Involvement of neuropilin-1 in radiation-induced cell death via modulation of DNA double-strand break repair in glioblastoma T98G cells.
Kaori Tsutsumi, Kouta Kawahara, Mizuki Kojima, Ayu Yuasa, Mitsuki Imazato, Juri Kidachi, Nanoha Yamamoto, Hisashi Nakano
Biochimica et biophysica acta. General subjects, 130906, 130906, 15 Jan. 2026, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, Glioblastoma (GBM) is the most malignant form of brain tumor and is characterized by resistance to chemotherapy, radiotherapy, and combined chemoradiotherapy. Neuropilin-1 (NRP1) is a transmembrane receptor known to play critical roles in angiogenesis, tumor progression, and radioresistance. However, its precise role in radiation-induced cellular responses, particularly in GBM, remains unclear. In this study, we aimed to elucidate the mechanism underlying radiation resistance via NRP1 by examining the effects of NRP1 depletion in the p53-mutant GBM T98G cell line. Short interfering RNA-mediated suppression of NRP1 significantly reduced clonogenic survival following irradiation. Although the expression of caspase-3 and p21 was up-regulated in NRP1-suppressed cells, radiation-induced apoptosis and senescence did not significantly increase. γH2AX foci, a marker of radiation-induced DNA double-strand breaks (DSBs), were comparable between control and NRP1-suppressed cells. However, the DSB repair capacity was reduced in NRP1-suppressed cells, as evidenced by a higher number of unrepaired DSBs 24 h after irradiation. The number of 53BP1 foci, one of an important molecule in non-homologous end joining (NHEJ) of the DNA repair pathways, decreased in NRP1 suppression cells 0.5 h after X-ray irradiation. These changes were also observed in another GBM cell line, LN-18. The phosphorylation status of AKT, a key molecule in the survival pathway, remained unchanged in NRP1-suppressed cells compared to control cells. These findings suggest that NRP1 may regulate radiosensitivity by modulating DNA repair pathways in p53-mutated GBM T98G cells. NRP1 could serve as a potential therapeutic target for improving the response of radioresistant tumors such as GBM.

The balance among radiation-induced cell death pathways in the p53-mutant human glioblastoma cell line T98G: A preliminary study.
Hisashi Nakano, Juri Kidachi, Mitsuki Imazato, Mizuki Kojima, Kaori Tsutsumi
Biomedical research (Tokyo, Japan), 46, 3, 101, 110, 2025, [Peer-reviewed], [Corresponding author], [Domestic magazines]
English, Scientific journal, The specific contributions of apoptosis, necrosis, autophagy, and cellular senescence pathways in malignant tumor cells (especially p-53 defective or mutated tumors) are unclear. We evaluated the cell viability, apoptosis, autophagic cell death, and cell senescence of T98G cells irradiated with 6 megavoltage (MV) X-rays at 0, 2, 4, and 8 Gy. The cell-death rate obtained by a colony formation assay was used to derive the cell-surviving fraction at each irradiation dose. We evaluated the relative balance between each irradiation dose and the cell-death pathway by a four-dimensional (4D) plot generated by incorporating the cell-death rate, autophagic cell death, and cell senescence. A dose-dependent decrease in the cell-survival rate was observed, with no significant apoptosis induction at any dose. Autophagic cell death and cellular senescence both exhibited dose-dependent increases, with autophagy dominating at 2-4 Gy and senescence more prominent at 8 Gy. The complex relationships among apoptosis, autophagy, and senescence in T98G remain unresolved. Our results highlight the dose-dependent shifts in autophagy and senescence, providing a foundational understanding of cell-death dynamics in radiation-resistant tumors and perhaps paving the way for novel strategies that exploit these pathways to enhance glioblastoma treatments' efficacy.

The dynamic relationship between inorganic polyphosphate and adenosine triphosphate in human non‐small cell lung cancer H1299 cells
Kaori Tsutsumi, Thititip Tippayamontri, Mari Hayashi, Nobuto Matsuda, Yusaku Goto
FEBS Open Bio, Wiley, 01 Jan. 2024, [Peer-reviewed], [Lead author, Corresponding author], ［Internationally co-authored］, [International Magazine]
Scientific journal, Inorganic polyphosphate (polyP) plays a vital role in cellular energy metabolism and signaling, owing to its structure and high‐energy phosphate bonds. Intracellular ATP functions both as a cellular energy source and a key factor in cell death, and ATP dynamics in tumor cells are crucial for advancing cancer therapy. In this study, we explored the interplay between polyP and ATP in cellular energy metabolism. Treatment with polyP did not affect cell proliferation of human non‐small cell lung cancer H1299 and human glioblastoma T98G cell lines as compared to their respective control cells until 72 h post‐treatment. The mitochondrial membrane potential (MMP) in polyP‐treated cells was low, contrasting with the time‐dependent increase observed in control cells. While the ATP content increased over time in untreated and Na‐phosphate‐treated control cells, it remained unchanged in polyP‐treated cells. Furthermore, the addition of cyclosporine A, a mitochondrial permeability transition pore (mPTP) inhibitor, failed to restore ATP levels in polyP‐treated cells. We performed lactate assays and western blot analysis to evaluate the effect of polyP on glucose metabolism and found no significant differences in lactate secretion or glucose‐6‐phosphate dehydrogenase (G6PD) activity between polyP‐treated and control cells. Additional pyruvate restored MMP but had no effect on the cellular ATP content in polyP‐treated cells. Moreover, we observed no correlation between the Warburg effect and glucose metabolism during ATP depletion in polyP‐treated cells. Further investigation is warranted to explore the roles of polyP and ATP in cancer cell energy metabolism, which might offer potential avenues for therapeutic interventions.

Evaluation of Image Classification for Quantifying Mitochondrial Morphology using Deep Learning.
Kaori Tsutsumi, Keima Tokunaga, Shun Saito, Tatsuya Sasase, Hiroyuki Sugimori
Endocrine, metabolic & immune disorders drug targets, 01 Jul. 2022, [Peer-reviewed], [Lead author], [International Magazine]
English, Scientific journal, BACKGROUND: Mitochondrial morphology reversibly changes between division and fusion. As these changes (mitochondrial dynamics) reflect the cellular condition, they are one of the simplest indicators of cell state and predictors of cell fate. However, it is currently difficult to classify them using a simple and objective method. OBJECTIVE: The present study aimed to evaluate mitochondrial morphology using Deep Learning (DL) technique. METHODS: Mitochondrial images stained by MitoTracker were acquired from HeLa and MC3T3-E1 cells using fluorescent microscopy and visually classified into four groups based on fission or fusion. The intra- and inter-rater reliabilities for visual classification were excellent [ (ICC(1,3), 0.961 for rater 1; and 0.981 for rater 2) and ICC(1,3), respectively]. The images were divided into test and train images, and a 50-layer ResNet CNN architecture (ResNet-50) using MATLAB software was used to train the images. The datasets were trained five times based on five-fold cross-validation. RESULT: The mean of the overall accuracy for classifying mitochondrial morphology was 0.73±0.10 in HeLa. For the classification of mixed images containing two types of cell lines, the overall accuracy using mixed images of both cell lines for training was higher (0.74±0.01) than that using different cell lines for training. CONCLUSION: We developed a classifier to categorize mitochondrial morphology using DL.

