微囊化PC12细胞的分泌特征及其致瘤性

Secretory characteristics and oncogenicity of microencapsulated PC12 cells

背景:有报道微囊化细胞移植不仅能避免免疫排斥反应,而且肿瘤细胞微囊化后可以消除其致瘤性。目的:观察大鼠肾上腺嗜铬细胞瘤细胞PC12细胞微囊化前后的分泌功能变化,及微囊化PC12细胞植入大鼠蛛网膜下腔后的存活情况和致瘤性。设计、时间及地点:动物观察实验,于2007-07/12在中山大学实验动物中心完成。材料:用微囊包裹PC12细胞。方法:将微囊化后第3～5天的PC12细胞植入12只雄性SD大鼠蛛网膜下腔。主要观察指标:检测微囊化前后PC12细胞去甲肾上腺素和甲硫氨酸脑啡肽的分泌情况;移植术后8周,回收移植的微囊化PC12细胞,检测存活情况和分泌功能;移植术后12周,对大鼠腰段脊髓予病理切片检查,观察移植物对脊髓组织的影响。结果:①PC12细胞经微囊包裹后,体外培养生长良好,除微囊化后第1天外,细胞微囊化前后去甲肾上腺素和甲硫氨酸脑啡肽分泌水平差异无显著性意义(P>0.05)。②回收移植术后的微囊化PC12细胞,再培养,其去甲肾上腺素和甲硫氨酸脑啡肽的分泌水平与移植前比较差异无显著性意义(P>0.05)。③移植术后12周,大鼠脊髓大体观察均未见新生物形成,病理切片显示神经细胞和髓鞘结构完整,少量淋巴细胞浸润,无纤维增生和坏死。结论:PC12细胞微囊化后可保持其活性和分泌功能;同种移植于蛛网膜下腔后,仍保持活性和分泌功能,无致瘤性。

BACKGROUND： It is reported that microencapsulated cells transplantation can prevent immunological rejection and eliminate tumor cell oncogenicity. OBJECTIVE： To observe the PC12 cells metergasis of secretion before and after microencapsulation, and the survival condition when microencapsulation PC 12 cells were implanted into subarachnoid cavity of rats. DESIGN, TIME AND SETTING： The animal observation was completed in the Animal Experiment Centre of Sun Yat-sen University during July to December in 2007. MATERIALS： PC 12 cells were encapsulated by microcapsules. METHODS： Three to five days after microencapsulation, the PC 12 cells were implanted into subarachnoid cavity of twelve male sprague-dawley rats. MAIN OUTCOME MEASURES： Secreted noradrenalin and met-enkephalin were observed before and after implantation. The implanted encapsulated PC 12 cells were retrieved to detect survival condition and secretion function at 8 weeks after surgery. The rat lumbar spinal cord was obtained for pathological section examination to survey the effect of grafts on myeloid tissue at 12 weeks after operation. RESULTS： The microencapsulated PC12 cells grew well in vitro. Except the first day after microencapsulation, there were no significant differences between the level of NE and M-EK before and after microencapsulation （P 〉 0.05）, and no significant differences between the level of NE and M-EK in the retrieved encapsulated PC 12 cells and pretransplant cells （P 〉 0.05）. There was no neoplasia appeared at 12 weeks after implantation. Pathological section showed that nerve cell and medullary sheath were integrated without fibroplasia or necrosis, and only a little of infiltration of lymphocytes appeared. CONCLUSION： Activity and secretion function can be kept by the microencapsulation technique on PC12 cells. When microencapsulated PC12 cells were implanted into subarachnoid cavity, the cells can maintain good activity and secretion without oncogenicity.