Publications by authors named "Takanori Nozawa"

6 Publications

  • Page 1 of 1

GLI3 Is Associated With Neuronal Differentiation in SHH-Activated and WNT-Activated Medulloblastoma.

J Neuropathol Exp Neurol 2021 01;80(2):129-136

Department of Pathology, Brain Research Institute, Niigata University.

Glioma-associated oncogene homolog 3 (GLI3), whose main function is to inhibit GLI1, has been associated with neuronal differentiation in medulloblastoma. However, it is not clear what molecular subtype(s) show increased GLI3 expression. GLI3 levels were assessed by immunohistochemistry in 2 independent cohorts, including a total of 88 cases, and found to be high in both WNT- and SHH-activated medulloblastoma. Analysis of bulk mRNA expression data and single cell RNA sequencing studies confirmed that GLI1 and GLI3 are highly expressed in SHH-activated medulloblastoma, whereas GLI3 but not GLI1 is highly expressed in WNT-activated medulloblastoma. Immunohistochemical analysis has shown that GLI3 is expressed inside the neuronal differentiated nodules of SHH-activated medulloblastoma, whereas GLI1/2 are expressed in desmoplastic areas. In contrast, GLI3 is diffusely expressed in WNT-activated medulloblastoma, whereas GLI1 is suppressed. Our data suggest that GLI3 may be a master regulator of neuronal differentiation and morphology in these subgroups.
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http://dx.doi.org/10.1093/jnen/nlaa141DOI Listing
January 2021

Expression of the ghrelin/growth hormone secretagogue receptor axis and its functional role in promoting tumor growth in primary central nervous system lymphomas.

Neuropathology 2020 Jun 10;40(3):232-239. Epub 2020 Jan 10.

Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan.

Ghrelin and its receptor, growth hormone secretagogue receptor (GHS-R), have been found in a variety of malignant tumor tissues, suggesting a biological function of the ghrelin/GHS-R axis in tumor growth and progression. Among central nervous system tumors, primary central nervous system lymphomas (PCNSLs) are relatively rare and characterized by a rapid progression and poor prognosis. In order to clarify ghrelin expression and its functional role in promoting tumor growth and progression in PCNSLs, we undertook an immunohistochemical investigation for ghrelin and GHS-R expression in 43 patients and tested the effect of ghrelin inhibition on lymphoma cells. Furthermore, we investigated the expression of CD105, a marker for tumor angiogenesis, to explore its association with the ghrelin/GHS-R axis. The Kaplan-Meier method and Cox's proportional hazards regression model were used to determine the association of ghrelin/GHS-R expression with overall survival rate. The immunohistochemical study showed moderate/strong immunostaining of cells for ghrelin and GHS-R in 40 patients (93.0%) and 39 patients (90.7%), respectively. A ghrelin inhibitor did not affect tumor cell proliferation in vitro. Expression levels of ghrelin and GHS-R were divided into high and low groups by the rate of moderate-strong staining cells to tumor cells. The survival rate was significantly lower in patients with high GHS-R expression (P = 0.0368 by log-rank test; P = 0.0219 by Wilcoxon test). In addition, multivariate analysis of overall survival using Cox's proportional hazards regression model indicated that GHS-R was a significant independent prognostic factor (P = 0.0426). CD105 expression on tumor vessels was positive in 33 patients (33/37, 89.2%). There was a positive correlation between the moderate-strong staining rate of ghrelin and CD105-positive vessel count. These results indicated that the ghrelin/GHS-R axis plays a potential role in promoting tumor growth and progression through neoangiogenesis, rather than the proliferation of tumor cells.
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http://dx.doi.org/10.1111/neup.12634DOI Listing
June 2020

EGFRvIII Is Expressed in Cellular Areas of Tumor in a Subset of Glioblastoma.

Neurol Med Chir (Tokyo) 2019 Mar 21;59(3):89-97. Epub 2019 Feb 21.

Department of Pathology, Brain Research Institute, University of Niigata.

Epidermal growth factor receptor variant III (EGFRvIII) is a tumor-specific cell surface antigen often expressed in glioblastoma and has drawn much attention as a possible therapeutic target. We performed immunohistochemistry on histology sections of surgical specimens taken from 67 cases with glioblastoma, isocitrate dehydrogenase-wild type, and evaluated the morphological characteristics and distribution of the EGFRvIII-positive tumor cells. We then evaluated the localization of EGFRvIII-expression within the tumor and peritumoral areas. EGFRvIII immunopositivity was detected in 15 specimens taken from 13 patients, including two recurrent specimens taken from the same patient at relapse. Immunofluorescence staining demonstrated that EGFRvIII-positive cells were present in cells positive for glial fibrillary acidic protein (GFAP), and some showed astrocytic differentiation with multiple fine processes and others did not shown. The EGFRvIII-positive cells were located in cellular areas of the tumor, but not in the invading zone. In the two recurrent cases, EGFRvIII-positive cells were markedly decreased in one case and retained in the other. With regard to overall survival, univariate analysis indicated that EGFRvIII-expression in patients with glioblastoma was not significantly associated with a favorable outcome. Double-labeling immunofluorescence staining of EGFRvIII and GFAP showed that processes of large, well differentiated, GFAP-positive glia extend to and surround less differentiated, EGFRvIII-positive glial cells in cellular areas of tumor. However, in the tumor periphery, EGFRvIII-positive tumor cells were not observed. This finding suggests that EGFRvIII is involved in tumor proliferation, but that invading glioma cells lose their EGFRvIII expression.
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http://dx.doi.org/10.2176/nmc.oa.2018-0078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6434422PMC
March 2019

The perivascular microenvironment in Epstein-Barr virus positive primary central nervous system lymphoma: The role of programmed cell death 1 and programmed cell death ligand 1.

