AbstractGastric carcinoma is a frequent malignant tumor worldwide. NM23 plays an important role in pathological processes, including in the occurrence and development of tumors. The purpose of this study is to examine the effect of NM23 transfection of human gastric carcinoma cells (BGC-823) on growth and metastases of BGC-823 abdominal cancer xenografts in nude mice. BGC-823 cells were transfected with an adenovirus vector forNM23(NM23-OE), transfected with an empty vector (NC), or were not transfected (Ctrl). Eighteen female BALB/c-nu mice were randomly divided into three groups (six per group) according to the type of BGC-823 cells administered by intraperitoneal injection. After 2 weeks, necropsies of mice were performed, abdominal circumferences were measured, and abdominal cavities were searched by ultrasound. In order to observe the xenografts in nude mice, there were gross macroscopic observations and microscopic observations. In addition, immunohistochemical analysis and western blot of NM23 were also performed. Green fluorescence in the NM23-OE and NC cells indicated successful transfection. The multiplicity of infection is 80%. A comparison of the three groups of mice indicated the NM23-OE group had positive conditions (abdominal circumferences: 81.83 ± 2.40 mm), but the other groups had negative conditions and enlarged abdomens (NC: 90.83 ± 2.32 mm; Ctrl: 92.67 ± 2.07 mm). Ultrasound observations confirmed large tumors in the NC and Ctrl groups, but did not find in the NM23-OE group. There were no obvious ascites in the NM23-OE group, but the cytological examination of ascites exfoliation in NC and Ctrl groups indicated that there were large and deep-stained gastric carcinoma cells. Tumor expression of NM23 was greater in the NM23-OE group than in the NC and Ctrl groups (bothp< 0.05). In conclusion, transfection of BCG-823 cells withNM23rather than an empty vector (NC) or no vector (Ctrl) led to reduced growth and metastases of abdominal cancer xenografts in nude mice.