p53 accumulation and apoptosis in embolized meningiomas

Preoperative embolization of meningiomas is performed to decrease blood loss at surgery. While it is also expected to reduce tumor recurrence by producing necrosis at the site of dural attachment, very little has been described about what happens to the non-necrotic tumor cells. We investigated how the proliferative activities of meningiomas were modified after embolization. In nine meningiomas which were embolized preoperatively, proliferative potentials and expression of cell cycle inhibitors were assessed immunohistochemically using MIB-1, anti-p53 (DO-1 and DO-7), and anti-p21 (WAF1/CIP1) monoclonal antibodies. To determine whether a cell underwent apoptotic death besides necrosis, we applied the terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling method. Results were compared with control meningiomas without embolization. MIB-1-positive cells often gathered in perinecrotic areas, although the mean MIB-1 staining index of the embolized meningiomas was not significantly different from the control. p53 and its downstream effector p21 accumulated mainly in the perinecrotic areas in eight of the nine embolized meningiomas. Apoptosis was also observed in the concomitant areas. Double staining for both MIB-1 and p21 frequently showed positive cells for both antibodies. The accumulation of MIB-1-positive cells in the embolized meningiomas may not be a sign of fast growth or malignancy, but it may implicate arrest of cell cycle by the p21. This study indicates that embolized meningiomas exhibit not only necrosis but also apoptosis and cell cycle arrest. The latter effects appear to be at least partly p53 dependent. Received: 16 September 1996 / Revised, accepted: 4 December 1996     

Topoisomerase II alpha as a reliable proliferation marker in meningiomas

The value of DNA Topoisomerase IIalpha expression as a proliferation marker in meningiomas was investigated. The correlation to MIB-1 expression and tumor grade in 85 meningiomas (60 classical, 19 atypical and 6 anaplastic) was analysed by immunohistochemistry. MIB-1 labeling indices (LI) were 1.1% (+/- 0.85) for classical meningiomas, 1.9% (+/- 1.5) for atypical meningiomas and 5.6% (+/- 4.1) for anaplastic meningiomas, differences statistically significant (p = 0.03, < 0.0001, < 0.0001). Topoisomerase IIalpha LIs were 1.4% (+/- 1.2) for classical, 3.2% (+/- 2.4) for atypical and 9.7% (+/- 6.6) for anaplastic meningiomas, differences statistically significant (p = 0.003, < 0.0001, < 0.0001). Proliferation indices based on cells staining for MIB-1 and Topoisomerase IIalpha correlated highly with one another (r= 0.906, p <0.0001). Topoisomerase IIalpha exhibited a more distinct, less variable nuclear staining pattern compared to MIB-1 expression. DNA Topoisomerase IIalpha LI represents a reliable alternative to MIB-1 as a proliferation marker in human meningiomas, especially for computer assisted assessment, where a distinct uniform staining pattern is required.     

Correlation between histological grade and MIB-1 and p53 immunoreactivity in meningiomas

OBJECTIVE: Meningiomas for the most part are slow-growing benign tumors, but complete removal can be difficult and recurrence is an issue. The aim of this study was to re-evaluate tumors diagnosed as meningioma previously in our hospital, according to the latest World Health Organization classification. We also examined the relationships among parameters such as brain invasion, histological grade and Ki-67 and p53 expression in these tumors. MATERIALS AND METHODS: Meningioma biopsy specimens numbering 60 (48 grade I, 11 grade II, and 1 grade III tumors) were examined immunohistochemically using monoclonal antibodies for Ki-67 (MIB-1) and p53 protein. The MIB-1 labeling index (LI) for each tumor was calculated as a percentage based on the number of stained cells per total cells counted. The level of p53 expression in each sample was semiquantatively evaluated as < 1%, 1 - 10%, 10 - 70%, or > 70%. Any value > 1% was accepted as presence of p53 expression. RESULTS: Of the 60 meningiomas, 7 (11.7%) exhibited brain invasion. The mean MIB-1 LI values for the grade I and grade II tumors were 1.1% and 2.3%, respectively. The corresponding levels of p53 protein expression in these groups were 54.1% and 72.7%. The MIB-1 LI and the level of p53 expression in the one grade III meningioma were 6.7% and 10 - 70%, respectively. Histological grade was significantly correlated with MIB-1 LI and with p53 expression (p < 0.01 for both). Brain invasion was not correlated with histological grade, MIB-1 LI, or p53 expression. CONCLUSION: The results indicate that MIB-1 LI and p53 protein expression are good indicators of histological grade in meningioma and may be particularly valuable for distinguishing borderline atypical meningiomas. The number of cases was limited, but the findings also suggest that brain invasion is a prognostic parameter independent of grade, MIB-1 LI and p53 expression.     

