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

我们制作了抗辐射肿瘤和辐射敏感肿瘤小鼠。我们考虑了肿瘤的黏性和宽度，确定了使小鼠适当凋亡的辐射剂量。我们对每只老鼠照射10Gy射线。采用TUNNEL法、DNA阶梯法和流式细胞术检测各组小鼠辐照前后细胞凋亡的发生情况，未发现辐照前后细胞凋亡的发生有明显差异。我们还用SDS-PAGE和western blot方法检测了照射前后每只小鼠DNase II的出现情况，后者的DNase II出现率是前者的5倍。因此，辐射敏感性与体内DNase II水平无关。这一事实与其在体外不同。另一方面，我们利用体内转染试剂将DNase II基因表达到耐辐射肿瘤小鼠体内，并采用TUNNEL法、DNA阶梯法和流式细胞术检测转染和辐照前后细胞凋亡的发生情况。转染成功。但转染后细胞的辐射凋亡无明显变化。因此，转染DNase II很难使辐射敏感性发生变化。

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.