Development of Protein-Based Biotherapeutics That Penetrates Cell-Membrane and Induces Anti-Angiogenic Effect - Improved Cell-Permeable Suppressor of Cytokine Signaling (iCP-SOCS3) Proteins, Polynucleotides Encoding the Same, and Anti-Angiogenic Compositions Comprising the Same

摘要

In principle, protein-based biotherapeutics offers a way to control biochemical processes in living cells under non-steady state conditions and with fewer off-target effects than conventional small molecule therapeutics. However, systemic protein delivery in vivo has been proven difficult due to poor tissue penetration and rapid clearance. Protein transduction exploits the ability of some cell-penetrating peptide (CPP) sequences to enhance the uptake of proteins and other macromolecules by mammalian cells. Previously developed hydrophobic CPPs—named membrane translocating sequence (MTS), membrane translocating motif (MTM) and macromolecule transduction domain (MTD)—are able to deliver biologically active proteins into a variety of cells and tissues. Various cargo proteins fused to these CPPs have been used to test the functional and/or therapeutic efficacy of protein transduction. Previously, recombinant proteins consisting of suppressor of cytokine signaling 3 (SOSC3) fused to the fibroblast growth factor (FGF) 4-derived MTM were developed to inhibit inflammation and apoptosis. However, this SOCS3 fusion proteins expressed in bacteria cells were hard to be purified in soluble form. To address these critical limitations, CPP sequences called advanced MTDs (aMTDs) have been developed in this art. The development of this art has been accomplished by (i) analyzing previous developed hydrophobic CPP sequences to identify specific critical factors (CFs) that affect intracellular delivery potential and (ii) constructing artificial aMTD sequences that satisfy each critical factor. Furthermore, solubilization domains (SDs) have been incorporated into the aMTD-fused SOCS3 recombinant proteins to enhance solubility with corresponding increases in protein yield and cell-/tissue-permeability. These recombinant SOCS3 proteins fused to aMTD/SD having much higher solubility/yield and cell-/tissue-permeability have been named as improved cell-permeable SOCS3 (iCP-SOCS3) proteins. Previously developed SOCS3 recombinant proteins fused to MTM were only tested or used as anti-inflammatory agents to treat acute liver injury. In the present art, iCP-SOCS3 proteins have been tested for use as anti-angiogenic agents. Since SOCS3 is known to be an endogenous inhibitor of pathological angiogenesis, we reasoned that iCP-SOCS3 could be used as a protein-based intracellular replacement therapy for inhibiting angiogenesis in tumor cells. The results demonstrated in this art support this following reasoning: Cancer treatment with iCP-SOCS3 results in reduced endothelial cell viability, loss of cell migration potential and suppressed vascular sprouting potentials. In the present invention with iCP-SOCS3, where SOCS3 is fused to an empirically determined combination of newly developed aMTD and customized SD, macromolecule intracellular transduction technology (MITT) enabled by the advanced MTDs may provide novel protein therapy against cancer cell-mediated angiogenesis.