Papers - KAWAUCHI Keiko
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Roles of Loop Region in Folding Kinetics and Transcription Inhibition of DNA G-Quadruplexes Reviewed
64 609 - 619 2025.2
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Factors affecting liquid-liquid phase separation of RGG peptides with DNA G-Quadruplex Reviewed
Sumit Shil, Mitsuki Tsuruta, Keiko Kawauchi, Daisuke Miyoshi
ChemMedChem 20 ( 2 ) e202400460 2025.1
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The role of cytosine methylation in regulating the topology and liquid-liquid phase separation of DNA G-quadruplexes Reviewed
Mitsuki Tsuruta, Sumit Shil, Shinya Taniguchi, Keiko Kawauchi, Daisuke Miyoshi
Chemical Science 16 ( 10 ) 4213 - 4225 2025.1
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Bioinformatic analysis of actin-binding proteins in the nucleolus during heat shock Invited Reviewed
Shinya Taniguchi, Takeru Torii, Toshiyuki Goto, Kohei Takeuchi, Rine Katsumi, Mako Sumida, Sunmin Lee, Wataru Sugimoto, Masaya Gessho, Katsuhiko Itoh, Hiroaki Hirata, Junji Kawakami, Daisuke Miyoshi, Keiko Kawauchi
Genes 15 1580 2024.12
Authorship：Last author, Corresponding author
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NRAS DNA G-quadruplex-targeting molecules for sequence-selective enzyme inhibition Reviewed
Yoshiki Hashimoto, Hiroki Kubo, Keiko Kawauchi, Daisuke Miyoshi
Chem. Commun. 60 13179 - 13182 2024.11
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Non-canonical olfactory pathway activation induces cell fusion of cervical cancer cells. Reviewed International journal
Keigo Araki, Takeru Torii, Kohei Takeuchi, Natsuki Kinoshita, Ryoto Urano, Rinka Nakajima, Yaxuan Zhou, Tokuo Kobayashi, Tadayoshi Hanyu, Kiyoshi Ohtani, Kimiharu Ambe, Keiko Kawauchi
Neoplasia 57 101044 - 101044 2024.8
Authorship：Last author
Multinucleation occurs in various types of advanced cancers and contributes to their malignant characteristics, including anticancer drug resistance. Therefore, inhibiting multinucleation can improve cancer prognosis; however, the molecular mechanisms underlying multinucleation remain elusive. Here, we introduced a genetic mutation in cervical cancer cells to induce cell fusion-mediated multinucleation. The olfactory receptor OR1N2 was heterozygously mutated in these fused cells; the same OR1N2 mutation was detected in multinucleated cells from clinical cervical cancer specimens. The mutation-induced structural change in the OR1N2 protein activated protein kinase A (PKA), which, in turn, mediated the non-canonical olfactory pathway. PKA phosphorylated and activated furin protease, resulting in the cleavage of the fusogenic protein syncytin-1. Because this cleaved form of syncytin-1, processed by furin, participates in cell fusion, furin inhibitors could suppress multinucleation and reduce surviving cell numbers after anticancer drug treatment. The improved anticancer drug efficacy indicates a promising therapeutic approach for advanced cervical cancers.
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Quantitative Effects of the Loop Region on Topology, Thermodynamics, and Cation Binding of DNA G-quadruplexes Reviewed International journal
Minori Nakata, Naoki Kosaka, Keiko Kawauchi, Daisuke Miyoshi
ACS Omega 9 ( 32 ) 35028 - 35036 2024.7
The thermal stability of G-quadruplexes is important for their biological roles. G-quadruplexes are stable in the presence of cations such as K+ and Na+ because these cations coordinate in the G-quartet of four guanine bases. It is well known that the number of G-quartets and the configuration of the guanine bases affect the binding affinity of the cation. Recently, structures formed in the loop regions connecting the guanine stretches have attracted significant attention, because the loop region affects G-quadruplex properties, such as topology, thermal stability, and interactions with proteins and small molecules. Considering these effects, the loop region can also affect the binding affinity of the cations. Here, we designed a series of G-quadruplex-forming DNA sequences that contain a hairpin in a loop region and investigated the effects of the sequence and structure of the loop region on the cation binding affinity as well as the thermal stability of the G-quadruplex as a whole. First, structural analysis of the DNA sequences showed that the hairpin at the loop plays a key role in determining G4 topology (strand orientation). Second, in the case of the G-quadruplexes with the hairpin-forming loop region, it was found that a longer loop length led to a higher thermodynamic stability of the G-quadruplex as well as higher cation binding affinity. In contrast, an unstructured loop region did not lead to such effects. Interestingly, the cation binding affinity was correlated to the thermodynamic stability of the hairpin structure at the loop region. It was quantitatively demonstrated that the stable loop region stabilized the whole G-quadruplex structure, which induced higher cation binding affinity. These systematic and quantitative results showed that the loop region is one of the determinants of cation binding and expanded the possibilities of drug development targeting G4s by stabilizing the loop region.
