Expression of Fas Antigen and Its Mediation of Apoptosis in Human Gastric Cancer Cell Lines

Abstract

Fas, a member of the tumor necrosis factor receptor/nerve growth factor receptor family, induces apoptosis by crosslinking with Fas ligand or anti‐Fas antibody in a variety of cultured cells. We examined the expression of Fas antigen and its mediation of apoptosis in six human gastric carcinoma cell lines. Flow cytometric analysis and western blotting revealed relatively high expression of Fas antigen in MKN‐74 (wild‐type p53 gene) and MKN‐45 (wild‐type), followed by MKN‐1 (mutated), MKN‐7 (mutated) and KATO‐III (deleted). MKN‐28 (mutated) showed minimal expression of the antigen. The expression was apparently enhanced by interferon‐γ, except for MKN‐1 and MKN‐28. Anti‐Fas antibody (100 ng/ml) induced nuclear fragmentation characteristic of apoptosis. Apoptosis occurred in a delayed fashion and the apoptotic index at 72 h was approximately 60% in MKN‐74, 35% in MKN‐45, and 20% in MKN‐1 and KATO‐III. A DNA ladder was noted in MKN‐74 at 72 h. Expression levels of P53 and P21Wafl did not change for up to 48 h in MKN‐74. The biological effects did not correlate with endogenous Bcl‐2 expression. These results indicated that a) Fas antigen is variably expressed in human cultured gastric carcinoma cells, b) the protein transduces an apoptotic signal which leads to delayed cell death, and c) susceptibility to the antibody correlates well with the expression level of Fas antigen.

Expression of Fas and Fas ligand in human gastric adenomas and intestinal-type carcinomas: correlation with proliferation and apoptosis

“…Western blot analysis showed that only one antibody for Fas or FasL detected single bands of about 45 and 37 kDa, corresponding to Fas and FasL, respectively. Moreover, Fas and FasL expressions were variable among the human gastric carcinoma cell lines we tested, and minimal expression of Fas was noted in MKN-28, which has been shown to be resistant to antiFas antibody-induced apoptosis [21]. Thus, it is unequivocal that Fas and FasL are expressed in human gastric tumors, although their actual roles and biological significance are largely unknown.…”

“…SDS-PAGE and Western blot analysis were performed as described previously [21]. To evaluate the specificity of antibodies against human Fas and FasL, one polyclonal and two monoclonal anti-Fas antibodies and one polyclonal and three monoclonal anti-FasL antibodies were used.…”

Modulation of apoptosis by endogenous Bcl-xL expression in MKN-45 human gastric cancer cells

“…Fas is a 45 kDa cell surface proteins that mediates apoptosis in a variety of cell types (Trauth et al, 1989;Yonehara et al, 1989;Itoh et al, 1991;Oehm et al, 1992;Ogasawara et al, 1993). Fas is expressed by several tumor, including gastric cancers (Hayashi et al, 1997). Western blot analysis demonstrated intense expression of Fas antigen in MKN-45 gastric cancer cells.…”

Enhanced Disease Severity inHelicobacter pylori-Infected Mice Deficient in Fas Signaling

“…Differential expression of the Fas receptor is detected both in cell lines derived from human gastric cancers (12) and in gastric carcinoma tissue specimens (36). Bennett et al (2) detected enhanced Fas ligand expression in 30 gastric carcinomas and suggested that expression of Fas ligand allows gastric cancers to escape immune surveillance by inducing cell death in infiltrating lymphocytes.…”