Feasibility of an Ultrasound-Based Method for Measuring Talar Displacement during the Anterior Drawer Stress Test Using a Telos Device: A Preliminary Study.
Kaori Tsutsumi, Utayo Nakaya, Yuta Koshino, Mari Tateno, Kazuhisa Matsumoto, Mai Tanaka, Mika Yokoyama, Tatsunori Horie, Mina Samukawa, Tamotsu Kamishima, Harukazu Tohyama
International journal of environmental research and public health, 19, 4, 18 Feb. 2022, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, This study was conducted to measured talar displacement using ultrasound during an anterior drawer test (ADT) with a Telos device. Five adults (3 men and 2 women; 8 ankles; mean age: 23.2 y) with a history of ankle sprain and eight adults (5 men and 3 women; 16 ankles; mean age: 22.1 y) without a history of ankle sprain were recruited into a history of ankle sprain (HAS) and a control group, respectively. Talar displacement was observed in response to load forces applied by a Telos device during the ultrasound stress imaging test. The ultrasound probe was placed 5 mm inside from the center of the Achilles tendon on the posterior ankle along the direction of the major axis. The inter-rater reliability for the present method was classified as good and excellent (ICC(2,2) = 0.858 and 0.957 at 120 N and 150 N, respectively) in the control group and excellent (ICC(2,2) = 0.940 and 0.905 at 120 N and 150 N, respectively) in the HAS group, according to specific intraclass correlation coefficient values. We found that talar displacement during the ADT was lower in the HAS group than in the control group. Analysis of the receiver operating characteristic curve revealed that the quantitative ultrasound-based ADT using a Telos device was superior to the X-ray-based test in detecting reduced ankle joint mobility during the ADT (area under the curve of 0.905 and 0.726 at a force of 150 N using ultrasound-based and X-ray-based tests, respectively). Further investigation is needed; nevertheless, this preliminary study suggests that the ultrasound-based quantitative ADT using a Telos device might detect talar displacement more sensitively than the conventional stress X-ray.

Contribution of Neuropilin-1 in Radiation-Survived Subclones of NSCLC Cell Line H1299
Kaori Tsutsumi, Ayaka Chiba, Yuta Tadaki, Shima Minaki, Takahito Ooshima, Haruka Takahashi
Current Issues in Molecular Biology, Sep. 2021, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal

Chromosomal Location of Genes Differentially Expressed in Tumor Cells Surviving High-Dose X-ray Irradiation: A Preliminary Study on Radio-Fragile Sites
Kaori Tsutsumi, Moe Masuda, Hiroyuki Date
Current Issues in Molecular Biology, 43, 2, 1133, 1141, MDPI AG, Sep. 2021, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, Altered gene expression is a common feature of tumor cells after irradiation. Our previous study showed that this phenomenon is not only an acute response to cytotoxic stress, instead, it was persistently detected in tumor cells that survived 10 Gy irradiation (IR cells). The current understanding is that DNA double-strand breaks (DSBs) are recognized by the phosphorylation of histone H2AX (H2AX) and triggers the ataxia-telangiectasia mutated (ATM) protein or the ATM- and Rad3-related (ATR) pathway, which activate or inactivate the DNA repair or apoptotic or senescence related molecules and causes the expression of genes in many instances. However, because changes in gene expression persist after passaging in IR cells, it may be due to the different pathways from these transient intracellular signaling pathways caused by DSBs. We performed microarray analysis of 30,000 genes in radiation-surviving cells (H1299-IR and MCF7-IR) and found an interesting relation between altered genes and their chromosomal loci. These loci formed a cluster on the chromosome, especially on 1q21 and 6p21-p22 in both irradiated cell lines. These chromosome sites might be regarded as “radio-fragile” sites.

Association between Physical Activity Levels and Body Composition among Healthy Older Japanese Adults during a Snowy Winter: A Cross-Sectional Study.
Tomoko Shimoda, Teppei Suzuki, Kaori Tsutsumi, Mina Samukawa, Sadako Yoshimura, Katsuhiko Ogasawara
International journal of environmental research and public health, 17, 15, 23 Jul. 2020, [Peer-reviewed], [International Magazine]
English, Scientific journal, BACKGROUND: Despite a long average lifespan, increased life expectancy does not guarantee higher quality of life. METHODS: To contribute in understanding some determinants of healthy life expectancies in older Japanese individuals in a snowy winter region, we investigated the indicators of health. Local residents (n = 124) in the city of Iwamizawa volunteered for health examinations from January 2016 to March 2016. We recorded activity via daily steps for 2-week periods. In addition, we measured body composition, grip strength, and assessed nutritional status. RESULTS: Analysis of body composition and daily activity indicated that women who walked more than 4000 steps had lower fat mass and increased muscle mass. Men with >3.0 metabolic equivalents (METs) when walking had lower body fat. CONCLUSION: For healthy older Japanese individuals in this snowy winter region, walking >4000 steps daily for women and exercise of >3.0 METs for men may indicate health-promoting activities.

Cellular calcification induced by inorganic polyphosphate involves ATP depletion and opening of the mitochondrial permeability transition pore (mPTP).
Kaori Tsutsumi, Tatsuya Sasase
FEBS open bio, 9, 9, 1617, 1622, Sep. 2019, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, Inorganic polyphosphate (polyP) is a linear polymer containing tens to hundreds of orthophosphate residues linked by high-energy phosphoanhydride bonds. PolyP promotes osteocalcification and bone mineralization in both mouse and human osteoblastic cells. In the present study, we examined the molecular mechanism by which polyP affects mitochondrial metabolism to promote cellular calcification in MC3T3-E1 osteoblastic cells. The cellular content of adenosine triphosphate (ATP) was diminished one day after polyP treatment, and this was accompanied by increased conversion to adenosine diphosphate. Furthermore, mitochondrial membrane potential was significantly decreased in polyP-treated cells. These results suggest that the depletion of intracellular ATP and the decrease in mitochondrial membrane potential induced by polyP treatment may be a trigger to promote cell calcification.

A Peptide Derived from Phosphoinositide 3-kinase Inhibits Endocytosis and Influenza Virus Infection.
Yoichiro Fujioka, Aya O Satoh, Kosui Horiuchi, Mari Fujioka, Kaori Tsutsumi, Junko Sasaki, Prabha Nepal, Sayaka Kashiwagi, Sarad Paudel, Shinya Nishide, Asuka Nanbo, Takehiko Sasaki, Yusuke Ohba
Cell structure and function, 44, 1, 61, 74, 25 Apr. 2019, [Peer-reviewed], [Domestic magazines]
English, Scientific journal, Endocytosis mediates the internalization and ingestion of a variety of endogenous or exogenous substances, including virus particles, under the control of intracellular signaling pathways. We have previously reported that the complex formed between the small GTPase Ras and phosphoinositide 3-kinase (PI3K) translocates from the plasma membrane to endosomes, signaling from which thereby regulates clathrin-independent endocytosis, endosome maturation, influenza virus internalization, and infection. However, the molecular mechanism by which the Ras-PI3K complex is recruited to endosomes remains unclear. Here, we have identified the amino acid sequence responsible for endosomal localization of the Ras-PI3K complex. PI3K lacking this sequence failed to translocate to endosomes, and expression of the peptide comprising this PI3K-derived sequence inhibited clathrin-independent endocytosis, influenza virus internalization, and infection. Moreover, treatment of cells with this peptide in an arginine-rich, cell-penetrating form successfully suppressed influenza virus infection in vitro and ex vivo, making this peptide a potential therapeutic agent against influenza virus infection.Key words: signal transduction, endocytosis, endosome, imaging, influenza virus.

