Immunological probes for oestradiol receptors in human breast tumours.
Monoclonal antibodies have been prepared against a soluble oestradiol receptor (REC) preparation partially purified from human myometrium by oestradiol affinity chromatography. The antibodies were detected by their ability to immunoprecipitate receptor bound [125I] oestradiol. One of the antibodies (D5) has been studied in detail. It will only precipitate REC after activation by salt, heat, low pH or KCNS and will not react with nuclear RE. It will not react with androgen, progesterone or glucocorticoid receptors nor with sex hormone binding globulin; it will only combine with REC from human sources. D5 recognizes a cytoplasmic 29 kdalton protein (p29) that can be separated from both type I and II soluble oestradiol binding proteins. p29 can react with activated REC and is qualitatively and quantitatively related to REC. IRMA and histochemical methods have been developed for quantitating p29 and relating its amount to receptors in human breast tumours. With both methods, highly significant (P less than 0.001) correlations with REC but not RP have been obtained. Both methods indicate that many REC-RP+ tumours contain p29. The histochemical method detects marked cellular heterogeneity in some tumours. The function of p29 is not known. It is an REC-related antigen that may be a previously undetected component of the oestradiol receptor machinery.
D000911:Antibodies, Monoclonal / Q000276:immunology; D001943:Breast Neoplasms / Q000032:analysis*; D011232:Chemical Precipitation; D002846:Chromatography, Affinity; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D008024:Ligands; D008970:Molecular Weight; D011506:Proteins / Q000032:analysis; D011959:Receptors, Estradiol / Q000032:analysis* / Q000276:immunology; D011960:Receptors, Estrogen / Q000032:analysis*
D000911:Antibodies, Monoclonal; D008024:Ligands; D011506:Proteins; D011959:Receptors, Estradiol; D011960:Receptors, Estrogen