Effect of mesenchymal stem cells from human gastric cancer on the tumor growth of gastric cancer-bearing mice

Abstract

Objective To investigate the effect of mesenchymal stem cells from human gastric cancer(hGC-MSCs)on the tumor growth of gastric cancer-bearing mice. Methods Gastric cancer cell line SGC-7901 cells were cultured and inoculated subcutaneously in the right back of BABL/c nude mice with a number concentration of 1×107 for each one to form the mice tumor- bearing model. The tumor- bearing mice receiving different doses(0.5×106, 1.0×106, 2.0×106) of hGCMSCs were classified into the experimental groups, while those receiving PBS served as the control group.The changes in tumor volume were measured, and the expression of proliferating cell nuclear antigen(PCNA)and matrix metalloproteinase(MMP)- 9 was detected by immunohistochemistry, real- time quantitative polymerase chain reaction(Real- time PCR) and Western blotting in each group. Results The tumor volume in the control group and the experimental groups was(1.06± 0.15),(2.21±0.44),(3.38±1.23),and(4.60±0.86)cm3, respectively(P< 0.05).The immunohistochemical results showed that the average optical density of PCNA in the control group and experimental groups was 0.349±0.008,0.376±0.013,0.441±0.012 and 0.500±0.022, respectively, and that of MMP- 9 was 0.341±0.027, 0.429±0.015, 0.474±0.006 and 0.527±0.033, respectively(P<0.01).The Real- time PCR confirmed that the mRNA expression of PCNA in the control group and experimental groups were 1.000±0.000, 1.640±0.013, 1.890±0.021 and 2.150±0.021, respectively, and that of MMP- 9 was 1.000±0.000, 1.810±0.101, 2.310±0.004 and 2.700±0.034 respectively(P<0.05). Western blotting revealed the expression of PCNA in the control group and the experimental groups was 14.99±0.90, 17.64±0.90, 25.11±0.40 and 28.31±1.10, respectively,and that of MMP- 9 was 18.48±1.30,32.95±1.20,67.26±1.20 and 141.16±3.80, respectively(P< 0.01). Conclusion hGC- MSCs can promote the tumor growth of gastric cancer- bearing mice in vivo, and its mechanism may be associated with the upregulated expression of PCNA and MMP-9. Key words: Gastric cancer; Mesenchymal stem cells; Proliferating cell nuclear antigen; Matrix metalloproteinase-9