Forefoot and hindfoot kinematics in subjects with medial tibial stress syndrome during walking and running.
Takumi Okunuki, Yuta Koshino, Masanori Yamanaka, Kaori Tsutsumi, Masato Igarashi, Mina Samukawa, Hiroshi Saitoh, Harukazu Tohyama
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 37, 4, 927, 932, Apr. 2019, [Peer-reviewed], [International Magazine]
English, Scientific journal, Excessive foot pronation during static standing, walking and running has been reported as a contributing factor for the development of medial tibial stress syndrome (MTSS). The motion of foot pronation consists of hindfoot and forefoot motion. However, no previous studies have investigated forefoot and hindfoot kinematics during walking and running in subjects with MTSS. The current study sought to compare hindfoot and forefoot kinematics between subjects with and without MTSS while walking and running. Eleven subjects with MTSS and 11 healthy controls (each group containing 10 males and one female) participated in the current study. Segment angles of the hindfoot and forefoot during walking and running barefoot on a treadmill were recorded using three-dimensional kinematic analysis. An independent t-test was used to compare kinematic data between groups. Subjects with MTSS exhibited significantly greater hindfoot eversion and abduction (p < 0.05) during walking and running than subjects without MTSS, significantly greater forefoot eversion and abduction (p < 0.05) during walking, and significantly greater forefoot abduction during running (p < 0.05). Hindfoot and forefoot kinematics during walking and running were significantly different between subjects with and without MTSS. For prevention and rehabilitation of MTSS, it may be important to focus on not only hindfoot but also forefoot kinematics during both running and walking. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Investigation of dose-rate effects and cell-cycle distribution under protracted exposure to ionizing radiation for various dose-rates.
Yusuke Matsuya, Stephen J McMahon, Kaori Tsutsumi, Kohei Sasaki, Go Okuyama, Yuji Yoshii, Ryosuke Mori, Joma Oikawa, Kevin M Prise, Hiroyuki Date
Scientific reports, 8, 1, 8287, 8287, 29 May 2018, [Peer-reviewed], [International Magazine]
English, Scientific journal, During exposure to ionizing radiation, sub-lethal damage repair (SLDR) competes with DNA damage induction in cultured cells. By virtue of SLDR, cell survival increases with decrease of dose-rate, so-called dose-rate effects (DREs). Here, we focused on a wide dose-rate range and investigated the change of cell-cycle distribution during X-ray protracted exposure and dose-response curves via hybrid analysis with a combination of in vitro experiments and mathematical modelling. In the course of flow-cytometric cell-cycle analysis and clonogenic assays, we found the following responses in CHO-K1 cells: (1) The fraction of cells in S phase gradually increases during 6 h exposure at 3.0 Gy/h, which leads to radio-resistance. (2) Slight cell accumulation in S and G2/M phases is observed after exposure at 6.0 Gy/h for more than 10 hours. This suggests that an increase of SLDR rate for cells in S phase during irradiation may be a reproducible factor to describe changes in the dose-response curve at dose-rates of 3.0 and 6.0 Gy/h. By re-evaluating cell survival for various dose-rates of 0.186-60.0 Gy/h considering experimental-based DNA content and SLDR, it is suggested that the change of S phase fraction during irradiation modulates the dose-response curve and is possibly responsible for some inverse DREs.

Factors affecting bone mineral density among snowy region residents in Japan: Analysis using multiple linear regression and Bayesian network model
Teppei Suzuki, Tomoko Shimoda, Noriko Takahashi, Kaori Tsutsumi, Mina Samukawa, Sadako Yoshimura, Katsuhiko Ogasawara
Journal of Medical Internet Research, 20, 5, e10, Journal of Medical Internet Research, 01 May 2018, [Peer-reviewed]
English, Scientific journal

Modeling cell survival and change in amount of DNA during protracted irradiation
Yusuke Matsuya, Kaori Tsutsumi, Kohei Sasaki, Yuji Yoshii, Takaaki Kimura, Hiroyuki Date
JOURNAL OF RADIATION RESEARCH, 58, 3, 302, 312, May 2017, [Peer-reviewed]
English, Scientific journal

Nutritional Status and Body Composition of Independently Living Older Adults in a Snowy Region of Japan.
Shimoda T, Suzuki T, Takahashi N, Tsutsumi K, Samukawa M, Yoshimachi S, Goto T, Enomoto H, Kise N, Ogasawara K, Yoshimura S
Gerontology & geriatric medicine, 3, 2333721417706854, Jan. 2017, [Peer-reviewed]
English, Scientific journal

Inorganic polyphosphate enhances radio-sensitivity in a human non-small cell lung cancer cell line, H1299
Kaori Tsutsumi, Yusuke Matsuya, Tomoki Sugahara, Manami Tamura, Satoshi Sawada, Sagiri Fukura, Hisashi Nakano, Hiroyuki Date
Tumor Biology, 39, 6, 1010428317705033, SAGE Publications Ltd, 01 Jan. 2017, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal

冬期における豪雪地域住民の年代別体組成および骨密度の実態 高齢者の筋肉量と骨密度に着目して　　　　　　　　　　　　　　　
下田 智子, 鈴木 哲平, 堤 香織, 高橋 紀子, 寒川 美奈, 後藤 輝明, 吉町 昌子, 小笠原 克彦, 良村 貞子
日本未病システム学会学術総会抄録集, 23回, 125, 125, (一社)日本未病学会, Oct. 2016
Japanese

Detection and measurement of rheumatoid bone and joint lesions of fingers by tomosynthesis: a phantom study for reconstruction filter setting optimization
Yohei Ono, Tamotsu Kamishima, Nobutoshi Yasojima, Kenichi Tamura, Kaori Tsutsumi
Radiological Physics and Technology, 9, 1, 6, 14, Springer Tokyo, 01 Jan. 2016, [Peer-reviewed], [Last author]
English, Scientific journal

Tomosynthesis can facilitate accurate measurement of joint space width under the condition of the oblique incidence of X-rays in patients with rheumatoid arthritis
Yohei Ono, Rina Kashihara, Nobutoshi Yasojima, Hideki Kasahara, Yuka Shimizu, Kenichi Tamura, Kaori Tsutsumi, Kenneth Sutherland, Takao Koike, Tamotsu Kamishima
BRITISH JOURNAL OF RADIOLOGY, 89, 1062, 20150967, 2016, [Peer-reviewed]
English, Scientific journal

Evaluation of the cell survival curve under radiation exposure based on the kinetics of lesions in relation to dose-delivery time
Yusuke Matsuya, Kaori Tsutsumi, Kohei Sasaki, Hiroyuki Date
JOURNAL OF RADIATION RESEARCH, 56, 1, 90, 99, Jan. 2015, [Peer-reviewed]
English, Scientific journal

Quantitative estimation of DNA damage by photon irradiation based on the microdosimetric-kinetic model
Yusuke Matsuya, Yosuke Ohtsubo, Kaori Tsutsumi, Kohei Sasaki, Rie Yamazaki, Hiroyuki Date
JOURNAL OF RADIATION RESEARCH, 55, 3, 484, 493, May 2014, [Peer-reviewed]
English, Scientific journal

Morphogenetic Study on the Maturation of Osteoblastic Cell as Induced by Inorganic Polyphosphate
Kaori Tsutsumi, Nagahito Saito, Yumi Kawazoe, Hong-Kean Ooi, Toshikazu Shiba
PLOS ONE, 9, 2, e86834, Feb. 2014, [Peer-reviewed], [Lead author]
English, Scientific journal

