1. Medical Physics Department, School of Medical Basic Sciences, Tehran University of Medical Sciences, Tehran, Iran ; 2. Cellular and Molecular Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Cell J. 2011 Summer;13(2):83-90. Epub 2011 Aug 24.
In this study, we investigated the combined effect of 2-Methoxyestradiol (2ME2) and (60)Co on the cytogenetic damage of iododeoxyuridine (IUdR) in the spheroid model of U87MG glioblastoma cancer cell lines by alkaline comet assay.
U87MG cells were cultured as spheroids with diameters of 350 µm. As control, the spheroids of one plate were not treated. Other cultures were pretreated with 2ME2 (250 µM) for one volume doubling time (1 VDT). After this time, the subsequent treatments were performed according to the following groups: Vehicle (this sample was not treated in the 2(nd) VDT) Treated with 2ME2 (250 µM) for 1 VDT Treated simultaneously with 2ME2 (250 µM) and IUdR (1 µM) for 1 VDT Treated with 2ME2 (250 µM) for 1 VDT then irradiated with (60)Co (2 Gy) Treated simultaneously with 2ME2 (250 µM) and IUdR (1 µM) for 1 VDT then irradiated with (60)Co (2 Gy) Then the DNA damage was evaluated using the alkaline comet assay method.
The results showed that 2ME2 in combination with gamma irradiation of (60)Co significantly (p<0.001) increased the DNA damage by IUdR as compared to the control group. Thus the combination of these two agents increased the cytogenetic effects of IUdR in the spheroid culture model of U87MG glioblastoma cell lines.
By inhibiting the HIF-1α protein and preventing the G0 phase arrest, 2ME2 causes an increased progression into S phase and increases the IUdR absorption. Then the DNA damage in the spheroid cells increases as the uptake of IUdR is increased. These results suggest that the combined use of 2ME2 and (60)Co can increase the radiosensitization effect of IUdR.
本研究通过碱性彗星试验，探讨 2-甲氧基雌二醇（2ME2）和（60）Co 对碘脱氧尿苷（IUdR）在 U87MG 神经胶质瘤细胞球体模型中的细胞遗传学损伤的联合效应。
将 U87MG 细胞培养为直径 350μm 的球体。作为对照，一个平板的球体不进行处理。其他培养物用 2ME2（250µM）预处理一个倍增时间（1VDT）。在此时间之后，根据以下组进行后续处理：载体（此样品在第 2VDT 中未进行处理） 用 2ME2（250µM）处理 1VDT 同时用 2ME2（250µM）和 IUdR（1µM）处理 1VDT 用 2ME2（250µM）处理 1VDT 然后用（60）Co（2Gy）照射 同时用 2ME2（250µM）和 IUdR（1µM）处理 1VDT 然后用（60）Co（2Gy）照射 然后用碱性彗星试验方法评估 DNA 损伤。
结果表明，与对照组相比，2ME2 与γ射线（60）Co 联合使用显著（p<0.001）增加了 IUdR 引起的 DNA 损伤。因此，这两种药物的联合使用增加了 U87MG 神经胶质瘤细胞球体培养模型中 IUdR 的细胞遗传学效应。
通过抑制 HIF-1α 蛋白并防止 G0 期停滞，2ME2 导致 S 期进展增加，并增加 IUdR 的吸收。然后，随着 IUdR 摄取量的增加，球体细胞中的 DNA 损伤增加。这些结果表明，2ME2 和（60）Co 的联合使用可以增加 IUdR 的放射增敏作用。
