Four individually druggable MET hotspots mediate HGF-driven tumor progression
Cristina Basilico, Anna Hultberg, Christophe Blanchetot, Natalie de Jonge, Els Festjens, Valérie Hanssens, Sjudry-Ilona Osepa, Gitte De Boeck, Alessia Mira, Manuela Cazzanti, Virginia Morello, Torsten Dreier, Michael Saunders, Hans de Haard, Paolo Michieli
Cristina Basilico, Anna Hultberg, Christophe Blanchetot, Natalie de Jonge, Els Festjens, Valérie Hanssens, Sjudry-Ilona Osepa, Gitte De Boeck, Alessia Mira, Manuela Cazzanti, Virginia Morello, Torsten Dreier, Michael Saunders, Hans de Haard, Paolo Michieli
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Research Article Oncology

Four individually druggable MET hotspots mediate HGF-driven tumor progression

Abstract

Activation of MET by HGF plays a key role in tumor progression. Using a recently developed llama platform that generates human-like immunoglobulins, we selected 68 different antibodies that compete with HGF for binding to MET. HGF-competing antibodies recognized 4 distinct hotspots localized in different MET domains. We identified 1 hotspot that coincides with the known HGF β chain binding site on blades 2–3 of the SEMA domain β-propeller. We determined that a second and a third hotspot lie within blade 5 of the SEMA domain and IPT domains 2–3, both of which are thought to bind to HGF α chain. Characterization of the fourth hotspot revealed a region across the PSI-IPT 1 domains not previously associated with HGF binding. Individual or combined targeting of these hotspots effectively interrupted HGF/MET signaling in multiple cell-based biochemical and biological assays. Selected antibodies directed against SEMA blades 2–3 and the PSI-IPT 1 region inhibited brain invasion and prolonged survival in a glioblastoma multiforme model, prevented metastatic disease following neoadjuvant therapy in a triple-negative mammary carcinoma model, and suppressed cancer cell dissemination to the liver in a KRAS-mutant metastatic colorectal cancer model. These results identify multiple regions of MET responsible for HGF-mediated tumor progression, unraveling the complexity of HGF-MET interaction, and provide selective molecular tools for targeting MET activity in cancer.

Authors

Cristina Basilico, Anna Hultberg, Christophe Blanchetot, Natalie de Jonge, Els Festjens, Valérie Hanssens, Sjudry-Ilona Osepa, Gitte De Boeck, Alessia Mira, Manuela Cazzanti, Virginia Morello, Torsten Dreier, Michael Saunders, Hans de Haard, Paolo Michieli

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Figure 11

Neoadjuvant therapy with anti-MET mAbs reduces metastasis dissemination in a mouse model of orthotopic mammary carcinoma.

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Neoadjuvant therapy with anti-MET mAbs reduces metastasis dissemination ...
Luciferase-expressing MDA-MB-231 human triple-negative mammary carcinoma cells were injected bilaterally into the mammary fat pad of immunodeficient NOD-SCID mice along with HGF-secreting, immortalized human mammary fibroblasts. Mice were stratified on the basis of tumor volume and randomly assigned to 5 different treatment groups (irrelevant IgG1, 10 mg/kg; WT52, 10 mg/kg; WT46, 10 mg/kg; a combination of WT52 and WT46, 5 + 5 mg/kg; JNJ-38877605, 20 mg/kg; n = 6). Antibodies were administered twice weekly by i.p. injection; JNJ-38877605 was administered daily by oral gavage. Tumor volume was followed over time by caliper measurement. After 4 weeks of treatment, tumors were surgically removed, and neoadjuvant therapy was interrupted. Two weeks after surgery, mice were injected with luciferin, sacrificed, and subjected to autopsy. Metastatic dissemination was determined by bioluminescence analysis of isolated organs. (A) Analysis of tumor volume over time. Statistical significance was calculated by a Student’s t test (n = 12). (B) Bioluminescence analysis of isolated lungs at autopsy. Red bars indicate average values. Statistical significance was determined as in A (n = 6). (C) Representative images of lung sections stained with H&E. Original magnification, ×100. The data shown are derived from a representative experiment. An analogous experiment conducted with 5 mice per group generated overlapping results.