Details of a Researcher - Hanaoka, Kenjiro

Papers - Hanaoka, Kenjiro

Division display 21 - 40 of about 155 ／ All the affair displays >>

Rapid Visualization of Deeply Located Tumors In Vivo by Intravenous Administration of a gamma-Glutamyltranspeptidase-Activated Fluorescent Probe

Nakada Akihiro, Maruyama Takuma, Kamiya Mako, Hanaoka Kenjiro, Urano Yasuteru

BIOCONJUGATE CHEMISTRY 33 ( 3 ) 523 - 529 2022.03

Research paper (scientific journal), Accepted, ISSN 1043-1802

Access to Document (DOI)

Sulfide catabolism ameliorates hypoxic brain injury

Marutani E., Morita M., Hirai S., Kai S., Grange R.M.H., Miyazaki Y., Nagashima F., Traeger L., Magliocca A., Ida T., Matsunaga T., Flicker D.R., Corman B., Mori N., Yamazaki Y., Batten A., Li R., Tanaka T., Ikeda T., Nakagawa A., Atochin D.N., Ihara H., Olenchock B.A., Shen X., Nishida M., Hanaoka K., Kevil C.G., Xian M., Bloch D.B., Akaike T., Hindle A.G., Motohashi H., Ichinose F.

Nature Communications (Nature Communications) 12 ( 1 ) 3108 2021.12

Research paper (scientific journal), Joint Work, Accepted

The mammalian brain is highly vulnerable to oxygen deprivation, yet the mechanism underlying the brain’s sensitivity to hypoxia is incompletely understood. Hypoxia induces accumulation of hydrogen sulfide, a gas that inhibits mitochondrial respiration. Here, we show that, in mice, rats, and naturally hypoxia-tolerant ground squirrels, the sensitivity of the brain to hypoxia is inversely related to the levels of sulfide:quinone oxidoreductase (SQOR) and the capacity to catabolize sulfide. Silencing SQOR increased the sensitivity of the brain to hypoxia, whereas neuron-specific SQOR expression prevented hypoxia-induced sulfide accumulation, bioenergetic failure, and ischemic brain injury. Excluding SQOR from mitochondria increased sensitivity to hypoxia not only in the brain but also in heart and liver. Pharmacological scavenging of sulfide maintained mitochondrial respiration in hypoxic neurons and made mice resistant to hypoxia. These results illuminate the critical role of sulfide catabolism in energy homeostasis during hypoxia and identify a therapeutic target for ischemic brain injury.

Access to Document (DOI)

Discovery of an F-actin-binding small molecule serving as a fluorescent probe and a scaffold for functional probes.

Takagi T, Ueno T, Ikawa K, Asanuma D, Nomura Y, Uno SN, Komatsu T, Kamiya M, Hanaoka K, Okimura C, Iwadate Y, Hirose K, Nagano T, Sugimura K, Urano Y

Science advances (Science Advances) 7 ( 47 ) eabg8585 2021.11

Research paper (scientific journal), Accepted, ISSN 2375-2548

Actin is a ubiquitous cytoskeletal protein, forming a dynamic network that generates mechanical forces in the cell. There is a growing demand for practical and accessible tools for dissecting the role of the actin cytoskeleton in cellular function, and the discovery of a new actin-binding small molecule is an important advance in the field, offering the opportunity to design and synthesize of new class of functional molecules. Here, we found an F-actin-binding small molecule and introduced two powerful tools based on a new class of actin-binding small molecule: One enables visualization of the actin cytoskeleton, including super-resolution imaging, and the other enables highly specific green light-controlled fragmentation of actin filaments, affording unprecedented control of the actin cytoskeleton and its force network in living cells.

Access to Document (DOI)

Recent advances in detection, isolation, and imaging techniques for sulfane sulfur-containing biomolecules

Echizen H., Sasaki E., Hanaoka K.