A Simulation Study of the Radiation-Induced Bystander Effect: Modeling with Stochastically Defined Signal Reemission
Kohei Sasaki, Kosuke Wakui, Kaori Tsutsumi, Akio Itoh, Hiroyuki Date
COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE, 2012, 389095, 2012, [Peer-reviewed]
English, Scientific journal

Visualization of Ras-PI3K interaction in the endosome using BiFC
Kaori Tsutsumi, Yoichiro Fujioka, Masumi Tsuda, Hideaki Kawaguchi, Yusuke Ohba
CELLULAR SIGNALLING, 21, 11, 1672, 1679, Nov. 2009, [Peer-reviewed], [Lead author]
English, Scientific journal

Increased Motility and Invasiveness in Tumor Cells That Survive 10 Gy Irradiation
Kaori Tsutsumi, Masumi Tsuda, Natsuka Yazawa, Hirotaka Nakamura, Seiichiro Ishihara, Hisashi Haga, Motoaki Yasuda, Rie Yamazaki, Hiroki Shirato, Hideaki Kawaguchi, Takeshi Nishioka, Yusuke Ohba
CELL STRUCTURE AND FUNCTION, 34, 2, 89, 96, 2009, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal

Matrixmetalloproteinases: Up-regulated in subclones that survived 10-Gy irradiation
Takeshi Nishioka, Motoaki Yasuda, Kaori Tsutsumi, Hisashi Haga, Hiroki Shirato
Radiation Medicine - Medical Imaging and Radiation Oncology, 25, 8, 430, 431, Oct. 2007
English

X-ray irradiation altered chemosensitivity of a p53-null non-small cell lung cancer cell line
Kaori Tsutsumi, Motoaki Yasuda, Takeshi Nishioka
Cell Structure and Function, 31, 2, 47, 52, 2006, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal

Induction of calcification in MC3T3-E1 cells by inorganic polyphosphate
Y Kawazoe, T Shiba, R Nakamura, A Mizuno, K Tsutsumi, T Uematsu, M Yamaoka, M Shindoh, T Kohgo
JOURNAL OF DENTAL RESEARCH, 83, 8, 613, 618, Aug. 2004, [Peer-reviewed]
English, Scientific journal

Modulation of mitogenic activity of fibroblast growth factors by inorganic polyphosphate
T Shiba, D Nishimura, Y Kawazoe, Y Onodera, K Tsutsumi, R Nakamura, M Ohshiro
JOURNAL OF BIOLOGICAL CHEMISTRY, 278, 29, 26788, 26792, Jul. 2003, [Peer-reviewed]
English, Scientific journal

Involvement of inorganic polyphosphate in expression of SOS genes
K Tsutsumi, M Munekata, T Shiba
BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION, 1493, 1-2, 73, 81, Sep. 2000, [Peer-reviewed], [Lead author]
English, Scientific journal

Inorganic polyphosphate and polyphosphate kinase: Their novel biological functions and applications
T Shiba, K Tsutsumi, K Ishige, T Noguchi
BIOCHEMISTRY-MOSCOW, 65, 3, 315, 323, Mar. 2000
English

An Analysis of DNA-based Computing Process　　　　　　　　　　　　　　　
Hirayama, T, Shiba, T, Yamamoto, M, Tsutsumi, K, Takiya, S, Munekata, M, Suzuki, K, Ohuchi, A
The Fourth International Symposium on Artificial Life and Robotics, 358, 361, 1999

Experimental Results in DNA Computation: solution of an HPP with eight vertices　　　　　　　　　　　　　　　
Hirayama, T, Shiba, T, Yamamoto, M, Tsutsumi, K, Suzuki, K, Takiya, S, Munekata, M, Ohuchi, A
Preliminary Proceedings of DNA Based Computers 5, 249, 1999

Inorganic polyphosphate and the induction of rpoS expression
T Shiba, K Tsutsumi, H Yano, Y Ihara, A Kameda, K Tanaka, H Takahashi, M Munekata, NN Rao, A Kornberg
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 94, 21, 11210, 11215, Oct. 1997, [Peer-reviewed]
English, Scientific journal

p53変異型ヒト神経膠芽腫細胞における細胞死経路バランスに関する予備的研究
木立樹里, 中野永, 今里光希, 小島瑞生, 堤香織, 日本分子生物学会年会プログラム・要旨集(Web), 47th, 2024

神経膠芽腫細胞の放射線感受性におけるNRP-1の役割
今里光希, 中野永, 木立樹里, 小島瑞生, 堤香織, 日本分子生物学会年会プログラム・要旨集(Web), 47th, 2024

ラットシュワン細胞の生存率と遺伝子発現に対するヒストン脱アセチル化酵素阻害薬の持続的効果
丁源, 西尾太一, 堤香織, 真先敏弘, 岡優一郎, 前島洋, 日本生物学的精神医学会(Web), 46th, 2024

A Study on Estimating the Angle of Oblique Lumbar Spine Radiographs Using Virtual X-ray Images for Training
山本吏理亜, 堤香織, 吉村高明, 杉森博行, 日本診療放射線技師会誌, 71, 10, 2024

超音波装置を用いたストレス荷重時の足関節前方移動距離計測の試み　　　　　　　　　　　　　　　
中谷 詩世, 館野 真理, 堀江 達則, 松本 和久, 寒川 美奈, 遠山 晴一, 堤 香織, 超音波検査技術, 44, 2, 277, 277, Apr. 2019, [Peer-reviewed], [Corresponding author]
(一社)日本超音波検査学会, Japanese

二次元画像を用いた脊柱アライメント評価法の妥当性検証
石田 優子, 寒川 美奈, 谷 祐児, 堤 香織, 大場 健裕, 鶴喰 涼, 三上 兼太朗, 山中 正紀, 遠山 晴一, 日本臨床スポーツ医学会誌, 24, 4, S312, S312, Oct. 2016
(一社)日本臨床スポーツ医学会, Japanese

放射線の長時間照射中における細胞周期と放射線感受性の解析　　　　　　　　　　　　　　　
松谷 悠佑, 吉井 勇治, 堤 香織, 伊達 広行, 森 諒輔, 佐々木 恒平, 及川 青亮, 北海道放射線技術雑誌, 81, 127, 127, Oct. 2016
(公社)日本放射線技術学会-北海道部会, Japanese

Medial tibial stress syndrome症例におけるトレッドミル走行時の膝および股関節運動に対する前・後足部運動の比較
奥貫 拓実, 越野 裕太, 遠山 晴一, 堤 香織, 五十嵐 將斗, 江沢 侑也, 寒川 美奈, 山中 正紀, 日本臨床スポーツ医学会誌, 24, 4, S315, S315, Oct. 2016
(一社)日本臨床スポーツ医学会, Japanese

