低水平电离辐射的抗肿瘤转移作用及临床应用前景初探

经低剂量Ｘ射线照射后，荷瘤小鼠肺转移结节明显减少；与低剂量环磷酰胺（ＣＹ）合用后也可使荷瘤小鼠的肺转移结节减少。对小鼠体内免疫功能检测研究表明：小鼠脾脏细胞（ＮＫ）活性，ＬＡＫ活性以及对白细胞介素－２（ＩＬ－２）的反应性均显著增强；当与低剂量ＣＹ合用时，上述抗肿瘤免疫功能也提高，可见低水平照射能通过有效地激活体内抗肿瘤免疫功能而具有显著的抗转移效果，它为探讨低水平电离辐射临床应用可能性提供了较为可靠的实验依据。

Anti-metastasis effect of low-level ionizing radiation and possibility of its clinical application

Reduction of pulmonary metastases was observed in tumor-bearing mice exposed to low-dose whole body X-irradiation. The anti-metastasis was better when low-dose X-irradiation was used in combination with low-dose cyclophosphamide. The activities of murine splenic NK cells and II-2- induced LAK cells, and the reactivity of splenocytes to IL-2 increased significantly in tumor-bearing mice treated with low-dose X-irradiation. These anti-tumor immune fuctions were also augmented in the mice treated with both low-dose X-irradiation and cyclophosphamide. These results domonstrated that low-dose X-irradiation had effective antimetastastic effect through the activation of the in vivo anti-tumor immunity, thereby providing a reliable evidence for the possibility of its clinical application.