Survivin在脑膜瘤中的表达及其与p53、PCNA相关性研究

目的:探讨Survivin在脑膜瘤中的表达及与p53、PCNA相关性。方法:应用免疫组化SP法检测97例脑膜瘤组织、18例正常脑膜组织中survivin、p53、PCNA蛋白表达情况,结果进行统计学分析。结果:Survivin在脑膜瘤组织中表达的阳性率(65.9%)明显高于正常脑膜组织中的表达(0%)(P<0.001)。Survivin在脑膜瘤Ⅱ级(85.7%)和Ⅲ级(93.8%)中阳性表达率均明显高于脑膜瘤I级(51.7%)(P<0.001)。Survivin同p53表达共阳性23例,共阴性29例,两者的表达呈正相关(rs=0.451,P<0.01)。Survivin与PCNA蛋白表达共阳性45例,共阴性24例,两者的表达呈正相关(rs=0.640,P<0.01)。结论:Survivin是脑膜瘤形成和发展过程中重要的抗凋亡基因之一。Survivin与p53、PCNA在脑膜瘤的发生、增殖和恶化过程中可能起协同作用,其详细机制有待进一步研究。     

Immunohistochemical evaluation of intracranial recurrent meningiomas: correlation of topoisomerase II alpha expression and cell proliferative potential]

Most of meningiomas belong to benign tumor. But inspite of Simpson grade I surgical resection, it had been reported that a part of these cases recurred after initial operation. In discussing tumor recurrence in meningioma, it is important to evaluate not only the extent of surgical resection and malignancy but also cell proliferative potential, which had been studied immunohistochemically by using BudR, PCNA and MIB-1. Recently, it is known that topoisomerase (Topo) II alpha expression becomes remarkable in tumorigenesis. The correlation with cell proliferative potential has been reported. In this paper we evaluated the relationship of cell proliferative potential and tumor recurrence immunohistochemically by using Topo II alpha and MIB-1 monoclonal antibody in the 21 recurrent cases of meningiomas and hemangiopericytomas. As a result, mean Topo II alpha staining index (SI) and MIB-1 SI initial surgical resection were 2.29% and 3.41%, respectively, at recurrence these SIs had risen at 4.3% and 6.25%, respectively. As to the interval from initial surgical resection to recurrence, in the cases which recurred under 3 years Topo II alpha SI and MIB-1 SI were 3.13% and 5.00%, on the other hand, in the cases which recurred later than 3 years were 1.16% and 1.30%, respectively. Topo II alpha SI and MIB-1 SI 1 of former cases were higher than latter cases. Furthermore good correlation between the Topo II alpha SI and MIB-1 SI was found. It is concluded that Topo II alpha expression was as well available for the marker of cell proliferative potential and for one of the predicting factors for tumor recurrence in meningioma and hemangiopericytoma as MIB-1 SI.     

