Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One of the hallmarks of glioblastoma is its inherent tendency to recur. At this point patients with relapsed GBM show a survival time of only few months. The molecular basis of the recurrence process in GBM is still poorly understood. The aim of the present study was to investigate the genetic profile of relapsed GBM compared to their respective primary tumors. We have included 20 paired GBMs. In all tumor samples, we have analyzed p53 and PTEN status by sequencing analysis, EGFR amplification by semiquantitative PCR and a wide-genome fingerprinting was performed by microsatellite analysis. Among primary GBM, we observed twelve type 2 GBM, four type 1 GBM and four further GBM showing neither p53 mutations nor EGFR amplification (non-type 1-non-type 2 GBM). Upon recurrence, we have detected two molecular patterns of tumor progression: GBM initially showing either type 1 or type 2 profiles conserved them at the time of relapse. In contrast, non-type 1-non-type 2 GBM acquired the typical pattern of type 2 GBM and harbor EGFR amplification without p53 mutation. New PTEN mutations upon relapse were only detected in type 2 GBM. Additional LOH were more frequently identified in relapses of type 2 GBM than in those showing the type 1 signature. Taken together, our results strongly suggest that recurrences of GBM may display two distinct pattern of accumulation of molecular alterations depending on the profile of the original tumor.
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PMID:Different molecular patterns in glioblastoma multiforme subtypes upon recurrence. 1964 52

Signal transducer and activator of transcription 3 (STAT3) regulates diverse cellular processes, including cell growth, differentiation, and apoptosis, and is frequently activated during tumorigenesis. Recently, putative glioblastoma stem cells (GBM-SCs) were isolated and characterized. These cells can self-renew indefinitely in culture, are highly tumorigenic, and retain the ability to differentiate in culture. We have found that treatment of GBM-SCs with two chemically distinct small molecule inhibitors of STAT3 DNA-binding inhibits cell proliferation and the formation of new neurospheres from single cells. Genetic knockdown of STAT3 using a short hairpin RNA also inhibits GBM-SC proliferation and neurosphere formation, confirming that these effects are specific to STAT3. Although STAT3 inhibition can induce apoptosis in serum-derived GBM cell lines, this effect was not observed in GBM-SCs grown in stem cell medium. Markers of neural stem cell multipotency also decrease upon STAT3 inhibition, suggesting that STAT3 is required for maintenance of the stem-like characteristics of these cells. Strikingly, even a transient inhibition of STAT3 leads to irreversible growth arrest and inhibition of neurosphere formation. These data suggest that STAT3 regulates the growth and self-renewal of GBM-SCs and is thus a potential target for cancer stem cell-directed therapy of glioblastoma multiforme.
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PMID:STAT3 is required for proliferation and maintenance of multipotency in glioblastoma stem cells. 1965 81

Danthron (1,8-dihydroxyanthraquinone), is one of component from Rheum palmatum L. (Polygonaceae), has been shown several biological activities but did not show to induce apoptosis in human brain tumor cells. The aim of this study is to investigate the mechanisms by danthron for the induction of apoptotic potential on human brain glioblastoma multiforms GBM 8401 cell line. Danthron showed a marked concentration- and time-dependent inhibition of GBM 8401 cell viability and induced apoptosis in a dose-and time-dependent manner. There was an attenuation of mitochondrial membrane potential (DeltaPsi(m)) with the alterations of Bcl-2/Bax protein ratio in GBM 8401 cells, indicating the participation of a mitochondria-related mechanism. Pretreatment of a caspase-8 inhibitor (Z-IETD-FMK), caspase-9 inhibitor (Z-LEHD-FMK) and caspase-3 inhibitor (Z-DEVE-FMK) significantly increased the viable of GBM 8401 cells implied that the participations of caspases. Western blotting analysis also showed the activation of initiator caspase-8 and caspase-9, and executor caspase-3 in GBM 8401 cells. Meanwhile, danthron also promoted the generation of reactive oxygen species (ROS) and cytosolic Ca(2+) in GBM 8401 cells. Taken together, our data showed that danthron induced apoptosis in GBM 8401 cells through mitochondria-related and caspase-related pathways, and it may be further evaluated as a chemotherapeutic agent for human brain cancer.
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PMID:Danthron induced apoptosis through mitochondria- and caspase-3-dependent pathways in human brain glioblastoma multiforms GBM 8401 cells. 1978 69

