Abstract: Objective To investigate the relation between marrow mesenchymal stem cells tumorigenesis and tyrosine kinase signaling molecules such as HGF、IL-6，BFGF in vitro .Methods The tumor microenvironment was simulated by co-culture MSCs with C6 and the normal microenvironment was simulated by co-culture MSCs with astrocytes; MSCs were divided into three groups:Experimental group(co-cultured with C6), Control group (co-cultured with astrocytes) Blank control group ( MSCs alone) ；P53 and MDM2 of MSCs in each group were measured by PCR, Western blotting ；HGF，IL-6 and BFGF expression in each group were detected by ELISA ; the STAT3 protein expression of MSCs treated with corresponding ELISA amount tyrosine kinase signaling molecule were detected by immunofluorescence. Results Experimental group cells showed tumor cell-like morphology. MDM2 mRNA in experimental group was the control group 1.56±0.21 fold(P<0.05);MDM2 protein in experimental group increased 90±7% as compared to control group (P<0.01)；P53 mRNA decreased to 0.55±0.10 and the level of mutant P53 protein increased to 87±5% in experimental group as compared to control group (P<0.01); HGF and IL-6 significantly increased in Experimental group as compared to Control group (P<0.05). P-STAT3 expression increased in IL-6 overdose group as compared to IL-6 normaldose group. (P<0.01). Conclusion IL-6 can induce mesenchymal stem cells tumorigenesis in vitro simulated tumor microenvironment.

Key words: Tumor microenvironment, mesenchymal stem cells, STAT3