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

The implications of hormone treatment for cancer risk, screening and treatment in transgender individuals

There is evidence that gender-affirming hormone treatment (GAHT) for transgender individuals modulates their risk for specific malignancies including breast and prostate cancer, and meningiomas. However, there is insufficient data to make precise risk estimates accounting for age and inherited cancer risk. As such, screening recommendations remain broad. Even less evidence exists for best practice in the management of active or historical cancers in the transgender population. Guidance is therefore mainly extrapolated from cisgender populations but with considerations of the significant benefits of GAHT in the face of any hormonal risk. Clinical experience, the multidisciplinary team and shared decision making with the patient are vital in providing person-centred care, while further research is acquired.

Presentation and management of spinal meningioma and its association with breast carcinoma-case series and systematic review

OBJECTIVE

Benign spinal intradural tumors are rare entities and there have been relatively few case series describing the epidemiology and characteristics of these tumors. Here, we evaluate the presentation, demographics, pathology and outcomes associated with the surgical management of spinal meningioma in our unit over a 6-year period.

RESULTS

A total of 68 cases presented to the operating surgeon during a 6-year period. Of these, over 80% (n = 55) were in females. Seventy-nine percent of the meningiomas were observed in the thoracic region (n = 54). Weakness and gait disturbance were the most common presenting complaints. Surgery significantly improved both motor outcome (p < 0.001) and health related qualities of life (SF36, p < 0.01).Seventeen percent of spinal meningioma cases (n = 12) had a preceding cancer diagnosis. Of these 75% (n = 9/12) were attributable to breast cancer. Overall, breast cancer preceded a diagnosis of a spinal meningioma in 16.4% of female cases (9/55). This is higher than expected number of breast cancer based on UK population and those reported in literature for breast cancer and intracranial meningioma.

CONCLUSION

Spinal meningioma is disproportionately over-represented in females. Patients present with neurological deficits and surgery improved both neurology and patient reported quality of life. Relative to the known UK prevalence of breast cancer, there is a significantly higher than expected association between spinal meningioma and a preceding history of breast cancer.

Estrogen hormone replacement therapy in incidental intracranial meningioma: a growth-rate analysis

Incidental meningiomas (IMs) are the most common intracranial neoplasms, especially in perimenopausal women. There is ongoing debate on whether their incidence is increased by hormone replacement therapy. Meningiomas often express estrogen receptors, which were linked to higher proliferative activity according to some reports. Consequently, there is a theoretical risk of estrogen-based HRT (e-HRT) leading to an increase in tumor growth and thus altering the natural history of IMs. However, clinical data is lacking to support this notion. To identify differences in the natural history of IM after e-HRT exposure. We queried the NorthShore Meningioma Database for patients with ≥ 6 months of e-HRT. They were compared with age-matched IM controls. Forty patients were included in the e-HRT group (mean age 62.1 ± 12.0 years; mean duration of HRT 5.3 ± 4.5 years) and 80 in the no-HRT group (mean age 62.2 ± 12 years). Radiographic appearance was similar between groups. The average 2D tumor diameter was 35% lower in the e-HRT group (p = 0.02), with an absolute growth-rate of half of the no-HRT group (p = 0.02). Radiographic and clinical progression-free survival were 1.2 years and 3.3 years longer in the e-HRT group, respectively. These preliminary results suggest that e-HRT may be safe in incidental meningiomas.

Meningioma in Breast Cancer Patients: Population-based Analysis of Clinicopathologic Characteristics

OBJECTIVES

Although an association between meningioma and breast cancer (BC) has been postulated, clear mechanisms remain obscure. By conducting population-based analyses in women with both BC and meningioma, hypothesis-generating causal links were pursued.

METHODS

Using the US SEER 18 registry (2004 to 2009), clinicopathologic and demographic characteristics from cohorts of women with only BC (n=279,821) or meningioma (n=19,570) diagnoses were compared with 412 women with both diagnoses (BC-meningioma).