Gliosarcoma (GS) is a glioblastoma with a sarcomatous component that is presumed to be a metaplastic differentiation of glioma cells. We studied the clinical relevance of this histological glioblastoma subentity within the pediatric population. We obtained patient data from the German HIT-GBM database, which contains clinical data for more than 600 pediatric patients with centrally reviewed high-grade gliomas. By applying defined inclusion criteria (diagnosis of GS proven by central neuropathological review; patient age 0 to 21 years), four patients were identified. In addition, after a review of the English medical scientific literature, 19 additional cases were found. The relative frequency of GS in the German HIT-GBM database was only 1.9%. In the whole series of 23 pediatric GS patients, including previously reported cases, the male-to-female-ratio was 1.2:1. GS was found in all pediatric age groups with a median age of 11 years, but there was an unexpectedly high accumulation in infants (6 of 23 <3 years of age, 26%). GS showed a strong predilection of the cerebral hemispheres (22 out of 23 cases). Increased intracranial pressure was the leading symptom of a short clinical history with a median duration of 0.7 month. Interestingly, six patients (26%) were reported with a history of cranial radiotherapy prior to GS diagnosis. In 60% of the GS patients in our series, gross total resection was achieved. Median overall (OS) and event-free survivals (EFS) of the total cohort were 12.1 and 9.8 months, respectively. In conclusion, GS is a very rare tumor entity in children. Literature review suggests a relatively higher incidence in infants and in patients with a previous history of radiotherapy.
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PMID:Clinical and epidemiological characteristics of pediatric gliosarcomas. 1980 21

Gamma-secretase inhibitors have been proposed as drugs able to kill cancer cells by targeting the NOTCH pathway. Here, we investigated two of such inhibitors, the Benzyloxicarbonyl-Leu-Leu-Nle-CHO (LLNle) and the N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), to assess whether they were effective in killing human glioblastoma tumor-initiating cells (GBM TIC) in vitro. We found that only LLNle was able at the micromolar range to induce the death of GBM TICs by apoptosis. To determine the cellular processes that were activated in GBM TICs by treatment with LLNle, we analyzed the amount of the NOTCH intracellular domain and the gene expression profiles following treatment with LLNle, DAPT, and DMSO (vehicle). We found that LLNIe, beside inhibiting the generation of the NOTCH intracellular domain, also induces proteasome inhibition, proteolytic stress, and mitotic arrest in these cells by repressing genes required for DNA synthesis and mitotic progression and by activating genes acting as mitotic inhibitors. DNA content flow cytometry clearly showed that cells treated with LLNle undergo arrest in the G(2)-M phases of the cell cycle. We also found that DAPT and L-685,458, another selective Notch inhibitor, were unable to kill GBM TICs, whereas lactacystin, a pure proteasome inhibitor, was effective although at a much less extent than LLNle. These data show that LLNle kills GBM TIC cells by inhibiting the proteasome activity. We suggest that LLNle, being able to target two relevant pathways for GBM TIC survival, may have a potential therapeutic value that deserves further investigation in animal models.
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PMID:z-Leucinyl-leucinyl-norleucinal induces apoptosis of human glioblastoma tumor-initiating cells by proteasome inhibition and mitotic arrest response. 2014 40

A 4-year-old Dutch warmblood mare was presented with a 10-month history of ataxia and proprioceptive deficits. Computed tomography defined a large, non-contrast enhancing mass in the left cerebral hemisphere. Necropsy examination revealed a tumour that effaced much of the piriform and temporal lobes. Microscopically the lesion was classified as a grade IV glioblastoma with an oligodendroglial component (GBM-O). The tumour was composed of highly pleomorphic cells organized in different patterns within a fibrillary stroma. There were multiple foci of necrosis. At the periphery of the tumour neoplastic oligodendroglioma-like cells were embedded in an extracellular mucinous matrix. Most neoplastic cells were strongly immunoreactive for glial fibrillary acidic protein; however, the oligodendroglioma cells did not express this marker. Cells forming microvascular proliferations were positively labelled for expression of factor VIII and smooth muscle actin. All neoplastic cells were negative for Neu-N and synaptophysin. The proliferation index was up to 5%. All neoplastic cells and normal brain tissue from the horse were uniformly negative for expression of epidermal growth factor receptor (EGFR), EGFR vIII mutant and the phosphatase and tensin homologue (PTEN) compared with positive control human GBM tissue. To our knowledge this is the first report of a GBM-O in the horse.
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PMID:A grade IV glioblastoma with an oligodendroglial component (GBM-O) in a horse. 1989 10

Glioblastoma, GBM, is the most frequent brain malignancy in adults. Patients with these tumors survive only, approximately, one year after diagnosis and rarely survive beyond two years. This poor prognosis is, in part, due to our insufficient understanding of the complex aggressive nature of these tumors and the lack of effective therapy. In GBM, over-expression of EGFR and/or its constitutively activated variant EGFRvIII is a major characteristic and is associated with tumorigenesis and more aggressive phenotypes, such as, invasiveness and therapeutic resistance. Consequently, both have been major targets for GBM therapy, however, clinical trials of EGFR- and EGFRvIII-targeted therapies have yielded unsatisfactory results and the molecular basis for the poor results is still unclear. Thus, in this review, we will summarize results of recent clinical trials and recent advances made in the understanding of the EGFR/EGFRvIII pathways with a key focus on those associated with intrinsic resistance of GBM to EGFR-targeted therapy. For example, emerging evidence indicates an important role that PTEN plays in predicting GBM response to EGFR-targeted therapy. Aberrant Akt/mTOR pathway has been shown to contribute to the resistant phenotype. Also, several studies have reported that EGFR/EGFRvIII's cross-talk with the oncogenic transcription factorSTAT3 and receptor tyrosine kinases, (c-Met and PDGFR) potentially lead to GBM resistance to anti-EGFR therapy. Other emerging mechanisms, including one involving HMG-CoA reductase, will also be discussed in this mini-review. These recent findings have provided new insight into the highly complex and interactive nature of the EGFR pathway and generated rationales for novel combinational targeted therapies for these tumors.
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PMID:EGFR-targeted therapy in malignant glioma: novel aspects and mechanisms of drug resistance. 2003 Jun 24

