Publications by authors named "Yu Kanemaru"

11 Publications

  • Page 1 of 1

Low Detection Rate of H3K27M Mutations in Cerebrospinal Fluid Obtained from Lumbar Puncture in Newly Diagnosed Diffuse Midline Gliomas.

Diagnostics (Basel) 2021 Apr 9;11(4). Epub 2021 Apr 9.

Department of Neurosurgery, Brain Research Institute, Niigata University, Niigata 951-8585, Japan.

Recent studies have suggested the feasibility of detecting H3K27M mutations in the cerebrospinal fluid of diffuse midline glioma (DMG) patients. However, cerebrospinal fluid from patients in these studies were collected mainly during biopsy, ventriculo-peritoneal shunt procedures or postmortem. We assessed circulating tumor DNA (ctDNA) extracted from cerebrospinal fluid (CSF) and plasma in a series of 12 radiographically suspected and/or pathologically confirmed diffuse midline glioma patients and assessed for K27M mutation using digital droplet PCR. In 10 patients, CSF was obtained by lumbar puncture at presentation. A definitive detection of K27M mutation was achieved in only one case (10%); K27M mutation was suspected in three other cases (30%). K27M mutation was detected in two patients in CSF obtained by ventricular tap during a ventriculo-peritoneal shunt for obstructive hydrocephalus. Cases in which a definitive assessment was possible (definite K27M or definite wildtype) tended to be younger (median 7.5 years vs. 40.5 years; = 0.07) and have a higher concentration of CSF protein (median 123 mg/dL vs. 27.5 mg/dL; = 0.21) compared to nondefinite cases. Low proliferation and apoptotic rates seemed to be characteristics of DMG unfavorable for liquid biopsy. More advanced lesions with necrosis and evidence of dissemination were unlikely to be candidates for lumbar puncture due to the fear of exacerbating obstructive hydrocephalus. Methods to safely sample CSF and a more sensitive detection of ctDNA are necessary for reliable liquid biopsy of DMG at presentation.
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http://dx.doi.org/10.3390/diagnostics11040681DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8070169PMC
April 2021

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

MGMT Expression Contributes to Temozolomide Resistance in H3K27M-Mutant Diffuse Midline Gliomas.

Front Oncol 2019 21;9:1568. Epub 2020 Jan 21.

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

Diffuse midline gliomas (DMGs) show resistance to many chemotherapeutic agents including temozolomide (TMZ). Histone gene mutations in DMGs trigger epigenetic changes including DNA hypomethylation, one of which is a frequent lack of O6-methyl-guanine-DNA methyltransferase () promoter methylation, resulting in increased MGMT expression. We established the NGT16 cell line with K27M and G328E gene mutations from a DMG patient and used this cell line and other DMG cell lines with gene mutation (SF7761, SF8628, JHH-DIPG1) to analyze promoter methylation, MGMT protein expression, and response to TMZ. Three out of 4 DMG cell lines (NGT16, SF8628, and JHH-DIPG1) had unmethylated promoter, increased MGMT expression, and showed resistance to TMZ treatment. SF7761 cells with gene mutation showed promoter methylation, lacked MGMT expression, and sensitivity to TMZ treatment. NGT16 line showed response to ALK2 inhibitor K02288 treatment . We confirmed that MGMT expression contributes to TMZ resistance in DMG cell lines. There is an urgent need to develop new strategies to treat TMZ-resistant DMGs.
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http://dx.doi.org/10.3389/fonc.2019.01568DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985080PMC
January 2020

Dramatic response of BRAF V600E-mutant epithelioid glioblastoma to combination therapy with BRAF and MEK inhibitor: establishment and xenograft of a cell line to predict clinical efficacy.

Acta Neuropathol Commun 2019 07 25;7(1):119. Epub 2019 Jul 25.

From the Departments of Neurosurgery, Niigata University, 1-757 Asahimachidori, Chuo-ku, Niigata, Japan.

