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Estrogen-induced synthesis and secretion of proteins in the human breast cancer cell line MCF-7

1981; Pergamon Press; Volume: 15; Linguagem: Inglês

10.1016/0022-4731(81)90300-9

1878-2353

Nicole Mairesse, N. Devleeschouwer, Guy Leclercq, P. Galand,

Biotin and Related Studies

The estrogen-induced tumor protein previously described by us in the receptor-positive MCF-7 cells was resolved here by two-step fractionation into four proteins of 46, 5Z 54 and 60,000 Mr. These proteins differ from the uterine IP (48,000 Mr) by being slightly more acidic and by lacking creatine kinase activity. Furthermore, they are not stimulated in Evsa-T cells lacking the estrogen receptors. In MCF-7 cells estrogenic stimulation also provokes a broad spectrum of changes in the secreted proteins. Some proteins (of 37, 46, 54 and 60,000 Mr) are synthetised and secreted at higher than basal rate. A preexisting protein of low turn-over rate (50,000 Mr) is secreted at higher rate after E2 treatment. In view of these observations, it seems obvious that the examination of a sole protein as a criterion of hormone-dependence should be misleading.