| Meningiomas are common human intracranial tumors that arise from meningothelial cells found in the arachnoid villi of the meninges, the membrances covering the brain and spinal cord, meningiomas are primarily benign tumors that may be cured by excision, although some are inoperable or invasive and are not amenable to surgical removal. The association of gender-specific hormone receptors with these tumors is indicated by a wealth of clinical and epidemiological data, including the greater predilection for females, the documented association between meningiomas and breast carcinomas in the same patients, and the promotion of symptomatic aggressive growth of previously asymptomatic tumors during pregenancy and the luteal phase of the menstrual cycle. Steroid hormone receptor act as transcription factors that mediate the biological effects of steroids by regulating gene expression at a predominantly transcriptional level. Meningiomas often contain steroid hormone receptors. Numerous studies have been performed that examined the role of the androgen receptor (AR) and prestrogen receptor(PR) in meningiomas and the correlation of receptor presence with the clinicopathological features of meningiomasare unclear. Further investigations into AR should increase our understanding of the biology of meningiomas. In this study, we examined immunohistochemical expression of AR and PR in 57cases of meningiomas.Materials and Methods:Fifty-seven patients with primary meningiomas, operated on in thedepartment of Neurosurgery at the ZHEJIANG university second affiliated hospital from Jan. 2000 to December. 2001, were selected from the Department of Pathology files. Among them, 17 cases weremen and 40 were women , aged from 29 to 74 years with a mean age of 52 years. According to the criteria of WHO(1999), all cases were reviewed and eval uated for tumor grade and histological subtype. There were 45 benign, 5 atypical and 7 malignant meningiomas .The 4 urn tumor sections were used for immunohistochemical staining for AR and PR. Paraffin-embedded tissue sections of the meningiomas were stained with antibodies against PR and AR using Envision System immunohistochemical technique. Those cell nuclers whose colors were stained to be brown-yellow were identified to be PR or AR positive cells. Cell counting was performed at high power(400X) .Using sweat' s criteria[34],we counted 100 nuclei from 3 separate areas for each section. PR and AR positive grade was scored as follows-(<10%, +(10%~29%), -(30%~49%), (>50%). The immunohistochemical staining kit for AR and PR were purchased from Wuhan Boster Biotechnilogical company. The experiment was performed according to the instructional manual of the kit. Prostate cancer tissue section and breast cancer tissue section were provided by Wuhan Boster Biotechnological company and used as positive control for AR and PR, respectively. PBS, instead of the first antibody, was used as a negative control.AnalysisSPSS10. 0 statistical computer programs were used, if P<0. 05, it means that difference between two groups is significant.Results1 Immunoreactivity of AR in meningiomasIn most tumors, AR expression was observed in the nucleus. In few tumor sections, AR was observed in the cytoplasm. In addition to the meningiomacells, cells of the microvascular endothelial proliferations and smooth muscle of the tumor vascular walls were frequently AR positive. Of the 57 cases of meningiomas 29(50.8%) showed positive AR immunoreactivity. The AR positivity rates were 44. 4%(20/45) in the benign meningiomas, 60%(3/5) in the atypical meningiomas and 85. 7%(6/7) in malignant respectively. Malignant meningiomas had a significantly higher AR positivity rate when compareed with atypical and benign meningiomas(P<0.05). (Table 1)2 Immunoreactivity of PR in meningiomasIn most tumors, PR expression was observed in the nucleus. In few tumor sections, PR was observed in the cytoplasm. In addition to the meningioma cells, cells of the microvascular endothelial proliferations and smooth mus... |
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