Janssens J P, Wittevrongel C, De Loecker W
Cancer Res. 1984 Dec;44(12 Pt 1):5650-6.
Human mammary tumor cells in continuous culture (MCF-7 cells) are hormone- and radiosensitive. The interaction of both factors is analyzed. Ionizing irradiation lowers the concentration of both the estradiol and progesterone receptors per cell. The reduction is dose dependent. However, the effects on the cytoplasmic and nuclear forms of the receptors are not similar. For the estradiol receptor, an accumulation in the nuclear fraction is observed 48 hr after irradiation when no appreciable amounts of estrogens are present. After administration of 10(-8) M estradiol, the cytoplasmic clearance is comparable to the unirradiated controls. However, nuclear accumulation is impaired. The processing of the nuclear estrogen receptor remains identical. Nuclear progesterone receptor is not significantly increased due to irradiation in the absence of progestins. Cytoplasmic decrease after incubation with progestins is unaffected. Again, nuclear accumulation is impaired in contrast to the unchanged processing of the nuclear form of the progesterone receptor. A decrease in "nuclear acceptor sites" for both receptors after irradiation may be an explanation for these observations. No significant effects of ionizing irradiation are observed in the initial steps of steroid hormone action.
连续培养的人乳腺肿瘤细胞（MCF - 7细胞）对激素和辐射敏感。分析了这两种因素的相互作用。电离辐射降低了每个细胞中雌二醇和孕酮受体的浓度。这种降低是剂量依赖性的。然而，对受体的细胞质和核形式的影响并不相似。对于雌二醇受体，在不存在大量雌激素的情况下，照射后48小时观察到核部分有积累。给予10(-8) M雌二醇后，细胞质清除率与未照射的对照相当。然而，核积累受到损害。核雌激素受体的加工过程保持不变。在没有孕激素的情况下，辐射不会使核孕酮受体显著增加。与孕激素孵育后细胞质的减少不受影响。同样，与孕酮受体核形式加工过程不变形成对比的是，核积累受到损害。照射后两种受体的“核受体位点”减少可能是这些观察结果的一个解释。在类固醇激素作用的初始步骤中未观察到电离辐射的显著影响。