Neuropathology 2018 Apr 24;38(2):125-134. Epub 2017 Oct 24.

Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan.

It has been shown that high expression of certain immune checkpoint molecules, including those of the programmed death protein 1/programmed death ligand 1 (PD-1/PD-L1) axis, can be utilized to regulate immunosuppression in the microenvironment of malignant neoplasms. For the purpose of clarifying the immune-escape mechanism of primary central nervous system lymphomas (PCNSLs), particularly in Epstein-Barr virus (EBV)-positive cases, markers for PD-1, PD-L1, tumor-associated macrophages (TAMs), and tumor-infiltrating lymphocytes (TILs) in 39 surgical specimens of PCNSLs (17 EBV-positive, 22 EBV-negative) were investigated by immunohistochemistry. Staining for PD-L1 was scored as follows: (-), no staining; (1+), 0-30% positive cells; (2+), 30-60% positive cells; and (3+), >60% positive cells. In EBV-positive cases, PD-L1 was detected in both lymphoma cells and TAMs in 12/17 cases, and in TAMs only in 4/17 cases. The mean number of PD-1, TIA-1 (a marker for cytotoxic T-cells), and FOXP3 (a marker for regulatory T-cells)-positive TILs in EBV-positive cases was 36.4 ± 45.9, 390 ± 603, and 9.88 ± 15.1, respectively. In EBV-negative cases, PD-L1 was detected in both lymphoma cells and TAMs in 11/22 cases, and in TAMs only in 4/22 cases. The mean of PD-1, TIA-1 and FOXP3-positive lymphocytes in EBV-negative cases was 67.3 ± 82.0, 158 ± 206 and 9.32 ± 17.5, respectively. We found no significant difference in the number of FOXP3-positive, lymphocytes between EBV-positive and negative cases. However, there were significantly higher numbers of PD-1-positive lymphocytes in the former, and significantly higher numbers of TIA-1-positive lymphocytes in the latter (P < 0.05). The combined data indicate that expression of PD-L1 by lymphoma cells and TAMs mediate the trafficking of TILs, which may explain the immune-escape process of PCNSLs. In addition, EBV infection appears to affect the trafficking mechanism of TILs, and may thus play an important role in the microenvironment immunity of these tumors.
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http://dx.doi.org/10.1111/neup.12435DOI Listing
April 2018

Reliable diagnosis of IDH-mutant glioblastoma by 2-hydroxyglutarate detection: a study by 3-T magnetic resonance spectroscopy.

Neurosurg Rev 2018 Apr 27;41(2):641-647. Epub 2017 Sep 27.

Department of Neurosurgery, Brain Research Institute, University of Niigata, Niigata, Japan.

We have previously reported that reliable detection of 2-hydroxyglutarate (2HG) in isocitrate dehydrogenase (IDH)-mutant WHO grade 2 and 3 gliomas is possible utilizing 3.0-T single-voxel magnetic resonance spectroscopy (SVMRS). We set out to determine whether the same method could be applied to detect 2HG in IDH-mutant glioblastoma. Forty-four patients harboring glioblastoma underwent pre-operative MRS evaluation to detect 2HG and other metabolites. Presence of IDH-mutations was determined by IDH1 R132H immunohistochemical analysis and DNA sequencing of surgically obtained tissues. Six out of 44 (13.6%) glioblastomas were IDH-mutant. IDH-mutant glioblastoma exhibited significantly higher accumulation of 2HG (median 3.191 vs. 0.000 mM, p < 0.0001, Mann-Whitney test). A cutoff of 2HG = 0.897 mM achieved high sensitivity (100.0%) and specificity (92.59%) in determining IDH-mutation in glioblastoma. Glioblastoma with high 2HG accumulation did not have significantly longer overall survival than glioblastoma with low 2HG accumulation (p = 0.107, log-rank test). Non-invasive and reliable detection of 2HG in IDH-mutant glioblastoma was possible by 3.0-T SVMRS.
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http://dx.doi.org/10.1007/s10143-017-0908-yDOI Listing
April 2018

[Clinical Study on Cerebellar Contusion:A Report on 9 Cases and Literature Review].

No Shinkei Geka 2015 Oct;43(10):901-6

Department of Neurosurgery, Niigata City General Hospital.

We report 9 cases of cerebellar contusion from April 2011 to September 2014 at our department. Frequency, clinicoradiological findings, mechanism of injury, treatments, and outcomes were retrospectively analyzed. Of 239 head injury cases admitted to our department during the same period, 9(3.8%)were diagnosed as cerebellar contusion. Among these 9 cases, 7 were men, and 2 were women. The patient age ranged from 12 to 83 years with a mean age of 64.7 years. The mechanism of injury was traffic accident in one patient, and fall in 8. All cases were associated with direct head trauma to the occiput, and radiographic studies showed occipital bone fracture in 8 cases. Six cases were managed conservatively. Three cases underwent suboccipital craniectomies and clot evacuations. Glasgow Outcome Scale(GOS)score at discharge were Good Recovery(GR)in 2, Moderate Disability(MD)in 2, Severe Disability(SD)in 3, Vegetative State(VS)in 1, and Dead(D)in 1. GOS scores in surgically treated cases were GR in 1, SD in 1, and VS in 1. Supratentorial severe traumatic lesions were concomitant with poor prognosis. Coup injury was a significant cause of cerebellar contusion. External decompression and clot evacuation were useful in patients who suffered severe cerebellar contusion;however, concomitant supratentorial lesions influenced the prognosis.
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http://dx.doi.org/10.11477/mf.1436203144DOI Listing
October 2015
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