Assay of oestrogen and progestin receptors in human meningioma cytosols using immunological methods

Abstract

Oestrogen (ER) and progestin receptors (PR) were assayed in human meningioma cytosol by radioligand binding assay with Scatchard plot analysis and by monoclonal antibody based enzyme immunoassays. For comparison, human breast cancer tissues were used. Results of both assays agreed very well. For human breast cancer, receptor levels assayed with both methods showed a highly significant correlation (ER: r = 0.96; n = 74 and PR: r = 0.95; n = 19). Also for meningioma cytosols a good agreement was observed between the result of both assays. Thus, most meningiomas were devoid of ER but contained significant concentrations of PR. PR levels in meningioma determined with the enzyme immunoassay correlated well with those found by Scatchard plot analysis. After logarithmic transformation of the data the regression line was; PR(EIA) = 0.83 × PR(Scatchard) + 0.36 (r = 0.917; n = 24). The recognition of the progestin binder in meningioma by a monoclonal antibody against the progestin receptor is a further indication that progestin binding in meningioma occurs to a true receptor.