AFP抗体标记USPIO在SD大鼠肝癌中MRI显像及分布变化的实验研究

发布时间：2018-05-15 22:16

本文选题：大鼠 + 原发性肝癌　；参考：《扬州大学》2014年硕士论文

【摘要】：在我国肝细胞癌(Hepatocellular, HCC)的发病率居全球首位,其死亡率居恶性肿瘤死亡的第二位。肝癌的早期发现、早期诊断决定着其临床治疗的效果及患者预后。临床常用的检测手段包括血清AFP检测和各种影像学手段。甲胎蛋白(Alpha-fetoprotein, AFP)是HCC特异性标志物,80%的患者可出现甲胎蛋白的升高。如果将抗AFP抗体与某些显影剂或(和)抗癌药物相连,可以实现对肝癌的靶向成像和靶向治疗,使得影像诊断和临床治疗的同时进行成为可能。本实验拟通过对小剂量二乙基亚硝胺(DENA)诱导SD大鼠原位肝癌模型的MR分子成像、动态观察和病理学对照,研究靶向AFP的超小型超顺磁性纳米粒子在HCC中的特异性靶向成像和分布规律,本研究主要包括两部分。第一部分：sD大鼠肝癌模型的建立及靶向AFP-USPIO在SD大鼠肝癌中的MR成像表现目的：建立SD大鼠肝癌模型,进行AFP抗体标记USPIO增强扫描,观察大鼠肝癌特异性MRI成像。方法：定期配制浓度为0.1mg/ml的DENA水溶液,予25只雄性SD大鼠自由饮用,喂养14周后改为空白饮用水。16-18周时选取利于实验观察的大鼠肝癌模型20只,完全随机分成2组：实验组10只,对照组10只。所有大鼠先行MRI T2WI平扫,实验组注入AFP-USPIO(靶向组),对照组注入USPIO(非靶向组)2h后行T2WI增强扫描,观察病灶的信号变化情况,测量增强前后病灶、肝脏的信号强度,计算其对比噪声比(CNR)；处死大鼠后,取病灶标本行HE、AFP免疫组化染色和普鲁士蓝染色分析。结果：MRI扫描T2WI示肝内多发大小不等的高、稍高信号及混杂信号结节影,选取直径3mmm的结节作为实验对象进行观察。病灶境界显示清楚,大部分信号均匀,呈高、稍高信号。实验组、对照组分别注入AFP-USPIO、USPIO后2h增强扫描,在注射AFP-USPIO前后,大鼠肝脏-肿瘤的CNR分别为10.0+2.45和4.73士2.51,差异有统计学意义(P0.001,t=11.23)：而注射USPIO前后肝脏-肿瘤的CNR分别为9.15+1.24和9.96±1.63,差异无统计学意义(P=0.186,t=-1.43)。病理结果HE染色显示,选取作为MRI观察的病灶均为肝细胞肝癌, AFP免疫组织化学结果显示肝癌细胞胞浆内大量表达AFP。普鲁士蓝铁染色结果显示,实验组肿瘤组织间隙及肿瘤细胞内见较多蓝染颗粒,对照组肿瘤组织内蓝染颗粒则较少。结论：二乙基亚硝胺诱发SD大鼠肝癌的模型建立方便,成瘤率高。增强后AFP-USPIO靶向造影剂在大鼠肝癌组织聚集,降低肿瘤组织的信号,虽然肿瘤肝脏的对比噪声比减低,但有助于肝癌的定性诊断。第二部分：AFP-USPIO在大鼠肝癌组织中的分布变化的实验研究目的：研究抗体标记超顺磁性氧化铁纳米粒(AFP-USPIO)在大鼠肝癌组织中随时间的分布变化情况,为下一步偶联化疗药物的纳米粒子在肿瘤内的分布提供理论支持。方法：建立SD大鼠肝癌模型10只,方法及要求同上。先进行MR T2WI平扫,再分别注入实验组(n=5) AFP-USPIO、对照组(n=5) USPIO后0.5小时、1小时、2小时、6小时、12小时、24小时分别行MR增强扫描,测量各时间点病灶、肝脏组织的信号强度,分别计算各时间点的肝脏-肿瘤的对比噪声比(CNR)及瘤体的信号强度下降百分比(PSIL)。结果：MRI平扫T2WI序列上肿瘤组织呈高、稍高信号,部分信号欠均匀。实验组注射靶向对比剂后0.5-1小时肿瘤组织T2信号强度下降不明显,在2-8小时瘤体信号随着时间延长逐渐减低,瘤体在4h出现一个强化高峰期,并持续性强化,而12-24小时瘤体信号稍呈上升趋势。对照组注射靶向对比剂后各时间点肿瘤组织信号未见减低。实验组和对照组瘤体的信号测定值差异具有统计学意义(F=164.5,P0.01),实验组和对照组的肝脏的信号测定值差异不具有有统计学意义(F=4.6,P0.01)。实验组和对照组的肿瘤-肝脏CNR计算值差异具有统计学意义(F=132.7,P0.01)。结论：通过MR扫描动态观察AFP-USPIO增强后肿瘤的信号变化,推断其在肿瘤组织中的分布变化情况。增强后2h-8h瘤体随着时间推移,呈持续性强化,4-8h纳米粒子在肿瘤组织的聚集达到峰值,12h后逐步退出。
[Abstract]:In our country, the incidence of Hepatocellular (HCC) is the first in the world, and the death rate is second of the death of malignant tumor. Early diagnosis of liver cancer, early diagnosis determines the effect of clinical treatment and prognosis of the patients. Clinical detection methods include serum AFP test and various imaging methods. Alpha-fetoprot Ein, AFP) is a specific marker of HCC, and 80% of the patients may have a rise in alpha fetoprotein. If the anti AFP antibody is linked with some developer or (and) anticancer drugs, the target imaging and targeting therapy of liver cancer can be achieved. It is possible to make imaging diagnosis and clinical treatment simultaneously. This experiment is intended to pass a small dose of two ethyl sub. The MR molecular imaging of the hepatoma model of SD rats induced by nitramine (DENA), the dynamic observation and the pathological comparison, were used to study the specific targeting imaging and distribution of super small superparamagnetic nanoparticles targeting AFP in HCC. This study mainly included two parts.
Part I: establishment of sD rat liver cancer model and MR imaging of targeted AFP-USPIO in SD rat liver cancer.
Objective: to establish a SD rat liver cancer model and AFP antibody labeled USPIO enhanced scan to observe the specific MRI imaging of liver cancer in rats.
Methods: a DENA aqueous solution of 0.1mg/ml was regularly prepared, and 25 male SD rats were given free drinking. After feeding for 14 weeks, 20 rats were selected for the experimental observation of drinking water for 14 weeks. The rats were randomly divided into 2 groups: the experimental group 10 and the control group 10. The rats were first MRI T2WI plain scan, and the experimental group injected AFP-USPI. O (Ba Xiangzu), the control group was injected with USPIO (non target group) 2h after T2WI enhanced scan, observed the signal change of the focus, measured the focus of the lesion, the signal intensity of the liver, calculated the contrast noise ratio (CNR). After the death of rats, the lesion was taken HE, AFP immunization histochemical staining and Prussian blue staining analysis.