Prognostic significance of Ki-67/MIB-1 proliferation index in meningiomas

Even though tumor grade, subtype, and extent of resection are strong prognostic factors in human meningiomas, the growth of this tumor is still unpredictable, and additional prognostic markers are needed. Thus, immunohistochemical determination of proliferative activity using the Ki-67 equivalent antibody MIB-1 has gained increased attention. However, the reported prognostic significance of this marker in meningiomas is not fully clarified. The aim of this study was to investigate the prognostic role of MIB-1 proliferation index (PI) in a series of meningiomas comprising 23 benign, 17 atypical, and 9 anaplastic tumors. MIB- 1 PI increased with increasing tumor grade and discriminated significantly benign from atypical and anaplastic meningiomas whereas no difference was found between the latter two grades. However, due to the considerable overlap of PI values between the various grades, one should be circumspect before using this criterion for tumor grading. Furthermore, MIB-1 PIs were significantly higher in recurrent tumors compared with non-recurrent and a reliable MIB-1 PI cut-off value of 10% was established. This value, however, cannot automatically be adapted by other laboratories and must be regarded just as a guideline. In conclusion, MIB-1 PI appears as an important prognostic factor and should be used in combination with traditional histological criteria for malignancy in order to identify meningiomas with increased risk of recurrence.     

Allelic losses in neurofibromatosis 2-associated meningiomas

More than 50% of patients with neurofibromatosis 2 (NF2) develop meningiomas. Recently, a higher proliferative activity, more mitotic figures, and greater nuclear pleomorphism have been described for NF2-associated meningiomas compared with sporadic ones. To analyze whether such histological differences could reflect underlying genetic differences, we examined 30 meningiomas from 22 NF2 patients for allelic losses on those chromosome arms that are frequently affected by deletions in sporadic meningiomas. In addition, we assessed the proliferative activity of the tumors and studied NF2 germline mutations. Twenty-three meningiomas corresponded to WHO grade I (10 fibrous, 6 psammomatous, 4 transitional, 3 meningothelial) and 7 to WHO grade II. The average MIB-1 index was 1.60 +/- 0.85 (WHO grade I: 1.41 +/- 0.80, WHO grade II: 2.13 +/- 0.82). When compared with several published studies of sporadic meningiomas, the MIB-1 index in NF2-associated meningiomas was not higher. Loss of heterozygosity (LOH) flanking or within the NF2 locus at 22q12 was detected in 100% of the tumors. LOH on 1p was the second most frequent abnormality (40%), followed by losses on 10q (27%), 6q and 14q (24%), 18q (23%), and 9p (17%). LOH on 19q and 17p, which is not commonly seen in sporadic meningiomas, was also only rarely detected in NF2-associated meningiomas. NF2 gene mutations were detected in 8 of 15 patients analyzed and were located in exons 2, 5, 6, 7, and 8. We conclude that sporadic and NF2-associated meningiomas share a common spectrum and frequency of allelic deletions as well as, in contrast to previous observations, a similar proliferative activity.     

MIB-1(Ki-67) index and transforming growth factor-alpha (TGFα) immunoreactivity are significant prognostic predictors for meningiomas

Mitotic index >6, proliferating cell nuclear antigen (PCNA) index >5%, high tumour grade and absence of progesterone receptors (PR) are significant predictors for poor outcome in meningiomas. Since MIB-1 (Ki-67) is a more specific cell proliferation marker, and overexpression of TGF-alpha is also associated with tumour progression, we compared the prognostic significance of these factors with the other indices. Intracranial meningiomas from 21 men and 36 women (age 54.5±1.7, mean±sem) were classified as 24 benign, 24 atypical and nine malignant. Twenty-one of the 57 tumours recurred (mean interval to recurrence was 57.3±13.1 months). The mean follow-up period for patients without tumour recurrence was 81.9±8.7 months. MIB-1 labelling index (LI) was expressed as percentage of labelled nuclei to total tumour nuclei counted in the most densely labelled areas. Analysis of variance revealed significant differences between tumour grades for MIB-1 labelling indices (0.75±0.21 for benign, 3.2±0.57 for atypical, 6.04±1.48 for malignant; P≤0.0066), and between malignant and non-malignant meningiomas for TGFα staining scores (P≤0.029). MIB-1 LI also correlated with mitotic and PCNA indices (P≤0.0001), but not with age of the patients. Male patients had higher tumour MIB-1 LI than females (P≤0.0128). Univariate analysis indicated that MIB-1 LI>3%, TGFα score >4 (scoring scale 0–5), mitotic index >6, and negative PR status were significant factors for worse outcome. Higher MIB-1 LI, TGFα score and mitotic index as continuous variables were also significant negative predictors. With multivariate analysis, both MIB-1 LI and TGFα score remained significant factors when paired with all other variables: TGFα or MIB-1 LI, respectively, mitosis, PCNA, tumour grade, PR status, age, sex, postoperative radiation therapy. We conclude that MIB-1 LI and TGFα score are important independent prognostic indicators for patients with meningiomas.     