RESULTS

BC diagnosis preceded meningioma by >2 months in 48% of women; 20% had synchronous (within 2 mo) disease. Median meningioma size was 1.9 and 2.4 cm in the BC-meningioma and meningioma cohorts, respectively (P=0.0009). Among BC-meningioma patients, meningioma size was similar whether diagnosed >2 months prior, synchronously, or >2 months after BC. Meningioma was pathologically confirmed in 38% of BC-meningioma and 51% of meningioma patients. Distribution of BC histologies was comparable in patients with and without meningioma, with ductal type predominating (80% in BC-meningioma, 83% in BC). Although hormone receptor status of invasive BC was not significantly different between BC-meningioma and BC groups, the BC-meningioma cohort had fewer women with ER+/PR+ in situ disease (P=0.006). BC stage among women with meningioma was more advanced versus women with BC only.

CONCLUSIONS

Women with BC and meningioma have smaller-sized meningiomas and more advanced BCs compared with women having only 1 diagnosis. As there was no temporal relationship between size and latency between tumor diagnoses, the disparity in meningioma size between BC-meningioma and meningioma cohorts may have BC-associated biological components that warrant further study.

Pathophysiology of Meningioma Growth in Pregnancy

Meningioma is among the most frequent brain tumours predominantly affecting elderly women. Epidemiological studies have shown that at the age of fertility the incidence is relatively low. The biological behaviour of meningioma in pregnancy is different from other meningiomas. The possible explanation is rooted in the complex physiological changes and hormonal differences during pregnancy. The increased meningioma growth observed in pregnancy is presumably the result of endocrine mechanisms. These include increase in progesterone, human placental lactogen (hPL) and prolactin (PRL) serum levels. In contrast, levels of pituitary hormones such as follicle stimulating hormone (FSH), luteinizing hormone (LH) and human chorionic gonadotropin (hCG) produced by the placenta are decreasing in the mother prior to childbirth. Besides, vascular factors also play a crucial role. Peritumoral brain edema (PTBE), with well-known causative association with vascular endothelial growth factor (VEGF), can often be seen both with imaging and in the surgical specimens. Our aim is to assess published research on this topic including diagnostic and therapeutic guidelines, and to provide a clinically useful overview on the pathophysiology and biological behaviour of this rare complication of pregnancy.

Molecular Genetics of Intracranial Meningiomas with Emphasis on Canonical Wnt Signalling

Research over the last decade recognized the importance of novel molecular pathways in pathogenesis of intracranial meningiomas. In this review, we focus on human brain tumours meningiomas and the involvement of Wnt signalling pathway genes and proteins in this common brain tumour, describing their known functional effects. Meningiomas originate from the meningeal layers of the brain and the spinal cord. Most meningiomas have benign clinical behaviour and are classified as grade I by World Health Organization (WHO). However, up to 20% histologically classified as atypical (grade II) or anaplastic (grade III) are associated with higher recurrent rate and have overall less favourable clinical outcome. Recently, there is emerging evidence that multiple signalling pathways including Wnt pathway contribute to the formation and growth of meningiomas. In the review we present the synopsis on meningioma histopathology and genetics and discuss our research regarding Wnt in meningioma. Epithelial-to-mesenchymal transition, a process in which Wnt signalling plays an important role, is shortly discussed.

Body mass index and the risk of meningioma, glioma and schwannoma in a large prospective cohort study (The HUNT Study)

BACKGROUND

Obesity increases the risk for a number of solid malignant tumours. However, it is not clear whether body mass index (BMI) and height are associated with the risk of primary tumours of the central nervous system (CNS).

METHODS

In a large population study (The Nord-Trøndelag Health Study (HUNT Study)) of 74 242 participants in Norway, weight and height were measured. During follow-up, incident CNS tumours were identified by individual linkage to the Norwegian Cancer Registry. Sex- and age-adjusted and multivariable Cox regression analyses were used to evaluate BMI and height in relation to the risk of meningioma, glioma and schwannoma.

RESULTS

A total of 138 meningiomas, 148 gliomas and 39 schwannomas occurred during 23.5 years (median, range 0-25) of follow-up. In obese women (BMI ≥ 30 kg m(-2)), meningioma risk was 67% higher (hazard ratio (HR)=1.68, 95% confidence interval (CI): 0.97-2.92, P-trend=0.05) than in the reference group (BMI 20-24.9 kg m(-2)), whereas no association with obesity was observed in males. There was no association of BMI with glioma risk, but there was a negative association of overweight/obesity (BMI ≥ 25 kg m(-2)) with the risk of schwannoma (HR=0.48, 95% CI: 0.23-0.99). However, the schwannoma analysis was based on small numbers. Height was not associated with the risk for any tumour subgroup.

