Dao T L, Chistakos S S, Varela R
Cancer Res. 1975 May;35(5):1128-34.
Biochemical parameters characterizing growth, functional activity, and hormone dependence were compared in the normal mammary gland, the 7,12-dimethylbenz(a)anthracene-induced hyperplastic aveolar nodule (HAN), and the mammary tumor in the rat. The rate of DNA synthesis in HAN was significantly lower than the rates in either the normal mammary gland cells or the mammary tumor cells cultured in medium containing identical hormone supplement for the same duration of time. The rate of casein synthesis in the explants of pregnant rat mammary gland and HAN was greatly stimulated when cultured in medium containing insulin, cortisol, and prolactin. The mammary tumor, however, failed to produce an increase in casein synthesis under the same experimental conditions. The specific estradiol-binding proteins were either absent or present in very low concentrations in HAN. In contrast, mammary tumor cytosol contained high concentrations of specific estrogen-binding proteins. The normal mammary gland, in spite of its low cellularity, had twice as many estradiol-binding macromolecules as did HAN. Altogether, these results show that HAN cell populations differ from normal mammary gland and mammary tumor cells by their nonresponsiveness to hormonal stimulation for growth and by their lack of specific receptors for extradiol. They retain, however, the functional capacity to synthesize casein, a biochemical property that the mammary tumor does not posses.
对正常乳腺、7,12 - 二甲基苯并(a)蒽诱导的增生性腺泡结节（HAN）和大鼠乳腺肿瘤中表征生长、功能活性及激素依赖性的生化参数进行了比较。在含有相同激素补充剂的培养基中培养相同时间后，HAN中DNA合成速率显著低于正常乳腺细胞或乳腺肿瘤细胞中的速率。当在含有胰岛素、皮质醇和催乳素的培养基中培养时，妊娠大鼠乳腺和HAN外植体中的酪蛋白合成速率受到极大刺激。然而，在相同实验条件下，乳腺肿瘤的酪蛋白合成并未增加。HAN中要么不存在特异性雌二醇结合蛋白，要么其浓度非常低。相比之下，乳腺肿瘤细胞溶质含有高浓度的特异性雌激素结合蛋白。正常乳腺尽管细胞数量少，但其雌二醇结合大分子数量是HAN的两倍。总之，这些结果表明，HAN细胞群体与正常乳腺和乳腺肿瘤细胞不同，它们对激素刺激生长无反应，且缺乏雌二醇特异性受体。然而，它们保留了合成酪蛋白的功能能力，这是乳腺肿瘤所不具备的生化特性。
