131Ⅰ标记抗CD20单克隆抗体在荷瘤裸鼠体内的放射免疫显像

目的 探讨131I-anti-CD20McAb经瘤内注射后在荷人Burkitt's淋巴瘤细胞系Raji细胞移植瘤裸鼠体内的放射免疫显像.方法 131I标记物的标记采用IODO-GEN碘化标记;注射标记物后第1、3、7、15天将荷瘤裸鼠SPECT显像后活杀,定标器测量并计算瘤、血等12种器官或组织的%ID/g值,根据MIRD委员会推荐的公式计算肿瘤累积吸收剂量.结果 131I-anti-CD20McAb瘤内注射组的SPECT显像结果优于腹腔注射组和131I-IgG瘤内注射组,该组肿瘤%ID/g值在给药后第1、3和7天分别为后两组的1.4～17倍和1.7～3.7倍,肿瘤累及吸收剂量在给药后第3、7和15天分别为后两组的1.5～2.5倍和6.0～12.6倍.结论 131I-anti-CD20McAb经瘤内途径给药可以使肿瘤获得最高的放射性药物摄取率,为下一步运用该途径进行放射免疫治疗提供了实验依据.     

抗人肝癌单克隆抗体对荷瘤裸鼠的放射免疫定位及治疗

以１３１－碘标记抗人肝癌单克隆抗体Ｈｅｐａｍａ－１（以下简称１３１－Ｈｅｐ）进行裸鼠人原发性肝癌（ＰＨＣ）的体内肿瘤定位（ＲＩＩ）及杀伤作用（ＲＩＴ）的研究。单抗系小鼠ＩｇＧ＿１，选用高效液相法纯化，Ｉｏｄｏｇｅｎ法标记１３１－ＮａＩ。行ＲＩＩ时，每鼠从尾静脉注射１３１－Ｈｅｐ１．１１×１０￣７Ｂｑ；行ＲＩＴ时，从腹腔注入１３１－Ｈｅｐ１．８５×１０￣１０Ｂｑ。结果：Ｈｅｐ能选择性地积聚于肿瘤组织，对肿瘤生长有明显的抑制作用，并能显著延长荷瘤鼠的生存时间。     

^131I标记抗CD20单克隆抗体在荷瘤裸鼠体内的放射免疫显像

目的探讨^131I-anti-CD20McAb经瘤内注射后在荷人Burkitt’s淋巴瘤细胞系Raji细胞移植瘤裸鼠体内的放射免疫显像。方法^131I标记物的标记采用IODO-GEN碘化标记；注射标记物后第1、3、7、15天将荷瘤裸鼠SPECT显像后活杀，定标器测量并计算瘤、血等12种器官或组织的％ID／g值，根据MIRD委员会推荐的公式计算肿瘤累积吸收剂量。结果^131I-anti-CD20McAb瘤内注射组的SPECT显像结果优于腹腔注射组和^131I-IgG瘤内注射组，该组肿瘤％ID／g值在给药后第1、3和7天分别为后两组的1．4～17倍和1．7～3．7倍，肿瘤累及吸收剂量在给药后第3、7和15天分别为后两组的1．5～2．5倍和6．0～12．6倍。结论^131I-anti—CD20McAb经瘤内途径给药可以使肿瘤获得最高的放射性药物摄取率．为下一步运用该途径进行放射免疫治疗提供了实验依据。     

放射档记抗HBx单克隆抗体在荷人肝癌裸鼠模型中的放射免疫定位研究

乙型肝炎病毒Ｘ抗原同原发性肝细胞癌之间的密切关系已引起人们的广泛注意。研究表明Ｘ抗原在肝癌组织中的表面活跃，抗ＨＢｘ抗体对肝癌组织有较强的特异性亲和力。本实验同德国癌症中心合作，应用基因工程技术生产的Ｘ抗原免疫动物，成功地制备了抗ＨＢｘ单克隆抗体，并应用＾［３］Ｉ标记抗ＨＢｘ单抗进行了人肝癌裸鼠模型的放射免疫显像及放射组织分布研究。γ照相结果显示实验组给药后第３天肿瘤即获阳性显像，第７天时更加清晰     

抗乳腺癌人单克隆抗体用于裸鼠移植瘤显像

乳腺癌的发病率占恶性肿瘤的7～10％,是女性癌症致死的主要原因之一。在我国女性乳癌发病率约为23/10万人,仅次于子宫颈癌。以单克隆抗体为工具,探索乳腺癌的诊断和治疗问题,有重要临床价值。由于人体对鼠单克隆抗体产生明显排异反应,所以只有制备人单克隆抗体才能有效、安全地解决体内定位诊断和治疗的问题。为此,我们采用人鼠种间杂交骨髓瘤细胞SMH-D_(33)与人淋巴结B细胞融合,制备了人单克隆抗体CH·1(HMcAb-CM·1),进行实验研究,现报道如下。     

