Absence of estrogen receptor-β expression in metastatic ovarian cancer

Abstract

We found varying amounts of ERalpha and ERbeta in normal ovaries, lower levels of ERbeta expression in ovarian epithelial cancer primary tumors, and only ERalpha in metastatic tumors. Our findings indicate that a fundamental difference might exist between primary and metastatic cells, which could be caused by intrinsic or extrinsic factors that regulate ER gene expression.

Hormonal treatments and epithelial ovarian cancer risk

“…In a breast cancer cell line, ERb had antimitotic activity, which was not affected by the presence or absence of estrogen (23) . This antimitotic activity is in line with the observations, that the great majority of ERb-positive cells do not proliferate (24) , and that ERb expression is decreased in cancer when compared to normal tissue (25,26) .…”

“…Decreased expression of estrogen receptor, in particular ERb, and progesterone receptors has been reported in neoplastic ovarian cells (26,31,32) . In a recently published study, ovarian cancer cells showed decreased ERb expression when compared to normal ovarian epithelium.…”

“…It has been shown that human ovarian surface epithelial cells express ERa, ERb, and PR messenger RNA (26,27) , which makes it possible that sex steroid hormones play a role in the pathogenesis of ovarian carcinoma. Decreased expression of estrogen receptor, in particular ERb, and progesterone receptors has been reported in neoplastic ovarian cells (26,31,32) .…”

Polymorphisms of Estrogen Receptors: Risk Factors for Invasive Melanoma – A Prospective Study

“…The hypothesis that polymorphisms of the ER genes could have a role in melanoma comes from the analysis that ERα and ERβ affect cellular proliferation and differentiation. Studies of endocrine-related cancers (such as breast, endometrium, and ovary cancer) demonstrate that estrogens may have opposite effects on cell proliferation as a consequence of their complex mechanism of action involving binding to either ERα or ERβ [5,13,14,15,16]. Estrogens regulate growth, differentiation, and the functioning of a variety of tissues.…”

“…In estrogen-dependent tumors, ERα is involved in proliferation, whereas ERβ inhibits cell growth. The decrease in ERβ expression reflects tumor cell dedifferentiation, and an increased ERα:ERβ ratio represents a critical stage in tumor progression [5,8,13,14]. Although ERα is the most ubiquitous ER, ERβ is significantly expressed in prostate [15,17], lung [18], colon [6,7], and melanocytic lesions [2].…”