title: CD24 expression causes the acquisition of multiple cellular properties associated with tumor growth and metastasis.
abstract: The glycosylphosphatidylinositol-anchored membrane protein CD24 functions as an adhesion molecule for P-selectin and L1 and plays a role in B-cell development and neurogenesis. Over the last few years, a large body of literature has also implicated CD24 expression in tumorigenesis and progression. Here, we show that ectopic CD24 expression can be sufficient to promote tumor metastasis in experimental animals. By developing a doxycycline-inducible system for the expression of CD24 in breast cancer cells, we have also analyzed the cellular properties that CD24 expression influences. We found that CD24 expression increased tumor cell proliferation. Furthermore, in addition to promoting binding to P-selectin, CD24 expression also indirectly stimulated cell adhesion to fibronectin, collagens I and IV, and laminin through the activation of alpha3beta1 and alpha4beta1 integrin activity. Moreover, CD24 expression supported rapid cell spreading and strongly induced cell motility and invasion. CD24-induced proliferation and motility were integrin independent. Together, these observations implicate CD24 in the regulation of multiple cell properties of direct relevance to tumor growth and metastasis.
authors.affiliation: Forschungszentrum Karlsruhe, Institut für Toxikologie und Genetik, Karlsruhe, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Baumann
authors.forename: Natascha
authors.initials: N
authors.lastname: Cremers
authors.forename: Frans
authors.initials: F
authors.lastname: Kroese
authors.forename: Gertraud
authors.initials: G
authors.lastname: Orend
authors.forename: Ruth
authors.initials: R
authors.lastname: Chiquet-Ehrismann
authors.forename: Toshi
authors.initials: T
authors.lastname: Uede
authors.forename: Hideo
authors.initials: H
authors.lastname: Yagita
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Sleeman
mesh_terms: D000818:Animals; D051927:CD24 Antigen / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D008325:Mammary Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D051381:Rats; D011916:Rats, Inbred F344; D014162:Transfection
chemical_list: D051927:CD24 Antigen; D005353:Fibronectins