Biomolecules (Biomolecules) 11 ( 11 ) 2021.11

Research paper (scientific journal), Accepted

Hydrogen sulfide and its oxidation products are involved in many biological processes, and sulfane sulfur compounds, which contain sulfur atoms bonded to other sulfur atom(s), as found in hydropersulfides (R-S-SH), polysulfides (R-S-Sn-S-R), hydrogen polysulfides (H2Sn), etc., have at-tracted increasing interest. To characterize their physiological and pathophysiological roles, selective detection techniques are required. Classically, sulfane sulfur compounds can be detected by cyanolysis, involving nucleophilic attack by cyanide ion to cleave the sulfur–sulfur bonds. The generated thiocyanate reacts with ferric ion, and the resulting ferric thiocyanate complex can be easily detected by absorption spectroscopy. Recent exploration of the properties of sulfane sulfur compounds as both nucleophiles and electrophiles has led to the development of various chemical techniques for detection, isolation, and bioimaging of sulfane sulfur compounds in biological samples. These include tag-switch techniques, LC-MS/MS, Raman spectroscopy, and fluorescent probes. Herein, we present an overview of the techniques available for specific detection of sulfane sulfur species in biological contexts.

Access to Document (DOI)

A Sulfonyl Azide-Based Sulfide Scavenger Rescues Mice from Lethal Hydrogen Sulfide Intoxication

Miyazaki Y., Marutani E., Ikeda T., Ni X., Hanaoka K., Xian M., Ichinose F.

Toxicological Sciences (Toxicological Sciences) 183 ( 2 ) 393 - 403 2021.10

Research paper (scientific journal), Accepted, ISSN 10966080

Exposure to hydrogen sulfide (H2S) can cause neurotoxicity and cardiopulmonary arrest. Resuscitating victims of sulfide intoxication is extremely difficult, and survivors often exhibit persistent neurological deficits. However, no specific antidote is available for sulfide intoxication. The objective of this study was to examine whether administration of a sulfonyl azide-based sulfide-specific scavenger, SS20, would rescue mice in models of H2S intoxication: Ongoing exposure and post-cardiopulmonary arrest. In the ongoing exposure model, SS20 (1250 μmol/kg) or vehicle was administered to awake CD-1 mice intraperitoneally at 10 min after breathing 790 ppm of H2S followed by another 30 min of H2S inhalation. Effects of SS20 on survival were assessed. In the post-cardiopulmonary arrest model, cardiopulmonary arrest was induced by an intraperitoneal administration of sodium sulfide nonahydrate (125 mg/kg) in anesthetized mice. After 1 min of cardiopulmonary arrest, mice were resuscitated with intravenous administration of SS20 (250 μmol/kg) or vehicle. Effects of SS20 on survival, neurological outcomes, and plasma H2S levels were evaluated. Administration of SS20 during ongoing H2S inhalation improved 24-h survival (6/6 [100%] in SS20 vs 1/6 [17%] in vehicle; p =. 0043). Post-arrest administration of SS20 improved 7-day survival (4/10 [40%] in SS20 vs 0/10 [0%] in vehicle; p =. 0038) and neurological outcomes after resuscitation. SS20 decreased plasma H2S levels to pre-arrest baseline immediately after reperfusion and shortened the time to return of spontaneous circulation and respiration. These results suggest that SS20 is an effective antidote against lethal H2S intoxication, even when administered after cardiopulmonary arrest.

Access to Document (DOI)

Matrix metalloprotease–14 is a target enzyme for detecting peritoneal metastasis in gastric cancer

Ogawa S., Kubo H., Murayama Y., Kubota T., Yubakami M., Matsumoto T., Ohashi T., Okamoto K., Kuriki Y., Hanaoka K., Urano Y., Otsuji E.

Photodiagnosis and Photodynamic Therapy (Photodiagnosis and Photodynamic Therapy) 35 102420 2021.09