CONCLUSION

These results suggest that BMI is positively associated with meningioma risk in women, and possibly, inversely associated with schwannoma risk.

Hormone replacement therapy and risk of meningioma in women: a meta-analysis

PURPOSE

The relationship between hormone replacement therapy (HRT) and the incidence of meningioma in women has been investigated in several epidemiologic studies, but their results were not entirely consistent. Here, we performed a meta-analysis of case-control and cohort studies to analyze this association.

METHODS

The PubMed database was searched from inception to 30 September 2012 to identify relevant studies that met pre-stated inclusion criteria. We also reviewed reference lists from the retrieved articles. Two researchers evaluated study eligibility and extracted the data independently. Odds ratios (ORs) or relative risks and 95 % confidence intervals (CIs) were extracted and pooled using the fixed-effect or random-effects models.

RESULTS

A total of 11 studies (six case-control and five cohort studies) were included in this meta-analysis, involving 1,820,954 participants, of whom 3,249 had meningioma. When compared to never users of HRT, the pooled OR with ever users for meningioma was 1.29 (95 % CI 1.03-1.60). Sensitivity analyses restricted to postmenopausal women yielded similar results (OR: 1.22; 95 % CI 1.02-1.46). Subgroup analyses showed that the pooled ORs were 1.27 (95 % CI 1.08-1.49, p < 0.05) and 1.12 (95 % CI 0.95-1.32) for current and past users of HRT, respectively.

CONCLUSION

Hormone replacement therapy use is associated with an increased risk of meningioma in women, as well as in postmenopausal women. Besides, the significant risk elevation is present in current users but not in past users. Future research should attempt to establish whether this association is causal and to clarify its mechanisms.

Hormonal therapy for fertility and huge meningioma: a purely random association?

Sexual hormones have been related to the growth of meningiomas, also due to the almost constant expression of hormonal receptors by tumoral cells. A case of a woman with previous history of multiple treatment for infertility, harboring a huge meningioma is here described. The tumor was surgically resected and the immunohistochemical examination revealed a high expression of progesterone receptors on tumoral cells surface. A putative role of past progesterone administration in the growth of meningioma has been hypothesized. Particular caution should be paid whenever adopting sexual hormonal therapy, especially for fertility. A radiological examination (ideally MRI) could be advised before starting therapy, in order to rule out any intracranial meningioma.

The relationship between urinary bisphenol A levels and meningioma in Chinese adults

BACKGROUND

Estrogen has been implicated as a risk factor for meningioma. Bisphenol A (BPA), a widely used synthetic xenoestrogen, has already been reported to be associated with several estrogen-sensitive tumors.

METHOD

An exploratory association study of 243 meningioma cases and 258 frequency-matched healthy controls was conducted, using subjects from a hospital-based study to demonstrate the association of urine BPA concentration and the risk of meningioma. The specimens and data of patients were collected at Union Hospital, Wuhan, China, from 2009 to 2010.

RESULTS

A positive association between increasing levels of urinary BPA and meningioma was observed, independent of confounding factors such as gender, age, race, body mass index, HRT use, BMI, and family history of cancer. Compared to quartile 1 (referent), the multivariate-adjusted odds ratio of meningioma associated with quartile 4 was 1.45 (95 % CI, 1.02-1.98) (P trend = 0.03).

CONCLUSION

In this case-control study from China, a clear association between urinary BPA concentrations and diagnosis of meningioma was detected.

Brain tumors and hormonal factors: review of the epidemiological literature

BACKGROUND

To date, the etiology of primary tumors of the central nervous system (mainly gliomas and meningiomas) is poorly understood. The role of sex hormones has been suggested, based on clinical, experimental, biological, and epidemiological data.

OBJECTIVE

To review the epidemiological studies on the relation between hormonal factors and the occurrence of glioma and meningioma, in order to identify new research developments.

METHODS

Articles published until September 2010 were selected by considering exogenous and endogenous exposures and specific brain tumors. Standardized information was collected from 20 articles: 15 concerning gliomas and 13 meningiomas.

