Estrogen and progesterone receptor subtype expression in normal and malignant ovarian epithelial cell cultures

OBJECTIVE: Epidemiologic data suggest that the malignant transformation of ovarian epithelium may be linked to altered steroid hormone homeostasis. STUDY DESIGN: Estrogen receptor-alpha, estrogen receptor-beta, progesterone receptor A, and progesterone receptor B messenger RNA and protein expression were evaluated by reverse transcriptase-polymerase chain reaction and Western blot analysis in primary cell cultures of human ovarian surface epithelium (n = 23 cultures) and Cedars-Sinai ovarian cancer (n = 23 cultures). RESULTS: The ratio of estrogen receptor-alpha/estrogen receptor-beta messenger RNA expression was 10 times higher in primary ovarian cancer cultures (9.94 +/- 3.90) than in normal ovarian surface epithelium cultures (1.00 +/- 0.16, P = .04). Estrogen receptor-alpha/estrogen receptor-beta protein ratio in primary ovarian cancer cultures (2.13 +/- 0.43) was twice that of normal human ovarian surface epithelium cultures (1.00 +/- 0.13, P = .05). Individual estrogen receptor-alpha and estrogen receptor-beta messenger RNA and protein expression were not significantly different. Progesterone receptor B protein levels in primary ovarian cancer cultures (2.08 +/- 0.42) were twice that of normal surface ovarian epithelium cultures (1.00 +/- 0.10, P = .04), although differences in progesterone receptor B messenger RNA and progesterone receptor A protein expression were not observed. CONCLUSION: Malignant ovarian epithelial cells demonstrated multiple alterations in the expression of sex steroid hormone receptors.