Pimm M V, Baldwin R W
Eur J Cancer Clin Oncol. 1984 Apr;20(4):515-24. doi: 10.1016/0277-5379(84)90238-4.
Monoclonal antibody 791T /36 (IgG2b) directed against human osteogenic sarcoma-associated antigens has been used to examine quantitative aspects of in vivo tumour localization into osteogenic sarcoma xenografts. With small doses of antibody (less than 40 micrograms) the extent of localization consistently correlated with xenograft size, an average of 36% of the total body burden of radiolabelled antibody being present/g tumour after 2 or 3 days. Parallel studies with labelled control IgG2b showed a similar correlation, but only 7% of the total body radiolabel was localized/g tumour. With the 791T /36 antibody, the tumour: blood ratio did not increase with tumour size except with the largest xenografts (800-900 mg), where up to 30-40% of the total body radioactivity was localized within the xenografts and this was sufficient to produce a measurable decrease in its blood level. There was also a significant correlation between the dose of injected radiolabelled antibody and the amount localized in xenografts but only up to a dose of about 100 micrograms, beyond which the amount localized was not directly proportional to the injected dose. The maximum level of radiolabelled antibody localized in xenografts was 70 micrograms antibody/g tumour tissue. It was not possible to displace radiolabelled antibody already localized in xenografts by systemic administration of a large dose of unlabelled antibody. The rate of localization of antibody was such that maximum uptake, measured as the absolute amount of localized antibody, was seen 2-4 days after injection. After this time the absolute amount of antibody in the tumours declined, but not as rapidly as the blood and whole body levels, so that the tumour: blood ratio continued to increase with time.
针对人骨肉瘤相关抗原的单克隆抗体791T /36（IgG2b）已被用于研究体内肿瘤在骨肉瘤异种移植中的定位定量情况。使用小剂量抗体（小于40微克）时，定位程度始终与异种移植瘤大小相关，注射2或3天后，每克肿瘤中存在的放射性标记抗体平均占全身负荷的36%。用标记的对照IgG2b进行的平行研究显示了类似的相关性，但每克肿瘤中仅定位了全身放射性标记的7%。使用791T /36抗体时，除了最大的异种移植瘤（800 - 900毫克）外，肿瘤与血液的比率并未随肿瘤大小增加，在最大的异种移植瘤中，全身放射性的30 - 40%定位在异种移植瘤内，这足以使其血液水平出现可测量的下降。注射的放射性标记抗体剂量与在异种移植瘤中定位的量之间也存在显著相关性，但仅在约100微克的剂量范围内，超过该剂量后，定位的量与注射剂量不成正比。在异种移植瘤中定位的放射性标记抗体的最大水平为每克肿瘤组织70微克抗体。通过全身给予大剂量未标记抗体，无法取代已定位在异种移植瘤中的放射性标记抗体。抗体的定位速率使得在注射后2 - 4天观察到以定位抗体的绝对量衡量的最大摄取量。在此之后，肿瘤中抗体的绝对量下降，但不如血液和全身水平下降迅速，因此肿瘤与血液的比率随时间持续增加。
