The Role Of Different Phenotypic Bone Marrow-derived Mesenchymal Stem Cells In Gastric Carcinogenesis Induced By Helicobacter Pylori Infection

Objective : To study the role of different phenotypic Bone marrow-derived mesenchymal stem cells in gastric carcinogenesis induced by chronic Helicobacter pylori infection.Method:1. Establish the model of MET induction in MSCs with the use of 150ng/ml BMP-7 for 24 h. To further confirm the efficiency of induction, the assays of PCR, Western blot and Immunofluorescence staining were used. 2. To compare the biological characteristics of e MSCs with f MSCs, migration ability was detected by transwell system and proliferation ability was conducted by CFSE proliferation assay. To compare the status of Wnt signaling in e MSCs and f MSCs, the m RNA and protein expression of β-catenin, TCF-4 and FZD5 were examined. To test whether BM-MSC and MET-BM-MSC have different pluripotency, the protein expression levels of Nanog was quantified by western blot. 3. To further study the effects of Hp on the biological characteristics of e MSCs and f MSCs, e MSCs/f MSCs were co-cultured with Hp supernatant for 12 h. Then the proliferation ability, migration ability and the expression of Wnt signaling were detected as mentioned above. 4. To investigate the effects of e MSCs and f MSCs on tumor growth, MFC alone, e MSCs with or without MFC and f MSCs with or without MFC were implanted into the right armpit of nude mice respectively. After 14 days, nude mice were sacrificed and the tumors were analyzed then.Result:1. After incubation with 150ng/ml BMP-7 for 24 h, the cell morphology of MSCs was change from fibroblast-like to epithelial-like cells with a polygonal cell body and short cytoplasmic projections. The results showed that BMP-7 treatment on MSCs with 100ng/ml or 150ng/ml for 24 h significantly upregulated E-cadherine and downregulated the mesenchymal markers(Vimentin and FSP-1) both in gene and protein expression. 2. Compared with f MSCs, e MSCs exerted stronger proliferation ability and more activated Wnt signaling pathway, while the weaker migration ability and pluripotency. 3. After Co-culture with Hp supernatant for 12 h, H. pylori infection activates the proliferation, migration and wnt/β-catenin signaling both in e MSCs and f MSCs in vitro. 4. Both e MSCs and f MSCs promoted MFC tumor growth in nude mice.Conclusion:BMP-7 successfully induced fibroblast-like MSCs(f MSCs) changed into epithelial-like cells MSCs(e MSCs).The e MSCs and f MSCs showed different biological characteristics with or without Hp infection. Both the MSCs and f MSCs promoted the growth of gastic cancer.