Immunohistochemical expression of inducible nitric oxide synthase (iNOS) in human brain tumors: relationships of iNOS to superoxide dismutase (SOD) proteins (SOD1 and SOD2), Ki-67 antigen (MIB-1) and p53 protein

In this study, inducible nitric oxide synthase (iNOS) expression in a series of 158 human primary brain tumors was analyzed. To gain some insight into the biological significance of iNOS expression in tumor cells, comparative immunohistochemical analyses were employed to characterize the expression of iNOS, superoxide dismutase (SOD) proteins (SOD1 and SOD2), Ki-67 antigen (MIB-1) and p53 protein in these cells. Sixteen (39.0%) of the 41 glioblastoma multiforme (GBM) specimens showed iNOS immunoreactivity. Positive immunoreactions with iNOS were also detected in 2/8 anaplastic astrocytomas, 1/17 astrocytomas, 1/14 medulloblastomas and 1/11 primitive neuroectodermal tumors, but no positive reactions were observed in oligodendrogliomas (0/11), ependymomas (0/5), schwannomas (0/21), meningiomas (0/23) or pituitary adenomas (0/7). The MIB-1 labeling index of GBMs that expressed iNOS was significantly higher than that of GBMs that did not (0.025< P <0.05, Wilcoxon rank-sum test). Unlike iNOS-negative tumors, all iNOS-positive tumors coexpressed SOD1 or SOD2. In particular, there was a significant correlation between iNOS induction and SOD1 expression (P =1.65x10(-10), Fisher's exact test) in GBM specimens. There was no significant relationship between iNOS and p53 protein in any type of primary brain tumor (P >0.05, Fisher's exact test). No significant immunohistochemical reactions with iNOS, MIB-1 or p53 protein were observed in normal brain tissue sections. We conclude that primary brain tumors express iNOS, and that iNOS expression in brain tumor cells may depend, in part, on cellular proliferation potential. Based on the fact that SOD1 scavenges oxidative-stress species originating from large amounts of nitric oxide (NO) produced by iNOS, iNOS-expressing brain tumor cells may protect themselves against NO cytotoxicity by overinducing SOD1.     

脑膜瘤组织中EGFR、PCNA表达及其意义

目的 探讨表皮生长因子受体（epidermal growth factor receptor,EGFR)表达与脑膜瘤增殖活性的关系。方法 采用LSAB免疫组化方法检测39例脑膜瘤中EGFR、增殖细胞核抗原（proliferating cell nuclear antigen,PCNA)的表达。结果 脑膜瘤中EGFR表达阳性率为92.3%(36/39)，不同级别脑膜瘤中EGFR表达强度的差异有显著性（P＜0.01)。PCNA标记指数（PCNA labeling index,PCNA LI)与脑膜瘤的病理分级有明显相关（P＜0.01)。EGFR与PCNA表达呈显著正相关（P＜0.01)。结论 EGFR可能在某些脑膜瘤的恶性发展中起重要作用。     

The effect of cyclin D expression on cell proliferation in human gliomas.

The expression of three cyclin D subtypes was defined immunohistochemically with cyclin D1, D2 and D3 monoclonal antibodies in 52 human glioma biopsies and eight control samples of normal brain tissue. PCNA labeling indices (LI) were used to evaluate proliferation in the glioma biopsies. LI of cyclin D1, D2 and D3 were compared with histological grade and the proliferating cell nuclear antigen (PCNA) LI. Cyclin D1 expression only was observed in normal brain tissue, but marked overexpression of cyclin D1 and cyclin D3 was observed in glioma. Cyclin D1 LI increased with malignancy, in parallel with an increase in PCNA LI. Lower expression of cyclin D2 was found in a small fraction of the gliomas, but its LI did not vary significantly with grade. Cyclin D3 was mainly expressed by malignant gliomas and was rarely observed in low-grade glioma. Cyclin D2 and D3 expression correlated with PCNA LI, but not as strongly as for cyclin D1. Expression of cyclin D1 is closely related to both the oncogenesis and progression of glioma, while cyclin D3 is associated with transformation to a malignant phenotype. Cyclin D2 is weakly expressed and shows no marked relationship with any aspect of tumorigenesis. The exact contribution of cyclin D subtypes to cell cycle progression in neoplastic and reactive cells remains to be defined.     