Research paper (scientific journal), Accepted, ISSN 15721000

Background: Accurate diagnosis of peritoneal metastasis in gastric cancer (GC) is important to determine the appropriate treatment. This study aimed to examine whether matrix metalloprotease–14 (MMP–14) was a candidate enzyme in fluorescence imaging for the diagnosis of peritoneal metastasis in GC. Methods: GC and normal peritoneal (NP) tissues from 96 and 20 patients, respectively were evaluated for MMP–14 expression. Live cell imaging of GC cell lines (NUGC4, MKN45, MKN74, HGC-27, and Kato-III) was performed using the MMP–14-activatable fluorescence probe; BODIPY-MMP. Furthermore, the overall survival (OS) was calculated in all patients (n = 96). Results: MMP–14 expression was significantly higher in GC tissues (median: 3.57 ng/mg protein; range:0.64–24.4 ng/mg protein) than in NP tissues (median: 1.34 ng/mg protein; median: 0.53–3.09 ng/mg protein) (P < 0.01). Receiver operating characteristic curves showed that the area under the curve, sensitivity, and specificity were 0.907, 84.4%, and 90.0%, respectively. In live cell imaging using the BODIPY-MMP, fluorescence was observed in five GC cell lines. In the analysis of OS, the high expression of the MMP–14 group had a significantly poorer OS rate than the low expression of the MMP–14 group (P = 0.02). In the multivariate analyses, MMP-14 expression was an independent risk factor for OS (hazard ratio: 2.33; 95 % confidence interval: 1.05–5.45; P = 0.04). Conclusion: MMP–14 is a promising enzyme in intraoperative fluorescence imaging for peritoneal metastasis in GC, especially in patients with poor prognosis.

Access to Document (DOI)

Establishment of live-cell-based coupled assay system for identification of compounds to modulate metabolic activities of cells

Yanagi K., Komatsu T., Ogihara S., Okabe T., Kojima H., Nagano T., Ueno T., Hanaoka K., Urano Y.

Cell Reports (Cell Reports) 36 ( 1 ) 109311 2021.07

Research paper (scientific journal), Accepted, ISSN 2211-1247

In this study, we present a live-cell-based fluorometric coupled assay system to identify the compounds that can regulate the targeted metabolic pathways in live cells. The assay is established through targeting specific metabolic pathways and using “input” and “output” metabolite pairs. The changes in the extracellular output that are generated and released into the extracellular media from the input are assessed as the activity of the pathway. The screening for the glycolytic pathway and amino acid metabolism reveals the activities of the present drugs, 6-BIO and regorafenib, that regulate the metabolic fate of tumor cells.

Access to Document (DOI)

Design, synthesis and evaluation of enzyme-responsive fluorogenic probes based on pyridine-flanked diketopyrrolopyrrole dyes

Jenni S., Ponsot F., Baroux P., Collard L., Ikeno T., Hanaoka K., Quesneau V., Renault K., Romieu A.

Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy (Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy) 248 119179 2021.03

Research paper (scientific journal), Accepted, ISSN 13861425

The ever-growing demand for fluorogenic dyes usable in the rapid construction of analyte-responsive fluorescent probes, has recently contributed to a revival of interest in the chemistry of diketopyrrolopyrrole (DPP) pigments. In this context, we have explored the potential of symmetrical and unsymmetrical DPP derivatives bearing two or one 4-pyridyl substituents acting as optically tunable group(s). The unique fluorogenic behavior of these molecules, closely linked to N-substitution/charge state of their pyridine unit (i.e., neutral pyridine or cationic pyridinium), has been used to design DPP-based fluorescent probes for detection of hypoxia-related redox enzymes and penicillin G acylase (PGA). In this paper, we describe synthesis, spectral characterization and bioanalytical validations of these probes. Dramatic differences in terms of aqueous stability and enzymatic fluorescence activation were observed. This systematic study enables to delineate the scope of application of pyridine-flanked DPP fluorophores in the field of enzyme biosensing.

Access to Document (DOI)

Recent advances in probe design to detect reactive sulfur species and in the chemical reactions employed for fluorescence switching

Echizen H., Hanaoka K.

