The basic research about gene-radiation therapy using DNase II gene

我们制作了耐辐射肿瘤和辐射敏感肿瘤的小鼠。我们考虑了肿瘤的粘性和宽度，确定了合适的辐射剂量，使小鼠有适当的细胞凋亡。我们对每只小鼠进行10Gy伽马射线照射。用隧道法、DNA梯形条带和流式细胞仪检测照射前后各组小鼠细胞凋亡的发生情况，未发现照射前后小鼠细胞凋亡发生的明显差异。用SDS-PAGE和免疫印迹法检测照射前后每只小鼠的DNase II的出现情况，后者DNase II的出现是前者的5倍。因此，辐射敏感性与体内DNase II水平无关。另一方面，我们用体内转染剂将DNase II基因表达到辐射耐药肿瘤小鼠体内，并用隧道法、DNA梯形图和流式细胞术检测了转基因和照射前后细胞凋亡的发生情况。转染法成功。而辐射诱导的细胞凋亡不受基因转染组的影响。因此，DNase II基因的导入很难改变其辐射敏感性。

We made mice with radiation-resistant tumor and radiation-sensitive tumor. We considered stickiness and width of tumor and decided the radiation dose which made a proper apoptosis on the mice. We irradiated 10Gy gamma ray to each mice. We checked the occurrence of apoptosis on each mice before and after the irradiation with TUNNEL method, ladder of DNA and flowcytometry Then we did not detect the apparent difference of occurrence of apoptosis between the former and the latter. We also checked the occurrence of DNase II on each mice before and after the irradiation with SDS-PAGE and the western blot method, and the occurrence of DNase II on the latter was five times as the occurrence of DNase II on the former. Therefore the radiation sensitivity cannot correlate with DNase II level in vivo. This fact differs from its in vitro.On the other hand, we expressed DNase II gene to the mice with radiation-resistant tumor using in vivo transfection regent, and checked the occurrence of apoptosis before and after the transfection and the irradiation with TUNNEL method, ladder of DNA and flowcytometry. The transfection was successful. However, the radiation apoptosis did not change by the transfection. Therefore it is difficult that the transfection of DNase II makes a change of radiation sensitivity.