Shiu R P
Cancer Res. 1979 Nov;39(11):4381-6.
Prolactin receptors have been identified for the first time in a number of human breast cancer cell lines and a normal human breast cell line maintained in long-term tissue culture. Optimal conditions for determining the binding of 125I-labeled human prolactin to these cells were established. Five different tumor cell lines have different content of prolactin receptors ranging from 2,300 to 26,000 sites/cell. All tumor cell lines contained more prolactin receptors than does one normal breast cell line (1700 sites/cell). The prolactin receptors in these human mammary tumor cells not only bind human prolactin but also recognize other lactogenic hormones such as human growth hormone, human placental lactogen, and sheep prolactin, but not animal growth hormone, which are not lactogenic. The affinity (Ka) of binding of human prolactin to these cells is 4 x 10(9) M-1 (Kd = 2.5 x 10(-10)M). The hormone specificity and affinity for hormone of these human mammary tumor cells are very similar to that found for the rabbit mammary gland. These human mammary tumor cell lines in long-term culture should prove very useful to study the biology of prolactin receptors in living human cells and the role of prolactin in the tumorigenesis of the human breast.
在多种人乳腺癌细胞系以及长期组织培养的正常人乳腺细胞系中首次鉴定出催乳素受体。确定了125I标记的人催乳素与这些细胞结合的最佳条件。五种不同的肿瘤细胞系中催乳素受体含量不同，范围为2300至26000个位点/细胞。所有肿瘤细胞系含有的催乳素受体都比一种正常乳腺细胞系（1700个位点/细胞）多。这些人乳腺肿瘤细胞中的催乳素受体不仅能结合人催乳素，还能识别其他催乳激素，如人生长激素、人胎盘催乳素和绵羊催乳素，但不能识别非催乳性的动物生长激素。人催乳素与这些细胞结合的亲和力（Ka）为4×10⁹ M⁻¹（Kd = 2.5×10⁻¹⁰ M）。这些人乳腺肿瘤细胞对激素的特异性和亲和力与兔乳腺中的情况非常相似。长期培养的这些人乳腺肿瘤细胞系对于研究活体细胞中催乳素受体的生物学特性以及催乳素在人乳腺癌发生中的作用应会非常有用。
