RESUMO
BACKGROUND & OBJECTIVE: Fas, a death factor, can induce apoptotic death of cells. Many malignant tumor cells expressed Fas can not develop apoptotic death, this may be because of low Fas expression. Therefore we investigate the relationship between expression level of Fas and anti-Fas biological responsiveness. METHODS: With direct immunofluorescence flow cytometry, the expression of Fas was detected in bladder carcinoma cell line EJ, TNF alpha treated EJ, and Fas gene transfected EJ. The three kinds of EJ cells died by apoptosis were induced with anti-Fas antibody DX2 IgG1K and determined by SCGE and flow cytometry (FCM). RESULTS: Expression of Fas in bladder carcinoma cell line EJ, TNF alpha treated EJ, and Fas gene transfected EJ was 19.18%, 28.03%, and 68.69%, respectively. Cellular apoptosis induced with anti-Fas antibody DX2 IgG1K in bladder carcinoma cell line EJ was least, in TNF alpha treated EJ moderate, and in Fas gene transfected EJ the most. CONCLUSIONS: Fas gene transfection is an effective method to increase Fas expression; the sensitivity of EJ cell line to Fas-mediated apoptosis is mainly dependent upon the expression of Fas.
