Annual Report 2017

Koichi Ichimura, Tatsuya Ozawa, Yoshiko Nakano, Makoto Miyazaki, Mai Kitahara, Yuko Hibiya, Sanae Matsuzaki, Yuki Yomoda, Yumi Miyamoto, Arata Tomiyama, Shunichiro Miki, Sakura Shimizu-Kuzuoka, Mutsumi Takadera, Nobuyoshi Sasaki, Sae Ishimaru, Hidenobu Suzuki, Naomi Abe, Yutaro Yamamoto, Ayana Nakajima, Kenji Fujimoto, Yuko Matsushita, Kaishi Satomi, Takahiro Yamauchi

Introduction

 The Division of Brain Tumor Translational Research focuses on translational research on various types of malignant brain tumors to improve diagnostic accuracy, identify novel molecular markers, and develop new treatment. In order to meet the molecular criteria defined by the WHO Classification published in 2016, we develop robust molecular tests and perform molecular diagnostics for brain tumors through a number of nation-wide multi-center collaboration. We also develop novel targeted therapies, perform preclinical studies, and conduct clinical trials in collaboration with clinicians.

Our team and what we do

 We are the team of neurosurgeons, pediatric neuro-oncologists, postgraduate students, and laboratory technicians who are dedicated to brain tumor research. We provide molecular tests to patients operated at the Department of Neurosurgery and Neuro-oncology of the National Cancer Center Hospital (NCCH) as well as a number of external collaborators. We are in charge of performing molecular tests for the Japan Children's Cancer Group (JCCG) central diagnostic service. A total of 149 pediatric brain tumors were examined in 2017.

Research activities

1. Molecular diagnosis of pediatric brain tumors

 Among the various pediatric brain tumors collected through the JCCG and Japan Pediatric Molecular Neuro-oncology Group (JPMNG) as well as other cooperative institutes, we conduct a targeted sequencing for all exons of selected 93 genes, genome-wide DNA methylation analysis and RNA sequencing for those tumors that do not have characteristic mutations/fusions. Several targetable mutations including NTRK1 or novel fusions including ROS1 have been identified. We have also developed a robust pyrosequencing test to determine PFA/PFB in posterior fossa ependymoma.

2. Molecular analysis for adult gliomas

 We are currently developing an in vitro diagnostic kit to determine 1p/19q codeletion to facilitate molecular diagnostics of adult gliomas under the medical insurance. We are in charge of investigating molecular markers using tumor specimens collected from patients enrolled in several on-going clinical trials for brain tumors.

3. Development of a novel targeted therapy for glioblastoma

 Our preclinical experiments in collaboration with the Division of Cancer Stem Cell successfully demonstrated the anti-tumor effect of eribulin against glioblastoma. On the basis of this result, an investigator-initiated clinical trial to test the efficacy of eribulin against therapy-refractory GBM was launched in January 2018. We have also showed that a combination of eribulin and radiation was more effective than eribulin or radiation alone to suppress growth of glioblastoma cells in vivo.

4. Genomic analysis of central nervous system germ cell tumors (CNS GCT)

 We are developing a novel targeted therapy against mutated KIT in CNS GCT in collaboration with a company. A single cell transcriptomic study in CNS GCTs has also been started.

Clinical trials

 We are conducting molecular analysis for the BIOMARK clinical trial, in which the efficacy of Bevacizumab together with the Stupp regimen on glioblastomas is evaluated. The patient enrollment has been completed in January 2017 and 112 tumor specimens have been collected and are being analyzed for DNA methylation, targeted sequencing and RNA sequencing. We are also in charge of molecular tests in a number of JCOG clinical trials, as well as other Phase I/II studies.

Education

 Ten postgraduate students (doctoral course: eight, master's course: two), one research resident, and one clinical chief resident did research work during the period from January 2017 to March 2018 at the Division of Brain Tumor Translational Research. Two of the postgraduate students (one Ph.D., one master) successfully obtained degrees.

Future prospects

 As the leading translational research center on malignant brain tumors in Japan, we continue to organize nationwide and international collaboration and conduct research on all types of malignant brain tumors. We will continue to offer a molecular diagnostic service of brain tumors. Novel targeted therapies are being developed, and a thorough genomic analysis to investigate molecular pathogenesis of brain tumors will be continuously performed. Our laboratory acts as a

hub for young dedicated clinician investigators to meet, collaborate, and push forward with neuro-

oncological research together. Our goals are to improve diagnosis and treatment for brain tumor patients, and help develop world-class neuro-

oncology research in Japan.

