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Lack of Fas-pathway gene mutations in primary resected esophageal squamous cell carcinoma.

BACKGROUND
The Fas system regulates a number of physiological and pathological processes of cell death. Many types of cancer cells are resistant to Fas-mediated apoptosis by several mechanisms, including mutations of the genes involved in Fas-mediated apoptosis. The present study aimed to detect Fas pathway gene alterations in primary resected esophageal squamous cell carcinoma (ESCC).


METHODS
Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) were used to analyze the expression of Fas in 34 archival specimens from patients with primary resected ESCC. We then explored the possibility of mutations in the genes involved in the proximal pathway of Fas mediated apoptosis (Fas, FADD). We analyzed exon 9 (death domain) of the Fas gene and exon 1 (death effective domain) of the FADD gene for gene mutations in these 34 specimens by polymerase chain reaction and DNA sequencing.


RESULTS
Immunohistochemistry and RT-PCR revealed that Fas was expressed in all primary resected ESCC specimens analyzed. However, we did not detect any structural alterations in exon 9 of the Fas gene or exon 1 of the FADD gene.


CONCLUSIONS
Inhibition of Fas-mediated apoptosis may not be due to gene mutations in the critical exon 9 of the Fas gene and exon 1 of the FADD gene in esophageal squamous cell carcinoma.