Kunikazu Yoshimura

Expression of Rb2/p130 protein correlates with the degree of malignancy in gliomas.

It has been reported that there is an inverse correlation between the immunohistochemical expression of Rb2/p130, a member of the retinoblastoma gene family, and the degree of malignancy in at least some histological types. In order to investigate the expression of this protein in gliomas, we evaluated 58 samples from patients with resected gliomas. We focused on the relationship between the degree of malignancy of the glioma and the immunohistochemical detection of Rb2/p130. Expression of Rb2/p130 was observed in 38 glioma specimens (65.5%), including a high expression level in low-grade glioma specimens (>30% positive cells in 84% of tumors) and a low expression level in high-grade glioma specimens (>30% positive cells in 12% of tumors). The most aggressive of the gliomas exhibited very low to undetectable levels of Rb2/p130. Moreover, we observed an inverse correlation between Rb2/p130 expression and the degree of malignancy. These findings suggest that the differentiation of gliomas might be partially mediated by the Rb2/p130 gene, and that Rb2/p130 expression can additionally be an indicator of a better prognosis in patients with gliomas.

ULTRASTRUCTURAL CHARACTERIZATION OF CENTRAL NEUROCYTOMAS USING COLLAGEN GEL CULTURE

Central neurocytoma is a rare brain tumor with neuronal differentiation. Cultured central neurocytoma cells are poorly described because of the tumors scarcity. Two central neurocytomas were cultured using a monolayer culture for first few passages, and then a portion of each specimen was cultured in a collagen gel. Immunostaining for synaptophysin or glial fibrillary acidic protein performed on the primary culture revealed the presence of cells expressing synaptophysin and cells expressing glial fibrillary acidic protein. Cells expressing synaptophysin tended to disappear in passage 2, whereas the cells expressing glial fibrillary acidic protein remained. Ultrastructurally, samples in passage 5 obtained from the collagen gel cultures revealed neuron-like cells with prominent nucleoli, cell processes containing dense core vesicles and clear vesicles, and synapse-like structures. By contrast, samples obtained from passage 5 of monolayer cultures failed to reveal ultrastructural neuronal characteristics. These results suggest that spatial cell growth and the presence of collagen, i.e., extracellular matrix, may be necessary to retain neuronal differentiation in a central neurocytoma.

Colcemid-induced apoptosis of cultured human glioma: Electron microscopic and confocal laser microscopic observation of cells sorted in different phases of cell cycle

The effect of the antitubulin agent colcemid on human glioma cells was investigated by sorting cells with different DNA content and subjecting them to confocal laser microscopy and transmission electron microscopy. The human glioma cell line U251MG was exposed to colcemid at a concentration of 0.05 microg for 16 h. Flow cytometric analysis revealed the accumulation of cells in S/G2M phase. Cells harvested from each of G0/G1 and S/G2M peaks were then analyzed by confocal laser microscopy and transmission electron microscopy. Confocal laser microscopy revealed that colcemid-treated cells harvested from the G0/G1 peak contained mitotic and apoptotic cells in addition to interphase cells. Electron microscopy confirmed that colcemid-treated cells in the G0/G1 peak had fragmented nuclei typical of apoptotic cells and mitotic cells with altered chromatin structure. Some mitotic cells obtained by mitotic shake-off after treatment with colcemid showed DNA strand breaks defined by in situ nick end labeling. The present study indicates that mitotic as well as interphase apoptosis occurs in U251MG cells following colcemid treatment.

A case of petrous bone myxoid chondrosarcoma associated with cerebellar hemorrhage

We report a rare case in which a myxoid chondrosarcoma originated from the petrous bone and invaded the cerebellar hemisphere with hemorrhage. Neuroimaging showed the characteristic feature of multiple small cysts along the solid tumor, and the cystic formation was confirmed as a mucoid secretion by Alcian blue staining and electron microscopic examination. This tumor recurred following partial removal and stereotaxic radiosurgery.

5-ALA fluorescence-guided endoscopic surgery for mixed germ cell tumors

Abstract5-Aminolevulinic acid (5-ALA) fluorescence-guided surgery is widely used for detection and planning of resection of malignant gliomas and other brain tumors. However, no reports have described 5-ALA fluorescence-guided surgery or direct visualization of germ cell tumors. Here, we report two cases of germ cell tumors in which a positive 5-ALA fluorescent signal was visualized with a neuroendoscope. Both cases had a tumor in the pineal region that was associated with hydrocephalus. The patients underwent surgery after administration of 5-ALA. After ventricular puncture of the anterior horn, we could observe the ventricular wall and tumor using the Karl Storz Photodynamic diagnosis system endoscope. Then, biopsy of the pineal tumor and endoscopic third ventriculostomy were performed in both cases. In case 1, a 22-year-old man, part of the ventricular wall and tumor tissue showed red fluorescence. In case 2, a 16-year-old man, part of the fornix and infundibular recess showed red fluorescence, and the tumor showed relatively weak red fluorescence. The histopathological diagnosis of both cases was pure germinoma. This is the first report of direct visualization of mixed germinomas with 5-ALA fluorescence-guided endoscopic surgery. This method not only allows visualization of the tumor mass, but may also be useful for detailed observation in the ventricular wall.

Establishment of a tumor sphere cell line from a metastatic brain neuroendocrine tumor

Neuroendocrine tumors are rare, and little is known about the existence of cancer stem cells in this disease. Identification of the tumorigenic population will contribute to the development of effective therapies targeting neuroendocrine tumors. Surgically resected brain metastases from a primary neuroendocrine tumor of unknown origin were dissociated and cultured in serum-free neurosphere medium. Stem cell properties, including self-renewal, differentiation potential, and stem cell marker expression, were examined. Tumor formation was evaluated using intracranial xenograft models. The effect of temozolomide was measured in vitro by cell viability assays. We established the neuroendocrine tumor sphere cell line ANI-27S, which displayed stable exponential growth, virtually unlimited expansion in vitro, and expression of stem-cell markers such as CD133, nestin, Sox2, and aldehyde dehydrogenase. FBS-induced differentiation decreased Sox2 and nestin expression. On the basis of real-time PCR, ANI-27S cells expressed the neuroendocrine markers synaptophysin and chromogranin A. Intracranial xenotransplanted brain tumors recapitulated the original patient tumor and temozolomide exhibited cytotoxic effects on tumor sphere cells. For the first time, we demonstrated the presence of a sphere-forming, stem cell-like population in brain metastases from a primary neuroendocrine tumor. We also demonstrated the potential therapeutic effects of temozolomide for this disease.

Fat necrosis appearing as intraorbital tumour: Case report

Abstract A 33-year-old male presented with an extremely rare case of intraorbital fat necrosis. A magnetic resonance imaging scan showed a 10-mm mass lesion within the right lateral rectal muscle. Surgical removal was performed. Histological analysis showed diffuse adipose cells surrounded by macrophage cells. Fat necrosis was diagnosed.

Research the Mechanism of Various Antineoplastic Agents with Use of Flow Cytometry in Vitro Glioma Cells

Nowadays, steady progress like in endovascular, microsurgical, neuroendoscopic fields, affect deeply neurosurgergical field, too. But in spite of arising so many innovations, average survival time in glioma is a year and five year survival rate is 8%. These results have not slightly changed for 30 years.(*1) For us to continue research glioma in future, our purpose discloses what we should be going to do for improve prognosis and needs to analyze data about tumor cells in the various views. In our laboratory, we research brain tumor with flow cytometory. In this chapter, we describe how to analyze the mechanism of various antineoplastic agents for tumor cells centered glioma and research results with flow cytometry.