Epithelioid glioblastoma is a rare aggressive variant of glioblastoma (GBM) characterized by a dismal prognosis of about 6 months and frequent leptomeningeal dissemination. A recent study has revealed that 50% of epithelioid GBMs harbor three genetic alterations - BRAF V600E mutation, TERT promoter mutations, and homozygous deletions of CDKN2A/2B. Emerging evidence support the effectiveness of targeted therapies for brain tumors with BRAF V600E mutation. Here we describe a dramatic radiographical response to combined therapy with BRAF and MEK inhibitors in a patient with epithelioid GBM harboring BRAF V600E mutation, characterized by thick spinal dissemination. From relapsed tumor procured at autopsy, we established a cell line retaining the BRAF V600E mutation, TERT promoter mutation and CDKN2A/2B loss. Intracranial implantation of these cells into mice resulted in tumors closely resembling the original, characterized by epithelioid tumor cells and dissemination, and invasion into the perivascular spaces. We then confirmed the efficacy of treatment with BRAF and MEK inhibitor both in vitro and in vivo. Epithelioid GBM with BRAF V600E mutation can be considered a good treatment indication for precision medicine, and this patient-derived cell line should be useful for prediction of the tumor response and clarification of its biological characteristics.
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http://dx.doi.org/10.1186/s40478-019-0774-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6659204PMC
July 2019

Comparison of circulating tumor DNA between body fluids in patients with primary central nervous system lymphoma.

Leuk Lymphoma 2019 12 15;60(14):3587-3589. Epub 2019 Jul 15.

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

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http://dx.doi.org/10.1080/10428194.2019.1639169DOI Listing
December 2019

Podoplanin Expression and IDH-Wildtype Status Predict Venous Thromboembolism in Patients with High-Grade Gliomas in the Early Postoperative Period.

World Neurosurg 2019 Aug 15;128:e982-e988. Epub 2019 May 15.

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

Objective: Venous thromboembolism (VTE) often is encountered in patients with high-grade gliomas. The underlying mechanisms are unclear, as is the optimal prophylactic protocol. The purpose of the present study was to identify risk factors of VTE and examine the validity of early VTE detection in high-grade gliomas.

Methods: We reviewed the medical records of 165 patients with newly diagnosed high-grade glioma treated at Niigata University Hospital during the years 2009 to 2016. If the serum D-dimer levels increased to 5.0 μg/mL or more, computed tomography was performed to detect VTE. Furthermore, immunohistochemistry with antibodies against podoplanin was performed on available 101 tumor tissues.

Results: Of the 165 patients, 44 (26.7%) developed VTE. Of the 44 patients, 34 (79.5%) developed VTE within 7 days after surgery. No fatal VTE occurred and major complications secondary to anticoagulation occurred in only 2 (1.2%) patients. On multivariate analysis, lower Karnofsky Performance Scale status, podoplanin expression, and isocitrate dehydrogenase-wildtype status were independently associated with the risk of VTE (P < 0.05).

Conclusions: We found that most VTEs occurred early in the postoperative period and commonly in patients with lower Karnofsky Performance Scale status and isocitrate dehydrogenase-wildtype gliomas, which expressed podoplanin.
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http://dx.doi.org/10.1016/j.wneu.2019.05.049DOI Listing
August 2019

MGMT Expression Contributes to Temozolomide Resistance in H3K27M-Mutant Diffuse Midline Gliomas and MGMT Silencing to Temozolomide Sensitivity in IDH-Mutant Gliomas.

Neurol Med Chir (Tokyo) 2018 Jul 31;58(7):290-295. Epub 2018 May 31.

Department of Neurosurgery, Brain Research Institute, Niigata University.

Histone H3 mutations are frequently found in diffuse midline gliomas (DMGs), which include diffuse intrinsic pontine gliomas and thalamic gliomas. These tumors have dismal prognoses. Recent evidence suggests that one reason for the poor prognoses is that O-methylguanine-DNA methyltransferase (MGMT) promoter frequently lacks methylation in DMGs. This review compares the epigenetic changes brought about by histone mutations to those by isocitrate dehydrogenase-mutant gliomas, which frequently have methylated MGMT promoters and are known to be sensitive to temozolomide.
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http://dx.doi.org/10.2176/nmc.ra.2018-0044DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6048353PMC
July 2018

[Bilateral Internal Carotid Artery Dissection Caused by Elongated Styloid Processes:A Case Report].

