Treatment bias was demonstrated regarding resection and second-line therapies. However, bias and imbalances were controllable in the cohorts available from the 5-aminolevulinic acid study so that the present data now provide Level 2b evidence (Oxford Centre for Evidence-based Medicine) that survival depends on complete resection of enhancing tumor in glioblastoma multiforme.
Indications of intracranial hypotension, induced by suction drainage, being the main pathomechanism of PHBS are discussed. A serious warning is issued regarding the use of suction drainage after intracranial surgery.
Activation of the Wnt/wingless signalling cascade is a key mechanism in developmental morphogenesis, whereas aberrant nuclear accumulation of beta-catenin in adult tissues seems to be associated with neoplastic transformation and tumour progression. Adamantinomatous craniopharyngiomas carry activating mutations in exon 3 of the beta-catenin gene, which results in a distinct pattern of nuclear beta-catenin accumulation in up to 95% of respective tumour specimens. To better characterise the impact of nuclear beta-catenin aggregation in these neoplasms, we systematically examined epithelial differentiation and cell cycle-associated molecules in accumulating compared to non-accumulating tumour cell clusters using a cohort of 65 adamantinomatous craniopharyngiomas. Monoclonal antibodies directed against cytokeratins 5/6 (CK5/6) were utilised to differentiate squamous from simple epithelium, the latter being identified by immunoreactivity for cytokeratins 8 and 18 (CK8/CK18). Intriguingly, nuclear beta-catenin accumulation in whorl-like tumour cell clusters was always associated with a distinct CK8 and CK18 immunoreactivity, whereas surrounding non-accumulating tumour cells showed exclusively squamous differentiation indicated by CK5/6 expression. In addition, a low proliferation activity combined with an increased expression of p21(WAF1/CIP1), a key control protein of the cell cycle, was observed in beta-catenin accumulating cells. Our data support an impact of nuclear beta-catenin on different cytoarchitectural and epithelial differentiation patterns in adamantinomatous craniopharyngiomas.
Activating beta-catenin (CTNNB1) mutations can be identified in the majority of adamantinomatous craniopharyngiomas (adaCP), suggesting an aberrant Wnt signaling pathway in this histopathologically peculiar tumor entity. However, there is no proven evidence that nuclear translocation of beta-catenin is associated with CTNNB1 mutations and target gene activation. We performed a laser-microdissection-based study comparing beta-catenin accumulating vs. non-accumulating tumor cells. Mutational analysis and gene expression profiling using real-time polymerase chain reaction were conducted in adamantinomatous and papillary tumor specimens. Target gene activation, that is, over-expression of Axin2 could be detected in adaCP, especially in tumor cells with nuclear beta-catenin accumulation. In addition, increased expression of BMP4 was identified in the accumulating cell population, which supports the hypothesis of an oral ectodermal origin. Interestingly, accumulating and non-accumulating tumor cell populations carried CTNNB1 mutations within exon 3. We extended the analysis, therefore, towards genetic regions encoding for membrane linkage and active/passive nuclear transport mechanisms (exon 4 and exon 8-13), but could not detect any alteration. This is the first report demonstrating an association between nuclear beta-catenin accumulation and target gene activation in adaCP. The results confirm the Wnt signaling pathway as molecular basis of the distinct and challenging clinical and morphological phenotype of adaCP.
Extratemporal epilepsy surgery is effective according to findings on long-term follow-up. The outcome at the first 2-year follow-up visit is a reliable predictor of long-term Engel Class I postoperative outcome.
BackgroundSOX2, a high mobility group (HMG)-box containing transcription factor, is a key regulator during development of the nervous system and a persistent marker of neural stem cells. Recent studies suggested a role of SOX2 in tumor progression. In our previous work we detected SOX2 in glioma cells and glioblastoma specimens. Herein, we aim to explore the role of SOX2 for glioma malignancy in particular its role in cell proliferation and migration.MethodsRetroviral shRNA-vectors were utilized to stably knockdown SOX2 in U343-MG and U373-MG cells. The resulting phenotype was investigated by Western blot, migration/invasion assays, RhoA G-LISA, time lapse video imaging, and orthotopic xenograft experiments.ResultsSOX2 depletion results in pleiotropic effects including attenuated cell proliferation caused by decreased levels of cyclinD1. Also an increased TCF/LEF-signaling and concomitant decrease in Oct4 and Nestin expression was noted. Furthermore, down-regulation of focal adhesion kinase (FAK) signaling and of downstream proteins such as HEF1/NEDD9, matrix metalloproteinases pro-MMP-1 and -2 impaired invasive proteolysis-dependent migration. Yet, cells with knockdown of SOX2 switched to a RhoA-dependent amoeboid-like migration mode which could be blocked by the ROCK inhibitor Y27632 downstream of RhoA-signaling. Orthotopic xenograft experiments revealed a higher tumorigenicity of U343-MG glioma cells transduced with shRNA targeting SOX2 which was characterized by increased dissemination of glioma cells.ConclusionOur findings suggest that SOX2 plays a role in the maintenance of a less differentiated glioma cell phenotype. In addition, the results indicate a critical role of SOX2 in adhesion and migration of malignant gliomas.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.