RESULTS

An increased glioma risk was observed with later menarche and menopause, while a reduced glioma risk was observed with hormone replacement therapy (HRT) and oral contraceptive use, despite duration of use had no effect on risk. Meningioma risk increased after menopause and with HRT use. No clear association was found with pregnancy and breastfeeding.

CONCLUSION

Results are globally concordant with the biologic hypothesis assuming that female sex hormones are protective against glioma and may increase the risk of meningioma. However, new epidemiological studies should be conducted in order to confirm these associations and to refine the role of hormonal factors in brain etiology.

Is there an association between meningioma and hormone replacement therapy?

PURPOSE

Molecular and clinical observations suggest a role of sex steroid hormones in the occurrence of meningioma. However, there is limited and often conflicting data on the use of hormone replacement therapy (HRT) as a possible risk factor for meningioma. The goal of this study was to investigate whether there is an association between a diagnosis of meningioma and either current or past HRT use in women.

METHODS

We retrospectively reviewed records in the Mayo Clinic Jacksonville electronic patient database between 1993 and 2003 to identify women with a diagnosis of either symptomatic or incidentally discovered, clinically silent meningioma. Records were also searched to identify women with a documented history of either current or past HRT use.

RESULTS

Of the 355,318 women, ages 26 to 86, evaluated for any medical issue, 18,037 (5%) were documented as current or past HRT users. A total of 1,390 women with a history of symptomatic or incidentally discovered meningiomas were identified, 156 (11%) of whom were either current or past HRT users. A logistic regression analysis, adjusted for age, demonstrated a positive association between a diagnosis of meningioma and HRT use, with an odds ratio of 2.2 (95% CI, 1.9 to 2.6; P < .0001). The frequency of meningioma in women with either current or past HRT use was 865 in 100,000, whereas the frequency of meningioma in women without the history of HRT use was 366 in 100,000.

CONCLUSION

The study provides evidence of a positive association between HRT use and diagnosis of meningioma, and therefore, HRT use may be a risk factor for meningioma.

Increased prevalence of obesity and obesity-related postoperative complications in male patients with meningiomas

OBJECTIVE

The female preponderance of meningiomas may reflect hormonal influences on meningioma growth. We hypothesized that because obesity affects male steroid hormone synthesis, male patients with meningiomas might exhibit a high obesity rate, which, in turn, might increase their frequency of postoperative complications.

METHODS

We retrospectively reviewed male patients who underwent craniotomy for benign meningiomas at our institution between 2001 and 2005 (n = 32) and used male patients undergoing craniotomy for aneurysms (n = 32) or glioblastomas (n = 32) from 2001 to 2005 as control subjects. Body mass index (BMI) greater than 30 kg/m was considered obese.

RESULTS

Male patients with meningiomas had a higher average BMI (30.2 kg/m) than male patients with aneurysms (BMI = 27.5 kg/m) or gliomas (BMI = 25.9 kg/m) (P = 0.04). The obesity rate in men with meningiomas (47%) exceeded that in men with aneurysms (19%) or gliomas (3%) (P = 0.2). The median age-normalized BMI percentile was greater in men with meningiomas (67 th percentile) than in men with aneurysms (49th percentile) or gliomas (52 nd percentile) (P = 0.02). Deep vein thrombosis/pulmonary embolus was more common in men with meningiomas (19%) than in men with aneurysms (0%) or gliomas (3%) (P = 0.002). Wound infections were more common in men with meningiomas (6%) than in men with aneurysms (3%) or gliomas (0%) (P = 0.2). The 53% of obese patients with meningiomas who were readmitted with postoperative complications exceeded the 18% of nonobese patients with meningiomas who were readmitted (P = 0.03); complications included deep vein thrombosis and pulmonary embolus (27 and 12%, respectively, in obese and nonobese patients with meningiomas) and postoperative fever (53 and 35%, respectively, in obese and nonobese patients with meningiomas).

CONCLUSION

We found that many men with meningiomas are obese, suggesting a hormonal influence on meningiomas in men as well as women. Our results also underscore the high risk of postoperative complications in obese male patients with meningiomas.

