Objective: To investigate the expression of five apoptosis-related proteins, Fas, Fas ligand (FasL), Fas-associated death domain protein (FADD), caspase 8, and mutant p53, in human esophageal squamous cell carcinoma (ESCC) tissue, and analyze the association of these proteins with ESCC malignant progression.
Methods: 116 ESCC specimens obtained during operation. Tissue microarray composed of the 116 specimens of cancerous tissues and corresponding paracancerous normal epithelium tissues was constructed. The expression of Fas, FasL, FADD, caspase 8, and mutant p53 was detected in the ESCC tissues and paracancerous normal epithelium tissues and analysis was conducted for the correlation between the expression of these proteins and the pathoclinical features and prognosis. involvement, differentiated grade, pTNM stages and disease-free survival.
Results: The positive rate of Fas in the ESCC tissues was 41.4%, significantly lower than that in the normal squamous epithelium was 95.7%, P < 0.001). The positive rates of FasL and FADD in the ESCC tissues were 76.7% and 50.0%, both significantly higher than those in the normal squamous epithelium (39.7% and 7.8%, both P < 0.001). Caspase 8 was strongly positive in the whole normal esophageal epithelium tissue except basal and superbasal cells, but negative in ESCC. Mutant p53 protein was negative in the normal esophageal epithelium tissue, with only several cases positive in the basal cells, but was diffusely positive in ESCC tissues with a positive rate of 37.1%. The expression of Fas in the well and moderately differentiated ESCC tissues was significantly higher than in the poorly differentiated ones (P = 0.022). The patients with positive expression of FADD had lower disease-free survival rate (P = 0.0028). The expression of Fas, FasL, caspase 8, and mutant p53 was not related with disease-free survival rate (P > 0.05).
Conclusion: The apoptosis-related markers, such as Fas, FasL, FADD, caspase 8, and mutant p53 protein may play important roles in the development and progression of ESCC, and FADD can be used as a marker to predict the advance and prognosis of ESCC.