抗前列腺特异膜抗原单克隆抗体的标记及在荷瘤裸鼠体内的分布研究

目的:研究125I标记的抗前列腺特异膜抗原(PSMA)单克隆抗体(125Ⅰ-Ed-5)及正常小鼠IgG(125Ⅰ-NMIgG)在荷人前列腺癌瘤裸鼠体内的分布,探讨应用125Ⅰ-Ed-5进行放射免疫显像诊断和放射免疫治疗实验性人前列腺癌的可行性.方法:建立荷人前列腺癌裸鼠移植瘤模型,用125Ⅰ标记抗PSMA单克隆抗体Ed-5和NMIgG,125Ⅰ-Ed-5和125Ⅰ-NMIgG经尾静脉注入荷瘤裸鼠体内,于注射后24、48、72、120小时分批处死,测定肿瘤和血液、肝、肺等重要脏器的单位重量放射性比值(T/NT)、各组织摄取百分比(%ID/g),研究其在荷瘤裸鼠体内的放射性分布情况.结果:125Ⅰ-Ed-5的标记率为72.3%,放射性比活度为55.2MBq/mg,放射性化学纯度是90.2%,免疫活性分数为63%.在注射125Ⅰ-Ed-5后24～120小时内,裸鼠体内肿瘤部位出现选择性放射性浓聚:各组织的T/NT比值在72h达到最高,其中肿瘤/肌肉高达6.36.而在注射125Ⅰ-NMlgG的对照组中,裸鼠体内未见放射性浓聚,呈全身均匀性分布.结论:标记后的125Ⅰ-Ed-5免疫活性没有改变,在裸鼠体内对前列腺癌移植瘤有靶向定位作用,为进一步应用125Ⅰ-Ed-5进行前列腺癌放射免疫显像和放射免疫治疗的实验研究奠定基础.     

卵巢上皮性癌体内放射免疫显象后的免疫组化观察

We report the results of our immunohistochemical study on the distribution and the retention time of the injected labelled antibodies in both primary and recurrent ovarian epithelial carcinomas and the regional lymph nodes, following the radioimmunodetection with injection of 131I-labelled polyclonal antibodies (including 5 cases of intravenous injection group and 35 cases of subcutaneous injection group). Six other tumors or tumor-like lesions, 8 normal ovaries and 7 normal fallopian tubes were used for control. The results demonstrated: 1. The labelled antibodies were specific for ovarian epithelial carcinoma, 2. The concentration of the labelled antibodies in the lymph node metastasis was higher in the subcutaneous injection group than in the intravenous injection group. Therefore, the subcutaneous route should be used both for imaging and radioimmunotherapy of lymph node metastasis, 3. The retention time of the antibodies in the lymph node metastasis was not more than 24 days. With this reference, the total dose of radioimmunotherapy can be calculated.     

^I31I标记抗胃癌单克隆抗体3G9在荷瘤裸鼠体内定位的研究

3G9 is one of murine monoclonal antibodies against human gastric cancer produced by immunization of multiple human gastric cancer cell lines in sequence in our institute. In vitro 3G9 had a high specific binding capacity with human gastric cancer tissues and cell lines. 131I-labeled 3G9 and 125I-labeled normal murine IgG were injected into nude mice bearing xenograft or cells M85 and MGC803 of human gastric cancer in order to compare the differences between 3G9 and IgG distributions in tumor and various normal tissues. The distribution of radioactivity in vivo suggested that 131I-3G9 had a good ability of localization in tissues of gastric cancer. The tumor/blood, tumor/liver, tumor/stomach and tumor/muscle ratios were 1.23, 4.72, 7.25 and 10.28, respectively. The localization index of tumor was 2.62 at 48 hr and 4.13 at 96 hr. The radioactivity of 125I-IgG in tumor was much lower than that of 131I-3G9 and tended to decrease with time. The results of scintigraphy showed that there was distinct radioactivity in the tumor. In this group of nude mice, the minimum weight and diameter of tumor was 83 mg and 4 mm, respectively. The method of scintigraphy to analyse variation of radioactivity in tumor-bearing nude mice was established. The results showed that monoclonal antibody 3G9 could be useful in localization and treatment of human gastric cancer.     