Mechanisms of tumor-related brain edema

✓Cerebral edema contributes strongly to symptoms associated with brain tumors. Although the introduction of corticosteroids has greatly simplified treatment of patients with newly diagnosed tumors, these drugs are associated with marked side effects during the long-term treatment that is often necessary in the recurrences. Therefore, a better understanding of mechanisms related to the evolution and clearance of tumor-related edema with the aid of modern imaging and molecular methodology is clearly necessary. Recently, researchers have focused on molecular mechanisms of edema development and have demonstrated alternative routes—such as the inhibition of vascular endothelial growth factor receptor inhibitors—to be explored for treating edema. In this review the author focuses on established and current concepts regarding the pathophysiology of cerebral edema and its treatment.

Progesterone and estrogen receptors: opposing prognostic indicators in meningiomas

OBJECT

The preponderance of progesterone receptors (PRs) and the scarcity of estrogen receptors (ERs) in meningiomas are well known. The expression of PRs may relate to tumor grade and recurrence. Cytogenetic abnormalities are associated with aggressive behavior, recurrence, and progression. In this study, the authors focus on the prognostic implications of hormone receptors in meningiomas to help determine the clinical and biological aggressiveness of tumors and their correlations with cytogenetic abnormalities.

METHODS

Two hundred thirty-nine patients with meningiomas were separated into three groups. Group 1 (PR-positive group) comprised patients whose meningiomas displayed expression of PRs alone. Group 2 (receptor-negative group) included patients whose lesions did not have receptors for either progesterone or estrogen. Group 3 (ER-positive group) included patients whose tumors displayed expression of ERs. Clinical and histological findings, proliferative indices, tumor recurrence, and cytogenetic findings were analyzed by performing the Fisher exact test. Compared with the receptor-negative (Group 2) and ER-positive (Group 3) groups, the PR-positive group (Group 1) had a statistically significant lower proliferative index and a smaller number of patients in whom there were aggressive histopathological findings or changes in karyotype. In Groups 1, 2, and 3, the percentages of cases with aggressive histopathological findings were 10, 31, and 33%, respectively; the percentages of cases with chromosomal abnormalities were 50, 84, and 86%, respectively; and the percentages of cases in which there initially was no residual tumor but recurrence was documented were 5, 30, and 27%, respectively. A statistically significant increase in the involvement of chromosomes 14 and 22 was identified in receptor-negative and ER-positive de novo meningiomas, when compared with the PR-positive group. Abnormalities on chromosome 19 were statistically significantly higher in receptor-negative meningiomas than in PR-positive tumors.

CONCLUSIONS

The expression of the PR alone in meningiomas signals a favorable clinical and biological outcome. A lack of receptors or the presence of ERs in meningiomas correlates with an accumulation of qualitative and quantitative karyotype abnormalities, a higher proportional involvement of chromosomes 14 and 22 in de novo tumors, and an increasing potential for aggressive clinical behavior, progression, and recurrence of these lesions. Sex hormone receptor status should routinely be studied for its prognostic value, especially in female patients, and should be taken into account in tumor grading. The initial receptor status of a tumor may change in progression or recurrence of tumor.

Association of meningioma with reproductive factors

Meningiomas occur more commonly in females. The coincidence between meningioma and breast cancer and case reports of tumor growth during pregnancy support a hormonal hypothesis. A case control study was conducted to investigate this. Female subjects treated between 1987 and 1992 were identified from 3 hospitals in the Chicago area. Female spouses of male back pain patients were recruited as controls. A self-administered mail questionnaire focused on exogenous, endogenous and other hormonal factors, personal and family medical history as well as radiation exposures. Odds ratios and 95% confidence intervals were estimated using crude, stratified and multivariable logistic models including 219 cases and 260 controls. Participation rates were 86% among cases and 75% among controls. An increased odds ratio (OR) was observed comparing African Americans to Caucasians [OR = 2.4, 95% confidence interval (CI) = 1.0-6.1]. A protective effect was observed for pregnancy, which increased with number and age at first pregnancy. The odds ratio for 3 or more pregnancies compared to none was 0.3 (95% CI = 0.2-0.6). Age at menarche or total period of hormonal activity was not protective. Ever smokers showed a decreased odds ratio for meningioma (OR = 0.6, 95% CI = 0.4-0.9). The increased odds ratios with African Americans was retained in post-menopausal women, while the protective odds ratios for pregnancy, smoking and oral contraceptives (OCs) became stronger in pre-menopausal women. The pattern by duration and timing of use does not suggest an etiologic role for OCs or hormone replacement therapy. These data add to the evidence that factors known to influence endogenous hormones (pregnancy and indirectly smoking) may have protective effects for meningiomas primarily in premenopausal women.