Journal of Clinical Biochemistry and Nutrition (Journal of Clinical Biochemistry and Nutrition) 68 ( 1 ) 9 - 17 2021.01

Research paper (scientific journal), Accepted, ISSN 09120009

Reactive sulfur species, including hydrogen sulfide, hydropersulfide, and polysulfide, have many roles in biological systems. For example, hydrogen sulfide is involved in the relaxation of vascular smooth muscles and mediation of neurotransmission, while sulfane sulfur, which exists in cysteine persulfide/polysulfide, and glutathione persulfide/polysulfide, is involved in physiological antioxidation and cytoprotection mechanisms. Fluorescence imaging is well suited for real-time monitoring of reactive sulfur species in living cells, and many fluorescent probes for reactive sulfur species have been reported. In such probes, the choice of detection chemistry is extremely important, not only to achieve effective fluorescence switching and high selectivity, but also because the reactions may be applicable to develop other chemical tools, such as reactive sulfur species donors/scavengers. Here, we present an overview of both widely used and recently developed fluorescent probes for reactive sulfur species, focusing especially on the chemical reactions employed in them for fluorescence switching. We also briefly introduce some applications of fluorescent probes for hydrogen sulfide and sulfane sulfur.

Access to Document (DOI)

Fluorescent probes for detection of supersulfides

Sasaki E., Hanaoka K.

Seikagaku (Seikagaku) 93 ( 5 ) 604 - 612 2021

ISSN 00371017

Access to Document (DOI)

A cytosolically localized far-red to near-infrared rhodamine-based fluorescent probe for calcium ions

Numasawa K., Hanaoka K., Ikeno T., Echizen H., Ishikawa T., Morimoto M., Komatsu T., Ueno T., Ikegaya Y., Nagano T., Urano Y.

Analyst (Analyst) 145 ( 23 ) 7736 - 7740 2020.12

Research paper (scientific journal), Accepted, ISSN 00032654

Access to Document (DOI)

Hypoxia-inducible factor-1 alpha maintains mouse articular cartilage through suppression of NF-κB signaling

Okada K., Mori D., Makii Y., Nakamoto H., Murahashi Y., Yano F., Chang S.H., Taniguchi Y., Kobayashi H., Semba H., Takeda N., Piao W., Hanaoka K., Nagano T., Tanaka S., Saito T.

Scientific Reports (Scientific Reports) 10 ( 1 ) 5425 2020.12

Research paper (scientific journal), Accepted

HIF-1α, an essential transcription factor under hypoxic condition, is indispensable for chondrocytes during skeletal development but its expression and roles in articular chondrocytes are yet to be revealed. We examined HIF-1α protein expression and the hypoxic condition during mouse osteoarthritis (OA) development using state of the art hypoxic probes and found that its expression decreased as OA progressed, coinciding with the change in hypoxic conditions in articular cartilage. Gain- and loss-of-function of HIF-1α in cell culture experiments showed that HIF-1α suppressed catabolic genes such as Mmp13 and Hif2a. We confirmed these anticatabolic effects by measuring glycosaminoglycan release from wild type and conditional knock-out mice femoral heads cultured ex vivo. We went on to surgically induce OA in mice with chondrocyte-specific deletion of Hif1a and found that the development of OA was exacerbated. Increased expression of catabolic factors and activation of NF-κB signalling was clearly evident in the knock-out mice. By microarray analysis, C1qtnf3 was identified as a downstream molecule of HIF-1α, and experiments showed it exerted anti-catabolic effects through suppression of NF-κB. We conclude that HIF-1α has an anti-catabolic function in the maintenance of articular cartilage through suppression of NF-κB signalling.

Access to Document (DOI)

Calciprotein particle-induced cytotoxicity via lysosomal dysfunction and altered cholesterol distribution in renal epithelial HK-2 cells

Kunishige R., Mizoguchi M., Tsubouchi A., Hanaoka K., Miura Y., Kurosu H., Urano Y., Kuro-o M., Murata M.

Scientific Reports (Scientific Reports) 10 ( 1 ) 20125 2020.12

Research paper (scientific journal), Accepted

Dietary phosphate overload induces chronic kidney disease (CKD), and calciprotein particles (CPPs), a form of nanoparticle comprising calcium phosphate and serum proteins, has been proposed to cause renal toxicity. However, the mechanism of CPP cytotoxicity in renal tubular cells is unknown. Here we show that in renal proximal tubular epithelial HK-2 cells, endocytosed CPPs accumulate in late endosomes/lysosomes (LELs) and increase their luminal pH by ~ 1.0 unit. This results in a decrease in lysosomal hydrolase activity and autophagic flux blockage without lysosomal rupture and reactive oxygen species generation. CPP treatment led to vulnerability to H2O2-induced oxidative stress and plasma membrane injury, probably because of autophagic flux blockage and decreased plasma membrane cholesterol, respectively. CPP-induced disruption of lysosomal homeostasis, autophagy flux and plasma membrane integrity might trigger a vicious cycle, leading to progressive nephron loss.

