. In addition, the fusion protein inhibited FGF2-mediated stimulation of fibroblast proliferation. Thus, the SRH-DRS-B-p48 fusion can be considered as a promising agent for the therapy of solid tumors of various origin.