The management of brain edema in brain tumors

This review focuses on pathophysiology, clinical signs, and imaging of brain edema associated with intracranial tumors and its treatment. Brain edema in brain tumors is the result of leakage of plasma into the parenchyma through dysfunctional cerebral capillaries. The latter type of edema (ie, vasogenic edema) and the role of other types in brain tumors is discussed. Vascular endothelial growth factor-induced dysfunction of tight junction proteins probably plays an important role in the formation of edema. Corticosteroids are the mainstay of treatment of brain edema. When possible, corticosteroids should be used in a low dose (eg, 4 mg dexamethasone daily) to avoid serious side effects such as myopathy or diabetes. Higher doses of dexamethasone (16 mg/day or more), sometimes together with osmotherapy (mannitol, glycerol) or surgery, may be used in emergency situations. On tapering, one should be aware of the possible development of corticosteroid dependency or withdrawal effects.Novel therapies include vascular endothelial growth factor receptor inhibitors and corticotropin releasing factor, which should undergo further clinical testing before they can be recommended in practice.

Hormone replacement therapy in cancer survivors

OBJECTIVE

Thousands of women are treated each year for cancer; many of these are already in menopause, while other younger patients will go into early menopause due to surgery, or chemotherapy, or the need for radiotherapy to the pelvic region. In most cases the oncologist and the gynaecologist would advise these women against the use of HRT. The purpose of this paper is to review biological and clinical evidences in favour and against HRT use in the different tumours and to propose an algorithm that can help choosing the treatment for the single woman.

METHODS

We performed a systematic literature review through April 2002 concerning: (1) biological basis of hormonal modulation of tumour growth; (2) epidemiological data on the impact of HRT on different cancers risk in healthy women; (3) safety of HRT use in cancer survivors; (4) alternatives to HRT.

RESULTS

With the exception of meningioma, breast and endometrial cancer, there is no biological evidence that HRT may increase recurrence risk. In women with previous breast and endometrial cancer HRT is potentially hazardous on a biological basis, even if published data do not show any worsening of prognosis.

CONCLUSIONS

Even if a cautious approach to hormonal-dependent neoplasias is fully comprehensible and the available alternative treatment should be taken into greater consideration, the reticence to prescribe HRT in women previously treated for other non hormone-related tumours has neither a biological nor a clinical basis. An algorithm based on present knowledge is proposed.

Angiogenic factors in the central nervous system

The past decade has seen considerable advances in the understanding of angiogenesis. Blood vessel development and growth in the central nervous system are tightly controlled processes that are regulated by angiogenic factors. Angiogenic factors have been implicated in the pathogenesis of a wide variety of disorders, including primary and metastatic brain tumors, aneurysms, arteriovenous malformations, and cavernous malformations. The potential clinical applications of angiogenesis research include inhibition of angiogenesis to control brain tumors and therapeutic angiogenesis to promote collateral blood vessel formation among patients at risk of ischemia. This article summarizes the processes of blood vessel formation in the brain, examines the angiogenic factors that are prominent in the central nervous system, reviews the clinical use of angiogenesis inhibitors, and identifies areas for future investigation.

Hormone receptors in non-malignant meningiomas correlate with apoptosis, cell proliferation and recurrence-free survival

AIMS

A retrospective immunohistochemical and statistical analysis of patients with non-malignant meningiomas was undertaken to determine the correlation of steroid hormone receptor status with apoptosis, tumour cell proliferation, clinicopathological characteristics and prediction of recurrence.

