Effect of glycoprotein and protein hormones on human meningioma cell proliferation in vitro

Abstract

Speculation that meningiomas are subject to female hormone influence is supported by their higher incidence in women and reports of exacerbation of symptoms during pregnancy and the luteal phase of the menstrual cycle. Previous reports have concentrated on the effects of the steroid hormones oestradiol and progesterone on meningioma proliferation. In this study we have investigated the roles of the glycoproteins LH, FSH and human chorionic gonadotrophin (hCG), and the protein hormones prolactin (PRL) and human placental lactogen (hPL) on the proliferation of human meningiomas in vitro. The three glycoproteins had an inhibitory effect on meningioma proliferation ranging from 5.0-50.0%, 10.0-63.0% and 2.4-34.0% at the highest concentrations of LH (25 mIU/ml), FSH (15 mIU/ml) and hCG (30 IU/ml) respectively. Cultures were also treated with PRL (100 and 200 ng/ml) and hPL (5 and 10 ng/ml) and the protein hormones had a stimulatory effect on cell proliferation of 12.0-55.5% and 11.4-73.6% when treated with 200 ng/ml PRL and 10 micrograms/ml hPL respectively. Our data suggest that increasing levels of the protein hormones PRL and hPL, falling levels of hCG and the absence of LH and FSH in the second and third trimesters of pregnancy may play a role in the acceleration of meningioma growth in these stages of pregnancy.

Prolactin receptors in human meningiomas: characterization and biological role

“…These results are in agreement with recent observations of Boyle-Walsh et al (1995) who demonstrated that PRL acts in vitro as a mitogenic factor for human meningioma cells. These findings, together with our demonstration of the presence of PRL receptors in meningiomas, clearly indicate a direct action of the hormone on the growth of these tumours.…”

“…Among these, prolactin (PRL) has been demonstrated to exert significant stimulatory effects on the growth of various tumours such as breast (Manni et al 1985), liver (Buckley et al 1985) and prostate cancer (Johnson et al 1985), where specific PRL receptors have been identified (Witorsch 1979, Turcot-Lemay & Kelly 1982, Di Carlo et al 1984, Boutin et al 1989. Recently, it has been reported that PRL stimulates the proliferation of human meningioma cells in vitro (Jimenez-Hakim et al 1993, Boyle-Walsh et al 1995) and a possible involvement of the hormone has been suggested in the growth of this tumour.…”

Lack of prolactin receptor signaling in mice results in lactotroph proliferation and prolactinomas by dopamine-dependent and -independent mechanisms

“…The inhibitory growth response of lactotrophs to PRL is quite different from the proliferative effect exhibited in nonpituitary cell types (14)(15)(16)(17)(18)(19)(21)(22)(23)(24)(25), in human prolactinoma cells (44), and in a transformed rat lactotroph cell line (20). It is, however, consistent with models of PRL effects on EGF and TGF-α signaling cascades.…”

“…Previously, both we (3) and another group (11) concluded from our original studies of Drd2 -/-mice that PRL most likely functioned as a mitogen for lactotrophs. In the majority of tissues where it has been evaluated, PRL is mitogenic (14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25), with only a few tissues demonstrating an antiproliferative role (26)(27)(28)(29). However, we show here that in Prlr -/-mice, there are two factors contributing to the release of the lactotroph from its usual secretory and proliferative controls: a decrease in the normally inhibitory dopaminergic control and a second, direct effect at the level of the pituitary that is most consistent with an antiproliferative action of PRL on lactotrophs.…”

Effects of prolactin on intracellular calcium concentration and cell proliferation in human glioma cells

“…Besides these physiological effects, several studies have documented the involvement of PRL in the growth control of different tumors such as breast (Manni et al, 1985), liver (Buckley et al, 1985), and prostate cancer (Johnson et al, 1985), and effects of the hormone on the proliferation of neoplasic cells have also been shown. For example, it has been recently reported that PRL stimulates proliferation of human meningioma cells in vitro (JimenezHakim et al, 1993;Boyle-Walsh et al, 1995) and a possible involvement of this hormone has been suggested in the growth of this tumor.…”