ABSTRACT
PMC42 is a new human breast carcinoma cell line. In this report the content of estrogen, progesterone, and glucocorticoid receptors in PMC42 has been determined. The estrogen receptor content (1,750 cytoplasmic sites and 350 nuclear sites) was lower than that described for MCF7 and T47D. The cells would not proliferate in serum-free medium without the addition of beta-estradiol (optimum concentration 10(-8) M) or progesterone (5 X 10(-8) M). The addition of both hormones induced a more than additive increase in proliferation (P less than .005, n = 18). Similarly, addition of insulin or hydrocortisone induced proliferation; however, in this case, the effect of the hormones together was only additive. The addition of tamoxifen (10(-6) M) led to a significant decrease in cell numbers and inhibited the stimulatory effects of 10(-8) M beta-estradiol.
Subject(s)
Breast Neoplasms/physiopathology , Hematopoietic Stem Cells/physiology , Hormones/pharmacology , Receptors, Estrogen/analysis , Receptors, Progesterone/analysis , Breast Neoplasms/analysis , Breast Neoplasms/pathology , Cell Division/drug effects , Cell Line , Cell Nucleus/analysis , Cytoplasm/analysis , Estradiol/pharmacology , Female , Humans , Hydrocortisone/pharmacology , Insulin/pharmacology , Progesterone/pharmacology , Tamoxifen/pharmacologyABSTRACT
A new human breast carcinoma cell line (PMC42) has been further characterized. The cells can grow either as monolayers or as floating cords of cells. The cords grow in suspension for long periods but may spontaneously attach and grow out to form a typical PMC42 monolayer. Ultrastructurally, the cells resemble breast ductal cells in many respects. Both epidermal growth factor (EGF) and prolactin induce ultrastructural changes, and lipid production is stimulated markedly by both factors. EGF also promoted the attachment of the floating cords and the growth of cells from these cords as monolayer cultures. The karyotype of the cord cells is different from that previously described for the monolayer cultures. Cord cells are hypodiploid (mode 39), whereas the monolayer cultures are subtriploid (mode 66). Although the ploidy is different, the karyotypes are related with 9 marker chromosomes being common to both populations. In addition, cultures in which cords have attached and in which cells are growing out as monolayers are bimodal with 10-20% of the cells becoming pseudotetraploid with a mode of 77.