Medial tibial stress syndrome症例における走行時の後・前足部kinematicsおよび内側縦アーチの動態の検討
奥貫 拓実, 越野 裕太, 遠山 晴一, 堤 香織, 生田 亮平, 佐橋 健人, 横山 美翔, 江沢 侑也, 寒川 美奈, 齊藤 展士, 山中 正紀, 理学療法学, 43, Suppl.2, O, SP, Oct. 2016
【はじめに，目的】Medial tibial stress syndrome（MTSS）は運動時に脛骨後内側縁に疼痛が発生する症状とされ，ランニング障害の13～17%を占める下肢オーバーユース障害である。MTSSの危険因子として，荷重動作時の内側縦アーチ低下や後足部外反角度増大が報告されている。荷重動作時の内側縦アーチ低下や後足部運動は，前足部運動と関連することが知られているが，MTSS症例において前足部や内側縦アーチを含めた走行時の足部kinematicsは明らかではない。本研究の目的は，multi-segment foot modelを用いて，MTSS症例におけるトレッドミル走行時の後足部，前足部および内側縦アーチの動態の特徴を検討することとした。【方法】対象は，MTSS症例群11名（男性10名，女性1名，年齢：20.5±1.5歳，BMI：22.0±2.0kg/m²）および健常群11名（男性10名，女性1名，年齢：20.5±1.4歳，BMI：19.7±1.3 kg/m²）とした。MTSSの定義はYatesら（2004）の基準に従い，1）脛骨後内側縁の圧痛がある，2）圧痛部位が5cm以上である，3）X線画像上で脛骨疲労骨折の所見がない，こととした。Leardiniら（2007）のmulti-segment foot modelに準じて下腿と足部に反射マーカーを16個貼付し，赤外線カメラ6台（Motion Analysis社製：200 Hz）を用いて，裸足によるトレッドミル走行（12km/h）の5ストライドを記録・解析した。解析にはVisual 3D（C-motion社製）を用いて，下腿に対する後足部内外反・内外転，後足部に対する前足部内外反・内外転・底背屈および内側縦アーチ角（第1中足骨頭，舟状骨，踵骨下部のマーカーから成る角）を算出した。立脚相を100%に正規化し，対応のないt-検定を用いて各kinematicsを群間で比較した。有意水準はp＜0.05とした。【結果】MTSS症例群は健常群に比し，立脚相3～14%の区間で有意に後足部外反が大きく，立脚相0～28%および55～100%の2つの区間で有意に後足部外転が大きかった（p＜0.05）。さらに，MTSS症例群は立脚相21～35%の区間において健常群に比し，有意に前足部外転が大きかった（p＜0.05）。一方で，前足部内外反・底背屈および内側縦アーチ角では群間で差は認められなかった。【結論】本研究結果は，走行立脚相においてMTSS症例は後足部外反・外転および前足部外転が健常者に比べ，有意に大きいことを示した。したがって，MTSS症例では，後足部外反および外転の増大により足部内返し筋がより伸長された状態で遠心性収縮を要求され，脛骨後内側縁に牽引ストレスが生じる可能性がある。加えて，前足部外転および後足部外転の増大は，下腿に対し足部をより外側に向けた状態であることを示唆し，これは走行時の荷重応答および踏み切りに伴う足部内転フリーモーメントの発生に寄与し，脛骨に回旋ストレスが加わる可能性がある。したがって，MTSS症例に対する理学療法実施の際には，後足部だけでなく前足部運動にも着目する必要があることを示唆した。, (公社)日本理学療法士協会, Japanese

Medial tibial stress syndrome症例におけるトレッドミル走行時の足部kinematicsの特徴(第1報)
奥貫 拓実, 山中 正紀, 越野 裕太, 五十嵐 将斗, 江沢 侑也, 寒川 美奈, 堤 香織, 遠山 晴一, 日本臨床スポーツ医学会誌, 23, 4, S273, S273, Oct. 2015
(一社)日本臨床スポーツ医学会, Japanese

Morphological Alteration of Murine MC3T3-E1 Osteoblastic cells Induced by Inorganic Polyphosphate
Kaori Tsutsumi, Nagahito Saito, Yumi Kawazoe, Hong-Kean Ooi, Toshikazu Shiba, FASEB JOURNAL, 29, Apr. 2015, [Peer-reviewed], [Lead author, Corresponding author]
English, Summary international conference

テロスストレス装置を用いたX線足関節前方引き出しテストにおける性差の検討
横山 美翔, 寒川 美奈, 堤 香織, 田中 茉衣, 遠山 晴一, 理学療法学, 42, Suppl.2, P1, B, Apr. 2015
【はじめに，目的】足関節前方引き出しテストは，足関節不安定性評価によく用いられている方法である。しかしながら徒手による前方引き出しテストに関しては信頼性が低い（Lee，2014）という報告もみられることから，臨床ではテロスストレス装置を用いたX線前方引き出しテストも診断に行われている。前方引き出しストレステストは，ストレスを加えながら距骨前方移動量を定量的に計測する検査である。身体構造における性差は，筋横断面積（加賀谷，1998），筋厚（Kubo, 2003），関節弛緩性（Shultz, 2009）などに関して報告されており，性差が存在することが示唆されている。これまで，ストレス負荷時の距骨傾斜角をX線で計測した研究では，健常男女間で結果に差がみられている（Wilkerson, 2000）が，距骨前方引き出しテストにおける性差に関しては報告がみられていない。これまでの身体構造における性差に関する報告から，前方引き出しテストにおいても性差が生じる可能性がある。したがって本研究の目的は，テロスストレス装置を用いたX線足関節前方引き出しテストにおける距骨前方移動量の性差を検討することとした。【方法】対象は，足部に整形外科的及び神経学的既往歴のない男性10名（年齢21.9±0.7歳），女性8名（年齢21.3±0.7歳）の両足部とした。足関節不安定性に関しては，「足関節機能的不安定性の主観的評価法（，1991）」日本語版を用いて聴取した。Karlssonの先行研究に基づき，合計が81ポイント以上の場合，足関節機能的不安定性なしと判断した。X線ストレステスト時の測定位肢位は，検側を下にした側臥位で，股関節及び膝関節軽度屈曲位，足関節中間位とした。テロスストレス装置（Telos Stress Device, Griesheim, Germany）を足部に当て，内果と外果を結ぶ線は検査台に対して垂直とした。テロスストレス装置加圧点は脛骨内果から5cm近位とし，加圧なし（0N）時と最大加圧（120N）時のX線写真を撮影した。得られたX線画像より距骨の前方移動量を，脛骨後縁から距骨の最も近い関節面までを測定した。各画像は3回測定し，その平均値を用いて，最大加圧時と加圧なし時の差を算出した。算出した値を対応のないt検定により解析した。有意水準は5%とした。【結果】足関節不安定性に関する質問紙では，男性（右足99.5点，左足99.5点），女性（右足99.6点，左足99.6点）であり，足関節機能的不安定症の被験者は含まれていないことが示された。X線距骨前方引き出しテスト時の両側における距骨前方移動量は，男性2.5±1.2 cm，女性2.6±1.3 cmであり，差はみられなかった。また，一側下肢毎の検討では，右足で男性2.5±1.2 cm，女性2.9±1.4 cm，左足で男性2.5±1.3cm，女性2.2±1.1cmと，有意差は検出されなかった。【考察】本研究では，テロスストレス装置を用いたX線足関節前方引き出しテストにおいて，性差は検出されなかった。足関節構造の性差については，距骨の傾斜角が男性と比べて女性で大きい（Wilkerson, 2000）こと，及び足関節上方及び内側のスペースが女性より男性で広い（Murphy, 2014）こと等解剖学的性差の存在は示唆されていたが，本研究ではこれらと異なる結果を示した。足関節に限らず靭帯は，男性と比べて女性でより伸張性がみられる（Shultz, 2009）という報告もある。今回，足関節前方引き出し試験において性差はみられなかったため，臨床で本テスト実施時には性差の影響は小さいことが示唆される結果となった。一方，徒手で行われる足関節前方引き出しテストでは，足関節前距腓靭帯損傷の検査として足関節を内反も加えて行われることがある。しかしながら，テロスストレス装置による足関節前方引き出しテストでは，距骨は構造上前方に牽引されるのみである。したがって，ストレス負荷のかけ方によって靭帯の伸張性に性差が生じる可能性もある。また，足関節不安定性評価については被験者の主観でのみ判断されていることや，質問紙の結果から足関節機能的不安定症の被験者は含まれていなかったが，整形外科医による診断は実施していなかったことも，本研究の限界として挙げられる。【理学療法学研究としての意義】身体構造の性差については数多くの研究がされているが，靭帯伸張性に統一した見解は得られていない。本研究により，臨床で行われているテロスストレス装置を用いたX線足関節前方引き出しテストにおいては性差がみられなかったため，本試験においては性差による影響が小さい可能性が示唆された。, (公社)日本理学療法士協会, Japanese