O(6)-methylguanine DNA-methyltransferase (MGMT) promoter methylation status is a prognostic factor in newly diagnosed glioblastoma patients. However, it is not yet clear whether, and if so how, MGMT methylation status may change. Moreover, it is unknown whether the prognostic role of this epigenetic feature is retained during the disease course. A retrospective analysis was made using a database of 614 glioblastoma patients treated prospectively from January 2000 to August 2008. We evaluated only patients who met the following inclusion criteria: age > or = 18 years; performance status 0-2; histological diagnosis of glioblastoma at both first and second surgery for recurrence; postoperative treatment consisting of: (i) radiotherapy (RT) followed by adjuvant temozolomide (TMZ) until 2005 and (ii) TMZ concurrent with and adjuvant to RT after 2005; a time interval > or = 3 months between first and second surgery. MGMT status was evaluated at first and second surgery in all 44 patients (M:F 32:12, median age: 49 years, range: 27-67 years). In 38 patients (86.4%), MGMT promoter status was assessable at both first and second surgery. MGMT methylation status, changed in 14 patients (37%) of second surgery samples and more frequently in methylated than in unmethylated patients (61.5% vs 24%, P = .03). The median survival was significantly influenced only by MGMT methylation status determined at first surgery (P = .04). Significant changes in MGMT methylation status during the course of GBM occur more frequently in MGMT methylated than unmethylated cases. MGMT methylation status determined at first surgery appears to be of prognostic value; however, it is not predictive of outcome following second surgery.
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PMID:O(6)-methylguanine DNA-methyltransferase methylation status can change between first surgery for newly diagnosed glioblastoma and second surgery for recurrence: clinical implications. 2016 16

Fibroblast growth factor 1 (FGF1) has been suggested to have an important role in cell growth, proliferation, and neurogenesis. Human FGF1 gene 1B promoter (-540 to +31)-driven green fluorescence (F1BGFP) has been shown to monitor endogenous FGF1 expression. F1BGFP could also be used to isolate neural stem/progenitor cells from embryonic, neonatal, and adult mouse brains or to isolate glioblastoma stem cells (GBM-SCs) from human glioblastoma tissues. Here, we present evidence that transcription factor RFX1 could bind the 18-bp cis-elements (-484 to -467) of the F1B promoter, modulate F1BGFP expression and endogenous FGF1 expression, and further regulate the maintenance of GBM-SCs. These observations were substantiated by using yeast one-hybrid assay, electrophoretic mobility shift assay, chromatin immunoprecipitation assay, gain- and loss-of-function assays, and neurosphere assays. Overexpression of RFX1 was shown to down-regulate FGF-1B mRNA expression and neurosphere formation in human glioblastoma cells, whereas RNA interference knockdown of RFX1 demonstrated the opposite effects. Our findings provide insight into FGF1 gene regulation and suggest that the roles of FGF1 and RFX1 in the maintenance of GBM-SCs. RFX1 may negatively regulate the self-renewal of GBM-SCs through modulating FGF-1B and FGF1 expression levels by binding the 18-bp cis-elements of the F1B promoter.
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PMID:Regulation of FGF1 gene promoter through transcription factor RFX1. 2018 86

Isostrychnopentamine (ISP) is an indolomonoter-penic alkaloid that is present in the leaves of Strychnos usambarensis, an East African small tree. We have reported previously pro-apoptotic effects induced in vitro by ISP in the human HCT-116 colon cancer cell line, a model that displays relative sensitivity to apoptosis. In the present study, we observed that the in vitro growth inhibitory activities of ISP are similar in cancer cells that display sensitivity versus resistance to apoptosis. We made use of the U373 glioblastoma and the A549 non-small cell lung cancer (NSCLC) cell lines as models relatively resistant to apoptosis, and the human PC-3 prostate cancer cell line as a model relatively sensitive to apoptosis. While ISP induced transient decreases in [ATP]i and apoptosis in human U373 GBM cells, it did not provoke such features in A549 NSCLC cells. It thus seems that ISP-induced anti-cancer activity can lead to pro-apoptotic effects as a consequence, while apoptosis seems not to be the main cause by which ISP induces cancer cell death. ISP is a compound that merits further investigations in order to: i) identify the mechanism(s) of action by which it kills cancer cells, and ii) hemisynthesize novel ISP derivatives aiming to overcome, at least partly, the resistance of metastatic cancers to apoptosis.
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PMID:Isostrychnopentamine, an indolomonoterpenic alkaloid from Strychnos usambarensis, with potential anti-tumor activity against apoptosis-resistant cancer cells. 2019 41


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