[Growth inhibiting effect of glucocorticoids and progestins on tumor cells in vitro: effect on the rate of phospholipid reversal].
The growth-inhibiting effect of dexamethasone was estimated by the ability of the hormone to inhibit the proliferative activity of in vitro cultured hepatoma 22 cells. The effect of another steroid proliferation inhibitor, progesterone, was studied in primary cell cultures of human uterine carcinoma. The cytostatic effect of dexamethasone was observed only in slowly proliferating cells and was rapidly reversed by stimulation of cell division with fresh sera. Dexamethasone did not induce any conspicuous changes in the rate of 32P incorporation into hepatoma phospholipids. In 9 out of 14 human uterine carcinomas progesterone inhibited, whereas 17 beta-estradiol stimulated the 32P incorporation into phospholipids (phosphatidylinositol and phosphatidylcholine); this effect was manifested already after 15-min incubation of cells with the hormone. The resistance of uterine carcinoma cells to steroids was paralleled, as a rule, with the increase in the basal level of 32P incorporation into the phospholipids typical of actively proliferating cells. It was assumed that the inhibition of phospholipid exchange rate is related to the earliest manifestations of the growth-inhibiting effect of steroid hormones, at least progestins. In its turn, stimulation of the proliferative activity of cells may relieve this effect of steroids, eventually resulting in a temporary decrease of the cell sensitivity to hormones.
M A
MA
Krasil'nikov
V A
VA
Shatskaia
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002855:Chromatography, Thin Layer; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D008114:Liver Neoplasms, Experimental / Q000473:pathology*; D010743:Phospholipids / Q000378:metabolism*; D011372:Progestins / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects*; D014594:Uterine Neoplasms / Q000473:pathology*
D005938:Glucocorticoids; D010743:Phospholipids; D011372:Progestins; D003907:Dexamethasone
Rost-ingibiruiushchee deĭstvie gliukokortikoidov i progestinov na opukholevye kletki in vitro: vliianie na skorost' obrashcheniia fosfolipidov.