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Hisae Tateishi-Karimata, Keiko Kawauchi, Shuntaro Takahashi, Naoki Sugimoto
Journal of the American Chemical Society 146 ( 12 ) 8005 - 8015 2024.3
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Inhibitory Effects of Shikonin Dispersion, an Extract of Lithospermum erythrorhizon Encapsulated in β-1,3-1,6 Glucan, on Streptococcus mutans and Non-Mutans Streptococci. Reviewed International journal
Ryota Nomura, Yuto Suehiro, Fumikazu Tojo, Saaya Matayoshi, Rena Okawa, Masakazu Hamada, Shuhei Naka, Michiyo Matsumoto-Nakano, Rika Unesaki, Kazuya Koumoto, Keiko Kawauchi, Takahito Nishikata, Tatsuya Akitomo, Chieko Mitsuhata, Masatoshi Yagi, Toshiro Mizoguchi, Koki Fujikawa, Taizo Taniguchi, Kazuhiko Nakano
International journal of molecular sciences 25 ( 2 ) 2024.1
Shikonin is extracted from the roots of Lithospermum erythrorhizon, and shikonin extracts have been shown to have inhibitory effects on several bacteria. However, shikonin extracts are difficult to formulate because of their poor water solubility. In the present study, we prepared a shikonin dispersion, which was solubilized by the inclusion of β-1,3-1,6 glucan, and analysed the inhibitory effects of this dispersion on Streptococcus mutans and non-mutans streptococci. The shikonin dispersion showed pronounced anti-S. mutans activity, and inhibited growth of and biofilm formation by this bacterium. The shikonin dispersion also showed antimicrobial and antiproliferative effects against non-mutans streptococci. In addition, a clinical trial was conducted in which 20 subjects were asked to brush their teeth for 1 week using either shikonin dispersion-containing or non-containing toothpaste, respectively. The shikonin-containing toothpaste decreased the number of S. mutans in the oral cavity, while no such effect was observed after the use of the shikonin-free toothpaste. These results suggest that shikonin dispersion has an inhibitory effect on S. mutans and non-mutans streptococci, and toothpaste containing shikonin dispersion may be effective in preventing dental caries.
DOI： 10.3390/ijms25021075
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Loss of p53 function promotes DNA damage-induced formation of nuclear actin filaments. Reviewed International journal
Takeru Torii, Wataru Sugimoto, Katsuhiko Itoh, Natsuki Kinoshita, Masaya Gessho, Toshiyuki Goto, Ikuno Uehara, Wataru Nakajima, Yemima Budirahardja, Daisuke Miyoshi, Takahito Nishikata, Nobuyuki Tanaka, Hiroaki Hirata, Keiko Kawauchi
Cell death & disease 14 ( 11 ) 766 - 766 2023.11
Joint Work
Authorship：Last author, Corresponding author
Tumor suppressor p53 plays a central role in response to DNA damage. DNA-damaging agents modulate nuclear actin dynamics, influencing cell behaviors; however, whether p53 affects the formation of nuclear actin filaments remains unclear. In this study, we found that p53 depletion promoted the formation of nuclear actin filaments in response to DNA-damaging agents, such as doxorubicin (DOXO) and etoposide (VP16). Even though the genetic probes used for the detection of nuclear actin filaments exerted a promotive effect on actin polymerization, the detected formation of nuclear actin filaments was highly dependent on both p53 depletion and DNA damage. Whilst active p53 is known to promote caspase-1 expression, the overexpression of caspase-1 reduced DNA damage-induced formation of nuclear actin filaments in p53-depleted cells. In contrast, co-treatment with DOXO and the pan-caspase inhibitor Q-VD-OPh or the caspase-1 inhibitor Z-YVAD-FMK induced the formation of nuclear actin filament formation even in cells bearing wild-type p53. These results suggest that the p53-caspase-1 axis suppresses DNA damage-induced formation of nuclear actin filaments. In addition, we found that the expression of nLifeact-GFP, the filamentous-actin-binding peptide Lifeact fused with the nuclear localization signal (NLS) and GFP, modulated the structure of nuclear actin filaments to be phalloidin-stainable in p53-depleted cells treated with the DNA-damaging agent, altering the chromatin structure and reducing the transcriptional activity. The level of phosphorylated H2AX (γH2AX), a marker of DNA damage, in these cells also reduced upon nLifeact-GFP expression, whilst details of the functional relationship between the formation of nLifeact-GFP-decorated nuclear actin filaments and DNA repair remained to be elucidated. Considering that the loss of p53 is associated with cancer progression, the results of this study raise a possibility that the artificial reinforcement of nuclear actin filaments by nLifeact-GFP may enhance the cytotoxic effect of DNA-damaging agents in aggressive cancer cells through a reduction in gene transcription.