線量率の違いを考慮した細胞生存率モデルの有用性
MATSUTANI YUSUKE, SASAKI KOHEI, TSUTSUMI KAORI, DATE HIROYUKI, 北海道放射線技術雑誌, 75, 75, 135, 135, 25 Oct. 2013
(公社)日本放射線技術学会-北海道部会, Japanese

放射線によるDNA損傷の定量的モデル解析と生物学的効果比
MATSUTANI YUSUKE, OTSUBO YOSUKE, TSUTSUMI KAORI, YAMAZAKI RIE, SASAKI KOHEI, DATE HIROYUKI, 日本放射線影響学会大会講演要旨集, 56th, 97, 97, 01 Oct. 2013
(一社)日本放射線影響学会, Japanese

コンフルエント単層細胞環境における放射線誘発バイスタンダー効果のシミュレーション
SASAKI KOHEI, MATSUYA YUSUKE, TSUTSUMI KAORI, ITO AKIO, DATE HIROYUKI, 日本放射線影響学会大会講演要旨集, 56th, 111, 111, 01 Oct. 2013
(一社)日本放射線影響学会, Japanese

ストレス負荷超音波撮影法による足関節不安定症の定量的評価の試み　　　　　　　　　　　　　　　
堤 香織, 寒川 美奈, 遠山 晴一, 日本臨床スポーツ医学会誌, 21, 4, S178, S178, Oct. 2013, [Peer-reviewed], [Lead author]
(一社)日本臨床スポーツ医学会, Japanese

超音波装置を用いた足関節に対する前方引き出し負荷と移動距離計測の試み　　　　　　　　　　　　　　　
中谷 詩世, 福良 沙霧, 寒川 美奈, 神島 保, 遠山 晴一, 堤 香織, 北海道放射線技術雑誌, 75, 116, 116, Oct. 2013
(公社)日本放射線技術学会-北海道部会, Japanese

修復効果を含む新しい細胞生存率モデルの検討
IZUI KOSUKE, SASAKI KOHEI, TSUTSUMI KAORI, DATE HIROYUKI, 北海道放射線技術雑誌, 73, 73, 127, 127, 05 Nov. 2012
(公社)日本放射線技術学会-北海道部会, Japanese

光子線照射がもたらす細胞核内損傷に関する解析
OTSUBO YOSUKE, IZUI KOSUKE, SASAKI KOHEI, TSUTSUMI KAORI, DATE HIROYUKI, 北海道放射線技術雑誌, 71, 71, 126, 126, 25 Oct. 2011
(公社)日本放射線技術学会-北海道部会, Japanese

Matrix Metalloproteinase's Are Up-regulated in Sub-clones That Survived 10Gy Irradiation: A Possible Role of Hypoxic-inducible Factor-alpha (HIF1a)
T. Nishioka, K. Tsutsumi, T. Takeshima, H. Shirato, M. Yasuda, INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 78, 3, S631, S631, 2010
English, Summary international conference

Cell Motility and Invasion of Surviving Tumor Cells after 10 Gy Irradiation
K. Tsutsumi, M. Tsuda, N. Yazawa, H. Nakamura, M. Yasuda, R. Yamazaki, H. Shirato, H. Kawaguchi, Y. Ohba, T. Nishioka, INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 75, 3, S538, S539, 2009
English, Summary international conference

Visualization of an interaction between Ras and Ras-binding domain in living cells by bimolecular fluorescence complementation
Kaori Tsutsumi, Masumi Tsuda, Hideaki Kawaguchi, Yusuke Ohba, FASEB JOURNAL, 22, Apr. 2008, [Peer-reviewed], [Lead author]
English, Summary international conference

Novel function of transcription factor ATF5: Blockade of p53-dependent apoptosis induced by irradiation
T. Nishioka, M. Yasuda, H. Haga, R. Yamazaki, K. Tsutsumi, H. Shirato, INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 72, 1, S43, S43, 2008
English, Summary international conference

Three-dimensional tumor cell movement in collagen gel: mesenchymal-to-amoeboid transition in a sub-clone that survived 10 Gy irradiation
T. Nishioka, H. Haga, Y. Miyai, M. Yasuda, K. Tsutsumi, R. Yamazaki, H. Shirato, K. Kawabata, INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS, 69, 3, S148, S148, 2007
English, Summary international conference

人体のメカニズムから学ぶ 放射線生物学
松本 義久
メジカルビュー社, 03 Feb. 2017, 4758317259, 315

“Challenge for identification of key molecules that characterize the property of tumor cells that survive radiotherapy"　　　　　　　　　　　　　　　
堤 香織
Cycle de conférences JSPS Strasbourg et MUFJ, Mar. 2010

Jun. 2025 - Present
日本メディカルAI学会　　　　　　　　　　　　　　　

Role and function of Neuropilin 1 in radioresistance of malignant glioblastoma
Grants-in-Aid for Scientific Research
01 Apr. 2023 - 31 Mar. 2026
堤 香織
本研究は、ニューロピリン1の放射線抵抗性との関連性と、神経膠芽腫の放射線抵抗性獲得メカニズムを明らかにすることを目的とする。先行研究において放射線照射を生き残った腫瘍細胞株で共通してニューロピリン1遺伝子の発現増加を観察したことを踏まえ、ヒト神経膠芽腫由来細胞株T98Gに6 MV 10 GyのX線を照射し、生き残った細胞株群T98G-IRを樹立した。T98G-IRのニューロピリン1遺伝子発現量を親株と比較したところ、先行研究同様に発現の増加が認められた。T98G-IR の運動能をwound healing assayで観察したところ、Type-Iコラーゲンをコートしたディシュ上での運動能亢進が認められた。また、T98G-IRの10 Gy X線照射によるDNAの二本鎖切断数は、親株と比較して有意に増加した。次に、siRNAを用いてヒト神経膠芽腫細胞株T98G細胞内のニューロピリン1遺伝子の発現を抑制し、2 Gy 6MVのX線を照射した後の放射線感受性をコロニー形成法によって観察した。ニューロピリン1の発現抑制細胞では、コントロールと比較してX線照射後の細胞生存率が低下した。しかしながら、ニューロピリン1の発現抑制細胞では、PI3Kカスケード上流ならびに下流のPDGFRAとSOX-2の発現が僅かに増加することをリアルタイムPCRにより確認し、細胞生存率の低下と相反する結果となった。アポトーシスに関連するカスパーゼ3遺伝子、細胞周期関連遺伝子p21の発現は僅かに増加した。タンパクレベルでは、AKTの活性化、カスパーゼ3の活性化にコントロールと比較して有意な変化は観察されなかったが、p21の発現はニューロピリン1の発現抑制細胞で増加した。アネキシンVを用いたアポトーシス細胞の観察では、コントールとニューロピリン1の発現抑制細胞に有意な差異はみられなかった。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 23K07126

