Rüdiger Klein

Heterogeneous regional expression patterns of matrix metalloproteinases in human malignant gliomas.

The aim of the study was to assess the differential intra‐ and intertumoral heterogeneity and patterns of matrix metalloproteinase expression in human glioblastomas in vivo. 12 glioblastoma samples were analyzed for MMP expression by semi‐quantitative RT‐PCR. A total of 56 samples (8 adjoining regions of 6 glioblastoma tumors) were immunohistochemically examined for the expression and regional distribution of gelatinase‐A (MMP‐2), gelatinase‐B (MMP‐9), matrilysin (MMP‐7) and stromelysin‐1 (MMP‐3). Gelatinase‐A mRNA was detected in all samples, gelatinase‐B was found in numerous samples. Correspondingly, strong expression levels of both gelatinase protein was seen in immunohistochemistry. Gelatinase‐A was expressed by both tumor cells and endothelium while gelatinase‐B was found to be restricted to endothelial cells. Stromelysin‐1 protein was not detected in any of the samples. Matrilysin was found around tumor cells of three samples from one patient only. The strong immunoreactivity seen for gelatinase‐A around tumor cells and blood vessels suggests a role in both tissue degradation and tumor neoangiogenesis which is in accordance with previously published in vitro data. The marked localization of gelatinase‐B to the endothelium and its presence in non‐infiltrative benign lesions, however, makes a direct proteolytic role of gelatinase‐B on ECM components during glioma invasion appear unlikely. Its close association with vascular structures, however, might indicate a link to neoangiogenesis. The significance of matrilysin which was only seen in tumor cells in three samples remains unclear. Stromelysin‐1, though strongly expressed in cell lines, does not appear to play a role in glioblastoma tumors in vivo.

Increased microglia proliferation separates pilocytic astrocytomas from diffuse astrocytomas: a double labeling study.

Abstract. It is not known how many non-tumorous cells in gliomas contribute to the proliferation rate. We investigated the proliferative activity of microglia in an immunohistochemical double-labeling study of pilocytic astrocytomas and astrocytomas WHO grade II–IV using the antibodies MIB-1 (Ki67) as proliferation-marker and Ki-M1P (CD68) as microglia marker. We found the highest indices of proliferating microglia in pilocytic astrocytomas with an average rate of 32% (±6.8) of all proliferating cells. In contrast, the proliferation indices of microglia were lowest in fibrillary astrocytomas with 8.6% (±2.5) of all proliferating cells. In anaplastic astrocytomas and glioblastomas the percentage of proliferating microglia showed a slight increase to 8.8% (±3.6) and 13.4% (±8.7), respectively. We conclude that microglial cells in astrocytic brain tumors proliferate and show different proliferative activities at different grades of malignancy with the highest rates of proliferating microglia especially in pilocytic astrocytomas. Thus, the proliferation rate does not solely reflect the proliferation of tumor cells, but also of non-tumorous cells. This should be considered in particular when proliferation rates are used as a criterion for prognosis and grading of pilocytic astrocytomas.

Spontaneous regression of experimental gliomas--an immunohistochemical and MRI study of the C6 glioma spheroid implantation model.

OBJECTIVE The orthotopic C6 glioma spheroid implantation model has been used to examine factors of neoangiogenesis, growth factor release, and protease expression as well the effect of antitumor agents. The present study systematically investigates the long-term course of orthotopically implanted C6 spheroid gliomas. METHODS Reaggregated C6 spheroid tumors were implanted into the forebrain of 48 male Sprague-Dawley rats (32 immunocompetent, 16 thymectomized). The animals were examined by MRI at postoperative day (POD) 7, 14, 21, 28, 32, 45, 60, and 70. The MRI protocol included a T2-w and T1-w SE sequence before and after application of contrast medium and a CISS 3D sequence for volumetry. A total of six animals were selected after each MR exam from both groups and sacrificed for HE light microscopy and CD8+ T-lymphocyte, ED1+ macrophage, CD31+ endothelial cell immunohistochemistry. RESULTS The tumors progressed to reach a maximum volume on day 28: 0.23 +/- 0.05 ml in the thymectomized and 0.16 +/- 0.021 ml in the immunocompetent group. Tumors then consistently regressed to vanish completely by POD 70. The influx of cytotoxic CD8+ T-lymphocytes correlated with tumor progression and the tumors reached a larger size in the thymectomized group. However, the time course of tumor regression was the same for both groups. CONCLUSION The present data suggest that the orthotopic C6 glioma implanted into Sprague-Dawley rats will progress within a time span of approximately 4 weeks and can then retrogress again spontaneously. This finding has to be taken into account when deciding on a study protocol and the appropriate animal model. The C6 glioma model may be suitable to study the cell biological steps involved in the phenomenon of spontaneous tumor regression.

