Transfection of beta 4 integrin subunit into a neoplastic keratinocyte line fails to restore terminal differentiation capacity or influence proliferation.
Loss of expression of specific integrins is a feature of poorly differentiated oral squamous cell carcinomas (SCCs) and cell lines derived from them. In order to test whether there is a direct link between reduced alpha 6 beta 4 integrin expression and abnormal keratinocyte growth and differentiation we 'repaired' an SCC line. H376, by transfection of the beta 4 integrin subunit. We analysed five independent beta 4 transfectant clones and compared them with four empty vector control clones and with the parental cell line. Elevated cell surface expression of alpha 6 beta 4 was not correlated with changes in anchorage dependent or independent growth and was not sufficient to induce expression of the terminal differentiation marker, involucrin. Introduction of the beta 4 integrin subunit did not have a major effect on cell adhesion to laminin 1 or 5 and did not result in formation of stable anchoring contacts. We conclude that loss of alpha 6 beta 4 is not directly responsible for the abnormal behaviour of the H376 cell line.
Jones
J
J
Keratinocyte Laboratory, Imperial Cancer Research Fund, London.
Sugiyama
M
M
Giancotti
F
F
Speight
P M
PM
Watt
F M
FM
D015703:Antigens, CD / Q000235:genetics*; D000954:Antigens, Surface / Q000096:biosynthesis*; D002294:Carcinoma, Squamous Cell / Q000503:physiopathology*; D002448:Cell Adhesion; D002454:Cell Differentiation; D002455:Cell Division; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D015151:Immunoblotting; D039161:Integrin alpha6beta4; D039663:Integrin beta4; D016023:Integrins / Q000096:biosynthesis*; D009062:Mouth Neoplasms / Q000503:physiopathology*; D014162:Transfection
D015703:Antigens, CD; D000954:Antigens, Surface; D039161:Integrin alpha6beta4; D039663:Integrin beta4; D016023:Integrins