title: Anti-Fas antibody-induced apoptosis in human colorectal carcinoma cell lines: role of the p53 gene.
abstract: The cell surface Fas antigen transducts an apoptotic signal by its crosslinking with Fas ligand or anti-Fas antibody in a variety of human cultured cells. In this study, we examined the expression of Fas antigen and its mediation of apoptosis in six human colorectal carcinoma cell lines. A flow cytometric analysis revealed that LoVo, DLD-1, WiDr and SW837 cell lines showed higher expression levels of Fas antigen, in contrast to lower expression in COLO201 and COLO320DM. Interferon-gamma enhanced the expression of Fas antigen in all of the cell lines examined. Both Fas ligand and Fas-associated phosphatase-1 (FAP-1) were expressed only in COLO320DM. Anti-Fas antibody induced apoptosis in LoVo carrying wild-type p53 gene, but not in the other five cell lines carrying mutated p53 gene. The transfection of wild-type p53 gene using an adenovirus vector upregulated P53 protein in WiDr and SW837 cells, both of which showed, however, no increase in apoptotic cells by anti-Fas antibody treatment. These results indicated that (1) Fas antigen was variably expressed, regardless of the p53 gene status and (2) the susceptibility to anti-Fas antibody-mediated apoptosis did not correlate to Fas, Fas ligand or FAP-1 expression levels. Therefore, we conclude that wild-type P53 expression might not necessarily be essential for Fas-mediated apoptosis in human colorectal carcinoma cell lines.
authors.affiliation: First Department of Pathology, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hayashi
authors.forename: S
authors.initials: S
authors.lastname: Tatebe
authors.forename: M
authors.initials: M
authors.lastname: Osaki
authors.forename: A
authors.initials: A
authors.lastname: Goto
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Ito