Journal of neuro-oncology
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Journal of neuro-oncology · Jun 2007
Comparative StudyExpression of MHC I and NK ligands on human CD133+ glioma cells: possible targets of immunotherapy.
Mounting evidence suggests that gliomas are comprised of differentiated tumor cells and brain tumor stem cells (BTSCs). BTSCs account for a fraction of total tumor cells, yet are apparently the sole cells capable of tumor initiation and tumor renewal. BTSCs have been identified as the CD133-positive fraction of human glioma, whereas their CD133-negative daughter cells have limited proliferative ability and are not tumorogenic. ⋯ Furthermore, pretreatment of CD133-positive cells with INF-gamma rendered them sensitive to NK cell-mediated lysis in vitro. There were no consistent differences in immunogenicity between the CD133-positive and CD133-negative cells in these experiments. We conclude that CD133-posistive and CD133-negative glioma cells may be similarly resistant to immune surveillance, but that INF-gamma may partially restore their immunogenicity and potentiate their lysis by NK cells.
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Journal of neuro-oncology · Jun 2007
Promoter hypermethylation profile of cell cycle regulator genes in pituitary adenomas.
Aberrant hypermethylation of CpG islands in the promoter region plays a causal role in the inactivation of various key genes involved in the cell cycle regulatory cascade, which could result in a loss of cell cycle control. The aim of the present study was to examine in more detail the prevalence and role of the promoter methylation of genes with a proven involvement in the cell cycle regulation of pituitary adenomas, since their tumorigenesis has not yet been clearly defined. We profiled the CpG island methylation status of a series of well-characterized cell cycle regulation genes: the RB1, p14(ARF), p15(INK4b), p16(INK4a), p21(Waf1/Cip1), p27(Kip1), and p73 genes, in 34 pituitary adenomas as determined by a methylation-specific polymerase chain reaction assay. ⋯ In contrast, none of the clinicopathological features, including the cell proliferation index, was significantly correlated with any particular methylation status. Our results suggested that aberrant hypermethylation of the key cell cycle regulatory genes occurs at a relatively high frequency in pituitary adenomas, especially in RB1 pathway genes with promoter hypermethylation of the p16(INK4a) gene being the most common deregulation. We further obtained evidence to indicate that RB1 and p16(INK4a) methylations tended to be mutually exclusive, but did occasionally coincide with other cell cycle regulation gene methylations.
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Journal of neuro-oncology · May 2007
Peritumoral edema after stereotactic radiosurgery for intracranial meningiomas and molecular factors that predict its development.
Stereotactic radiosurgery (SRS) is an effective treatment for small and medium-sized meningiomas. Although uncommon, peritumoral edema can develop as a delayed complication after SRS. The purpose of the study was to evaluate the clinical and molecular risk factors for peritumoral edema after SRS for intracranial meningiomas. ⋯ Clinical characteristics and molecular markers may identify patients with meningiomas at risk of peritumoral edema after SRS. Judicious use of steroids or perhaps the use of stereotactic fractionated radiation should be considered in these high-risk patients.
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Journal of neuro-oncology · Mar 2007
Acute morphological sequelae of photodynamic therapy with 5-aminolevulinic acid in the C6 spheroid model.
Aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) may represent a treatment option for malignant brain tumors. We used a three-dimensional cell culture system, the C6 glioma spheroid model, to study acute effects of PDT and how they might be influenced by treatment conditions. ⋯ PDT of experimental glioma results in rapid and significant cell death that could be verified as acute necrosis immediately after irradiation. This effect depended on O(2) concentration and spheroid size.
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Journal of neuro-oncology · Feb 2007
Assessment of verbal working memory before and after surgery for low-grade glioma.
While scarcely reported in low-grade glioma (LGG), accurate assessment of higher functions is essential to evaluate then preserve the quality of life. We assessed verbal working memory (vWM) in patients with LGG in language areas, before and after surgery, to evaluate the effect of glioma and resection on cognition, respectively. ⋯ In LGG, neuropsychological assessment is encouraged in addition to KPS. vWM evaluation before treatment showed that most patients had a cognitive deficit. Moreover, surgery induced a transient vWM worsening, which nevertheless recovers within 3 months. Specific rehabilitation might help to recover and even to improve the preoperative cognitive status.