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

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.