神经胶质瘤诱导骨髓基质干细胞定向迁移的初步研究

A pilot study of the directional migration of bone marrow-derived stem cells towards glioma in adult rats

目的探讨骨髓基质干细胞（BMSCs）对神经胶质瘤的定向迁移能力及其在脑内的分布规律。方法从雄性Wistar大鼠股骨和胫骨中分离出BMSCs并进行传代培养．采用免疫荧光检测BMSCs表面抗原并将其向脂肪细胞和成骨细胞方向诱导分化．证明BMSCs性质．立体定向接种C6胶质瘤细胞于Wistar大鼠脑内基底节区以建立鼠脑胶质瘤模型，7d后将5-溴脱氧尿嘧啶（BrdU）标记的BMSCs接种人鼠脑对侧半球、对侧脑室和鼠尾静脉。BMSCs移植14d后心脏灌注取脑制成石蜡切片，以HE染色确定胶质瘤性质，SABC法免疫荧光染色显示BMSCs对神经胶质瘤组织的定向迁移能力及其在脑内的分布规律。结果对侧半球组和对侧脑室组均可见移植的BMSCs多沿针道直线分布并向对侧胶质瘤迁移，在胶质瘤与正常脑组织交界处可见激发出绿色荧光的阳性BMSCs；鼠尾静脉组亦可见少量BMSCs阳性细胞分布在胶质瘤组织周围。结论BMSCs通过脑实质、脑室及静脉注射途径均可定向迁移到胶质瘤组织，提示BMSCs可作为一种新的细胞载体用于胶质瘤的基因治疗。

Objective To study the directional migration of bone marrow-derived stem cells （BMSCs） towards the glioma and the distribution of the migrated BMSCs in the brain. Methods In vitro cultured BMSCs isolated from the bone marrow of male Wistar rats were identified using immunofluorescence technique, and their stem cell properties were assessed by means of induced differentiation in vitro into adipocytes and osteoblasts. Wistar rat models bearing glioma were established by stereotactic injection of C6 glioma cells into the basal ganglia, and 7 days later, BrdU-labeled BMSCs were injected stereotactically into the contralateral hemisphere or the contralateral ventricle, or intravenously via the tail vein. The rats were sacrificed 14 days after the BMSC injection, and coronal paraffin sections （5μm thick） of the brain tissue were prepared. HE staining was used to observe the extent ofintracranial glioma growth, and the distribution of the BMSCs in the glioma tissue as well as in the brain tissue was identified with immunofluorescent staining. Results The BMSCs implanted into either the contralateral hemisphere or the contralateral ventricle were found to migrate towards the glioma mostly along the needle tract, and distinct green fluorescence emitted by the labeled BMSCs was detected on the boundary between the glioma and the normal brain tissue. A few fluorescent BMSCs were also seen around the glioma tissue after intravenous injection of the cells. Conclusion BMSCs injected into the cerebral parenchyma, contralateral ventricle, or the tail vein are capable of directional migration into the glioma tissue, suggesting their potential as a new vehicle for delivering therapeutic genes into the glioma tissue.