METHODS AND RESULTS

Paraffin sections from 51 primary intracranial totally resected benign and atypical meningiomas were immunohistochemically evaluated for the expression of progesterone (PR), oestrogen (ER) and androgen (AR) receptors, apoptotic rate, Bcl-2, p53 and Ki67 antigens. In addition to the above parameters, the mitotic index and the patients' clinicopathological data were statistically correlated and entered in a recurrence-free survival analysis. A high level of apoptotic cell death was associated with loss of PR expression by logistic regression analysis (P = 0.016). An inverse correlation existed between the mitotic index and PR counts (P = 0.009), while high Ki67 values correlated with increased ARs (P = 0.041). Atypical meningiomas had a lower ER staining score (P = 0.036). Multivariate analysis indicated that the absence of PR and large tumour size were significant factors for shorter disease-free intervals.

CONCLUSIONS

The results suggest that ER expression is lost or reduced in atypical meningiomas, whereas loss of PR expression is an indicator of increased apoptosis and early recurrence. PRs and ARs may also influence tumour cell proliferation.

Effects of steroid hormones on calcitonin gene-related peptide receptors in cultured human myometrium

OBJECTIVE

This study was designed to examine whether, with the use of human myometrial explants in culture, calcitonin gene-related peptide B receptors are regulated by steroid hormones.

STUDY DESIGN

Myometrial tissues were obtained from the lower uterine segments from women in a nonpregnant state and pregnant women who were not in labor undergoing cesarean delivery (39.1 +/- 0.2 weeks of gestation). Tissues were incubated in Dulbecco's modified Eagle's medium without phenol red, with either 17beta-estradiol (10(-9), 10(-8), 10(-7) mol/L), progesterone (10(-8), 10(-7), 10(-6) mol/L), or in a combination of 17beta-estradiol (10(-8) mol/L) and progesterone (10(-7) mol/L). Reverse transcriptase-polymerase chain reaction was performed to examine the expression of estrogen receptor-alpha, progesterone receptor, and Western blotting was used for calcitonin gene-related peptide B receptor protein measurement in the myometrium.

RESULTS

We found that (1) messenger RNA expression for both estrogen receptor-alpha and progesterone receptor in nonpregnant myometrium significantly declined within 48 hours explant culture; (2) estrogen receptor-alpha messenger RNA levels in the pregnant myometrium were 98.6%, 95.3%, and 89.8% at 12, 24, and 48 hours of incubation, respectively; (3) the levels of messenger RNA for progesterone receptor in the pregnant myometrium were 96.2%, 93.3%, 90.1%, at 12, 24, and 48 hours of incubation, respectively; (4) the 17beta-estradiol dose dependently inhibited calcitonin gene-related peptide B receptor protein in pregnant myometrium explant culture; (5) the progesterone dose dependently increased calcitonin gene-related peptide B receptor expression in pregnant myometrium explant culture; (6) the combined treatment with 17beta-estradiol (10(-8) mol/L) and progesterone (10(-7) mol/L) further enhanced myometrial calcitonin gene-related peptide B receptor protein expression.

CONCLUSION

We conclude from this study that (1) the messenger RNA expression of estrogen receptor-alpha and progesterone receptor in pregnant myometrium were maintained at relatively high levels (>89%) within 48 hours incubation and that this may be useful for in vitro studies that are designed to evaluate the effects of sex steroids on the human myometrium during pregnancy and that (2) estrogen inhibits and progesterone stimulates the expression of calcitonin gene-related peptide B receptors in cultured pregnant myometrial explants. We suggest that steroid hormone-regulated calcitonin gene-related peptide B receptor expression could underlie differential myometrial sensitivity to calcitonin gene-related peptide-induced relaxation.

VEGF in brain tumors

Vascular endothelial growth factor (VEGF) is a regulator of angiogenesis, vasculogenesis and vascular permeability. In this contribution, molecular and biological properties of VEGF are described. Furthermore, this article focuses on the evidence that angiogenesis in brain tumors is mediated by VEGF. Among the topics discussed are expression patterns of VEGF and its receptors in different brain tumors, possible regulatory mechanism involved in the VEGF-driven tumor angiogenesis and the involvement of VEGF in the genesis of peritumoral edema. Finally, anti-angiogenesis approaches to target VEGF/VEGF receptors are discussed.

