Expression of ErbB-1 and ErbB-2 in meningioma

Clinicopathological significance of concurrent ErbB receptor expression in human meningioma

In general, human meningiomas grow slowly and have a favourable prognosis; however, some are prone to recur despite their benign histology. Therefore, knowledge of their tumour biology is essential to determine objective biomarkers that can identify cases with an increased risk for recurrence and to generate effective treatment options. Thus, studies on the epidermal growth factor receptor (EGFR) family, comprising ErbB1/EGFR, ErbB2/HER2, ErbB3/HER3 and ErbB4/HER4, are important. We have recently published papers on the expression of each of these receptor proteins in human meningiomas. The present study aimed to assess the clinicopathological significance of their concurrent expression. A total of 185 grade 1 and 2 meningiomas with robust clinical data underwent immunohistochemical analyses with antibodies against the aforementioned receptors. All meningiomas exhibited upregulation of these receptor proteins relative to normal meninges. In addition, the expression of phosphorylated/activated ErbB1/EGFR1 and phosphorylated/activated ErbB2/HER2 was significantly associated with histological malignancy grade and prognosis, respectively. The concurrent upregulation of ErbB receptors in human meningioma supports their fundamental role in the tumourigenesis of these tumours, and they could thus be exploited in diagnostics, prognosis, and ultimately, in targeted clinical interventions.

Expression of Human Epidermal Growth Factor Receptor 2 in Meningiomas

Background: Meningiomas consist of 15%–30% of the primary intracranial tumors, and high-grade meningiomas have a higher recurrence after surgery. The human epidermal growth factor receptor 2 (HER2) status is important in the medical management of patients with various human cancers. This study aimed to evaluate HER2 expression in meningiomas and the correlation between this expression and age, gender, and grade. Materials and Methods: In a descriptive-analytic study, immunohistochemistry (IHC) with HER2 marker was done on confirmed cases of meningioma which were referred to the pathology laboratory from 2008 to 2015. The primary antihuman antibody against c-erbB-2 oncoprotein (DAKO Diagnostics) was used for IHC. Results: Of 117 patients, 68.4% were males. The mean age of the patients was 53.6 years. Grades I, II, and III tumors were 90.6%, 8.5%, and 0.9% of cases, respectively. Totally, 76 (65%) of patients were HER2 positive, with only 7.7% of highly expressed HER2. There was no significant correlation between the mean age (P = 0.672), age group (P = 0.256), sex (P = 0.574), and grade (P = 0.093) and HER2 expression status. Conclusions: We did not find a statistically significant correlation between age, sex, or grade and HER2 status; however, further studies with a higher number of Grades II and III meningiomas and using the fluorescent in situ hybridization in equivocal cases may be of benefit in this way.

Expression and clinical value of EGFR in human meningiomas

Background

Meningiomas are common intracranial tumors in humans that frequently recur despite having a predominantly benign nature. Even though these tumors have been shown to commonly express EGFR/c-erbB1 (epidermal growth factor receptor), results from previous studies are uncertain regarding the expression of either intracellular or extracellular domains, cellular localization, activation state, relations to malignancy grade, and prognosis.

Aims

This study was designed to investigate the expression of the intracellular and extracellular domains of EGFR and of the activated receptor as well as its ligands EGF and TGFα in a large series of meningiomas with long follow-up data, and investigate if there exists an association between antibody expression and clinical and histological data.

Methods

A series of 186 meningiomas consecutively operated within a 10-year period was included. Tissue microarrays were constructed and immunohistochemically analyzed with antibodies targeting intracellular and extracellular domains of EGFR, phosphorylated receptor, and EGF and TGFα. Expression levels were recorded as a staining index (SI).

Results

Positive immunoreactivity was observed for all antibodies in most cases. There was in general high SIs for the intracellular domain of EGFR, phosphorylated EGFR, EGF, and TGFα but lower for the extracellular domain. Normal meninges were negative for all antibodies. Higher SIs for the phosphorylated EGFR were observed in grade II tumors compared with grade I (p = 0.018). Survival or recurrence was significantly decreased in the time to recurrence analysis (TTR) with high SI-scores of the extracellular domain in a univariable survival analysis (HR 1.152, CI (1.036–1.280, p = 0.009)). This was not significant in a multivariable analysis. Expression of the other antigens did not affect survival.

Conclusion

EGFR is overexpressed and in an activated state in human meningiomas. High levels of ligands also support this growth factor receptor system to be involved in meningioma tumorigenesis. EGFR may be a potential candidate for targeted therapy.

The protein expression profile of meningioma cells is associated with distinct cytogenetic tumour subgroups

AIMS

Limited information exists about the impact of cytogenetic alterations on the protein expression profiles of individual meningioma cells and their association with the clinicohistopathological characteristics of the disease. The aim of this study is to investigate the potential association between the immunophenotypic profile of single meningioma cells and the most relevant features of the tumour.

METHODS

Multiparameter flow cytometry (MFC) was used to evaluate the immunophenotypic profile of tumour cells (n = 51 patients) and the Affymetrix U133A chip was applied for the analysis of the gene expression profile (n = 40) of meningioma samples, cytogenetically characterized by interphase fluorescence in situ hybridization.

RESULTS

Overall, a close association between the pattern of protein expression and the cytogenetic profile of tumour cells was found. Thus, diploid tumours displayed higher levels of expression of the CD55 complement regulatory protein, tumours carrying isolated monosomy 22/del(22q) showed greater levels of bcl2 and PDGFRβ and meningiomas carrying complex karyotypes displayed a greater proliferation index and decreased expression of the CD13 ectoenzyme, the CD9 and CD81 tetraspanins, and the Her2/neu growth factor receptor. From the clinical point of view, higher expression of CD53 and CD44 was associated with a poorer outcome.

CONCLUSIONS

Here we show that the protein expression profile of individual meningioma cells is closely associated with tumour cytogenetics, which may reflect the involvement of different signalling pathways in the distinct cytogenetic subgroups of meningiomas, with specific immunophenotypic profiles also translating into a different tumour clinical behaviour.

An immunohistochemical study of HER2 expression in meningioma and its correlation with tumor grade

Meningiomas account for about 15-30% of all primary intracranial tumors. According to the 2007 WHO classification, meningiomas are divided into three grades (I, II and III). Recurrence is an issue following surgical treatment of meningioma, especially in grades II and III. HER2 (also known as erbB-2) is a 185-kD transmembrane glycoprotein with tyrosine kinase activity. HER2 is expressed in some human malignancies and can be a potential target for therapeutic intervention with selective inhibitors. There are only a few studies on the relationship between meningioma and HER2 expression, and the results are different as well. The aim of this study was to determine this relationship. Seventy-two paraffin blocks of meningioma were selected randomly, and immunohistochemical staining was then performed for each specimen. Thirty-one of the 72 meningiomas were HER2-positive. HER2 expression was observed in 11 (55%) of the 20 grade II/III, and 20 (38.5%) of the 52 grade I meningiomas. Consequently, HER2 expression was detected in 43% of meningiomas. No significant difference was seen between grade I and grade II/III meningiomas, primary and recurrent tumors, and males and females from the point of view of HER2 expression.