小剂量X射线全身照射提高小鼠抗瘤能力的整体和离体研究

Augmentation of antitumor effects in mice by low dose X-ray whole body irradiation :in toto and in vitro studies

本文作者利用肿瘤血道转移和自发转移模型，从整体和离体两方面观察７５ｍＧｙＸ射线全身照射对小鼠抗瘤能力的影响。结果发现：①与假照组相比，照射组小鼠Ｂ１６黑色素瘤血道肺转移结节数明显降低（Ｐ＜０．０１）；过继转移至同系小鼠体内的脾细胞，可明显抑制Ｌｅｗｉｓ肺癌（ＬＬＣ）的局部生长和自发肺转移（Ｐ＜０．０５～０．０１）。②与假照组相比，体外检测照射组小鼠脾细胞对ＣｏｎＡＩＬ－２反应性增强（Ｐ＜０．０１），ＮＫ活性明显提高（Ｐ＜０．０１）；体内检测其巨噬细胞功能也显著增强（Ｐ＜０．０１），１２５ＩＵｄＲ标记黑色素瘤细胞在肺内的存留率显著降低（Ｐ＜０．０１）。上述结果提示，小剂量辐射可明显提高小鼠的抗瘤能力；机体免疫功能的增强可能是其抗肿瘤效应的主要机理之一。

By using the models of hematogenous and spontaneous tumor metastases,the influence of 75mGy X-ray whole-body irradiation on antitumor ability of mice was investigated in toto and in vitro.The results were as follows:(1)As compared with unirradiated control mice,the number of hematogenous pulmonary metastatic colonies of B16 melanoma decreased obviously(P<0.01) in 75mGy X-ray irradiated mice;the splenocytes of the irradiated mice adoptively transferred to syngeneic mice significantly inhibited Lewis lung carcinoma(LLC) growth and spontaneous pulmonary metastasis(P<0.05～0.01).(2) Comparing with those of unirradiated control mice,the in vitro response of NK cytotoxity of the splenocytesfrom irradiated mice to ConA and IL-2 increased greatly,the macrophage function was higher and the retention of 125 IUdR-labeled B16 melanoma cells in lungs was lower for the irradiated mice tested in vivo(P<0.01).Our results indicate that low dose radiation can augment murine antitumor ability;the enhancement of immunofunctions may be one of the main reasons for its antitumor effects.