Background/aims: The expression of CD40 in gastric cancer has not been studied. The aims of this study were to determine the expression of CD40 in gastric cancer and to investigate the effect of CD40 on the apoptosis of gastric cancer cells.
Methods: We examined the expression of CD40 by immunohistochemistry and flow cytometry. CD40 mRNA in 5 gastric cancer cell lines was analyzed by RT-PCR. To assess the effect of CD40 on the viability of gastric cancer cells, we performed MTT assay. The effect of CD40 signaling on the apoptosis of gastric cancer cells was examined by annexin V affinity assay.
Results: Twelve of twenty human gastric cancer tissues demonstrated positive staining for CD40. Among 5 gastric cancer cell lines, AGS cell line expressed membrane-bound CD40 antigen and CD40 mRNA. In AGS cells, CD40 stimulation significantly reduced the cell viability. CD40 ligation significantly increased the apoptosis in AGS cells compared to the control.
Conclusions: CD40 is expressed in human gastric cancer tissues and gastric cancer cell line, and induces apoptosis in gastric cancer cells. These results suggest that CD40 expression in gastric cancer may play an important role in host defense mechanism against the gastric cancer.