BACKGROUND: Embryonic neural stem cells (NSCs) have provided positive effects for the treatment of glioma. However, the source for embryonic NSCs remains limited and high amplification conditions are required. Bone marrow stromal cells (BMSCs) have been proposed for the treatment of glioma. OBJECTIVE: To investigate biological changes in NSCs and BMSCs following transplantation into rat models of glioma. DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Embryonic Stem Cell Research Laboratory of Yunyang Medical College from February 2006 to August 2008. MATERIALS: The rat C6 glioma cell line was purchased from Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; mouse anti-bromodeoxyuridine (BrdU) monoclonal antibody and Cy3-labeled goat anti-mouse IgG antibody was purchased from Upstate, USA. METHODS: A total of 95 Sprague Dawley rats were randomly assigned to three groups: NSC (n = 35), transplanted with > 6 × 106 NSCs via left medial hind limb; BMSC (n = 35), transplanted with > 1 × 106 BMSCs via left medial hind limb; model group (n = 25), injected with the same volume of 0.1 mmol/L phosphate buffered saline. MAIN OUTCOME MEASURES: Gliomal growth and size were assessed by nuclear magnetic resonance, and glioma morphological features were observed following hematoxylin-eosin staining and BrdU immunohistochemistry 3 and 4 weeks following transplantation. RESULTS: The average survival of rats in the BMSC, NSC, and model groups was 4.03, 4.28, and 3.88 weeks. At 3 weeks, there was no significant difference in the average glioma diameter between the BMSC and model groups (P > 0.05). However, gliomal diameter was significantly decreased in the NSC group compared with the model group (P < 0.05). At 4 weeks, there was no statistical difference between the groups (P > 0.05). BrdU immunohistochemistry revealed that BMSCs and NSCs appeared to migrate to the gliomas. CONCLUSION: NSCs inhibited glioma cell growth and prolonged rat survival. BMSCs did not significantly suppress glioma cell growth. BACKGROUND: Embryonic neural stem cells (NSCs) have provided positive effects for the treatment of glioma. However, the source for embryonic NSCs remains limited and high amplification conditions are required. Bone marrow stromal cells (BMSCs) have been proposed for the treatment of glioma OBJECTIVE: To investigate biological changes in NSCs and BMSCs following transplantation into rat models of glioma. DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Embryonic Stem Cell Research Laboratory of Yunyang Medical College from February 2006 to August 2008. MATERIALS: The rat C6 glioma cell line was purchased from Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; mouse anti-bromodeoxyuridine (BrdU) monoclonal antibody and Cy3-labeled goat anti-mouse IgG antibody was purchased from Upstate, USA. METHODS: A total of 95 Sprague Dawley rats were randomly assigned to three groups: NSC (n = 35), transplanted with> 6 x 106 NSCs via the left medial hind limb; BMSC (n = 35) transplanted with> 1 x 106 BMSCs via left medial hind limb; model group MAIN OUTCOME MEASURES: Gliomal growth and size were assessed by nuclear magnetic resonance, and glioma morphological features were observed following hematoxylin-eosin staining and BrdU immunohistochemistry 3 and 4 weeks following transplantation. RESULTS: The average survival of rats in the BMSC, NSC, and model groups was 4.03, 4.28, and 3.88 weeks. At 3 weeks, there was no significant difference in the average glioma diameter between the BMSC and model groups (P> 0.05). However, gliomal diameter At 4 weeks, there was no statistical difference between the groups (P> 0.05). BrdU immunohistochemistry revealed that BMSCs and NSCs had migrated to the gliomas.CONCLUSION: NSCs inhibited glioma cell growth and prolonged rat survival. BMSCs did not significantly suppress glioma cell growth.