A Novel Recombinant Soluble Splice Variant of Met Is a Potent Antagonist of the Hepatocyte Growth Factor/Scatter Factor-Met Pathway

Abstract

Purpose: The Met receptor tyrosine kinase and its ligand, hepatocyte growth factor/scatter factor (HGF/SF), are involved in a wide range of biological activities, including cell proliferation, motility, invasion, and angiogenesis. The HGF/SF-Met signaling pathway is frequently activated in a variety of cancers, and uncontrolled Met activation correlates with highly invasive tumors and poor prognosis. In this study, we investigated the inhibitory effect of a novel soluble splice variant of Met on the HGF/SF-Met pathway. Experimental Design: Using our alternative splicing modeling platform LEADS, we have identified a novel splice variant of the Met receptor, which encodes a truncated soluble form of the receptor. This variant was produced as a recombinant Fc-fused protein named Cgen-241A and was tested in various cell-based assays representing different outcomes of the HGF/SF-Met pathway. Results: Cgen-241A significantly inhibited HGF/SF-induced Met phosphorylation as well as cell proliferation and survival. In addition, Cgen-241A showed a profound inhibitory effect on cell scattering, invasion, and urokinase up-regulation. The inhibitory effects of Cgen-241A were shown in multiple human and nonhuman cell types, representing different modes of Met activation. Furthermore, Cgen-241A showed direct binding to HGF/SF. Conclusions: Taken together, our results indicate that Cgen-241A is a potent antagonist of the HGF/SF-Met pathway, underlining its potential as a therapeutic agent for the treatment of a wide variety of human malignancies that are dependent on this pathway.

Soluble c‐Met protein as a susceptible biomarker for gastric cancer risk: A nested case‐control study within the Korean Multicenter Cancer Cohort

“…Other preclinical studies demonstrated that the generated soluble truncated c-Met can (1) inhibit c-Met activation as induced in an HGF ligand-dependent as well as independent manner; (2) interrupt c-Met/HGF signaling by rejecting the formation of the active homodimers required for the signaling and (3) finally exhibit its potential as a therapeutic agent for anti-carcinogenic substances. 6,18,20,21 Our findings add to the evidence that the soluble form of c-Met protein naturally produced by proteolysis or amino acid translation in the human body has a consistently protective effect against the development of gastric cancer, thus supporting the anti-tumor potential of the soluble truncated cMet protein.…”

“…Recent studies also reported that c-Met/ HGF signaling induces aberrant cellular activities such as cell proliferation, motility, disassociation and morphological change, which can be effectively blocked by the antagonistic fragment of HGF/SF (NK4) [15][16][17] or by c-Met decoys, referring to the soluble truncated form of c-Met. [18][19][20] The soluble truncated form of c-Met competitively binds to HGF instead 3 Gastric cancer cases who diagnosed between 2 and 9 years from cohort enrollment. 4 Gastric cancer cases who diagnosed within 1 year from cohort enrollment.…”

Nonclinical Evaluation of the Serum Pharmacodynamic Biomarkers HGF and Shed MET following Dosing with the Anti-MET Monovalent Monoclonal Antibody Onartuzumab

“…High circulating HGF levels are frequently observed in multiple myeloma, however, low sMET levels were found to correlate with worse outcome in this disease (33). Pathway suppression by sMET is supported by studies in which recombinant MET-ECD was capable of inhibiting HGF-dependent activation of MET-expressing tumor cell lines (19) and had antitumor efficacy as a MET-ECD-Fc fusion protein in animal tumor models (20). Although these results suggest that sMET can act as a negative regulator by sequestering HGF, it is important to distinguish between recombinant MET ECDs and circulating endogenous sMET, which may have different properties, especially considering that the exact cleavage site(s) of sMET have yet to be described.…”

“…Several therapeutics that specifically inhibit MET signaling are currently in development (17)(18)(19)(20)(21)(22). Onartuzumab (MetMAb) is a monovalent monoclonal antibody that binds to the semaphorin (Sema) domain of MET in which it inhibits HGF binding and subsequent MET activation (23) and has demonstrated efficacy in multiple liganddriven mouse xenograft models (23)(24)(25).…”

Inhibition of MSP-RON signaling pathway in cancer cells by a novel soluble form of RON comprising the entire sema sequence

“…Nevertheless, the existence of these untranslated transcripts provides opportunities to study if they possess regulatory activities after recombinant expression. Unique RTK variants derived from cancer cells have been shown to have therapeutic effect in various tumor models (29)(30)(31). Thus, identification of RONΔ85 with antagonistic activities opens an avenue for the development of potential therapeutics for targeted cancer therapy.…”