壳寡糖对Hela细胞cyclin D1、bcl-xl和bcl-2 mRNA表达的影响

背景：研究表明壳寡糖具有抗肿瘤作用,但壳寡糖对cyclin D1、bcl-2和bcl-xl影响机制尚不清楚。 目的：观察壳寡糖抑制Hela细胞生长的作用,以及对细胞内cyclin D1、bcl-xl和 bcl-2 mRNA表达的影响。 方法：壳寡糖(0.1,0.5,1,2,5 g/L)刺激Hela细胞后,CCK8实验检测其对细胞生长的影响;运用实时荧光定量PCR方法在分子水平检测cyclin D1、bcl-xl和 bcl-2 mRNA在细胞中的表达情况。 结果与结论：壳寡糖可抑制Hela细胞的生长;随着壳寡糖的质量浓度由0.1 g/L增加至2 g/L,壳寡糖抑制cyclin D1,bcl-2,bcl-xl基因表达的作用也逐渐增强,在2 g/L时作用最强,但质量浓度过高时(5 g/L)抑制作用反而有所减弱。结果表明壳寡糖的抗肿瘤作用可能通过两方面进行：一方面壳寡糖可以抑制与细胞周期有关的cyclin D1 mRNA表达以抑制肿瘤细胞的增殖;另一方面壳寡糖可以抑制抗凋亡蛋白Bcl-2 和bcl-xl mRNA的表达以促进肿瘤细胞的凋亡;且对前者的作用强于后者。 关键词：荧光定量PCR;壳寡糖;Hela细胞;细胞周期蛋白 D1;bcl-xl;bcl-2 doi:10.3969/j.issn.1673-8225.2010.03.012     

Analysis of expression of estrogen (ER) and progesterone receptors (PR) in brain glial tumors and its correlation with expression of p53 protein and proliferating cell nuclear antigen (PCNA)

BACKGROUND AND PURPOSE: All the types of the glial cells contain estrogen (ER) and progesterone receptors (PR) but their occurrence in glial tumors of the brain is still controversial. The aim of this research was the clinical analysis of ER and PR expression in correlation with histological malignancy and expression of p53 and PCNA. MATERIAL AND METHODS: The investigation was carried out on a group of 56 patients operated on at the Neurosurgical Department of Wroclaw Medical University. The percentage of tumors containing ER and PR was assessed and mean receptor expressions were compared. Classical histological tests, immunohistochemical tests for ER, PR, p53 and PCNA with monoclonal antibodies (DACO) were performed for every specimen of tumor tissue. RESULTS: ER occurred in 24 cases (42.9%), PR in 10 cases (17.9%). 49% of highly malignant gliomas (WHO III and IV) were ER positive, whereas 29% of tumors grade I and II were ER positive. Frequencies of PR positive tumors were similar in both groups. Mean PR expression in p53 positive group was 8% and in p53 negative group 1.5% (p=0.017). Mean ER expression in PCNA positive group was 7.4%, whereas in PCNA negative group 2.7% (p<0.01). CONCLUSIONS: Frequency of ER occurrence is higher in highly malignant tumors. ER expression is correlated with proliferative activity (PCNA). PR expression is positively correlated with intensity of mutant p53 protein.     

