This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by DiStefano, J. F. Articles by Hagag, N. Search for Related Content PubMed PubMed Citation Articles by DiStefano, J. F. Articles by Hagag, N.

Role of Epidermal Growth Factor in the Expression of A431 Cancer Cell Protease and Red Blood Cell Cytotoxicity¹

Departments of Research [J. F. D., C. A. C.], Medicine [J. F. D.], and Laboratory Service [B. L.], Veterans Administration Medical Center, Northport, New York 11768, and Department of Medicine, Division of Oncology [J. F. D., N. H.], and Department of Pathology [B. L.], State University of New York at Stony Brook, Stony Brook, New York 11794

The role of epidermal growth factor in the regulation of the proteolytic and RBC cytolytic activity of the A431 cancer cell line has been evaluated using our previously described gelatin/polyacrylamide electrophoretic assay and tumor-induced RBC cytolysis assay, respectively. A431 cells maintained in 10% fetal bovine serum were actively cytolytic for RBC (release index, 53.0 ± 2.9%), whereas serum-starved cells maintained in serum-free medium were not cytolytic for RBC. RBC cytotoxicity was restored by adding as little as 3.4 pM epidermal growth factor to the serum-deprived cells. The RBC cytolytic stimulating activity of epidermal growth factor could be mimicked by the metal chelating agent 1,10-phenanthroline, suggesting a possible role for calcium ions in the action of epidermal growth factor and proteases. An enriched cell membrane preparation of A431 cells was also cytolytic for RBC but was unaffected by metal chelating agents. RBC-induced cytotoxicity was inhibited by the protease inhibitor leupeptin. Gelatin substrate gels of enriched A431 cell membrane preparations and serum-free supernatants revealed a pattern of high- and low-molecular-weight proteases that were stimulated by metal chelators and inhibited by leupeptin. The activity of these proteases appears to be regulated by epidermal growth factor by a process that may involve divalent cations.

¹ This research was supported by the Veterans Administration.

² Recipient of a Veterans Administration Career Development Award. To whom requests for reprints should be addressed, at Research Building 61, Northport Veterans Administration Medical Center, Northport, NY 11768.

Received 2/29/88. Revised 9/26/88. Accepted 10/ 4/88.