Access to Document (DOI)

Design of spontaneously blinking fluorophores for live-cell super-resolution imaging based on quantum-chemical calculations

Tachibana R., Kamiya M., Morozumi A., Miyazaki Y., Fujioka H., Nanjo A., Kojima R., Komatsu T., Ueno T., Hanaoka K., Yoshihara T., Tobita S., Urano Y.

Chemical Communications (Chemical Communications) 56 ( 86 ) 13173 - 13176 2020.11

Research paper (scientific journal), Accepted, ISSN 13597345

Access to Document (DOI)

Antibody Clicking as a Strategy to Modify Antibody Functionalities on the Surface of Targeted Cells

Komatsu T., Kyo E., Ishii H., Tsuchikama K., Yamaguchi A., Ueno T., Hanaoka K., Urano Y.

Journal of the American Chemical Society (Journal of the American Chemical Society) 142 ( 37 ) 15644 - 15648 2020.09

Research paper (scientific journal), Accepted, ISSN 00027863

We established a methodology for initiating cross-linking of antibodies selectively on the cell surface through intermolecular copper-free click reactions facilitated by increased effective concentrations of antibodies binding to target antigens. Upon cross-linking of tetrazine- and bicyclononyne-modified trastuzumab on the surface of HER2-overexpressing cells, increased antibody uptake and activation of intracellular signaling were observed. Our findings demonstrate that the cross-linking reaction can significantly alter the biophysical properties of proteins, activating their unique functionalities on targeted cells to realize an increased cargo delivery and synthetic manipulation of cellular signaling.

Access to Document (DOI)

How Viscous Is the Solidlike Structure at the Interface of Ionic Liquids? A Study Using Total Internal Reflection Fluorescence Spectroscopy with a Fluorescent Molecular Probe Sensitive to High Viscosity

Nishi N., Yamazawa T., Sakka T., Hotta H., Ikeno T., Hanaoka K., Takahashi H.

Langmuir (Langmuir) 36 ( 35 ) 10397 - 10403 2020.09

Research paper (scientific journal), Accepted, ISSN 07437463

Aiming at the evaluation of the viscosity of the interfacial solidlike structure of ionic liquids (ILs), we performed total internal reflection fluorescence (TIRF) spectroscopy for N,N-diethyl-N′-phenyl-rhodamine (Ph-DER), a fluorescent probe that is sensitive to viscosity in a high-viscosity range. TIRF spectra at the glass interface of trioctylmethylammonium bis(nonafluorobutanesulfonyl)amide (TOMAC4C4N), a hydrophobic IL, showed that the fluorescence intensity of Ph-DER increases with the decrease of the evanescence penetration depth, suggesting that there exists a high-viscosity region at the interface. In contrast, glycerol, which is a molecular liquid with a bulk viscosity similar to that of TOMAC4C4N, did not show such a fluorescence increase, supporting that the formation of a highly viscous solidlike structure at the interface is intrinsic to ILs. A model analysis suggested that the high viscous region at the glass interface of TOMAC4C4N is at least twice thicker than the ionic multilayers at the air interface, implying that the solid substrate enhances the ordering of the interfacial structure of ILs. The viscosity at the glass interface of TOMAC4C4N was found to be at least 40 times higher than that of the liquid bulk.