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The iron chelator deferriferrichrysin induces paraptosis via extracellular signal-related kinase activation in cancer cells. Reviewed International coauthorship International journal
Natsuki Kinoshita, Masaya Gessho, Takeru Torii, Yukako Ashida, Minori Akamatsu, Alvin Kunyao Guo, Sunmin Lee, Tatsuya Katsuno, Wataru Nakajima, Yemima Budirahardja, Daisuke Miyoshi, Takehiko Todokoro, Hiroki Ishida, Takahito Nishikata, Keiko Kawauchi
Genes to cells : devoted to molecular & cellular mechanisms 28 ( 9 ) 653 - 662 2023.9
Authorship：Last author, Corresponding author
Cancer cells generally exhibit increased iron uptake, which contributes to their abnormal growth and metastatic ability. Iron chelators have thus recently attracted attention as potential anticancer agents. Here, we show that deferriferrichrysin (Dfcy), a natural product from Aspergillus oryzae acts as an iron chelator to induce paraptosis (a programmed cell death pathway characterized by ER dilation) in MCF-7 human breast cancer cells and H1299 human lung cancer cells. We first examined the anticancer efficacy of Dfcy in cancer cells and found that Dfcy induced ER dilation and reduced the number of viable cells. Extracellular signal-related kinase (ERK) was activated by Dfcy treatment, and the MEK inhibitor U0126, a small molecule commonly used to inhibit ERK activity, prevented the increase in ER dilation in Dfcy-treated cells. Concomitantly, the decrease in the number of viable cells upon treatment with Dfcy was attenuated by U0126. Taken together, these results demonstrate that the iron chelator Dfcy exhibits anticancer effects via induction of ERK-dependent paraptosis.
DOI： 10.1111/gtc.13053
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Inhibitory Effect of Adsorption of Streptococcus mutans onto Scallop-Derived Hydroxyapatite. Reviewed International journal
Momoko Usuda, Mariko Kametani, Masakazu Hamada, Yuto Suehiro, Saaya Matayoshi, Rena Okawa, Shuhei Naka, Michiyo Matsumoto-Nakano, Tatsuya Akitomo, Chieko Mitsuhata, Kazuya Koumoto, Keiko Kawauchi, Takahito Nishikata, Masatoshi Yagi, Toshiro Mizoguchi, Koki Fujikawa, Taizo Taniguchi, Kazuhiko Nakano, Ryota Nomura
International journal of molecular sciences 24 ( 14 ) 2023.7
Hydroxyapatite adsorbs various substances, but little is known about the effects on oral bacteria of adsorption onto hydroxyapatite derived from scallop shells. In the present study, we analyzed the effects of adsorption of Streptococcus mutans onto scallop-derived hydroxyapatite. When scallop-derived hydroxyapatite was mixed with S. mutans, a high proportion of the bacterial cells adsorbed onto the hydroxyapatite in a time-dependent manner. An RNA sequencing analysis of S. mutans adsorbed onto hydroxyapatite showed that the upregulation of genes resulted in abnormalities in pathways involved in glycogen and histidine metabolism and biosynthesis compared with cells in the absence of hydroxyapatite. S. mutans adsorbed onto hydroxyapatite was not killed, but the growth of the bacteria was inhibited. Electron microscopy showed morphological changes in S. mutans cells adsorbed onto hydroxyapatite. Our results suggest that hydroxyapatite derived from scallop shells showed a high adsorption ability for S. mutans. This hydroxyapatite also caused changes in gene expression related to the metabolic and biosynthetic processes, including the glycogen and histidine of S. mutans, which may result in a morphological change in the surface layer and the inhibition of the growth of the bacteria.
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The iron chelator deferriferrichrysin induces paraptosis via extracellular-signal-regulated kinase activation in cancer cells Reviewed International coauthorship
Kinoshita N, Gessho M, Torii T, Ashida Y, Akamatsu M, Guo AK, Lee S, Katsuno T, Nakajima W, Budirahardja Y, Miyoshi D, Todokoro T, Ishida H, Nishikata T, Kawauchi K
Genes to Cells 28 ( 9 ) 653 - 662 2023.6
Authorship：Last author, Corresponding author
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Simple and fast screening for structure-selective G-quadruplex ligands. Reviewed International journal
Yoshiki Hashimoto, Yoshiki Imagawa, Kaho Nagano, Ryuichi Maeda, Naho Nagahama, Takeru Torii, Natsuki Kinoshita, Nagisa Takamiya, Keiko Kawauchi, Hisae Tatesishi-Karimata, Naoki Sugimoto, Daisuke Miyoshi
Chemical communications (Cambridge, England) 59 ( 33 ) 4891 - 4894 2023.4
Joint Work
Structural selectivity of G-quadruplex ligands is essential for cellular applications since there is an excess of nucleic acids forming duplex structures compared to G-quadruplex structures in living cells. In this study, we developed new structure-selective G-quadruplex ligands utilizing a simple and fast screening system. The affinity, selectivity, enzymatic inhibitory activity and cytotoxicity of the structure-selective G-quadruplex ligands were demonstrated along with a structural selectivity-cytotoxicity relationship of G-quadruplex ligands.
