Progestin-specific markers in human cell lines: biological and pharmacological applications.

We review the progestin-specific responses (induced proteins, increased enzymatic activity) described in uterus, mammary tumours and human breast cancer cell lines established from pleural effusions. Recent data from our laboratory using the T47D breast cancer cell line are then given. They include: (a) a general methodology for evaluating the specific effects of steroids on the production of [35S]methionine-labelled proteins released into the culture medium; (b) results concerning the specificity of regulation by the progestins of a 48 000 dalton protein secreted by T47D cells; (c) the evidence for androgen-specific proteins in the same cells; (d) A discussion of the criteria required to define the receptor responsible for a particular effect of steroids. Lastly, we consider the general interest of progestin-regulated proteins in cell culture for pharmacology and biology.