gms | German Medical Science

27. Deutscher Krebskongress

Deutsche Krebsgesellschaft e. V.

22. - 26.03.2006, Berlin

Alterations in the expression and increased shedding of collagen XVII in genetically generated oral-esophageal cancer cells

Meeting Abstract

  • corresponding author presenting/speaker Heike Kunert - Institute for Molecular Medicine and Cell Research, University of Freiburg, Deutschland
  • Claus Franzke - Dermatology Department, University of Freiburg
  • Michaela Doebele - Department of Medicine, University of Freiburg
  • Steffen Heeg - Department of Medicine, University of Freiburg
  • Sarah Hauß - Institute for Molecular Medicine and Cell Research, University of Freiburg
  • Gitta Goessel - Department of Medicine, University of Freiburg
  • Christoph Peters - Institute for Molecular Medicine and Cell Research, University of Freiburg
  • Hubert E. Blum - Department of Medicine, University of Freiburg
  • Oliver G. Opitz - Institute for Molecular Medicine and Cell Research, University of Freiburg

27. Deutscher Krebskongress. Berlin, 22.-26.03.2006. Düsseldorf, Köln: German Medical Science; 2006. DocOP407

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Veröffentlicht: 20. März 2006

© 2006 Kunert et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Introduction: The ability of a tumor cell to migrate across the extracellular matrix (ECM) is a prerequisite for metastasis. In our cellular model of human oral-esophageal carcinogenesis we were able to recapitulate tumor development in a stepwise fashion. Cyclin D1 overexpression and p53 inactivation led to immortalization, additional EGFR overexpression induced an in vitro transformed phenotype whereas additional c-myc overexpression resulted in invasive cancer cells. To study the ability of these different cells to migrate, we were interested in the expression and localization of the type II transmembrane protein collagen XVII, thought to be involved in metastasis. Collagen XVII is a hemidesmosomal epithelial adhesion protein, mediating the adhesion of cells to ECM. Its extracellular ectodomain can be proteolytically shed from the cell surface. This results in a loss of epithelial adhesion to the ECM and probably allows cells to migrate.

Methods: Collagen XVII expression was assayed in immortalized oral keratinocytes (OKF6D1/d.n.p53), in in vitro transformed OKF6D1/d.n.p53/EGFR and in malignant transformed OKF6D1/d.n.p53/EGFR/c-myc cells by RT-PCR and western blot analysis. The distribution of collagen XVII in those cells was studied by immunofluorescence. Furthermore, we analyzed the shedding of the collagen XVII ectodomain by western blot of the cell culture medium.

Results: RT-PCR revealed a downregulation of collagen XVII expression in transformed cells followed by an upregulation in cancer cells. Immunofluorescence demonstrated that collagen XVII is localized to the cell membrane in immortalized cells. In OKF6D1/d.n.p53/EGFR cells collagen XVII is translocated to the cytoplasm, whereas collagen XVII is relocated to the cell membrane in the OKF6D1/d.n.p53/EGFR/c-myc cells. Western blot analysis of the cell culture medium revealed an increased shedding of the collagen XVII ectodomain in the generated cancer cells overexpressing c-myc.

Conclusions: In our human cellular model of oral-esophageal carcinogenesis we demonstrated that collagen XVII is differentially expressed during carcinogenesis, being downregulated in in vitro transformed cells and upregulated in cancer cells. Additionally, cellular localization changed during these distinct steps of tumor development. Finally, shedding of the collagen XVII ectodomain is increased in cancer cells potentially allowing fully transformed cells to migrate through the extracellular matrix and to metastasize.