Constitutive co-expression of estrogen and progesterone receptor mRNA in human meningiomas by RT-PCR and response ofin vitro cell cultures to steroid hormones

Abstract

Although it is well recognised that human meningiomas are rich in progesterone receptor (PgR), controversy has existed about the presence of the estrogen receptor (ER) in these tumours. We have investigated the presence of both ER and PgR in a series of 20 human meningiomas, spanning the main histological groups, using reverse transcription linked PCR (RT-PCR). Total RNA was extracted from whole tissues and reverse transcribed to yield cDNA. This was amplified using primers specifically designed to detect ER and PgR. All samples co-expressed ER and PgR mRNA, irrespective of tumour classification, patient age or sex. In general, transcripts for PgR appeared considerably stronger than those for ER, and although this was a purely qualitative study, it suggests increased expression of PgR. Addition of exogenous 17beta-estradiol or progesterone to meningioma cell cultures showed that 2/4 cultures responded to these steroids. Our results confirm that human meningiomas do express gene transcripts for ER, and that previous failures to detect ER in these tumours may be due to the lack of sensitivity of the techniques employed. However, these receptors may not be functional in all tumours.

Association of meningioma with reproductive factors

“…Although estrogen receptors are not as common as progesterone receptors in meningiomas, gene transcripts for estrogen receptors may be expressed. 27 The protective effect of OCs is consistent with that observed for ovarian and endometrial cancer, 28 although this result is based on rather small numbers of OC users, the duration effect is inconsistent with a cumulative effect and our data did not allow exploration of other issues relating to OC use (such as infertility).…”

Brain tumors and hormonal factors: review of the epidemiological literature

“…Other studies observed growth of a meningioma in a transsexual patient after estrogen [13] and estrogen-progestin [14] therapies, or development of multiple meningiomas after long-term therapy with a progesterone agonist [15,16], which regressed after cessation of treatment [16]. These results are in accordance with data from in vitro studies showing a proliferation of meningioma cells when exposed to progesterone and estrogens together [17]. In contrast, growth inhibition and apoptosis induction were observed in glioma cells exposed to estrogens [18][19][20].…”

Meningioma: The Unusual Growth in a Transsexual Patient after Estrogen-Progesterone Therapy

“…Many of these studies also report that human meningioma cells proliferate when exposed to progesterone and estrogen [4]. Most meningiomas express functional progesterone rather than estrogen receptors [1,11] and show growth during the progesterone-predominant luteal phase [12].…”

“…More detailed molecular and immunohistochemical research provides evidence that meningiomas are hormone-sensitive tumors, with 70% of cells expressing progesterone receptors and around 30% expressing estrogen receptors [2][3][4]. Many of these studies also report that human meningioma cells proliferate when exposed to progesterone and estrogen [4].…”