小剂量X线全身照射对不同荷瘤时间小鼠的抗肿瘤转移效应

采用肿瘤血道转移模型，选用Ｂ１６黑色素瘤和Ｌｅｗｉｓ肺癌（ＬＬＣ）两种类型细胞，就小剂量Ｘ线全身照射对不同荷瘤时间小鼠的抗肿瘤转移效应进行研究。结果发现，于静脉注射Ｂ１６黑色素瘤或ＬＬＣ细胞后２４ｈ（Ｂ组）或第１３天（Ｃ组）接受７５ｍＧｙＸ线全身照射小鼠的肿瘤肺转移结节数明显低于未照射组（Ａ组）（Ｐ＜０．０５～０．００２）。比较不同照射时间的抗肿瘤转移效果时发现，静注Ｂ１６黑色素瘤的Ｂ组肺转移结节数仅为Ｃ组的５９％，而ＬＬＣ的Ｂ组则为其Ｃ组的７１％。检测注射Ｂ１６黑色素瘤第１４天各组小鼠的免疫功能时发现，Ｂ、Ｃ两组ＮＫ、ＬＡＫ细胞活性及脾细胞对ＩＬ－２反应性明显高于Ａ组（Ｐ＜０．０５～０．００１）。上述结果提示：小剂量Ｘ线全身照射提高荷瘤小鼠的免疫功能可能是其抗肿瘤转移作用的主要机制之一。

The Anti-metastasis Effect of Low Dose Total Body Irradiation on Mice with Variable Tumor Bearing Time

By using the model of tumor blood-borne metastases and two kinds of B16 melanoma and Lewis lung carcinoma(LLC) cells,the antitumor metastasis effect of low dose total body X-ray irradiation on mice with various tumor bearing time was first done in China.The results showed that after venous in jection of B16 melanoma or LLC cells, the number of pulmonary metastatic nodules were lower in those received TBI of 75 mGy X-ray at 24h (group B) or 13th day (group C) than those of nonirradiated mice (group A) (P<0. 05-0. 002).Comparing the efficiency of different exposure time on tumor bearing mice, the number of B16 melanoma metastatic nodules in group B was only 59% of that in group C,while the number of LLC metastatic nodules in group B was only 71% of that in group C. The immunofunctions of the mice assayed on the 14th day after venous in jection of B16 melanoma cells demonstrated that both NK,LAK activities and proliferation response of splenocytes to IL-2 in group B and C were increased significantly (P<0.05-0.001) as compared with those of group A.Our resultsindicated that the immunofunction enhancement of low dose total body irradiation on tumor bearing mice may be one of the main reasons for its antitumor metastasis effect.