Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
94 result(s) for "Seol, Ho Jun"
Sort by:
Early prediction of neurological outcome after barbiturate coma therapy in patients undergoing brain tumor surgery
After a difficult brain tumor surgery, refractory intracranial hypertension (RICH) may occur due to residual tumor or post-operative complications such as hemorrhage, infarction, and aggravated brain edema. We investigated which predictors are associated with prognosis when using barbiturate coma therapy (BCT) as a second-tier therapy to control RICH after brain tumor surgery. The study included adult patients who underwent BCT after brain tumor surgery between January 2010 and December 2016. The primary outcome was neurological status upon hospital discharge, which was assessed using the Glasgow Outcome Scale (GOS). In the study period, 4,296 patients underwent brain tumor surgery in total. Of these patients, BCT was performed in 73 patients (1.7%). Among these 73 patients, 56 (76.7%) survived to discharge and 25 (34.2%) showed favorable neurological outcomes (GOS scores of 4 and 5). Invasive monitoring of intracranial pressure (ICP) was performed in 60 (82.2%) patients, and revealed that the maximal ICP within 6 h after BCT was significantly lower in patients with favorable neurological outcome as well as in survivors (p = 0.008 and p = 0.028, respectively). Uncontrolled RICH (ICP ≥ 22 mm Hg within 6 h of BCT) was an important predictor of mortality after BCT (adjusted hazard ratio 12.91, 95% confidence interval [CI] 2.788-59.749), and in particular, ICP ≥ 15 mm Hg within 6 h of BCT was associated with poor neurological outcome (adjusted odds ratio 9.36, 95% CI 1.664-52.614). Therefore, early-controlled ICP after BCT was associated with clinical prognosis. There were no significant differences in the complications associated with BCT between the two neurological outcome groups. No BCT-induced death was observed. The active and timely control of RICH may be beneficial for clinical outcomes in patients with RICH after brain tumor surgery.
Histopathology and surgical outcome of symptomatic treatment-related changes after gamma knife radiosurgery in patients with brain metastases
A late-onset treatment-related changes (TRCs), which represent radiographic radiation necrosis (RN), frequently occur after stereotactic radiosurgery (SRS) for brain metastases and often need surgical treatment. This study aimed to validate the true pathology and investigate clinical implication of surgically resected TRCs on advanced magnetic resonance imaging (MRI). Retrospective analyses of 86 patients who underwent surgical resection after radiosurgery of brain metastases were performed. Fifty-four patients displayed TRCs on preoperative MRI, comprising pure RN in 19 patients (TRC-RN group) and mixed viable tumor cells in 35 patients (TRC-PD group). Thirty-two patients revealed the consistent diagnosis of progressive disease in both MRI and histopathology (PD–PD group). The TRC-PD group showed larger prescription isodose volume (9.4 cm 3 ) than the TRC-RN (4.06 cm 3 , p = 0.014) group and a shorter time interval from SRS to preoperative MRI diagnosis (median 4.07 months) than the PD–PD group (median 8.77 months, p = 0.004). Progression-free survival was significantly different among the three groups (p < 0.001), but not between TRC-RN and TRC-PD (post hoc test, p = 1.00), while no difference was observed in overall survival (p = 0.067). Brain metastases featured as TRCs after SRS frequently contained viable tumor cells. However, this histologic heterogeneity had a minor impact on benign local prognosis of TRCs after surgical resection.
Secretome analysis of patient-derived GBM tumor spheres identifies midkine as a potent therapeutic target
Glioblastoma (GBM) is the most lethal primary brain tumor with few treatment options. The survival of glioma-initiating cells (GICs) is one of the major factors contributing to treatment failure. GICs frequently produce and respond to their own growth factors that support cell proliferation and survival. In this study, we aimed to identify critical autocrine factors mediating GIC survival and to evaluate the anti-GBM effect of antagonizing these factors. Proteomic analysis was performed using conditioned media from two different patient-derived GBM tumor spheres under a growth factor-depleted status. Then, the antitumor effects of inhibiting an identified autocrine factor were evaluated by bioinformatic analysis and molecular validation. Proteins secreted by sphere-forming GICs promote cell proliferation/survival and detoxify reactive oxygen species (ROS). Among these proteins, we focused on midkine (MDK) as a clinically significant and pathologically relevant autocrine factor. Antagonizing MDK reduced the survival of GBM tumor spheres through the promotion of cell cycle arrest and the consequent apoptotic cell death caused by oxidative stress-induced DNA damage. We also identified PCBP4, a novel molecular predictor of resistance to anti-MDK treatment. Collectively, our results indicate that MDK inhibition is an important therapeutic option by suppressing GIC survival through the induction of ROS-mediated cell cycle arrest and apoptosis. Brain cancer: a key growth factor Targeting the growth factor midkine (MDK) may offer improved treatment for glioblastoma, the most lethal brain cancer. In glioblastoma, the tumor-initiating cells produce their own growth factors, encouraging themselves to keep multiplying, and making glioblastoma very difficult to treat. Do-Hyun Nam and Hyun Ju Kang at the Samsung Medical Center, Seoul, South Korea and coworkers screened the growth factors produced by two glioblastoma samples, then focused on a single cancer-associated factor, MDK. Antagonizing MDK slowed tumor cell growth, and further investigation showed that suppressing MDK restored the susceptibility of tumor cells to DNA damage and the mechanisms that weed out damaged cells. Noting that treatment efficacy varied between tumor samples, the researchers identified a biomarker for sensitivity to MDK treatment. These results point the way to new treatments for this particularly deadly cancer.
