Objective    To study the anti-tumor effect of eukaryotic expressing plasmid encoding soluble tumor necrosis factor-related apoptosis inducing ligand (sTRAIL) on human gastric cancer xenografts in nude mice.     Methods    Human gastric cancer cell line BGC-823 was inoculated subcutaneously into the back of nude mice and grew to tumor nodules. Multi-point intratumoral injection of pBud-EGFP-TRAIL was performed. The tumor-bearing mice receiving empty plasmid or normal saline served as control. The growth of tumors was observed and recorded. RT-PCR and Western blot analysis were used to detect the expression of sTRAIL in the tumor cells. HE staining was used to see the changes of tumor tissues

and TUNEL and electron microscopy for the apoptosis of cells.     Results    The protein and mRNA expression of sTRAIL in the pBud-EGFP-TRAIL group were positive

and the volume of tumor was statistically smaller than that of the control groups. Extensive dead tumor cells were seen in the pBud-EGFP-TRAIL group

and remarkable apoptosis was shown by TUNEL and electron microscopy.     Conclusion    Direct intratumoral injection of sTRAIL eukaryotic expressing plasmid suppresses the growth of gastric cancer xenografts in nude mice.