title: Truncation of activated leukocyte cell adhesion molecule: a gateway to melanoma metastasis.
abstract: Progression of human cutaneous primary melanoma is, among others, accompanied by de novo expression of activated leukocyte cell adhesion molecule (ALCAM/CD166) and enhanced activity of proteolytic cascades in the invasive, vertical growth phase (VGP) of lesions. The homophilic cell adhesion function of wild-type ALCAM mediates homotypic clustering of melanoma cells and would, thus, antagonize cell release from the primary tumor, an early prerequisite for metastasis. Stable transfection of a transmembrane, amino-terminally truncated ALCAM (DeltaN-ALCAM) into metastatic cells diminished cell clustering mediated by wild-type ALCAM. We have addressed the biological effects of DeltaN-ALCAM on tumorigenicity and found that the relief of cell clustering constraints promoted motility in vitro and the transition from expansive tumor growth to tissue invasion in reconstructed skin in culture. In a transplant tumor model, the changes were reflected in reduced subcutaneous tumor growth and in accelerated, spontaneous lung metastasis. These data indicate that the intact cell adhesion function of ALCAM may both favor primary tumor growth and represent a rate-limiting step for tissue invasion from VGP melanoma. ALCAM induction could, thus, provide an attractive target for proteolysis as a part of a more complex cellular program that couples growth and migration and facilitates dissemination.
authors.affiliation: Department of Biochemistry-NCMLS, University of Nijmegen, Nijmegen, The Netherlands.
authors.forename: Léon C L T
authors.initials: LC
authors.lastname: van Kempen
authors.forename: Friedegund
authors.initials: F
authors.lastname: Meier
authors.forename: Mikala
authors.initials: M
authors.lastname: Egeblad
authors.forename: Monique J F
authors.initials: MJ
authors.lastname: Kersten-Niessen
authors.forename: Claus
authors.initials: C
authors.lastname: Garbe
authors.forename: Ulrich H
authors.initials: UH
authors.lastname: Weidle
authors.forename: Goos N P
authors.initials: GN
authors.lastname: Van Muijen
authors.forename: Meenhard
authors.initials: M
authors.lastname: Herlyn
authors.forename: Henri P J
authors.initials: HP
authors.lastname: Bloemers
authors.forename: Guido W M
authors.initials: GW
authors.lastname: Swart
mesh_terms: D020410:Activated-Leukocyte Cell Adhesion Molecule / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary; D008545:Melanoma / Q000378:metabolism* / Q000503:physiopathology / Q000556:secondary; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D014162:Transfection; D014183:Transplantation, Heterologous
chemical_list: D020410:Activated-Leukocyte Cell Adhesion Molecule