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BACKGROUND Tumor cell invasion into adjacent normal brain is a mesenchymal feature of GBM and a major factor contributing to their dismal outcomes. Therefore, better understandings of mechanisms that promote mesenchymal change in GBM are of great clinical importance to address invasion. We previously showed that the bHLH transcription factor TWIST1 which(More)
Due largely to the inability to accurately quantify and characterize de novo deletion events, the mechanisms underpinning the pathogenic expansion of mtDNA deletions in aging and neuromuscular disorders remain poorly understood. Here, we outline and validate a new tool termed 'Digital Deletion Detection' (3D) that allows for high-resolution analysis of rare(More)
BACKGROUND Periostin is a secreted matricellular protein critical for epithelial-mesenchymal transition and carcinoma metastasis. In glioblastoma, it is highly upregulated compared with normal brain, and existing reports indicate potential prognostic and functional importance in glioma. However, the clinical implications of periostin expression and function(More)
We assayed the activity of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) in 60 human brain tumors to assess the effects of tumorigenesis in brain on DNA repair capability. Activity was not detectable (<0.5 fmol/10* cells, i.e., <300 molecules/cells) in 27% of the tumors. Measurable MGMT varied by more than 2 orders of magni tude,(More)
The extent of intratumoral mutational heterogeneity remains unclear in gliomas, the most common primary brain tumors, especially with respect to point mutation. To address this, we applied single molecule molecular inversion probes targeting 33 cancer genes to assay both point mutations and gene amplifications within spatially distinct regions of 14 glial(More)
Resistance to temozolomide (TMZ) based chemotherapy in glioblastoma multiforme (GBM) has been attributed to the upregulation of the DNA repair protein O(6)-methylguanine-DNA methyltransferase (MGMT). Inhibition of MGMT using O(6)-benzylguanine (BG) has shown promise in these patients, but its clinical use is hindered by poor pharmacokinetics that leads to(More)
Alkylating agents have long played a central role in the adjuvant therapy of glioblastoma (GBM). More recently, inclusion of temozolomide (TMZ), an orally administered methylating agent with low systemic toxicity, during and after radiotherapy has markedly improved survival. Extensive in vitro and in vivo evidence has shown that TMZ-induced(More)
BACKGROUND CpG methylation in the O(6)-methylguanine-DNA methyltransferase (MGMT) promoter is associated with better outcome following alkylating agent chemotherapy in glioblastoma (GBM) and anaplastic glioma (AG). To what extent improved response reflects low or absent MGMT activity in glioma tissue has not been unequivocally assessed. This information is(More)
PURPOSE AND BACKGROUND This is a report of a 53 year-old man with a glioblastoma multiforme (GBM) treated with an excessive dose of temozolomide (TMZ). METHODS This is a single case review of all clinically relevant records. O6-methylguanine-DNA methyltransferase activity was determined by a biochemical assay. RESULTS Following conventional radiotherapy(More)
  • Hong Sheng, Michael S Tseng, Mitchel S Bobola, John R Berger, Silber, S H T Bo +1 other
  • 2005
Paclitaxel (Taxol ®), a cytotoxic natural product that disrupts microtubule integrity, is being clinically evaluated for use against gliomas. We examined paclitaxel-induced killing in seven cell lines derived from human malignant astrocytic gliomas and medulloblastomas with the goal of characterizing range of sensitivity, contribution of P-glycoprotein(More)