高水素濃度下でＸ線被ばくが及ぼす生物学的影響の検証
科学研究費助成事業 基盤研究(C)
01 Apr. 2021 - 31 Mar. 2023
伊達 広行, 堤 香織
培養細胞液の高濃度水素条件を実現する上で必要な、バブリング方式の水素ガス発生装置と水素濃度測定器を購入した。純水を用いて高濃度水素水を生成し、水素濃度がどの程度になるかを測定した。この測定において、発生装置の初期状態や反復作業に依存して水素濃度の検出結果に比較的大きなバラツキがあることが判明したため、種々の条件にて繰り返し水素水生成試験を行った。水素水の抽出直後濃度とその後６時間程度までの水素濃度変化を調べ、最大１ppm程度の水素濃度が得られること、また時間とともに指数関数的に減少することを確認した。この水素濃度の経時変化を基に、細胞へＸ線を照射するタイミングと、免疫蛍光染色法による細胞核内ＤＮＡ二本鎖切断（ＤＳＢ）数の観測やコロニーアッセイによる細胞生存率測定などの手順について、対照実験のための幾つかの有効と考えられるプランを考案した。
一方、高濃度水素環境下での細胞の放射線によるダメージについて、高濃度水素条件下と対極にある高濃度酸素下での解析を踏襲したアプローチとして、照射面積による効果を観測する実験系や、損傷低減を組み入れた細胞生存率のモデル化の可能性について検討した。特に放射線の非標的効果について、高水素濃度下では低酸素環境下における状態と類似した結果をもたらす可能性があり、その検証に向けた正確な水素濃度環境における照射実験を模擬する微視的線量動力学（ＭＫ）モデルの改良を視野に入れて解析を進めている。
日本学術振興会, 基盤研究(C), 北海道大学, 21K12233

Role of inorganic polyphosphate on regulation of radio-sensitivity by modulating mitochondrial activity
Grants-in-Aid for Scientific Research
01 Apr. 2020 - 31 Mar. 2023
Tsutsumi Kaori
The aim of this study was to elucidate the mechanism of radio-sensitization of the human lung non-small cell lung cancer cell line (H1299) by inorganic polyphosphate (polyP). The mitochondrial membrane potential was decreased by polyP reatment in a pyruvate-dependent manner, while the intracellular ATP levels were decreased in a pyruvate-independent manner. The amount of lactate secretion and the glucose-6-phosphate dehydrogenase activity were not different respectively between the polyP-treated and control groups, and there was no association with the glycolytic system or pentose phosphate circuit. The polyP-induced decrease in intracellular ATP was also observed in the presence of cyclosporine A, an inhibitor of mitochondrial membrane permeability transition pore (mPTP) activity, suggesting that the polyPe-induced decrease in ATP was caused by a pathway other than mPTP activity.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 20K07987

Development and evaluation of program to improve nurse's assessment ability cooperating with hospital at home health consultation
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2015 - 31 Mar. 2018
Yoshimura Sadako, SUZUKI Teppei, TSUTSUMI Kaori, TAKAHASHI Noriko, SAMUKAWA Mina, TAMURA Naomi, SATOH Hitomi, FUNAKI Noriko, NIIOKA Ikuko
In order to improve the assessment ability of nurses, it is necessary to progress the ability to collect information on health consultation applicants and to improve accurate analytical skills. We developed a data management system that protects personal information. In this study, the data collected were BMI of local residents who need to have remote health consultation, body composition such as muscle mass, self-collected blood data and daily life habits etc. These data were shared by home nurse in charge of consultation and resident through the screen. The simulation training of analysis of each data by home nurse was efficient and effective in interview and inspection by home nurse while sharing data with remote health consultation applicant.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 15H05062

Molecular mechanisms of the cellular signaling by which inorganic polyphosphate promotes calcification on osteoblastic cell
Grants-in-Aid for Scientific Research
Apr. 2015 - Mar. 2018
Tsutsumi Kaori
Inorganic polyphosphate (polyP) is a linear polymer containing tens to hundreds of orthophosphate residues and found in all living organisms from bacteria to mammals. In the present study, we examined the molecular mechanism of polyP to promote calcification on MC3T3-E1 osteoblastic cells. Cells cultured with polyP were strongly stained with Alizarin red. Long-chain length of polyP was the most effective chain length. PolyP-treated cells induced the depletion of cellular ATP contents accompany with ADP conversion though treatment with polyP did not affect cell growth. In the polyP-treated cells, the mitochondria was swollen with low dense observed in electron microscopy. Mitochondrial membrane potential was significantly decreased in polyP-treated cells. These results suggested that the depletion of intracellular ATP and the decrease in mitochondrial membrane potential by polyP treatment would be a trigger to promote a cellular calcification.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Principal investigator, Competitive research funding, 15K01793

Detectability of protein concentration changes in MRI
Grants-in-Aid for Scientific Research
01 Apr. 2012 - 31 Mar. 2015
YAMAMOTO Toru, TSUTSUMI Kaori, THA Khin Khin
To investigate the possibility of noninvasive MR detection of pathologic changes in protein concentration, we measured the protein concentration dependency of permittivity, longitudinal and transverse relaxation rate. The transverse relaxation rate showed most accurate dependency. We also measured the transverse relaxation rate of cerebrospinal fluid in lateral ventricle and showed enough accuracy to detect pathologic―bacterial meningitis etc.―changes of protein concentration by developing a method to derive pixels that are free from cerebrospinal fluid flow.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 24650246

MRI 複素電気伝導度画像は細胞内分子のネットワーク構造を反映するか？　　　　　　　　　　　　　　　
科学研究費補助金萌芽研究
Apr. 2012 - Mar. 2014
山本 徹
文部科学省, Competitive research funding

The role of Neuropilin in radiation surviving tumor cells
Grants-in-Aid for Scientific Research
Apr. 2010 - Mar. 2012
TSUTSUMI Kaori
Radiotherapy is an important noninvasive treatment for many types of cancer.
Recently, remarkable progress of technology of radiotherapy leads to an improvement of local control rate. However, the emergence of tolerant cells during or after radiotherapy remains problematic. The patients who relapsed by repopulated tumor have worse prognoses because of more malignant character of repopulated tumor compared with that of before irradiation. Unfortunately, the molecular mechanisms of cause for tumor repopulation remain unknown. To elucidate the molecular profile of repopulated tumor, present study analyzed the cellular properties of surviving tumor after X-ray irradiation by using IR cells which is the model cell line of repopulated tumor. In the present study, we analyzed the role of Neuropilin 1(NRP1) in radiation surviving cells(IR cells). NRP1 is a well known as an angiogenesis and cell motility related molecule. Although the mRNA expression levels of NRP1 were up-regulated in IR cells compared with parental cells, the protein expression of NRP1 was the same level between parental cells and IR cells. To analyze the activity of angiogenesis in IR cells, we performed tube formation assay and Plasma Clot assay by using human umbilical vein endothelial cells(HUVEC). However, IR cells indicated the same levels of anginogenic activity compared to that of parental cells. The secretion level of vascular endothelial growth factor(VEGF) was also the same level between parental cells and IR cells using ELISA. On the other hand, the NRP1 localization in the cells was different between those two cell lines. Though NRP1 was observed as a vesicle-like constructs in both cell lines, the amount of vesicles was 1. 5-fold decreased in IR cells. These vesicles were not co-localized with EEA1, an early endosome-associated protein. The association of NRP1 with integrin 5 1 was not observed in both cells, whereas the interaction of integrin V 3 and NRP1 was detected by immunoprecipitation assay. Though these interactions were the same levels between two cells, integrin may associates with the control of NRP1 localization. Further studies will be necessary to clarify the function of up-regulated-NRP1 in IR cells, interaction between integrin and NRP1 may lead to control behavior of up-regulation of cell motility in IR cells.
Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, Principal investigator, Competitive research funding, 22791162

