title: Inhibition of ron kinase blocks conversion of micrometastases to overt metastases by boosting antitumor immunity.
abstract: Many "nonmetastatic" cancers have spawned undetectable metastases before diagnosis. Eventual outgrowth of these microscopic lesions causes metastatic relapse and death, yet the events that dictate when and how micrometastases convert to overt metastases are largely unknown. We report that macrophage-stimulating protein and its receptor, Ron, are key mediators in conversion of micrometastases to bona fide metastatic lesions through immune suppression. Genetic deletion of Ron tyrosine kinase activity specifically in the host profoundly blocked metastasis. Our data show that loss of Ron function promotes an effective antitumor CD8(+) T-cell response, which specifically inhibits outgrowth of seeded metastatic colonies. Treatment of mice with a Ron-selective kinase inhibitor prevented outgrowth of lung metastasis, even when administered after micrometastatic colonies had already been established. Our findings indicate that Ron inhibitors may hold potential to specifically prevent outgrowth of micrometastases in patients with cancer in the adjuvant setting.
authors.affiliation: Department of Oncological Sciences, Huntsman Cancer Institute, Salt Lake City, UT 84112, USA.
authors.forename: Henok
authors.initials: H
authors.lastname: Eyob
authors.forename: Huseyin Atakan
authors.initials: HA
authors.lastname: Ekiz
authors.forename: Yoko S
authors.initials: YS
authors.lastname: Derose
authors.forename: Susan E
authors.initials: SE
authors.lastname: Waltz
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Williams
authors.forename: Alana L
authors.initials: AL
authors.lastname: Welm
mesh_terms: D000818:Animals; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007109:Immunity / Q000235:genetics*; D051379:Mice; D061206:Neoplasm Micrometastasis / Q000235:genetics* / Q000473:pathology; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D047428:Protein Kinase Inhibitors; C080835:RON protein; D020794:Receptor Protein-Tyrosine Kinases