~（99m）Tc标记单克隆抗体对荷肺腺癌裸鼠的放射免疫显像研究

应用~（９９ｍ）Ｔｃ直接标记还原单克隆抗体的方法，对荷人肺腺癌裸鼠进行放免显像研究。经测定，此方法的标记率为９６％，经免疫组化法及间接免疫荧光法证实，标记后抗体仍保持较好的免疫活性。在荷瘤裸鼠体内的分布实验表明，经尾静脉注射标记抗体１６小时，在肿瘤组织中出现相对较高的特异性浓聚。γ－闪烁图显示出清晰的肿瘤图像。     

抗人肺癌单抗LC—1对荷人肺腺癌裸鼠的放射免疫定位

我们以荷人肺腺癌（ＬＡＸ－８３）裸鼠为动物模型，注入＾１３１Ｉ－ＬＣ－１，结果显示：注入１３１＾Ｉ－ＬＣ－Ｉ９６小时后，除牌、肾外，其余组织每克所含ｃｐｍ值均小于相同重量的肺癌组织；注入＾１３１Ｉ－ＬＣ－Ｉ１２０小时后，除血液外，其余各组织每克所含ｃｐｍ值均小于肺癌组织；肺腺癌细胞上＾１３１Ｌ－ＬＣ－１能被部分洗脱，但还保持一定含量。     

131I标记抗人成骨肉瘤单抗荷瘤裸鼠体内分布和放射免疫显像研究

目的 :研究13 1I标记抗人成骨肉瘤单克隆抗体在荷人成骨肉瘤裸鼠体内分布和放射免疫定位显像。方法 :采用Iodogen固相法标记制备13 1I HOSMcAb。 2 5只荷瘤裸鼠随机分为 5组 ,分别腹腔注射13 1I HOSMcAb后 ,于6、12、2 4、48和 72h 5个时间段进行裸鼠的体内分布研究 ;对 5只荷瘤裸鼠分别腹腔注射13 1I HOSMcAb后 ,于 6、12、2 4、48和 72h 5个时间段进行荷瘤裸鼠的放射免疫定位显像研究。结果 :在荷人成骨肉瘤裸鼠腹腔注射13 1I HOSMcAb后 ,12h肿瘤与血的T/NT比值为1 3 7,2 4h为 3 75 ,48h达到最高为 5 2 4。腹腔注射13 1I HOSMcAb后 ,12h肿瘤部位即可见明显放射性浓聚 ,48h本底明显降低 ,肿瘤呈放射性热区。结论 :13 1I HOSMcAb对成骨肉瘤定向性较好 ,对放射免疫定位显像有利 ,为进一步放射免疫治疗研究提供了理论基础     

Radiolocalization of xenografted human lung cancer with monoclonal antibody 8 in nude mice

A monoclonal antibody (MAb) 8 [immunoglobulin G3 (IgG3)], directed against a Mr 48,000 human lung cancer-associated antigen, was radiolabeled with either 125I or 131I, and its biodistribution was studied in nude mice bearing human lung cancer (TKB-2) over a 7-day period. 125I-labeled MAb 8 increased its binding to the tumor during the period, while the binding of 125I-labeled control IgG3 declined after initial uptake. At Day 7, percentages of injected dose of 125I-labeled MAb 8 bound to the tumor rose to 7.4%, which was a 4.4-fold increase from Day 1 and 16-fold binding of 125I-labeled control IgG3 at the same day. Tumor:blood ratios became 2.7:1 at Day 7, and tumor:liver, tumor:spleen, and tumor:kidney ratios were more than 9:1. Normal organs showed no significant uptake of 125I-labeled MAb 8, compared with those of 125I-labeled control IgG3. A clear image of the xenografted tumor was obtained at Day 5, and it further improved at Day 7, when 60% of whole body radioactivity was localized to the tumor. Autoradiography of the mouse with tumor confirmed the excellent localization of 125I-labeled MAb 8 to the tumor, although the radioactivity of the tumor was not uniformly distributed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that most of the radioactivity was present at the tumor in the form of degraded immunoglobulin. MAb 8 has a potential usefulness in the diagnosis and treatment of lung cancer.     

