Fas expression is downregulated in gastric cancer

The aim of the present study was to investigate Fas expression in tumor samples from patients with gastric cancer, in order to determine the involvement of the Fas signaling pathway. The protein expression levels of Fas, caspase-8, caspase‑3 and poly (adenosine diphosphate‑ribose) polymerase 1 (PARP1) were examined in gastric cancer specimens and their associations with clinical pathological parameters were analyzed with immunohistochemical staining and western blot analysis. The mRNA expression was quantified with quantitative PCR and apoptosis was examined with a FACScan flow cytometer. The results demonstrated that the downregulation of Fas expression was correlated with less histological differentiation, gender (male), and increased lymph node and distant metastases (P<0.05). In the AGS established gastric cancer cell line, upregulation of the Fas signaling pathway promoted the apoptosis of gastric cancer cells by upregulating the expression of caspase‑8 and caspase‑3, and downregulating the expression of PARP1. The present study demonstrated that Fas was associated with gastric cancer and promoted the apoptosis of gastric cancer cells via caspase‑8, caspase‑3 and PARP1. These results suggested that caspase‑8, caspase‑3 and PARP1 may be triggers of gastric cancer, and upregulation of caspase‑8 and caspase‑3 expression, or inhibition of PARP1 expression may improve the therapeutic outcome in patients with gastric cancer.