Results: MRI scan T2WI showed the high, slightly high signal and mixed signal nodules in the liver, and selected nodules of 3mmm in diameter as the experimental object. The focus state was clear, most of the signals were uniform, high and slightly high. The experimental group, the control group was injected with AFP-USPIO, the 2H enhanced scan after USPIO, and the AFP-USPIO injection of AFP-USPIO. Before and after, the CNR of rat liver tumor was 10.0+2.45 and 4.73 se 2.51 respectively, the difference was statistically significant (P0.001, t=11.23), and the CNR of liver tumor was 9.15+1.24 and 9.96 + 1.63 respectively before and after injection of USPIO, the difference was not statistically significant (P=0.186, t=-1.43).
The pathological results of HE staining showed that all the lesions observed as MRI were hepatocellular carcinoma, and the immunohistochemical results of AFP showed that a large number of AFP. Prussian blue iron staining results in the cytoplasm of the hepatoma cells showed that there were more blue stained granules in the tumor tissue and in the tumor cells in the experimental group, and the blue stained particles in the control group were less.
Conclusion: the model of two ethyl nitrosamine induced SD rat liver cancer is convenient, and the rate of tumor formation is high. The enhanced AFP-USPIO target contrast agent will gather in the rat liver cancer tissue and reduce the signal of tumor tissue, although the contrast noise ratio of tumor liver is reduced, it is helpful for the qualitative diagnosis of liver cancer.
The second part: Experimental Study on the distribution and change of AFP-USPIO in rat liver cancer tissue.
Objective: To study the changes of the time distribution of antibody labeled superparamagnetic iron oxide nanoparticles (AFP-USPIO) in rat liver cancer tissue, and provide theoretical support for the distribution of nanoparticles in the tumor in the next step.
Methods: 10 rat models of SD rat liver cancer were established. The methods and requirements were the same. First, MR T2WI was carried out, then the experimental group (n=5) AFP-USPIO was injected, and the control group (n=5) USPIO after USPIO, 0.5 hours, 1 hours, 2 hours, 6 hours, 12 hours and 24 hours respectively, and measured the focus of each time point, the signal intensity of liver tissue, and calculated the time of each time respectively. The ratio of liver to tumor contrast noise ratio (CNR) and percentage of tumor signal intensity decreased (PSIL).
Results: the tumor tissue in the MRI plain T2WI sequence was high, slightly high signal, and partial signal was not uniform. The decrease of T2 signal intensity in the tumor tissue was not obvious at 0.5-1 hours after the injection of target contrast agent in the experimental group, and the tumor body signal decreased gradually in 2-8 hours with time, and the tumor body appeared a strengthening peak in 4h, and continued to strengthen, and 12-24 hours. Tumor signal showed a slight upward trend. In control group, tumor signal did not decrease at any time after injection of targeted contrast agent.
The difference of the measured values of the signal of the tumor in the experimental group and the control group was statistically significant (F=164.5, P0.01). The difference in the measured values of the liver signal in the experimental group and the control group was not statistically significant (F=4.6, P0.01). The difference in the CNR calculation of the tumor liver of the experimental group and the control group was statistically significant (F=132.7, P0.01).
Conclusion: the changes in the signal of the tumor were observed dynamically by the MR scan, and the distribution of the tumor in the tumor tissue was deduced. After the enhancement, the 2h-8h tumor was continuously strengthened with time, and the aggregation of 4-8h nanoparticles reached the peak in the tumor tissue and gradually withdrew after 12h.

【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R735.7;R445.2

【参考文献】