Biodistribution and tumour localization of radiolabelled monoclonal antibody during continuous infusion in nude mice and with human tumour xenografts

The distribution in athymic nuce mice of radiolabelled monoclonal antibody 791 T/36 has been assessed during continuous infusion from subcutaneously implanted Alzet Osmotic Minipumps. During prolonged administration (up to 15 days) blood levels continued to rise. At 15 days, distribution of radiolabel was virtually identical to that seen after a single parenteral dose. Blood levels were in good agreement to those expected from whole body levels indicating satisfactory entry of antibody into the vascular compartment. Gel filtration chromatography of osmotic minipump contents and circulating radiolabel showed that the antibody had retained its structural integrity. In mice with human tumour xenografts examined after a 5-day infusion of a mixture of ¹³¹I-791 T/36 antibody and ¹²⁵I-control IgG2b, blood levels of both radiolabels were comparable to those expected from whole body levels and there was effective tumour localization of the antibody to 2.5 times that of control IgB.These studies have demonstrated that prolonged administration of monoclonal antibody is feasible, that antibody enters the vascular compartment satisfactorily and that it can then localize in tumour deposits.     

RADIOIMMUNOLOCALIZATION OF XENOGRAFTED HUMAN GASTRIC ADENOCARCINOMA WITH ~(131)I-LABELED MONOCLONAL ANTIBODY RWS_(4) IN NUDE MICE

The monoclonal antibody (MAb) RWS4 specific to membrane-associated antigen of human gastric adenocarcinoma was purified by protein A-Sepharose 4B affinity chromatography and labeled with 131I by chloramine-T method. 131-RWS,, was injected (65 μCi/10μg/0.2 ml, intraperitoneally) into the stomach cancer-bearing nude mice (solid tumor about 1 cm in diameter), and its biodistribution was studied by SPECT and gamma-counter over a peroid of 7 days. A clear image of transplanted tumor was observed on the 4th day, and the image became more clear on the 6th day. After SPECT scanning, the animals were killed on the 3rd to 7th day separately and radioactivity was detected in various organs. The ratios of T/NT were calculated. The results were shown as follows: tumor/blood, was 3.41±0.29 on the 6th day and the tumor/other organs (liver, spleen, stomach, lung, heart, kidney and brain etc.) were>3. The specificity of the 131I-RWS4 was 7.74±0.65.     

Enhanced clearance of radiolabeled murine monoclonal antibody by a syngeneic anti-idiotype antibody in tumor-bearing nude mice.

A syngeneic anti-idiotype monoclonal antibody (MAb) (CM-11) directed against an anti-carcinoembryonic antigen (CEA) murine MAb (NP-4) was evaluated as a second antibody (SA) to promote the rapid clearance of radiolabeled NP-4 from the blood. Initial studies confirmed that CM-11 IgG removed 131I-NP-4 IgG from the blood as effectively as a polyclonal donkey anti-goat IgG removed 131I-goat IgG. However, use of an F(ab')2 in place of either the NP-4 or CM-11 IgG was not as effective in removing primary radiolabeled antibody, despite the formation of high-molecular-weight complexes. In accordance with previous results, the timing and dose of the SA injection was critical for optimizing tumor uptake and improving tumor/non-tumor ratios. In nude mice bearing GW-39 human colonic tumor xenografts, a delay in the injection of CM-11 by 48 hr after injection of radiolabeled NP-4 was optimal, since this allowed maximum tumor accretion. At a 200:1 CM-11:NP-4 ratio, tumor uptake was reduced, suggesting inhibition of NP-4 binding to CEA within the tumor. Despite optimizing tumor uptake by delaying SA injection and adjusting its dose, the percentage of 131I-NP-4 in the tumor decreased 2- to 3-fold within 2 days after CM-11 injection. A similar effect was seen for 111In-labeled NP-4 IgG with CM-11. Injection of excess unlabeled NP-4 given to block CM-11 shortly after its injection failed to curtail the loss of NP-4 from the tumor. Our results suggest that high blood levels of MAb are important for sustaining NP-4 in the tumor. Radiation-dose predictions derived from biodistribution studies indicate that a higher tumor dose may be delivered using the SA method than with either 131I-NP-4 IgG or F(ab')2 alone. Use of the SA method with 90Y-labeled NP-4 IgG, as modeled from biodistribution studies with 111In-NP-4 IgG, would likely be limited by liver toxicity.     

Evaluation of L6, an anti-carcinoma murine monoclonal antibody, in tumor-bearing nude mice

L6 is a murine monoclonal antibody (MAb) binding to cells of most human carcinomas, mediating antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity, and inhibiting tumor growth in nude mice [10]. Fab and F(ab')2 fragments of L6, as well as intact MAb, have been evaluated for immunospecific localization in nude mice xenografted with a human lung carcinoma. They were compared with preparations of an isotype-matched control immunoglobulin, P1.17, after labelling with 125I or 131I. L6 Fab fragments prepared from MAb L6 and labelled with 67Ga via desferrioxamine were also tested. The data suggest that MAb L6 may be useful for in vivo detection of human carcinomas.     

