^（131）I－MGb2单克隆抗体对荷胃癌裸鼠放射免疫治疗效应

Radioimmunotherapy for Xenografted Human Gastric Carcinoma with 131I Labelled Monoclonal Antibody

本文通过对６６只荷胃癌裸鼠的实验研究探讨了１３１标记的抗胃癌单抗ＭＧｂ２对人胃癌移植物的放射免疫治疗效应．结果表明：（１）在给予９．２５ＭＢｑ／５０μｇ１３１Ｉ－ＭＧｂ２时，从给药后第二周起，肿瘤体积即明显小于对照，其肿瘤生长抑制率在给药后第三月达８４％．（２）在给予９．２５，１８．５，３７ＭＢｇ等不同剂量时，１３１Ｉ－ＭＧｂ２对肿瘤的生长抑制效应随着剂量的增加而增加，但１８．５ＭＢｑ为安全有效的治疗剂量。此外还观察了各组动物主要脏器和肿瘤组织的病理改变及１３１Ｉ—ＭＧｂ２的体内分布特点，并计算出１３１Ｉ－ＭＧｂ２在小鼠体内的累积吸收剂量。以上结果显示了１３１Ｉ－ＭＧｂ２对人胃癌放射免疫治疗的潜在价值。

In order to test the therapeutic efficacy of 131I--labelled McAb MGb2,66 nude mice with human gastric carcinoma xenografts were investigated.The results showed that(1)when giying 9.25MBq/50μg 131I--labelled MGb2,tumor regression was observed in 3 of 7 animals at the 2th and 3rd week following the injection and the tumor growth was inhibited over 84% in comparison with buffer treated animals;(2)when three different doses of 131I-MGb2 with 9.25MBq, 18. 5MBq and 37MBq were respectively injected into nude mice,the percentage of animals with tumor regression was progressively increased as the dosage of 131I--MGb2 was increasing but 18.5MBq was the safe and suitable dose.In biodistribution study,the results showed a maximum tumor intake of radioactivity of 16.22%(ID/g)at day 7 and a high level at day 14(9.19%)for the 131I--MGb2 group.In contrast,after injection of 131--NMIgG the 131I level in tumor declined exponentially from 6. 69% at day 1 to 0.58% at day 14.Furthermore,tumor in animals given 9.25MBq 131I--MGb2 absorbed 2337cGy during the experiment period of 14 days,and for animal given 131I--NMIgG,tumor absorbed only 680cGy.These findings suggest a potential value of 131I--MGb2 in radioimmunotherapy for human gastric carcinoma.