Identification of wild-type and exon 5 deletion variants of estrogen receptor beta in normal human mammary gland

We have examined messenger RNA (mRNA) expression of estrogen receptor (ER) alpha, wild-type ERbeta (mRNA and protein), and ERbeta exon 5 deletion variants (ERbeta delta5) in samples of normal human mammary gland obtained from 37 premenopausal subjects undergoing reduction mammoplasty. Comparing individual expression, ERbetaP mRNA predominated, expressed in 34 of 37 samples (91%), whereas ERalpha was found in 21 of 37 cases (57%). Receptor combinations were then analyzed and compared. Most samples either coexpressed ERalpha with ERbeta (54%) or expressed just ERbeta (38%). Immunohistochemical analysis revealed that ERbeta mRNA expression mirrored that of protein. Immunoreactivity was observed in the nucleus with additional evidence of cytoplasmic staining in those epithelial cells lining the breast ducts. Sporadic immunoreactivity was also detected in stromal cells. Expression of wild type and ERbeta delta5 was analyzed, and their association with ERalpha was compared. Most samples coexpressed wild-type ERbeta and the splice variant (62%; P = 0.05), with 30% exclusively expressing wild-type ERbeta. Although samples coexpressing wild type and variant ERbeta showed no statistical association with ERalpha, those samples expressing only wild-type ERP, showed a trend toward associations with ERalpha (P = 0.07). In conclusion, our data would support a role for ERbeta in the normal human mammary gland, where we propose it may be the dominant receptor.

The truncated estrogen receptor alpha variant lacking exon 5 is not involved in progesterone receptor expression in meningiomas

Human meningioma tissues are mostly estrogen receptor (ER) negative and progesterone receptor (PR) positive in ligand binding and enzyme immuno assays. To explain this apparently ER independent PR expression, we investigated the existence of a 'hidden' ER variant, which would be capable of activating transcription of the PR gene. Total RNA of seven meningiomas, two breast cancer tissues and of MCF7 cells was analyzed by RT-PCR using primers situated in exon 4 and exon 6. Differential hybridization of the PCR transcripts with probes in exon 4 and 5 respectively, revealed a wild type ER (wtER) fragment and an exon 5 deleted ER variant (ERDelta5). PCR products of two meningiomas were cloned for sequence analysis. The result confirmed the existence of a wtER and ERDelta5.RT-PCR followed by Southern analysis was performed on mRNA of 23 meningiomas to determine the amount of ERDelta5 relative to wtER, which was compared to the PR content of the tissues. In contrast to our initial hypothesis and literature data on breast cancer, there was no relationship between the ERDelta5/wtER ratio and PR protein concentration. It is therefore concluded that ERDelta5 mRNA does not play the dominant role in PR synthesis in meningioma tissue.

Expression and localization of placenta growth factor and PlGF receptors in human meningiomas

It has previously been suggested that in human brain tumours, endothelial cell proliferation during angiogenesis is regulated by a paracrine mechanism involving vascular endothelial growth factor (VEGF) and its receptors (VEGF receptor 1 and VEGF receptor 2). The mechanism of growth factor up-regulation is based on hypoxic activation of mRNA expression and mRNA stabilization and genetic events, leading to an increase of growth factor gene expression. The role of the other newly discovered VEGF family members with a high specificity for endothelial cells in the pathogenesis of glial neoplasms is unknown. To investigate which other members of the VEGF family are overexpressed in human brain tumours, the mRNA levels of placenta growth factor (PlGF), VEGF-A, and VEGF-B genes were determined by northern blot analysis in surgically obtained human meningiomas. In the 16 meningiomas examined, the mRNA for PlGF was highly expressed in four tumours and VEGF-A mRNA was highly abundant in three tumour samples. There was no close correlation between PlGF mRNA levels and VEGF-A expression levels. VEGF-B mRNA was abundantly expressed in all tumour samples at uniform levels. In a PlGF-positive tumour sample, immunoreactive VEGFR-1 and VEGFR-2 were detected in endothelial cells of the blood vessels. PlGF protein was detectable in most but not all capillaries of the tumour. PlGF is thus highly up-regulated in a subset of human meningiomas and may therefore have functions, in some tumour vessels, connected to endothelial cell maturation and tube formation. These findings suggest that PlGF, in addition to VEGF-A, may be another positive factor in tumour angiogenesis in human meningiomas.