Diagnosing dural metastases: the value of 1H magnetic resonance spectroscopy

Abstract The purpose of this study was to assess the value of MRI, MR spectroscopy (MRS) and intra-arterial angiography in the preoperative diagnosis of extra-axial dural-based masses. We prospectively studied 54 patients who underwent preoperative MRI, MRS and angiography. Histologically there were 50 meningiomas and four dural metastases. MRI and angiography did not allow reliable differentiation between meningiomas and metastases. MRS showed elevated choline/creatine ratios in both meningiomas and metastases, but there were prominent lipid signals in all metastases and a lactate peak in two. This spectroscopic pattern was not found in meningiomas. However, following embolisation, they showed similar spectra, due to ischaemia and necrosis. We therefore believe MRS to be valuable in differential diagnosis of dural metastases and meningiomas prior to embolisation.

Favorable outcome of giant cell glioblastoma in a child Report of an 11-year survival period

Giant cell glioblastomas are defined as glioblastomas with a marked predominance of bizarre, multinucleated giant cells. They represent about 5% of all glioblastomas and can occur at any site of the central nervous system, but the temporal and frontal lobes are the sites of predilection. Overall, giant cell glioblastomas show a prolonged survival period compared with common glioblastoma multiforme, and survival periods of 7 and 9 years have been reported in adults. Here we report on a child aged 11 years at diagnosis, who has so far survived for 11 years since operation and adjunctive radio- and chemotherapy.

Cytogenetic and histopathologic studies of congenital supratentorial primitive neuroectodermal tumors: A case report

Primitive neuroectodermal tumors (PNET) represent about 25% of primary central nervous system tumors in childhood, but congenital PNETs are rare. Cytogenetic studies and studies on molecular pathology have identified several genetic alterations in medulloblastoma, but molecular investigations on supratentorial PNETs are infrequent. We present a male newborn with a large congenital PNET of the right cerebral hemisphere and the molecular analysis of the tumor. Tumor tissue was investigated by routine histology and immunohistochemistry. Fluorescence in-situ hybridization was carried out on native tumor tissue to investigate deletions on chromosome 17p and to analyze c-Myc or N-Myc amplifications. Histologic examination revealed a primitive neuroectodermal tumor with massive extension covering almost the entire right hemisphere. Genetic analysis of the native tumor tissue of our patient excluded a deletion of chromosome 17p. An amplification of the c-Myc or N-Myc oncogene was absent using fluorescence in-situ hybridization. Despite unremarkable genetic analysis in our case prognosis was poor, suggesting that there are additional, yet unknown constitutional genetic aberrations in the pathogenesis of congenital supratentorial PNET.

Medulloblastoma displays distinct regional matrix metalloprotease expression.

Matrix metalloproteases (MMPs) play an important role in tissue remodeling and neoangiogenesis during tumor progression. Little is known about the presence and regional distribution of MMPs in medulloblastomas. Based on immunohistochemical, immunocytochemical and zymographical analysis the present study illustrates the differential pattern of MMP expression for the medulloblastoma compared to that of glioma and ependymoma. In 10 examined medulloblastoma tumors gelatinase-A was strongly expressed by clusters of tumor cells. Gelatinase-B was, similar to glioma and ependymoma, predominantly found around endothelial cells. The DAB signal for macrophage metalloelastase was seen around macrophages and matrilysin was expressed by single tumor cells. Stromelysin-1 protein was detected in medulloblastoma but not in glioma or ependymoma. From the presented data it follows that each tumor entity might display its own characteristic MMP expression pattern.

MAY 2004: NEWBORN WITH INTRACRANIAL MASS

May 2004: We present the case of a male newborn (38th week of gestation) with a 3‐week history of a sonographically detected parietal mass of 5‐cm diameter. The entire mass was removed at surgery. Surprisingly, microscopy revealed an intracerebral hemorrhage and nests of glycophorin‐A immunoreactive blasts and nucleated erythrocytes in the surrounding parenchyma. The final diagnosis was chronic intracerebral hemorrhage of unknown etiology with reactive changes of the surrounding brain tissue and perifocal extramedullary erythropoiesis. This case is unique because, to date, intracranial extramedullary erythropoiesis has only been described in chronic subdural hemorrhage.