Statistical modeling of dose response for the radiation effect analysis
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
2010 - 2012
DATE Hiroyuki, TSUTSUMI Kaori
The effects of radiation exposure on bio-cells were investigated by the Monte Carlo simulations of electrons and biologically active agents, and by the observation of DNA lesions in cell nuclei using immunofluorescent staining. The simulation study of electrons showed that the electron track structure created by the radiation affects strongly the lesion pattern in a cell. From a model analysis for the cell lethality and the observation of DNA lesions, it was found that the surviving fraction of cells is governed by the lesion number per cell following the Poisson statistics and the repair probabilities of the lesions.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 22510055

Cell motility of repopulated tumor cells after radiotherapy
Grants-in-Aid for Scientific Research
Apr. 2008 - Mar. 2010
TSUTSUMI Kaori
Radiotherapy is an important noninvasive treatment for many types of cancer. Recently, remarkable progress of technology of radiotherapy leads to an improvement of local control rate. However, the emergence of tolerant cells during or after radiotherapy remains problematic. The patients who relapsed by repopulated tumor have worse prognoses because of more malignant character of repopulated tumor compared with that of before irradiation. Unfortunately, the molecular mechanisms of cause for tumor repopulation remain unknown. To elucidate the molecular profile of repopulated tumor, present study analyzed the cellular properties of surviving tumor after X-ray irradiation by using IR cells which is the model cell line of repopulated tumor. The mRNA expression levels of matrix metalloproteinases (MMPs) were upregulated in IR cells compared with parental cells. IR cells possessed high gelatinase activities, and increased cell motility, and more invasiveness than parental cells on type-I collagen-coated well. However, phosphorylation of EGF receptor and ERK and cell growth were the same levels between parental cells and IR cells. On the other hand, IR cells adhered more tightly to collagen-coated dishes than parental cells. Consistently, integrin β1, paxillin, and phosphorylated FAK, that were cell-substrate adhesion molecules, were strongly localized at focal adhesions in IR cells, as visualized by immunofluorescence. Whereas, the expression levels of these adhesion molecules were not different between parental cells and IR cells. Increased invasion, migration, and adhesion in IR cells after irradiation might result from the differences of localization of focal adhesion molecules in the cells. These molecules may be important therapeutic targets for the control of repopulated tumors after radiotherapy.
Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, Principal investigator, Competitive research funding, 20790872

The secret of radiation-surviving cell : multidisciplinary approach to eradicate cancer
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
2008 - 2010
NISHIOKA Takeshi, YASUDA Motoaki, HAGA Hisahi, TUTSMI Kaori, SAKAI Masaharu, HOMMA Akiniro
Treatment with any cytotoxic agent can trigger surviving cells in a tumor to divide faster than before. This phenomenon is widely recognized as "repopulation". To better clarify the mechanism, gene expression profiling and pathological experiments were performed. A mouse fibrosarcoma cell line, QRsP, was used. Cells were irradiated with 10 Gy. Colony assay and cloning were performed. Six clones were established. cDNA analysis was performed on the clone that showed the largest number of colonies on the 2nd 10 Gy irradiation. Mouse transplantation experiment was then carried out. cDNA analysis showed that cyclin-dependent kinase inhibitors, p16 and p57 were down-regulated ; 14.8- and 12.0-fold, respectively for the tolerant clone. Matrix metalloproteinase 3 and 13 were up-regulated ; 22.5- and 25.8-fold, respectively. Transplantation ratio was 100% (5/5) for the tolerant clone whereas it was 40% (2/5) for the parent. Under light microscope, the mean mitotic cell number was 4.0+/-3.9 for the parent, and 12.8+/-3.4 for the tolerant clone (p<0.01, Student's t-test). This study implies that repopulation is not a temporary reaction to irradiation. It is caused probably by "clonal" gene-expression changes, though it remains unknown whether the changes are attributable to tolerant cell selection or to gene mutation/modification.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 20390319

Radiation-induced highly-malignant cancer cells: the mechanism and how to deal with it
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
2006 - 2007
NISHIOKA Takeshi, YASUDA Motoaki, HAGA Hisashi, HOMMA Akihiro, TSUTSUMI Kaori
Novel function of transcription factor ATF5: blockade of p53-dependent apoptosis induced by irradiation.
Purpose: p53-dependent cell death is considered as a predominant mechanism of tumor cell apoptosis induced by ionizing irradiation, and a large number of studies have shown that mutant p53-harboring tumor cells with a p53 gene mutation exhibit radioresistance. However, even tumor cells that express wild-type p53 display various degrees of radiosensitivity to ionizing irradiation. This indicates that there are additional pathways that affect p53-dependent cell death mechanisms. Here we describe a novel molecule that represses radiation-induced apoptosis by inhibiting trans-activation activity of p53.
Materials and Methods: We irradiated QRsP cells, a mouse transplantable malignant cell line, at 10Gy and from surviving colonies 24 sub-clones were established. These clonal cells were re-irradiated and the most readio-sensitive clone, QRsPIR-5, was used in the current experiment. All sub-cloned cells had the same morphological appearances as the parental QRsP cells and there were no p53 mutations of among any of the clones. Colony assay indicated that the survival fraction of QRsPIR-5 cells at a dose of 10 Gy was less than 20% of the survival fraction of the parental QRsP cells. Flow cytometer analysis also indicated a higher apoptotic index after infection with recombinant adenovirus containing wild-type p53 (Ad-p53) in QRsPIR-5 cells compared with the parent cell (26.5% vs. 7.1%). Interestingly, the parental and QRsPIR-5 cells had the same degree of tumorigenicity in a transplant experiment.
Results: Comprehensive cDNA array analyses demonstrated differential gene expressions between the parental and QRsPIR-5 cells, both in vitro and in vivo. Among these, 23 genes were expressed differently both in vitro and in vivo between the parent and QRsP-5 cells with a high stringent threshold (less than 0.5 or more than 2.0). One such gene, bZIP transcription factor ATF5, which might explain difference in radio-sensitivity. Exogenous expression of ATF5 gave QRsPIR-5 cells a radioresistance level similar to that of the parental cells (colony assay). Moreover, QRsPIR-5 cells gained resistance to Ad-p53-induced apoptosis. A luciferase reporter assay demonstrated that over-expressed ATF5 repressed the transcriptional activity of wild-type p53 drastically. Interestingly, time lapse analysis indicated accelerated motility in ATF5-transfected QRsPIR-5 cells.
Conclusion: It is likely that ATF5 is a potent repressor of p53. Elevated expression of ATF5 in a tumor may relate to enhanced malignant phenotypes, such as radio-resistance or greater cell motility.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 18390325

Radiobiology　　　　　　　　　　　　　　　
Competitive research funding