抗Ⅳ型胶原酶单抗在人肺癌裸鼠移植模型中的免疫显像

背景与目的：基质金属蛋白酶(matrix metalloproteinases,MMPs)在肿瘤生长和转移的多个环节发挥着重要作用,Ⅳ型胶原酶作为MMPs家族的重要成员之一已成为肿瘤研究的新靶点。本文通过荷瘤裸鼠的显像实验,评价抗Ⅳ型胶原酶单克隆抗体3G11的体内特异性分布。方法：用lodogen法将^131I或^125I标记亲和纯化的单抗3G11,ELISA检测标记前后单抗的活性变化。^131I-3G11在3种不同体系(生理盐水,小牛血清,裸鼠血清)中37℃温育,检测体外稳定性。每只正常BALB／c小鼠静脉注入388．5kBq ^125-I3G11,测定单抗的药动学指标。建立人高转移PG肺癌细胞移植肿瘤模型的BALB/c(nu/nu)裸鼠每只静脉注入6．44MBq ^131I-3G11,进行免疫显像。结果：单抗3G11经亲和纯化后纯度大于98％,碘标记使单抗活性降低10％～20％。单抗3G11的体内代谢呈二室模型分布,T1/2α为7．2h,T1/2β为345．2h。^131I-3G11标记物体外72h能基本保持稳定,在荷瘤裸鼠体内72h显像清晰,至120h效果更明显。结论：显像实验证明单抗3G11对肿瘤组织有较好的特异性和亲和性。     

Radioimmunodetection of human lung cancer xenografts by isotope labeling monoclonal antibody ALT-04 in nude mice

Three nude mouse models bearing the human lung cancer were established from two fresh surgical specimens and one cell line. Tumor histological structure and cell morphology were similar before and after transplantation. The monoclonal antibody ALT-04 (McAb ALT-04) against human lung cancer was labeled by 125I, 131I and 201Tl. Radioimmunodetection study showed that all the three kinds of xenografts in nude mice were specifically located by McAb ALT-04. Imaging examination confirmed the ability of isotope labeling McAb ALT-04 to detect the presence of transplanted human lung cancer tissues without the aid of background subtraction manipulations. It is suggested that McAb ALT-04 have the possibility of locating in the tumor diagnosis and guiding in the treatment.     

Biodistribution and radiation dose estimates for yttrium- and iodine-labeled monoclonal antibody IgG and fragments in nude mice bearing human colonic tumor xenografts

An anti-carcinoembryonic antigen murine monoclonal antibody designated NP-4, and its F(ab')2 and Fab' fragments, were coupled to the 1/1 mixture of 1-isothiocyanato-benzyl-3-methyl- and 1-methyl-3-isothiocyanato-benzyl-diethylenetriaminepentaacetic acid chelate and labeled with 111In or 88Y. Biodistribution studies in nude mice bearing a human colonic tumor xenograft were performed with these labeled conjugates, and comparisons were made to unconjugated NP-4 IgG and fragments labeled with 131I. Regardless of the labeling method, higher tumor uptake was found with the intact IgG than with the fragments, but due to faster blood clearance, tumor/blood ratios were higher for the fragments than for the IgG. Tumor uptake for the radiometal-labeled NP-4 was generally higher than the 131I-labeled NP-4. Tumor/nontumor ratios for the liver, kidney, and spleen were higher for the 111In- and 88Y-labeled NP-4 IgG than the respective radiometal-labeled fragments, but tumor/nontumor ratios for the 131I-NP-4 fragments were higher than the 131I-NP-4 IgG. Radiometal uptake in the kidney was approximately 8 and 150 times higher than the 131I-NP-4 F(ab')2 and Fab', respectively, and the clearance of radiometal activity in the kidneys was approximately 10 times slower than the radioiodine. Quantitation of 88Y or 111In activity in the femur showed 3-5%/g for the IgG and F(ab')2 and only 1-2%/g for the Fab'. The amount of radioactivity in the femur remained constant over time, and between 60 and 100% of the 88Y activity remained after flushing the core of the femur with saline, whereas 50-70% of the 111In and only 25-30% of the 131I activity remained after washing. Radiation dose estimates derived from these studies suggest that at the maximal tolerated dose 131I-NP-4 IgG would deliver 5.9 times the dose to the tumor as 90Y-labeled NP-4 IgG. 90Y-labeled fragments would not be useful due to higher doses to the kidneys than to the tumor. However, with 131I-labeled IgG and fragments there is greater flexibility to permit tumoricidal doses without excessive toxicity to the normal tissues.