List of papers published in January 2017 - March 2018

Journal

 1. Takayanagi S, Mukasa A, Tanaka S, Nomura M, Omata M, Yanagisawa S, Yamamoto S, Ichimura K, Nakatomi H, Ueki K, Aburatani H, Saito N. Differences in genetic and epigenetic alterations between von Hippel-Lindau disease-related and sporadic hemangioblastomas of the central nervous system. Neuro Oncol, 19:1228-1236, 2017

 2. Nakamura T, Yamashita S, Fukumura K, Nakabayashi J, Tanaka K, Tamura K, Tateishi K, Kinoshita M, Fukushima S, Takami H, Fukuoka K, Yamazaki K, Matsushita Y, Ohno M, Miyakita Y, Shibui S, Kubo A, Shuto T, Kocialkowski S, Yamanaka S, Mukasa A, Sasayama T, Mishima K, Maehara T, Kawahara N, Nagane M, Narita Y, Mano H, Ushijima T, Ichimura K. Genome-wide DNA methylation profiling identifies primary central nervous system lymphoma as a distinct entity different from systemic diffuse large B-cell lymphoma. Acta Neuropathol, 133:321-324, 2017

 3. Fukushima S, Yamashita S, Kobayashi H, Takami H, Fukuoka K, Nakamura T, Yamasaki K, Matsushita Y, Nakamura H, Totoki Y, Kato M, Suzuki T, Mishima K, Yanagisawa T, Mukasa A, Saito N, Kanamori M, Kumabe T, Tominaga T, Nagane M, Iuchi T, Yoshimoto K, Mizoguchi M, Tamura K, Sakai K, Sugiyama K, Nakada M, Yokogami K, Takeshima H, Kanemura Y, Matsuda M, Matsumura A, Kurozumi K, Ueki K, Nonaka M, Asai A, Kawahara N, Hirose Y, Takayama T, Nakazato Y, Narita Y, Shibata T, Matsutani M, Ushijima T, Nishikawa R, Ichimura K. Genome-wide methylation profiles in primary intracranial germ cell tumors indicate a primordial germ cell origin for germinomas. Acta Neuropathol, 133:445-462, 2017

 4. Nakamura T, Fukuoka K, Ikeda J, Yoshitomi M, Udaka N, Tanoshima R, Tateishi K, Yamanaka S, Ichimura K, Yamamoto T. Encouraging option of multi-staged gross total resection for a C11orf-RelA fusion-positive supratentorial anaplastic ependymoma. Brain Tumor Pathol, 34:160-164, 2017

 5. Pajtler KW, Mack SC, Ramaswamy V, Smith CA, Witt H, Smith A, Hansford JR, von Hoff K, Wright KD, Hwang E, Frappaz D, Kanemura Y, Massimino M, Faure-Conter C, Modena P, Tabori U, Warren KE, Holland EC, Ichimura K, Giangaspero F, Castel D, von Deimling A, Kool M, Dirks PB, Grundy RG, Foreman NK, Gajjar A, Korshunov A, Finlay J, Gilbertson RJ, Ellison DW, Aldape KD, Merchant TE, Bouffet E, Pfister SM, Taylor MD. The current consensus on the clinical management of intracranial ependymoma and its distinct molecular variants. Acta Neuropathol, 133:5-12, 2017

 6. Nomura M, Mukasa A, Nagae G, Yamamoto S, Tatsuno K, Ueda H, Fukuda S, Umeda T, Suzuki T, Otani R, Kobayashi K, Maruyama T, Tanaka S, Takayanagi S, Nejo T, Takahashi S, Ichimura K, Nakamura T, Muragaki Y, Narita Y, Nagane M, Ueki K, Nishikawa R, Shibahara J, Aburatani H, Saito N. Distinct molecular profile of diffuse cerebellar gliomas. Acta Neuropathol, 134:941-956, 2017

 7. Kameda M, Otani Y, Ichikawa T, Shimada A, Ichimura K, Date I. Congenital Glioblastoma with Distinct Clinical and Molecular Characteristics: Case Reports and a Literature Review. World neurosurgery, 101:817.e5-817.e14, 2017

 8. Masui K, Komori T, Kato Y, Masutomi K, Ichimura K, Ogasawara S, Kaneko MK, Oki H, Suzuki H, Nitta M, Maruyama T, Muragaki Y, Kawamata T, Sawada T, Shibata N. Elevated TERT Expression in TERT-Wildtype Adult Diffuse Gliomas: Histological Evaluation with a Novel TERT-Specific Antibody. Biomed Res Int, 2018:7945845, 2018

 9. Onishi S, Yamasaki F, Nakano Y, Takayasu T, Amatya VJ, Kolakshyapati M, Takeshima Y, Hirose T, Ichimura K, Sugiyama K, Kurisu K. RELA fusion-positive anaplastic ependymoma: molecular characterization and advanced MR imaging. Brain Tumor Pathol, 35:41-45, 2018

10. Yamamoto Y, Tomiyama A, Sasaki N, Yamaguchi H, Shirakihara T, Nakashima K, Kumagai K, Takeuchi S, Toyooka T, Otani N, Wada K, Narita Y, Ichimura K, Sakai R, Namba H, Mori K. Intracellular cholesterol level regulates sensitivity of glioblastoma cells against temozolomide-induced cell death by modulation of caspase-8 activation via death receptor 5-accumulation and activation in the plasma membrane lipid raft. Biochem Biophys Res Commun, 495:1292-1299, 2018