Abstract: Objective To investigate whether the activation and over expression of NF-κB and STAT3 play an important role in the malignant transformation of BMSCs in C6 glioma microenvironment. Methods To simulate the abnormal microenvironment，the conditioned medium of C6 glioma cells was used to culture BMSCs to build a co-cultured system .Cell surface markers were assessed by flow cytometry .The cells’ morphological features were observed by phase contrast Microscope. The IL-6 levels of cells’ supernatant were measured by ELISA assay. The protein and mRNA expression of STAT3 were tested by Real-time PCR and western blot. The mRNA expressions of NF-κBp65 and C-MYC were also measured by Real-time PCR. Results BMSCs were negative for CD45, but positive for CD29, CD90 .The experimental group cells showed typical morphology features of tumor cell. The IL-6 level in the experimental group(16.7±2.9ng/L)was significantly higher than that in the negative group（12.62±3.20 ng/L）.NF-κBp65,P-STAT3,C-MYC protein were significantly higher than the negative control group and blank group(P<0.05),and they were mainly situated in the nuclei, presenting in an activation state. Conclusion The malignant transformation of BMSCs was significantly related to the over expression and activation of NF-κBp65,STAT3.

Key words: bone marrow mesenchymal stem cells, NF-ΚB, STAT3