Translational Validation of Personalized Treatment Strategy Based on Genetic Characteristics of Glioblastoma
Glioblastoma (GBM) heterogeneity in the genomic and phenotypic properties has potentiated personalized approach against specific therapeutic targets of each GBM patient. The Cancer Genome Atlas (TCGA) Research Network has been established the comprehensive genomic abnormalities of GBM, which sub-classified GBMs into 4 different molecular subtypes. The molecular subtypes could be utilized to develop personalized treatment strategy for each subtype. We applied a classifying method, NTP (Nearest Template Prediction) method to determine molecular subtype of each GBM patient and corresponding orthotopic xenograft animal model. The models were derived from GBM cells dissociated from patient's surgical sample. Specific drug candidates for each subtype were selected using an integrated pharmacological network database (PharmDB), which link drugs with subtype specific genes. Treatment effects of the drug candidates were determined by in vitro limiting dilution assay using patient-derived GBM cells primarily cultured from orthotopic xenograft tumors. The consistent identification of molecular subtype by the NTP method was validated using TCGA database. When subtypes were determined by the NTP method, orthotopic xenograft animal models faithfully maintained the molecular subtypes of parental tumors. Subtype specific drugs not only showed significant inhibition effects on the in vitro clonogenicity of patient-derived GBM cells but also synergistically reversed temozolomide resistance of MGMT-unmethylated patient-derived GBM cells. However, inhibitory effects on the clonogenicity were not totally subtype-specific. Personalized treatment approach based on genetic characteristics of each GBM could make better treatment outcomes of GBMs, although more sophisticated classifying techniques and subtype specific drugs need to be further elucidated.
Ethnic delineation of primary glioblastoma genome
Glioblastoma (GBM) is the most malignant primary brain tumor in adults with substantial genomic alterations. The median survival is approximately 14.6 months, despite aggressive therapeutic intervention, which comprised of surgical resection, radiotherapy, and chemotherapy. Recent studies on cancer genomic have revealed crucial insights into dynamic molecular subgroups within GBM, which govern distinct clinical response and sensitivity of each individual to therapy. In the present study, we analyzed genomic composition of primary GBMs between two ethnic groups [IRCR (Institute of Refractory Cancer Research), and TCGA (The Cancer Genome Atlats)] to explore genomic and molecular features that constitute malignant behavior of glioblastoma based on distinct ethnicity. We identified enrichments of MAPK and p53 pathways in IRCR patients, while aberrant activation of Receptor Tyrosine Kinases (RTKs) were predominant in TCGA cohort. We also discovered differential clinical prognosis between two groups and explored essential features that present such diversity. Glioblastoma (GBM) is the most aggressive primary brain tumor. We analyzed recurrent somatic variants and molecular pathways that are enriched in different subpopulations.
Analysis of risk factors to predict communicating hydrocephalus following gamma knife radiosurgery for intracranial schwannoma
Communicating hydrocephalus (HCP) in vestibular schwannomas (VS) after gamma knife radiosurgery (GKRS) has been reported in the literature. However, little information about its incidence and risk factors after GKRS for intracranial schwannomas is yet available. The objective of this study was to identify the incidence and risk factors for developing communicating HCP after GKRS for intracranial schwannomas. We retrospectively reviewed a total of 702 patients with intracranial schwannomas who were treated with GKRS between January 2002 and December 2015. We investigated patients’ age, gender, tumor origin, previous surgery history, tumor volume, marginal radiation dose, and presence of tumor control to identify associations with communicating HCP following GKRS. To make predictive models of communicating HCP, we performed Cox regression analyses and constructed a decision tree for risk factors. In total, 29 of the 702 patients (4.1%) developed communicating HCP following GKRS, which required ventriculo‐peritoneal (VP) shunt surgery. Multivariate analyses indicated that age (P = 0.0011), tumor origin (P = 0.0438), and tumor volume (P < 0.0001) were significant predictors of communicating HCP in patients with intracranial schwannoma after GKRS. Using machine‐learning methods, we fit an optimal predictive model. We found that developing communicating HCP following GKRS was most likely if the tumor was vestibular origin and had a volume ≥13.65 cm3. Communicating HCP is not a rare complication of GKRS for intracranial schwannomas. Under specific conditions, communicating HCP following GKRS is warranted for this patient group, and this patient group should be closely followed up. 4.1% of intracranial schwannoma patients treated with gamma knife radiosurgery (GKRS) developed symptomatic communicating hydrocephalus (HCP) and required placement of a ventriculo‐peritoneal shunt. Developing communicating HCP following GKRS was most likely if the tumor was vestibular origin and had a volume ≥13.65 cm3.