Immunostaining for proliferating cell nuclear antigen: its role in determination of proliferation in routinely processed human brain tumor specimens

Alcohol- and formalin-fixed, paraffin-embedded samples of 71 brain tumors (35 gliomas, 22 metastatic carcinomas, 8 meningiomas and 6 other tumors) were investigated by immunocytochemistry with three different monoclonal antibodies against proliferating cell nuclear antigen (PCNA)/cyclin (19A2; 19F4; PC10). PC10 was found to work best; it is applicable to both alcohol- and formalin-fixed tumor samples. PCNA labeling indices (LIs) were compared in the same tumors with LIs obtained by Ki-67 immunostaining of frozen sections and by in vitro incubation with bromodeoxyuridine (BrdUrd); in the latter preparations, BrdUrd LIs could be compared with PCNA LIs in the very same areas of serial sections. In gliomas, PCNA LIs were 0.7–80.2% (mean 31.7%), in metastases 0–76.0% (mean 47.8%), and in meningiomas 0–53.0% (mean 19.3%). In general, PCNA LIs were highly significantly correlated with Ki-67 LIs (P=0.0002) and BrdUrd LIs (P=0.0001). However, when tumor subgroups are considered, only gliomas show a significant correlation with Ki-67 and BrdUrd LIs. Despite this statistical correlation, PCNA expression was out of proportion to proliferation indices as determined by both other methods in almost one third of all brain tumors. Immunocytochemistry for PCNA produces a broad spectrum of staining intensity of labeled nuclei, whose number is dependent upon the sensitivity of the immunocytochemical technique used. Thus, inter-oberserver and inter-laboratory variabilities in PCNA LI determination may occur. Overlapping of PCNA LIs between tumor subgroups of varying malignancy further limits the informational value for the individual case. In some classic meningiomas, high PCNA scores do not reflect the proliferative activity of the tumor, as Ki-67 and BrdUrd LIs are very low in these cases. We conclude that PCNA immunolabeling is of limited value in the individual tumor, mainly due to overexpression in many tumors, and at present cannot be recommended to replace Ki-67 and/or BrdUrd labeling methods for routine determination of proliferative activity in human tumor specimens.Supported in part by a grant from the Oncology Commission, Medical Faculty, University of Vienna     

Expression of retinoblastoma gene product and p21 (WAF1/Cip 1) protein in gliomas: correlations with proliferation markers, p53 expression and survival

Using immunohistochemistry we evaluated the expression of two negative regulators of the cell cycle, the retinoblastoma gene product (pRb) and the WAF1/Cip1 gene product (p21), in consecutive paraffin sections from 54 gliomas (49 astrocytomas and 5 oligodendrogliomas) and related it to clinicopathological parameters, proliferative fraction, p53 expression and survival. Survival analysis was restricted to the group of diffuse astrocytomas (48 patients). pRb expression did not correlate with histological type, grade or p53 expression, while a moderately strong correlation existed between pRb expression and the percentages of proliferating cell nuclear antigen (PCNA) and MIB-1-positive cells. In 30% of cases we observed diminished pRb expression (i.e., a low pRb/Ki-67 ratio), irrespective of grade or histological type. p21 protein was elevated in 50% of cases, especially within the higher grades. The percentage of p21-positive cells was not related to histological type or grade but correlated loosely with PCNA and pRb expression. A p53-negative/p21-negative phenotype was characteristic of oligodendrogliomas and low-grade astrocytomas, whereas the p53-positive/p21-positive, p53-positive/p21-negative and p53-negative/p21-positive phenotypes were almost equally distributed among high-grade tumors. In survival analysis (either univariate or multivariate) diminished pRb expression was not a statistically significant prognostic indicator. In contrast, p21 expression emerged as an important indicator of shortened disease-free survival, in both univariate and multivariate analyses. Moreover, the double-positive p53/p21 phenotype tended to be associated with a shorter overall survival. Our results suggest that Rb gene deregulation does not significantly affect prognosis but p21 expression may play an important role in disease-free survival of astrocytoma patients. Received: 14 August 1997 / Revised: 6 November 1997 / Accepted: 28 November 1997     

Loss of tumor suppressor in lung cancer-1 (TSLC1) expression in meningioma correlates with increased malignancy grade and reduced patient survival

