^（125）Ⅰ标记单抗MC5对载人肠癌裸鼠移植瘤生长的促进作用

The Stimulating Effect of^(125)I-labeled MC5 Monoclonal Antibody on human Rectal Adenocarcinoma Growth in Nude Mice

用１２５Ⅰ标记单抗ＭＣ５对载人直肠癌裸且进行实验性治疗研究。１２５Ⅰ－－ＭＣ５对体外直肠癌细胞的特异性结合率为０．４４４。每只小鼠腹腔注射单次剂量７．５ＭＢｑ的１２５Ⅰ－－ＭＣ５发现在４９ｄ后有促进肿瘤生长作用。平均瘤重增加１．５９９６±０．４０９９８。对照组为０．６６４６±０．３２６６ｇ，但两组比较没有统计学上差异（Ｐ＜０．２）。３Ｈ－－ＴｄＲ掺入肿瘤细胞的量检测，１２５Ⅰ－－ＭＣ５组为１５５３０．４±１３２７．６ｄｐｍ／ｇ，对照组为８６０８．５±１２５５．２ｄｐｍ／ｇ。两组比较有非常显著差异（Ｐ＜０．０１）。实验结果提示：抗结肠癌单抗ＭＣ５可以用作人肠癌的导向治疗。但１２５Ⅰ不是一个好的导向治疗标记同位素。低剂量幅射可能促进肿瘤生长。

A study on human rectal adenocarcinoma xenograft in nude mice treated by 125I labeled MC5 monoclonal antibody is reported.The specific binding rate of the 125I-MC5 to rectal cancer cells in vitro was 0.444.Each animal received(i.p)a single dose of 7. 5 MBq. It was found that 125I-MC5 was able to stimulate tumor groWth and the tumor mean weight increased 1. 5996±0.40999 at the 49th day after injection.While in the control group the mean weight in creased 0. 6646 ±0. 3266g, but the difference was not statistically significant (p>0.05).The amounts of 3H-TdR incorporation in experimental group and control group were 15530.4 ± 1327.6 Dpm/g and 8608.5±1255.2 Dpm/g respectively. The difference was statistically significant(p<0.01).The result suggests that McAb MC5 may be used in targeting therapy of human rectal cancer but 125I isn't a good labeled isotope in the targeting therapy.The low dose radiation may stimulates tumor growth.