[Anti-glioma activity of treatment by bone marrow stromal cells transfected with HSV-tk in the rat].

OBJECTIVE: To study the anti-glioma activity of treatment by bone marrow stromal cells (BMSCs) transfected with AdCMV-tk containing HSV-tk gene in rats. METHODS: Primary cultured BMSCs were obtained and transfected with HSV-tk (BMSCs/tk) and were injected into contralateral brain of glioma-bearing rats to observe their tropism for glioma cells. RT-PCR was performed to examine the transduct of tk gene after it was transduced into BMSCs. C6 glioma cells were co-cultured with BMSCs transfected with HSV-tk. MTT test was performed to examine its antitumor activity. BMSCs, after being transfected with HSV-tk, were injected into contralateral brain tissue of glioma-bearing rats to show their in vivo antitumor activity. Dynamic MRI was performed to monitor the development of intracranial glioma. RESULTS: Purified BMSCs were obtained by primary cultured bone marrow cells. After being transfected with HSV-TK, the cells still stably displayed extensive tropism for intracranial glioma and transcripted tk gene. RT-PCR showed that BMSCs/tk were transduced tk gene obviously at 21 days after AdCMV-tk transfection. BMSCs/tk showed a clear bystander effect after being co-cultured with C6 glioma cells in vitro. TUNEL assay showed that BMSCs/tk could obviously show bystander effect and induce apoptosis of glioma cells in vivo with an apoptosis positive ratio of 20.38% +/- 2.57%, showing a statistically significant difference in comparison with BMSCs group (2.56% +/- 0.52%, P = 0.023) and control group (2.74% +/- 0.38%, P = 0.025). Compared with the control group (21.40 +/- 1.63 days), BMSCs/tk transplantation significantly prolonged the survival time of glioma-bearing rats (52.60 +/- 13.11 days, P = 0.000). MRI detection showed that the least volume of intracranial glioma in BMSCs/tk group (8.28 +/- 2.64 mm3), significantly smaller than that in BMSCs group (134.51 +/- 16.37 mm3, P = 0.001) and control group (147.22 +/- 31.05 mm3, P = 0.001). Some of the intracranial gliomaa disappeared after transplantation of BMSCs/tk. CONCLUSION: BMSCs transfected with AdCMV-tk may become an effective therapy method in the treatment for glioma.