title: Chemotrap-1: an engineered soluble receptor that blocks chemokine-induced migration of metastatic cancer cells in vivo.
abstract: Cancer and dendritic cells recognize and migrate toward chemokines secreted from lymphatics and use this mechanism to invade the lymphatic system, and cancer cells metastasize through it. The lymphatic-secreted chemokine ligand CCL21 has been identified as a key regulatory molecule in the switch to a metastatic phenotype in melanoma and breast cancer cells. However, it is not known whether CCL21 inhibition is a potential therapeutic strategy for inhibition of metastasis. Here, we describe an engineered CCL21-soluble inhibitor, Chemotrap-1, which inhibits migration of metastatic melanoma cells in vivo. Two-hybrid, pull-down, and coimmunoprecipitation assays allowed us to identify a naturally occurring human zinc finger protein with CCL21 chemokine-binding properties. Further analyses revealed a short peptide (∼70 amino acids), with a predicted coiled-coil structure, which is sufficient for association with CCL21. This CCL21 chemokine-binding peptide was then fused to the Fc region of human IgG1 to generate Chemotrap-1, a human chemokine-binding Fc fusion protein. Surface plasmon resonance and chemotaxis assays showed that Chemotrap-1 binds CCL21 and inhibits CCL21-induced migration of melanoma cells in vitro with subnanomolar affinity. In addition, Chemotrap-1 blocked migration of melanoma cells toward lymphatic endothelial cells in vitro and in vivo. Finally, Chemotrap-1 strongly reduced lymphatic invasion, tracking, and metastasis of CCR7-expressing melanoma cells in vivo. Together, these results show that CCL21 chemokine inhibition by Chemotrap-1 is a potential therapeutic strategy for metastasis and provide further support for the hypothesis that lymphatic-mediated metastasis is a chemokine-dependent process.
authors.affiliation: Microvascular Research Laboratories, Bristol Heart Institute, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Bristol, United Kingdom.
authors.forename: Silvia
authors.initials: S
authors.lastname: Lanati
authors.forename: Darryl B
authors.initials: DB
authors.lastname: Dunn
authors.forename: Myriam
authors.initials: M
authors.lastname: Roussigné
authors.forename: Maxine S
authors.initials: MS
authors.lastname: Emmett
authors.forename: Virginie
authors.initials: V
authors.lastname: Carriere
authors.forename: Denis
authors.initials: D
authors.lastname: Jullien
authors.forename: Jessica
authors.initials: J
authors.lastname: Budge
authors.forename: Justin
authors.initials: J
authors.lastname: Fryer
authors.forename: Monique
authors.initials: M
authors.lastname: Erard
authors.forename: Françoise
authors.initials: F
authors.lastname: Cailler
authors.forename: Jean-Phillippe
authors.initials: JP
authors.lastname: Girard
authors.forename: David O
authors.initials: DO
authors.lastname: Bates
mesh_terms: D001665:Binding Sites; D002465:Cell Movement; D018932:Chemokine CCL2 / Q000378:metabolism; D054421:Chemokine CCL21 / Q000235:genetics / Q000378:metabolism; D018925:Chemokines / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002633:Chemotaxis / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay; D005822:Genetic Vectors / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000378:metabolism*; D008207:Lymphatic Metastasis / Q000517:prevention & control; D008545:Melanoma / Q000378:metabolism / Q000473:pathology*; D009369:Neoplasms / Q000473:pathology; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000378:metabolism / Q000494:pharmacology*
chemical_list: C515478:CCL21 protein, human; D018932:Chemokine CCL2; D054421:Chemokine CCL21; D018925:Chemokines; D007141:Immunoglobulin Fc Fragments; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase