99mTc-EGFR-McAb用于荷人肺腺癌裸鼠的放射免疫显像研究

目的:评价99mTc标记的表皮生长因子受体(Epidermal growth factor receptor,EGFR)单克隆抗体(Monoclone antibody,McAb)用于荷人肺腺癌裸鼠的放射免疫显像(Radioimmunoimaging,RII)效果,并进行相关比较分析.方法:①建立荷人肺腺癌裸鼠动物模型;②采用99mTc直接标记法标记抗EGFR的单克隆抗体,并对标记抗体的特性进行鉴定;③利用99Tc-EGFR-McAb进行荷人肺腺癌裸鼠模型的RII及体内分布研究.结果:99mTc对EGFR-McAb的标记率为91.5%±3.8%,标记抗体比活度为(2.8±0.2)MBq/μg,放射化学纯度为96.5%±3.2%.放射免疫显像结果显示,99mTc-EGFR-McAb对肿瘤组织有较高的亲和性,通过感兴趣区(Regional interest,ROI)技术测得T/NT比值为2.74±0.5,明显高于对照组(P＜0.05).标记抗体的体内分布结果与显像结果基本一致.结论:99mTc-EGFR-McAb用于荷人肺腺癌裸鼠的放射免疫显像能得到较理想的靶/非靶比值,EGFR是肺腺癌放射免疫显像研究值得推荐的目标抗原.     

~(99)Tc~m标记VEGFR-3高亲和融合多肽在荷人卵巢癌裸鼠体内的分布和显像研究

目的 研究~(99)Tc~m标记VEGFR-3高亲和融合肽(phage-SHSWHWLPNLRHYAS)在荷人卵巢癌裸鼠体内分布和放射免疫定位显像.方法 用NHS-MAG3为双功能鳌合剂,固相法合成多肽.~(99)Tc~m预亚锡直接标记法进行标记,纸层析法测定标记率.经尾静脉注射于荷瘤鼠体内,取不同时相进行SPECT显像,测定标记物在体内的分布情况并进行分析.结果 融合多肽的~(99)Tc~m标记率为95.27%,放射化学纯度为96%,放射性浓度24.6 MBq/ml.经鼠尾静脉注射后1 h,植瘤部位开始出现放射性浓集,肾脏、肝脏及膀胱组织也可见显像;注射后3 h肿瘤显像最清晰,每克组织注射百分剂量率(%ID/g)为(30.20±6.89).其余大部分脏器的T/NT值均达最高,最高为肌肉(13.13);注射后4 h肿瘤部位显像逐渐消退.对照组裸鼠的肿瘤部位始终未见显像.结论 筛选获得的VEGFR-3高亲和融合肽能够靶向荷瘤鼠体内肿瘤组织,实现肿瘤的靶向受体显像.     

131I-RP215McAb分子探针的制备、鉴定及荷人肺腺癌裸鼠放射免疫显像

目的 制备靶向肺腺癌细胞表面碳水化合物相关抗原(carbohydrate antigen 215,CA215)的核素分子探针131I-RP215单克隆抗体(monoclonal antibody,McAb),鉴定其理化性质并探讨其在荷瘤裸鼠模型中的体内分布情况和放射免疫显像特点.方法 采用氯胺T法对McAb RP215进行131I标记,Sephadex G25M柱纯化标记抗体,并鉴定其理化特性,观察该抗体标记物在荷A549裸鼠模型中的生物分布及放射免疫显像情况.结果 131I-RP215 McAb标记率为(91.03 ±2.36)％,纯化后的放化纯度为(93.15±1.40)％,比活度(3.37±0.42) MBq/μg;具有较好的稳定性及免疫活性.荷瘤裸鼠体内生物分布及SPECT显像结果显示,131 I-RP215 McAb能够在肿瘤组织中选择性浓聚,131I-RP215 McAb作用24h时,肿瘤/肌肉比达最高,且瘤体显影最清晰.结论 成功制备了特性理想的131I-RP215 McAb分子探针,在荷人肺腺癌裸鼠模型中有较好的显像效果.     

99Tcm-黄体生成素释放激素在荷人乳腺癌裸鼠体内的生物学分布

目的:研究99Tcm-黄体生成素释放激素(99Tcm-LHRH)在荷人乳腺癌裸鼠体内的生物学分布,探讨LHRH用于肿瘤诊断和靶向治疗的价值。方法:直接标记法99Tcm标记LHRH;25只荷瘤鼠随机分成5组,每组5只;荷人乳腺癌SK-BR3裸鼠尾静脉注射99Tcm-LHRH后断头处死小鼠,测定99Tcm-LHRH在各组荷瘤鼠体内的放射性分布,计算每克组织放射性占总注入放射性的百分比。结果:99Tcm-LHRH放化纯度95%,标志物稳定性好。荷瘤鼠注入99Tcm-LHRH后4 h,肿瘤/血液及肿瘤/肌肉的比值分别为12.89±1.67、36.81±5.64,99Tcm-LHRH主要分布于肿瘤、肝脏、血液,脑、肌肉等组织中放射性分布极低。结论:99Tcm-LHRH高特异地与人乳腺癌细胞结合,在乳腺癌显像和靶向治疗中有潜在的应用前景。     

~(131)I标记抗Peroxiredoxin I肺腺癌噬菌体抗体在荷瘤裸鼠体内的分布及其对肿瘤生长的抑制作用

目的研究抗Peroxiredoxin I(PrxI)肺腺癌相关单链抗体体外对肺腺癌细胞的增殖抑制;观察131I标记抗体在肺腺癌裸鼠模型体内分布、靶向显像及体内抑瘤作用。方法放射性核素计数法测定单链抗体细胞内摄水平;MTT法及流式细胞仪检测单链抗体抑制肺腺癌A549细胞生长情况;免疫印迹法检测单链抗体作用于A549细胞后对细胞内PrxI表达水平的影响。放射性核素131I标记纯化抗体,进行荷瘤裸鼠体内分布、SPECT放免显像及病理切片观察抑瘤作用。结果单链抗体干预后细胞PrxI蛋白表达水平较对照组下降(P<0.05)。体内分布研究表明单链抗体与肺腺癌组织有效结合。荷瘤裸鼠尾静脉注射131I标记抗体48h后,瘤/血和瘤/肌肉放射性比值均达到最大值4.06±0.13和5.17±0.97。SPECT示抗体注射后48hT/NT值明显高于12h、24h和72h(F均>86,P均<0.01)。治疗4周后,131I标记抗体治疗组肿瘤体积为(0.68±0.17)cm3,质量为(1.58±0.21)g,抑瘤率56.8%,与对照组比较有统计学差异。结论抗PrxI肺腺癌单链抗体能有效抑制肺腺癌细胞生长,131I标记单链抗体在体内能抑制...     

99Tcm标记Gd-DTPA-DG及其在裸鼠体内的生物分布

目的 探讨锝(99Tcm)标记顺磁性脱氧葡萄糖类MRI对比剂二乙三胺五乙酸-脱氧葡萄糖钆盐(Gd-DTPA-DG)的稳定性及在荷瘤裸鼠体内的生物分布,寻找一种核素与磁共振双模式影像探针.方法 对 Gd-DTPA-DG进行99Tcm标记,并对需要的Gd-DTPA-DG、氯化亚锡(SnCl2·2H2O)用量,pH,温度采用正交实验设计,确定最佳标记条件.采用薄层纸层析法(TLC)分析标记率,体外放置6 h,观察标记物的稳定性.将标记的99Tcm -Gd-DTPA-DG注入裸鼠体内,10、30 min及1、2、4、24 h后断头处死裸鼠,测定血液、心脏、脑、肝脏、脾脏、肺脏、肾脏、小肠、肌肉、肿瘤中的每克组织百分注射剂量率(%ID/g).结果 取10 mg Gd-DTPA-DG、0.6 mg SnCl2·2H2O,在pH值小于2时加入新淋洗的Na99TcmO4洗脱液(37 MBq),沸水反应30 min所得99Tcm -Gd-DTPA-DG放化纯度最高,可达98.5%,体外放置6 h,放化纯度仍大于96%.尾静脉注射99Tcm -Gd-DTPA-DG 2 h后,裸鼠肿瘤组织的摄取率约为(1.48±0.12)%ID/g,肿瘤与肌肉的放射性摄取比(T/NT)达2.91.结论 采用放射性核素99Tcm标记顺磁性对比剂Gd-DTPA-DG 简单易行;荷瘤裸鼠模型显示其具有良好的肿瘤靶向性,有望成为一种极具发展潜力的新型单光子发射计算机断层显像(SPECT)-MRI双模式影像探针.     

卵巢癌荷瘤裸鼠~(99m)TcCOC183B_2放射免疫显像结果分析

目的 :研究99mTc标记抗卵巢上皮癌单克隆抗体COC183B2 在荷瘤裸鼠体内的分布 ,并进行放射免疫显像 ,为临床应用提供依据。方法 :COC183B2 用预亚锡法标记后 ,经腹腔注入荷瘤裸鼠体内 ,在 2 4小时进行放射免疫显像 ,并观察裸鼠体内的生物学分布。结果 :与对照组相比 ,标记抗体在肿瘤组织中出现了特异性浓聚。获得清晰的显像 ,T/NT比值在 0 99～ 5 99之间 ,T/B比值为 1 19。结论 :说明COC183B2 可特异地与卵巢癌结合 ,具有导向卵巢癌的作用     

~(99m)Tc-C_(50)-F(ab′)_2放射免疫显像早期诊断卵巢癌的实验研究

【目的】探讨单克隆抗体 (McAB)的F(ab′) 2 片段在卵巢癌放射免疫显像诊断中的应用价值。【方法】利用胃蛋白酶消化抗癌胚抗原单克隆抗体 (C50 ) ,酶切产物经SDS PAGE电泳鉴定后 ,经SephadexG 10 0凝胶柱纯化 ,获得F(ab′) 2 片段。分别将99mTc标记的C50 ,F(ab′) 2 及正常鼠IgG行荷人卵巢癌裸鼠移植瘤放免显像 ,并比较其结果。【结果】①片段F(ab′) 2 的产率为 33%± 3 2 % ,其最大理论产率的 49%。酶联免疫吸附方法和免疫细胞化学染色均证实其保留较好的免疫活性。② 2 4h放射免疫显像可见片段组移植瘤部位有较高浓度的放射性物质聚集 ,肿瘤与非肿瘤组织放射性活度之比 (T/NT)片段组最高。【结论】利用单克隆抗体片段进行放免显像 ,效果优于全抗体。     

抗HIF-1α肺腺癌人源单链抗体的制备和放射免疫显像

目的 利用噬菌体抗体库技术制备特异性的抗缺氧诱导因子1α(hypoxia-inducible factor,HIF-1α)肺腺癌人源单链抗体(scFv),并用于荷人肺腺癌裸鼠体内放射免疫显像(radioimmunoimaging,RII)研究.方法 利用噬菌体抗体库技术筛选特异性抗HIF-1α肺腺癌人源scFv,并将其感染大肠杆菌HB2151,进行scFv的可溶性表达.接种肺腺癌A549细胞复制荷瘤裸鼠模型,尾静脉注射131I标记可溶scFv,于注射后24、48、72 、120 h进行SPECT平面静态检查,观察肿瘤内放射性浓聚情况,用感兴趣区(region of interest,ROI)技术分析T/NT值,取平面静态检查肿瘤显影清晰时进行SPECT/CT图像融合.结果 经鉴定证实制备出特异性的抗HIF-1α肺腺癌人源scFv,荷瘤裸鼠体内RII结果 显示131I-可溶scFv可以选择性地积聚于肿瘤组织,肿瘤区放射性浓聚、T/NT值均在72 h达到高峰,利用ROI技术得到的T/NT值此时最大可达3 19.72 h时融合图像肿瘤显像良好,图像清晰.结论 成功制备特异性抗HIF-1α肺腺癌人源scFv,131I标记后荷人肺腺癌裸鼠RII肿瘤显影良好.     

^99mTc标记单克隆抗体及片段对荷人结肠癌裸鼠的放射免疫显像研究

目的 探讨单克隆抗体ND1对大肠癌的诊断价值。方法 利用放射免疫法对荷人结肠癌裸鼠模型进行显像研究。结果 ^99mTc直接标记抗人结肠癌单克隆抗体ND1及F（ab)2片段,标记率为94%和87%,标记后抗体的免疫活性良好。注入荷人结肠癌裸鼠体内16小时后。肿瘤组织中出现较高的特异性浓聚,肿瘤轮廓显示清晰,F（ab)2片段的放射本底消除快,图像质量优于ND1。体内分布显示：ND1及F（ab)2片段可与移植瘤特异性结合。肿瘤与正常器官组织的放射比值（T/NT）、F（ab)2片段显高于ND1,ND1在肿瘤,血液及器官组织均有较高的放射性摄取,不利于放射性本底的消除。结论 ^99mTc-F(ab)2,对大肠癌的放射免疫显像图像清晰,优于^99mTc-ND1,为其临床应用提供了实验依据。     

99^Tc^m-MIBI显像评价人肺腺癌荷瘤裸鼠多药耐药状态

目的采用99^Tc^m-甲氧基异丁基异腈（MIBI）SPECT显像技术在BALB/c裸鼠的SPCA-1人肺腺癌移植瘤模型上观察应用维拉帕米逆转前后的肿瘤细胞摄取显像剂的情况,以探讨应用该方法评价肿瘤多药耐药状态的可行性。方法荷瘤裸鼠随机分为维拉帕米逆转组和对照组,在应用维拉帕米逆转前后分别进行99^Tc^m-MIBISPECT显像及感兴趣区（ROI）半定量分析,观察肿瘤多药耐药状态变化情况,并将其结果与流式细胞仪检测结果进行对比。结果对照组与逆转组逆转后显像、逆转组逆转前显像与逆转后显像之间15、60、120min的肿瘤摄取比值（TUR）差异有高度统计学意义（P〈0.01）。对照组和逆转组滞留率（RI）均与流式细胞仪检测的P-gp蛋白表达阳性细胞的百分率成负相关（P〈0.05）。结论99^Tc^m-MIBI显像与SPCA-1人肺腺癌肿瘤细胞P-gp的表达成负相关,可以较好地显示肿瘤的多药耐药状态,同时也可动态监测维拉帕米对SPCA-1人肺腺癌多药耐药逆转的效果。     

Biodistribution and preparation of technetium-99m-labeled D-D3 monoclonal antibody against pro-gastrin-releasing peptide (31-98) in mice

Background We previously reported that iodine-131(131I)-labeled anti-pro-gastrin-releasing peptide (ProGRP(31-98)) monoclonal antibody D-D3 could selectively accumulate in the tumor sites of nude mice ...     

99m Tc-HL91 "hot spot" imaging of mice bearing human carcinoma by gamma camera and the effects of tumor necrosis on imaging

Objective To evaluate the hypoxia-avid agent ^99m Tc-HL91 (^99m Tc labeled 4, 9-diaza-3, 3, 10, 10-tetramethyldodecan-2, 11-dione dioxime) as the tracer of tumor "hot spot" imaging and the influence of tumor necrosis on the image.
Methods After injection of ^99m Tc-HL91, 6 nude mice bearing human breast cancer MCF-7 and 18 nude mice bearing human pancreatic adenocarcinoma were subjected to gamma camera imaging, postmortem analysis, and autoradiography and imaging of tumor sections.
Results The image of tumor was identified 1 hour after injection of ^99m Tc-HL91.Images demonstrated gradually increased ^99m Tc-HL91 uptake in the tumor 1-12 hours after injection (P<0.05-0.001).Six hours after injection, the radioactivity ratios of tumor to thorax and tumor to head were higher than 2.1.Six hours after injection, the radioactivity ratios of tumor to brain, muscle, blood, heart, lung and kidney in pancreatic adenocarcinoma bearing nude mice were 101.0±114.7, 30.0±30.3, 19.9±21.9, 14.4±15.1, 3.71±2.41 and 0.46±0.26, respectively, and the radioactivity ratios in breast cancer MCF-7 bearing nude mice were close to these figures.The radioactivity of non-necrotic tumor was 3.77 times that of necrotic tumor.However, the radioactivity ratios of tumor to liver, intestine and stomach were lower than 1.3. Autoradiographs and images of tumor sections showed that the radioactivity was higher in the region of solid tumor than in the necrotic region.
Conclusion ^99m Tc-HL91 via gamma camera positively identifies regional tumor in nude mice bearing human cancer.^99m Tc-HL91 retention is lower in necrotic tumor than in non-necrotic tumor.The low radioactivity ratio of tumor to abdominal organs limits the application of ^99m Tc-HL 91 in detecting abdominal tumors.      

~(99m)Tc-PYM的制备、动物实验及临床研究

目的：研制适于临床肿瘤阳性显像的标记产品99mTC-PYM。方法：在原工作基础上，提高99mTc-PYM的放射性强度，并通过注射前往产品中加入维生素C，提高肿瘤对99mTc-PYM的摄取百分丰。结果：定量判断肺部恶性病灶的灵敏度、特异性和准确性分别为92％、100％和93％。结论：99mTC-PYM显像可用于肺癌诊断及分期，具有对疗效评价及预后判断的能力，该方法简便、安全，值得临床进一步推广应用。     

^131—I抗肺癌McAb在人肺癌裸鼠模型体内的放射...

Monoclonal antibodies (Lc86a-C5, Lc86a-H8) directed against human lung adenocarcinoma cell line LTEP-a-2 and normal BALB/c IgG were labelled with iodine-131 by chloramine T. The 131I-McAbs and 131I-IgG were respectively injected into the peritoneal cavities of nude mice bearing transplanted human lung adenocarcinoma cell line LTEP-a-2. After 72 h, the tumor tissue in nude mice injected with 131I-McAbs was distinguishable from normal tissues as a very clear image obtained during gamma scintigraphy. No difference was found between tumor and normal tissues in the nude mice injected with 131I-IgG. The tumor: blood ratio was 3.1:1 in nude mice injected with 131I-McAb(H8) and 0.9:1 in nude mice injected with 131I-IgG respectively. This indicates that the tumor tissue image was the result of specific binding of the 131I-McAbs, which have high specificity and affinity both in vitro and in vivo, to tumor cells, and these monoclonal antibodies may serve as potential agents in tumor diagnosis and treatment.     

~(131)I-抗肺癌McAb在人肺癌裸鼠模型体内的放射免疫显像

用氯胺T法将~(131)I标记抗人肺癌McAb(LC86a-C_5、LC86a-H_8)和正常BALB/c小鼠IgG分别腹腔注入人肺腺癌细胞株LTEP-a-2裸鼠模型体内,并定时γ照像。结果72h后,注射~(131)I-McAbs裸鼠肿瘤组织呈现清晰图像,与正常组织差别明显;而注射~(131)I-IgG裸鼠肿瘤组织与正常组织则无明显区别。96h后,注射~(131)I-McAb(LC86a-C_5)、~(131)I-McAb(LC86a-H_8)及~(131)I-IgG裸鼠的瘤血放射比值分别为3.1、2.8和0.9。提示肿瘤生长部位的清晰图像是~(131)I-McAb与肿瘤组织特异性结合的结果,进一步证实该标记McAb在体内外有较高的特异性及亲合力,可为临床肿瘤定位诊断及导向杀伤研究提供有效的手段。     

~(99)Tc~m-EC-MN鼻咽癌乏氧显像的实验研究

目的 通过对99Tcm-EC-MN在鼻咽癌体外及体内模型中生物学分布的研究,探讨99Tcm-EC-MN肿瘤乏氧显像的临床意义.方法 利用99TcmO4标记EC-MN,纸层析法测定标记率.99Tcm-EC-MN分别加入正常条件和乏氧条件下培养的鼻咽癌细胞株内,在不同时间段检测99Tcm-EC-MN在细胞内的分布差别.建立鼻咽癌裸鼠肿瘤模型,自荷瘤鼠尾静脉注入99Tcm-EC-MN 3.7 MBq(0.1 ml)后0.5、1、2、4、6和8 h分别进行平面显像,观察99Tcm-EC-MN的体内分布情况.在各时相分别处死荷瘤裸鼠,取各脏器组织标本、称重并测量放射性计数,计算各标本每克组织百分注射剂量率(%ID/g).对分离出的瘤体,应用CD34单克隆抗体及血管内皮生长因子(VEGF)单克隆抗体进行免疫组化染色.结果 正常条件和乏氧条件下培养的鼻咽癌细胞株对99Tcm-EC-MN的吸收差异有高度统计学意义(P<0.01).所有荷瘤裸鼠的肿瘤均呈阳性显像,静脉注射后0.5 h肿瘤灶即显影,4 h时显影最清晰.肿瘤/肌肉比值1、2、4 h分别达2.24倍、4.75倍、6.41倍.99Tcm-EC-MN在正常组织中清除快,主要经泌尿系统及肠道排出.免疫组化结果和放射性计数结果具有显著相关性(r>0.9,P<0.01).结论 99Tcm-EC-MN作为一种乏氧显像剂,具有良好的开发前景.     

Pre-clinical evaluation of a new indirectly labeled 99mTc-6-hydrazinopyridine-3-carboxylic acid (HYNIC)-depreotide with HYNIC as bifunctional chelator

Background  Technetium-99m or ^99mTc is widely used for labeling peptide in nuclear medicine. Somatostatin and its analog can inhibit tumor cell growth after binding with its receptor. This research was to study the preclinical effect of a new ^99mTc-6-hydrazinopyridine-3-carboxylic acid (HYNIC)-depreotide, indirect ^99mTc labeling of depreotide using HYNIC as a bifunctional chelator.

Methods  The cyclopeptide, cyclo-[(N-Me) Phe-Tyr-D-Trp-Lys-Val-Hcy], the linear peptide, and [ClCH₂-CO×b-Dap-Lys- Cys-Lys×amide] were synthesized by Fmoc solid-phase synthesis. The cyclopeptide and the linear peptide were linked by liquid-phase synthesis. The product depreotide was isolated and purified by high performance liquid chromatography and was confirmed by mass spectrography. Depreotide was labeled with ^99mTc through a direct labeling method, using HYNIC as a bifunctional chelator. Paper chromatography method was used to calculate the labeling rate, and through the comparative analysis selected the best mark conditions. The new ^99mTc-HYNIC-depreotide was tested by high-performance liquid chromatography (HPLC). The internalization and externalization rates of the new ^99mTc-HYNIC-depreotide were studied in A549 cells. Furthermore, biodistribution of the radiopeptide was studied in nude mice, bearing tumors from human lung carcinoma cells SPC-A1.

Results  The molecular of synthesize depreotide was 1358, and the purity of it was 95.29%. The labeling efficiency of ^99mTc-HYNIC-depreotide was highest at pH 6.0 and 15°C, about (70.95±0.84)%. The labeling rate of the new ^99mTc-HYNIC-depreotide rose to a peak of (20.75±0.48)% at 60 minutes in A549 cells at 37°C and decreased slightly later, while it elevated gradually during the time course at 4°C and 25°C. The internalization rate of the new ^99mTc-HYNIC-depreotide at 37°C increased gradually and reached the peak of 84.4% in 120 minutes, while the externalization rate of the new ^99mTc-HYNIC-depreotide was always less than 20%. In mice bearing the experimental SPC-A1 tumor, the new ^99mTc-HYNIC-depreotide demonstrated a high tumor uptake of (4.05±0.04)% ID/g at 1.5 hpi and remained high ((2.51±0.06)% ID/g) at 4 hpi. The tumor-to-lung activity concentration ratio (T/Lu) was very high for the new ^99mTc-HYNIC-depreotide at all time points. So did the tumor-to-muscle activity (T/Mu) and tumor-to-blood activity concentration ratios (T/Bl).

Conclusion  The findings suggested that the new ^99mTc-HYNIC-depreotide might be a promising candidate radiopharmaceutical for imaging somatostatin receptor positive lung cancer.