Effects of serum-free defined medium on MCF-7 cell nuclear estrogen-receptor levels.
We have examined the effects of serum-free defined medium on filled and unfilled nuclear estrogen-receptor levels in the MCF-7 breast tumor cell line. Transfer of the cells to defined medium resulted in an initial increase in nuclear receptor levels, primarily of unfilled receptors, followed by a decrease of both receptor types to starting levels. Cells maintained in 10% fetal calf serum-containing medium, and sampled identically to those transferred to defined medium, exhibited a gradual but continuous increase in filled nuclear receptor levels accompanied by a decrease in unfilled receptors occurring toward the end of the 1-week experimental period. These results suggest that experiments requiring maximal depletion of endogenous MCF-7 nuclear estrogen will be optimized by repeated washing with estrogen-depleted medium, while limited washing with the same medium may be counter-productive.
D001943:Breast Neoplasms / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003470:Culture Media; D004229:Dithiothreitol / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D005312:Fetal Blood; D006801:Humans; D007700:Kinetics; D011960:Receptors, Estrogen / Q000187:drug effects / Q000378:metabolism*
D003470:Culture Media; D004967:Estrogens; D011960:Receptors, Estrogen; D004229:Dithiothreitol