Meningiomas represent the second most common central nervous system tumor affecting adults. Two of the most frequent early events in meningioma tumorigenesis involve loss of expression of the neurofibromatosis 2 (NF2) and 4.1B genes. Recently, 4.1B was shown to interact with the tumor suppressor in lung cancer-1 (TSLC1) protein, prompting us to examine the expression of TSLC1 in meningiomas. We developed specific anti-TSLC1 antibodies to examine TSLC1 expression in normal human leptomeninges, human meningioma cell lines, and human meningiomas of different pathological grades by Western blot (n = 10) and immunohistochemistry (n = 123). Whereas TSLC1 was expressed in normal human leptomeninges by immunohistochemistry, TSLC1 expression was absent in 3 human malignant meningioma cell lines and markedly reduced or absent in 30% of benign meningiomas by Western blot. Restoration of TSLC1 expression in a TSLC1-deficient human meningioma cell line resulted in reduced cell proliferation. In a series of 123 meningiomas (98 adult and 25 pediatric), TSLC1 expression was absent in 48% of benign (WHO grade I), 69% of atypical (grade II), and 85% of anaplastic (grade III) meningiomas. Moreover, TSLC1 loss was associated with decreased patient survival, within the overall group, and in the atypical meningiomas. Collectively, these results suggest that TSLC1 plays an important role in meningioma pathogenesis.     

Evaluation of proliferative index and cell cycle protein expression in choroid plexus tumors in children

Choroid plexus tumors are papillary neoplasms originating from the epithelium of the choroid plexus within the cerebral ventricles. They may be highly proliferative tumors, but detailed studies confirming their proliferative potential are lacking. Accordingly, we performed a clinicopathological correlation study of neoplasms arising from the choroid plexus in children using immunohistochemistry to characterize both their proliferative potential and their degree of cell cycle dysregulation when compared to non-neoplastic choroid epithelium. Twelve children with choroid plexus papillomas (CPPs) and 11 with choroid plexus carcinomas (CPCs) were identified from the time period 1982-1997. The outcome and survival of these children following treatment was determined from the medical record. Immunohistochemical studies were performed on CPPs and CPCs in this patient population and on non-neoplastic choroid epithelium using antibodies to MIB-1, p53, cyclin E, retinoblastoma protein (pRB), p107, and E2F-1. In 5 children with CPCs, tumor tissue was available for immunohistochemistry at a second surgery after cycles of chemotherapy had been given. The mean survival for patients with CPPs was 8.5 years, and with CPCs 5.2 years with a minimum follow-up of 4 years for the group. The expression of cell cycle markers and MIB-1 was greater in CPCs than in CPPs or normal choroid plexus. The expression of MIB-1, p53, pRB, and E2F-1 was significantly lower in patients with CPCs after chemotherapy than before. The MIB-1 labeling index for CPC patients who are alive and well after treatments was 15.19+/-3.2 compared to 22.63+/-3.04 for patients who have died from their disease (P<0.05). We conclude that CPCs in children are characterized by a higher MIB-1 labeling index and greater cell cycle dysregulation than are CPPs. Chemotherapy may work in part on CPCs to decrease their proliferative potential and expression of cell cycle regulatory proteins.     

p38MAPK activation and DUSP10 expression in meningiomas

The mitogen activated protein kinase (MAPK) p38MAPK has been implicated in regulation of cell proliferation and apoptosis. However, expression, activation and regulation has not been studied in meningiomas, to our knowledge. p38MAPK is regulated, in part, by dual specificity phosphatases (DUSP) that inactivate signaling by dephosphorylation. DUSP10 is also a likely participant in regulating meningioma proliferation. Five fetal and an adult human leptomeninges and 37 meningioma cultures (MC) were evaluated for DUSP10 as well as phosphorylation of its substrates p38MAPK and p44/42MAPK by western blot and DUSP10 expression by polymerase chain reaction. Platelet derived growth factor-BB (PDGF-BB), transforming growth factor B1 (TGFB1) and cerebrospinal fluid effects on DUSP10 and signaling were also studied in vitro. DUSP10 and phospho-p38MAPK and phospho-p44/42MAPK were detected in all six leptomeninges. DUSP10 was detected in 13 of 17 World Health Organization grade I, 11 of 14 grade II and four of six grade III meningiomas. Phospho-p38MAPK was detected in nine of 17 grade I, two of six grade II, and four of six grade III meningiomas. In the majority of meningiomas DUSP10 expression correlated inversely with phosphorylation of p38MAPK. PDGF-BB increased DUSP10 in MC2 and MC4 and weakly in MC3. TGFB1 increased phosphorylation of p38MAPK and caspase 3 activation. Thus p38MAPK and DUSP10 likely participate in the pathogenesis of meningiomas.     