No Shinkei Geka 2018 Jan;46(1):53-59

Department of Neurosurgery, Nagano Red Cross Hospital.

We report a case of bilateral internal carotid artery(ICA)dissection associated with bilateral elongated styloid processes(ESPs). A 46-year-old man presented with transient aphasia and left visual disturbance at a business meeting. He complained of a foreign body sensation in his throat during swallowing for two years. Magnetic resonance imaging(MRI)demonstrated fresh small infarcts in the left corona radiata. Magnetic resonance angiography(MRA)revealed string signs bilaterally in the cervical ICAs. The patient was diagnosed with bilateral idiopathic ICA dissection and was treated with ozagrel and clopidogrel. Three-dimensional computed tomographic angiogram(3DCTA)indicated bilateral ESPs and bilateral ICA stenosis. 3DCTA with the patient's head tilting and neck extension revealed that each ICA was compressed by the ipsilateral ESP. A follow-up MRA showed complete normalization of bilateral ICAs after neck rest and anti-platelet therapy, following which, clopidogrel was stopped. The patient wore a soft cervical collar until the operation, to avoid contact between the ESPs and ICAs due to changes in head position. Bilateral ESP resection was performed to prevent recurrence of cerebral ischemic events caused by ICA dissection. The patient was discharged one week after the surgery without any neurological deficit. There was no recurrence of symptoms during the next eight months after the operation.
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http://dx.doi.org/10.11477/mf.1436203675DOI Listing
January 2018

Transient disappearance of microbleeds in the subacute period based on T2*-weighted gradient echo imaging in traumatic brain injury.

Acta Neurochir (Wien) 2016 07 22;158(7):1247-50. Epub 2016 Apr 22.

Department of Neurosurgery, Akita Red Cross Hospital, 222-1 Nawashirosawa, Saruta, Kamikitate, Akita, 010-1495, Japan.

We report three cases of traumatic microbleeds evaluated by sequential observation. Hypo-intensities on T2* gradient echo imaging (T2*GEI) appeared just 2-3 h after the injury (the hyper-acute period). However, these hypo-intensities on T2*GEI disappeared or became obscure 2-6 days after the injury (the subacute period). A follow-up MRI again revealed clear hypo-intensities on T2*GEI 1-3 months after the injury (the chronic period). Our cases indicate that hypo-intensities on T2*GEI might change dynamically from the hyper-acute to the chronic period. The differences of susceptibility effects by hematoma age might be the cause of this dynamic change.
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http://dx.doi.org/10.1007/s00701-016-2805-5DOI Listing
July 2016

[Pure motor monoparesis of a lower limb due to head injury: a case report].

Brain Nerve 2012 Dec;64(12):1427-30

Department of Neurosurgery, Akita Red Cross Hospital, Japan.

A 70-year-old woman sustained a head injury after a motor vehicle accident. Physical examination conducted on admission revealed pure motor monoparesis (PMM) and pathological reflexes in the right lower extremity. Her left lower extremity and upper extremities were intact. Computed tomography showed a spotty high-density lesion in the left precentral gyrus and a subgaleal hematoma in the left occipital region. Magnetic resonance imaging was performed on the next day. Fluid-attenuated inversion recovery (FLAIR) imaging demonstrated a high-intensity lesion in the left precentral gyrus, and T₂ imaging revealed a low-intensity lesion suggesting a small hemorrhage in the same area. The small hemorrhage and perifocal edema were identified on diffusion-weighted images in which low- and high-intensity lesions were observed in the anterior and posterior left precentral gyrus, respectively. Subsequent neurological examinations over 2 weeks showed improvement. We discuss the clinical presentation, diagnosis, and treatment of PMM due to head injury. We concluded that FLAIR and T₂ and diffusion-weighted imaging may be useful techniques for diagnosing PMM due to head injury.
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December 2012