CD133阳性肝癌细胞的干性鉴定及体内放射免疫靶向研究  

Characterization and radio-immunotargeting of CD133-positive liver cancer stem cells

作　　者：段丽群[1] 陈兴月[1] 侯研利 唐敏[1] 康强强[1] 舒锦[1] 李少林[1] 

机构地区：[1]重庆医科大学基础医学院放射医学教研室,重庆400016

出　　处：《肿瘤》2014年第4期310-317,共8页Tumor

基　　金：国家自然科学基金资助项目(编号:81171365;30970843);重庆市卫生局2011年医学科研计划项目(编号:2011-2-044)

摘　　要：目的:鉴定CD133+-HepG2肝癌细胞的干细胞特性,然后通过131I标记CD133单克隆抗体(131I-CD133抗体),研究其在人肝癌HepG2细胞裸鼠模型体内的生物学分布及对移植肿瘤的放射免疫靶向性。方法:采用免疫磁珠法分选出人肝癌CD133+-HepG2细胞,应用FCM法检测其CD133表达率,然后应用体外成球、克隆形成及体内成瘤实验鉴定其干细胞特性;采用氯胺T法制备131I-CD133抗体,并鉴定其标记率、放化纯度、稳定性及细胞结合活性;建立HepG2肝癌裸鼠模型,向模型鼠尾静脉注射131I-CD133抗体,2、12、24和48 h时测量并计算模型鼠体内各组织器官的每克组织百分注射剂量率;同时采用同型131I-IgG作为对照,比较24 h时2种标记物在HepG2肝癌裸鼠模型体内的各组织生物分布及肿瘤/非肿瘤组织比值。结果:成功分选出人肝癌CD133+-HepG2细胞,其CD133表达率为(93.58±3.74)%,并具有很强的体外成球、克隆形成及体内成瘤能力。131I-CD133抗体的标记率为(86.95±1.16)%,放化纯度为98.07%;与血清孵育48 h后,131I-CD133抗体的放化纯度仍为(89.63±0.64)%;131I-CD133抗体与CD133+-HepG2细胞的结合率最高可达(69.30±0.69)%。131I-CD133抗体注入HepG2肝癌裸鼠模型后,随着时间延长,包括肿瘤在内各组织器官的每克组织百分注射剂量率均降低;与131I-IgG对照组相比,131I-CD133抗体组在24 h时的肿瘤放射性摄取量以及肿瘤/非肿瘤组织(除血液和胃)比值明显增加(P<0.05)。结论:131I-CD133抗体在裸鼠体内能有效结合CD133+肝癌细胞,从而聚集在肿瘤组织中。推测CD133有可能成为肝癌治疗的新靶点。Objective： To identify the stem cell characteristics of human hepatocellular carcinoma CD133-positive （CD133^＋）-HepG2 cells, and to investigate the systemic distribution of ^131I-labeled anti- CD133 （^131I-CD1 33） antibody and their radio-immunotargeting in transplanted tumors of HepG2 cells in nude mice. Methods： Magnetic activated cell sorting （MACS） method was used to sort CD133^＋ cells from HepG2 cells. Flow cytometry was used to detect the expression of CD133 of the sorted cells. The stem cell properties of the sorted CD133^＋-HepG2 cells were validated by in vitro sphere-forming assay and colony-formation assay and in vivo tumor formation experiment. ^131I-CD133 antibody was prepared using chloramine T method, and its labeling efficiency, radiochemical purity, stability and cell-binding property were measured. The HepG2 tumor-bearing nude mouse model was established and injected with ^131I-CD133 antibody via tail vein. The percentage of inJected dose per gram of tissue （%ID/g） in major organs was calculated at 2, 12, 24, and 48 h after injection. Using isotype ^131I-IgG as a control, the biodistributions of these two labels in different organs/tissues and the tumor were compared, and a tumor/non-tumor （T/NT） ratio was calculated at 24 h after injection. Results： The CD133^＋-HepG2 cells were successfully sorted with a CD133 expression rate of （93.58±3.74）% and had strong abilities of sphere-, colony- and tumor-formation in vivo. The labeling efficiency and the radiochemical purity of ^131I-CD133 antibody were （86.95±1.16）% and 98.07%, respectively. After incubation with serum for 48 h, the radiochemical purity of ^131I-CD133 antibody was similar [（89.63± 0.64）%] to the value before incubation. The binding rate of ^131I-CD133 antibody to CD133^＋-HepG2 cells was up to （69.30±0.69）%. After intravenous injection of ^131I-CD133 antibody into HepG2 tumor-bearing mice, the %ID/g values of ^131I-CD133 antibody were reduced over time in different organs and tissu

关 键 词：癌 肝细胞 肿瘤干细胞 碘放射性核素 组织分布 放射免疫测定 CD133 

分 类 号：R735.7[医药卫生—肿瘤]