DOI： 10.1039/d3cc00556a
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Controlling liquid-liquid phase separation of G-quadruplex-forming RNAs in a sequence-specific manner. Reviewed International journal
Mitsuki Tsuruta, Takeru Torii, Kazuki Kohata, Keiko Kawauchi, Hisae Tateishi-Karimata, Naoki Sugimoto, Daisuke Miyoshi
Chemical communications (Cambridge, England) 58 ( 93 ) 12931 - 12934 2022.11
Joint Work
We constructed a minimum liquid-liquid phase separation model system to form liquid droplets using only G-quadruplex-forming oligonucleotides and R- and G-rich oligopeptides. We found that the G-quadruplex structure is an essential component for RNA to form droplets with the peptide. Based on this model system and our findings, droplet redissolution via structure transition from a G-quadruplex to a duplex was achieved in a sequence-specific manner.
DOI： 10.1039/d2cc04366a
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Intramolecular G-quadruplex-hairpin loop structure competition of a GC-rich exon region in the TMPRSS2 gene Reviewed International journal
Wataru Sugimoto, Natsuki Kinoshita, Minori Nakata, Tatsuya Ohyama, Hisae Tateishi-Karimata, Takahito Nishikata, Naoki Sugimoto, Daisuke Miyoshi, Keiko Kawauchi
Chemical Communications 58 ( 1 ) 48 - 51 2022.1
Joint Work
Authorship：Last author, Corresponding author Publisher：Royal Society of Chemistry (RSC)
We identified cytosine-rich regions adjacent to guanine-rich regions in the TMPRSS2 gene, which showed structural competition between a G-quadruplex and a hairpin loop. Furthermore, this competition significantly affected transcription efficiency.
DOI： 10.1039/d1cc05523b
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Anti-Malignant Effect of Tensile Loading to Adherens Junctions in Cutaneous Squamous Cell Carcinoma Cells Reviewed International journal
Dobrokhotov O, Sunagawa M, Torii T, Mii S, Kawauch K, Enomoto A, Sokabe M, Hirata H.
Frontiers in Cell and Developmental Biology 11 2021.11
Joint Work
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Detection of Intracellular Reactive Oxidative Species Using the Fluorescent Probe Hydroxyphenyl Fluorescein Invited Reviewed International journal
Wataru Sugimoto, Daisuke Miyoshi, Keiko Kawauchi
Methods Mol Biol. 2274 207 - 215 2021.5
Joint Work
Authorship：Corresponding author Publisher：Humana Press Inc.
Various fluorescent probes for the detection of intracellular reactive oxidative species (ROS) have been developed because ROS levels are closely associated with cellular states. Here, we describe a method for detection of intracellular ROS in living cells using the fluorescent probe, hydroxyphenyl fluorescein (HPF), which detects hydroxyl radicals and peroxynitrite. NIH3T3 cells and p53 knockout (p53−/−) mouse embryonic fibroblasts (MEFs) were transformed by expressing oncogenic RAS using a retrovirus system. The cells were treated with HPF at 37 °C for 30 min, and subsequently, images were acquired using a confocal fluorescence microscope at an excitation wavelength of 488 nm after washing with PBS.
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Novel Strategy of Photodynamic Therapy Targeting RAS mRNA with G-Quadruplex Ligands for Cancer Treatment Invited Reviewed International journal
Takeru Torii, Wataru Sugimoto, Keiko Kawauchi, Daisuke Miyoshi
Journal of Data Mining in Genomics & Proteomics 11 ( 2 ) 2020.8
Joint Work
Authorship：Corresponding author
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MMP24 as a Target of YAP is a Potential Prognostic Factor in Cancer Patients Reviewed International journal
Wataru Sugimoto, Katsuhiko Ito, Hiroaki Hirata, Yoshinori Abe, Takeru Torii, Yasumasa Mitsui, Yemima Budirahardja, Nobuyuki Tanaka, Keiko Kawauchi
Bioengineering 7 ( 18 ) 1 - 12 2020.2