[The effects of progestogens on a human endometrial cancer cell line Ishikawa and a human breast cancer cell line MCF-7].
The effects of Medroxyprogesterone acetate (MPA) and progesterone (P) on DNA and RNA contents of a human endometrial cancer cell line (Ishikawa) and a human breast cancer cell line (MCF-7) were studied using Flow cytometry. The results were as follows. MPA and P at a high dose of 10(-5) M inhibited their cell cycle progression through the G1 phase or G1-S phase boundary and showed a decrease in the number of cells which underwent DNA synthesis and mitosis. P at a low dose of 10(-7) M showed the lengthening of cell cycle time in the S phase. MPA at 10(-7) M had an inhibitory effect on the cell cycle progression of Ishikawa cells similar to that of a high dose of MPA whereas, in the case of MCF-7 cells, it showed a lengthening of duration in the S phase. Therefore, the dose-responsibility of these cells to MPA were shown to be different. A high dose of MPA and P showed a decrease in the cytoplasmic and nuclear RNA contents. A low dose of MPA and P had no marked effect on the RNA contents. From these results, it was clarified that MPA, especially at a high dose, could substantially inhibit RNA synthesis and DNA synthesis with a delay of the cell cycle progression in hormone responsive cancer cells.
D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D004273:DNA, Neoplasm / Q000096:biosynthesis; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008525:Medroxyprogesterone / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology*; D012334:RNA, Neoplasm / Q000096:biosynthesis; D014594:Uterine Neoplasms / Q000378:metabolism* / Q000473:pathology
D004273:DNA, Neoplasm; D012334:RNA, Neoplasm; D011374:Progesterone; D008525:Medroxyprogesterone