[Effect of estradiol on RNA biosynthesis of human breast carcinoma cells in vitro].

The possibility of differentiating estrogen-sensitive human breast cancer using incorporation studies with labeled uridine as a precursor of RNA metabolism is described. The purpose of this study was to explore inadequate function of the estrogen receptor as an alternative or supplementary aid in selecting patients for hormonal manipulation. The disadvantage of the test is that only hormone dependence of a proliferating tumor cell population can be evaluated. Highly differentiated breast cancer cells exhibit the greatest estrogen sensitivity. The hormone-dependent tumors of premenopausal women show an increase in RNA synthesis, whereas uridine incorporation appeared to be inhibited in postmenopausal women.