Analysis of PCNA, Ki67, AgNOR and p53 expression in brain glial tumors

BACKGROUND AND PURPOSE: The aim of this study was to evaluate clinical usefulness of proliferating cell nuclear antigen (PCNA), Ki67 antigen, p53 protein and silver-binding nucleolar organizer regions (AgNOR) in brain glial tumors. MATERIAL AND METHODS: The investigation of PCNA, Ki67 and p53 was carried out on a group of 120 patients with glial tumors operated on at the Neurosurgical Department of Wroclaw Medical University including 63 patients operated again because of recurrence. AgNOR was evaluated on a group of 64 patients including 38 patients operated again. Classical histological tests, immunohistochemical tests for PCNA, p53 and Ki67 activity with monoclonal antibodies (DACO) and histochemical tests for AgNOR were performed on every specimen of tumor tissue. The level of 40% for PCNA, 2.75 (equal to median) for AgNOR and 5% for Ki67 and p53 was adopted as significant. RESULTS: Mean expression of PCNA of glial tumors grade I and II was 32%, grade III and IV - 44% (p<0.05). Mean expression of AgNOR was 1.88 and 3.16 (p=0.00001), respectively. Average PCNA expression in recurrent tumors to 12 months was 52.7% and for later recurrences - 35.4% (p<0.05). Average expressions of AgNOR were 3.38 and 2.68 (p<0.05), respectively. Differences of Ki67 and p53 expressions were not significant. CONCLUSIONS: PCNA and AgNOR expressions correlate with proliferative activity, growth rate and histological malignancy, reaching high values in highly malignant and early recurrent tumors. Antigens Ki67 and p53 do not seem to be predictive markers of glial tumors.     

Clinical and histopathological analysis of proliferative potentials of recurrent and non-recurrent meningiomas

Proliferative potentials of meningiomas from 127 patients were examined immunohistochemically using the anti-Ki-67 monoclonal antibody, MIB-1, on paraffin sections, and the correlation among MIB-1 staining index (SI), histopathological finding, and clinial course of the disease was analyzed retrospectively. The mean MIB-1 SI of 50 male patients with meningioma was 5.5%, whereas that of 77 female patients was 2.7%. Higher MIB-1 SI were observed for younger patients. These age- and sex-related differences in MIB-1 SI were statistically significant. The patients were assigned to one of three groups: those with non-recurrent meningioma (n = 73); those with recurrent meningioma in whom the specimens obtained during the initial surgery were used to calculate the MIB-1 SI (n = 21); and those with recurrent meningioma for whom the specimens obtained during the surgery for recurrent tumors were used to calculate the MIB-1 SI (n = 33). The mean MIB-1 SI in these patients were 1.6%, 3.6%, and 8.8%, respectively, and there were statistically significant differences among these three groups. Statistical analyses reveal that meningiomas with a MIB-1 SI of 3% or more have a significantly high tendency for recurrence during the clinical courses, especially within the first 10-year follow-up periods. Moreover, there is statistically significant correlation between MIB-1 SI and recurrence in each Simpson’s grade. The time interval to the next recurrence for recurrent meningiomas is associated with the proliferative potential represented by the MIB-1 SI, and a correlation equation has been proposed to predict the date of the next recurrence. Analyses on cellularity of meningiomas revealed no statistically significant difference in cellularity between non-recurrent and recurrent meningiomas. There was no statistically significant relationship between cellularity and MIB-1 SI of meningiomas. In conclusion, examination on proliferative potentials of meningiomas using MIB-1 SI is very important for biological and histopathologicl analyses and the prediction of future recurrence. Received: 21 February 1995 / Revised: 28 September 1995 / Revised, accepted: 13 November 1995