Quantification of estrogen- and progesterone receptors from cryostat sectioned human tumor tissue: comparison of ligand binding and immunocytochemical assays.
We have recently described an assay procedure to measure estrogen and progesterone receptors in extracts from frozen sections by a ligand binding assay. With this methodological approach it is now possible to perform comparative experiments not only to DCC/Scatchard analyses from different tissue blocks, but also to immunocytochemical determinations in identical tissue blocks: (1) When receptor quantities measured by the two biochemical methods were compared, a high correlation of estrogen receptor content was found between determinations in supernatants from frozen sections and DCC/Scatchard analyses. A slightly poorer correlation in the comparison of the ligand binding assays was obtained for the progesterone receptor. (2) The percentage of tumor cells stainable by immunocytochemistry for estrogen and progesterone receptors could hardly be correlated to the receptor concentrations (fmol/mg) measured quantitatively by the two ligand binding assays. (3) As the final result tumor specimen could be grouped into classes of receptor status according to the presence or absence of a nuclear stain in immunocytochemical assays or according to receptor concentrations above or below distinct threshold which were fixed at 20 fmol/mg for Scatchard analyses of both receptor species, 20 fmol/mg for estrogen- and 40 fmol/mg for progestin receptors for the assay with sections. In this diagnostical consideration the concordance of both biochemical methods to the immunocytochemical assessment was high for estrogen and less pronounced for progesterone receptors. (4) In some breast cancer specimen analyzed biochemically an unspecific progestin binding component could be detected superimposed on the progesterone receptor peak after isoelectric focusing.
Institut für Biochemische Endokrinologie, Medizinische Universität, Lübeck, F.R.G.
G
G
Vollmer
J
J
Gerdes
R
R
Knuppen
D001943:Breast Neoplasms / Q000032:analysis* / Q000378:metabolism / Q000473:pathology; D003600:Cytosol / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007700:Kinetics; D008024:Ligands; D011960:Receptors, Estrogen / Q000032:analysis* / Q000378:metabolism; D011980:Receptors, Progesterone / Q000032:analysis* / Q000378:metabolism
D008024:Ligands; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D004958:Estradiol