Spatiotemporal genomic architecture informs precision oncology in glioblastoma
Raul Rabadan, Woong-Yang Park, Do-Hyun Nam and colleagues examine the genomic and transcriptomic profiles of tumors from 52 patients with glioblastoma using both bulk and single-cell analyses. They find that tumors that are isolated from distinct locations or at different times are seeded from different clones, suggesting the need for multisector biopsies. Precision medicine in cancer proposes that genomic characterization of tumors can inform personalized targeted therapies 1 , 2 , 3 , 4 , 5 . However, this proposition is complicated by spatial and temporal heterogeneity 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 . Here we study genomic and expression profiles across 127 multisector or longitudinal specimens from 52 individuals with glioblastoma (GBM). Using bulk and single-cell data, we find that samples from the same tumor mass share genomic and expression signatures, whereas geographically separated, multifocal tumors and/or long-term recurrent tumors are seeded from different clones. Chemical screening of patient-derived glioma cells (PDCs) shows that therapeutic response is associated with genetic similarity, and multifocal tumors that are enriched with PIK3CA mutations have a heterogeneous drug-response pattern. We show that targeting truncal events is more efficacious than targeting private events in reducing the tumor burden. In summary, this work demonstrates that evolutionary inference from integrated genomic analysis in multisector biopsies can inform targeted therapeutic interventions for patients with GBM.
Identification of transcriptome signature for predicting clinical response to bevacizumab in recurrent glioblastoma
Glioblastomas are among the most fatal brain tumors. Although no effective treatment option is available for recurrent glioblastomas (GBMs), a subset of patients evidently derived clinical benefit from bevacizumab, a monoclonal antibody against vascular endothelial growth factor. We retrospectively reviewed patients with recurrent GBM who received bevacizumab to identify biomarkers for predicting clinical response to bevacizumab. Following defined criteria, the patients were categorized into two clinical response groups, and their genetic and transcriptomic results were compared. Angiogenesis‐related gene sets were upregulated in both responders and nonresponders, whereas genes for each corresponding angiogenesis pathway were distinct from one another. Two gene sets were made, namely, the nonresponder angiogenesis gene set (NAG) and responder angiogenesis gene set (RAG), and then implemented in independent GBM cohort to validate our dataset. A similar association between the corresponding gene set and survival was observed. In NAG, COL4A2 was associated with a poor clinical outcome in bevacizumab‐treated patients. This study demonstrates that angiogenesis‐associated gene sets are composed of distinct subsets with diverse biological roles and they represent different clinical responses to anti‐angiogenic therapy. Enrichment of a distinct angiogenesis pathway may serve as a biomarker to predict patients who will derive a clinical benefit from bevacizumab. Agiogenesis‐related genes are composed of distinct subsets with diverse biological roles, and they represent differential clinical response to anti‐angiogenic therapy. Enrichment of distinct angiogenesis pathway may serve as a biomarker to predict subset of recurrent patients with glioblastoma who derive clinical benefit of bevacizumab.
Transcriptional regulatory networks of tumor-associated macrophages that drive malignancy in mesenchymal glioblastoma
Background Glioblastoma (GBM) is a complex disease with extensive molecular and transcriptional heterogeneity. GBM can be subcategorized into four distinct subtypes; tumors that shift towards the mesenchymal phenotype upon recurrence are generally associated with treatment resistance, unfavorable prognosis, and the infiltration of pro-tumorigenic macrophages. Results We explore the transcriptional regulatory networks of mesenchymal-associated tumor-associated macrophages (MA-TAMs), which drive the malignant phenotypic state of GBM, and identify macrophage receptor with collagenous structure (MARCO) as the most highly differentially expressed gene. MARCO high TAMs induce a phenotypic shift towards mesenchymal cellular state of glioma stem cells, promoting both invasive and proliferative activities, as well as therapeutic resistance to irradiation. MARCO high TAMs also significantly accelerate tumor engraftment and growth in vivo. Moreover, both MA-TAM master regulators and their target genes are significantly correlated with poor clinical outcomes and are often associated with genomic aberrations in neurofibromin 1 (NF1) and phosphoinositide 3-kinases/mammalian target of rapamycin/Akt pathway (PI3K-mTOR-AKT)-related genes. We further demonstrate the origination of MA-TAMs from peripheral blood, as well as their potential association with tumor-induced polarization states and immunosuppressive environments. Conclusions Collectively, our study characterizes the global transcriptional profile of TAMs driving mesenchymal GBM pathogenesis, providing potential therapeutic targets for improving the effectiveness of GBM immunotherapy.