The metalloproteinase ADAM-12 regulates bronchial epithelial cell proliferation and apoptosis.
OBJECTIVE
The ADAMs (a disintegrin and metalloproteinase) enzymes compose a family of membrane-bound proteins characterized by their multi-domain structure and ADAM-12 expression is elevated in human non-small cell lung cancers. The aim of this study was to investigate the roles played by ADAM-12 in critical steps of bronchial cell transformation during carcinogenesis.


METHODS
To assess the role of ADAM-12 in tumorigenicity, BEAS-2B cells were transfected with a plasmid encoding human full-length ADAM-12 cDNA, and then the effects of ADAM-12 overexpression on cell behaviour were explored. Treatment of clones with heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) neutralizing antibodies as well as an EGFR inhibitor allowed the dissection of mechanisms regulating cell proliferation and apoptosis.


RESULTS
Overexpression of ADAM-12 in BEAS-2B cells promoted cell proliferation. ADAM-12 overexpressing clones produced higher quantities of HB-EGF in their culture medium which may rely on membrane-bound HB-EGF shedding by ADAM-12. Targeting HB-EGF activity with a neutralizing antibody abrogated enhanced cell proliferation in the ADAM-12 overexpressing clones. In sharp contrast, targeting of amphiregulin, EGF or transforming growth factor-alpha failed to influence cell proliferation; moreover, ADAM-12 transfectants were resistant to etoposide-induced apoptosis and the use of a neutralizing antibody against HB-EGF activity restored rates of apoptosis to be similar to controls.


CONCLUSIONS
ADAM-12 contributes to enhancing HB-EGF shedding from plasma membranes leading to increased cell proliferation and reduced apoptosis in this bronchial epithelial cell line.
Rocks
N
N
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Estrella
C
C
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Paulissen
G
G
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Quesada-Calvo
F
F
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Gilles
C
C
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Guéders
M M
MM
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Crahay
C
C
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Foidart
J-M
JM
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Gosset
P
P
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Noel
A
A
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
Cataldo
D D
DD
Laboratory of Tumor and Development Biology, GIGA-Research (Groupe Interdisciplinaire de Génoprotéomique Appliquée) and Center for Experimental Cancer Research (CECR), University of Liège and CHU of Liège, Belgium, andUnité INSERM U774, Institut Pasteur de Lille, Lille, France.
D051722:ADAM Proteins / Q000378:metabolism*; D000072199:ADAM12 Protein; D000818:Animals; D017209:Apoptosis; D001980:Bronchi / Q000166:cytology*; D002460:Cell Line; D002465:Cell Movement; D049109:Cell Proliferation; D002999:Clone Cells; D004847:Epithelial Cells / Q000166:cytology* / Q000201:enzymology*; D066257:Heparin-binding EGF-like Growth Factor; D006801:Humans; D020287:In Situ Nick-End Labeling; D007279:Injections, Subcutaneous; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D016513:Mice, SCID; D009361:Neoplasm Invasiveness; D014162:Transfection
C587883:HBEGF protein, human; C587884:Hbegf protein, mouse; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D051722:ADAM Proteins; D000072199:ADAM12 Protein; C000606480:ADAM12 protein, human