Access to Document (DOI)

Real-time in vivo imaging of extracellular atp in the brain with a hybrid-type fluorescent sensor

Kitajima N., Takikawa K., Sekiya H., Satoh K., Asanuma D., Sakamoto H., Takahashi S., Hanaoka K., Urano Y., Namiki S., Iino M., Hirose K.

eLife (eLife) 9 1 - 18 2020.07

Research paper (scientific journal), Accepted

Adenosine 5’ triphosphate (ATP) is a ubiquitous extracellular signaling messenger. Here, we describe a method for in-vivo imaging of extracellular ATP with high spatiotemporal resolution. We prepared a comprehensive set of cysteine-substitution mutants of ATP-binding protein, Bacillus FoF1-ATP synthase e subunit, labeled with small-molecule fluorophores at the introduced cysteine residue. Screening revealed that the Cy3-labeled glutamine-105 mutant (Q105C-Cy3; designated ATPOS) shows a large fluorescence change in the presence of ATP, with submicromolar affinity, pH-independence, and high selectivity for ATP over ATP metabolites and other nucleotides. To enable in-vivo validation, we introduced BoNT/C-Hc for binding to neuronal plasma membrane and Alexa Fluor 488 for ratiometric measurement. The resulting ATPOS complex binds to neurons in cerebral cortex of living mice, and clearly visualized a concentrically propagating wave of extracellular ATP release in response to electrical stimulation. ATPOS should be useful to probe the extracellular ATP dynamics of diverse biological processes in vivo.

Access to Document (DOI)

A Fluorescent Probe for Rapid, High-Contrast Visualization of Folate-Receptor-Expressing Tumors In Vivo

Numasawa K., Hanaoka K., Saito N., Yamaguchi Y., Ikeno T., Echizen H., Yasunaga M., Komatsu T., Ueno T., Miura M., Nagano T., Urano Y.

Angewandte Chemie - International Edition (Angewandte Chemie - International Edition) 59 ( 15 ) 6015 - 6020 2020.04

Research paper (scientific journal), Accepted, ISSN 14337851

Folate receptors (FRs) are membrane proteins involved in folic acid uptake, and the alpha isoform (FR-α) is overexpressed in ovarian and endometrial cancer cells. For fluorescence imaging of FRs in vivo, the near-infrared (NIR) region (650–900 nm), in which tissue penetration is high and autofluorescence is low, is optimal, but existing NIR fluorescent probes targeting FR-α show high non-specific tissue adsorption, and require prolonged washout to visualize tumors. We have designed and synthesized a new NIR fluorescent probe, FolateSiR-1, utilizing a Si-rhodamine fluorophore having a carboxy group at the benzene moiety, coupled to a folate ligand moiety through a negatively charged tripeptide linker. This probe exhibits very low background fluorescence and afforded a tumor-to-background ratio (TBR) of up to 83 in FR-expressing tumor-bearing mice within 30 min. Thus, FolateSiR-1 has the potential to contribute to the research in the field of biology and the clinical medicine.

Access to Document (DOI)

Rational Design of a Near-infrared Fluorescence Probe for Ca<sup>2+</sup> Based on Phosphorus-substituted Rhodamines Utilizing Photoinduced Electron Transfer

Takahashi S., Hanaoka K., Okubo Y., Echizen H., Ikeno T., Komatsu T., Ueno T., Hirose K., Iino M., Nagano T., Urano Y.

Chemistry - An Asian Journal (Chemistry - An Asian Journal) 15 ( 4 ) 524 - 530 2020.02

Research paper (scientific journal), Accepted, ISSN 18614728

Fluorescence imaging in the near-infrared (NIR) region (650–900 nm) is useful for bioimaging because background autofluorescence is low and tissue penetration is high in this range. In addition, NIR fluorescence is useful as a complementary color window to green and red for multicolor imaging. Here, we compared the photoinduced electron transfer (PeT)-mediated fluorescence quenching of silicon- and phosphorus-substituted rhodamines (SiRs and PRs) in order to guide the development of improved far-red to NIR fluorescent dyes. The results of density functional theory calculations and photophysical evaluation of a series of newly synthesized PRs confirmed that the fluorescence of PRs was more susceptible than that of SiRs to quenching via PeT. Based on this, we designed and synthesized a NIR fluorescence probe for Ca2+, CaPR-1, and its membrane-permeable acetoxymethyl derivative, CaPR-1 AM, which is distributed to the cytosol, in marked contrast to our previously reported Ca2+ far-red to NIR fluorescence probe based on the SiR scaffold, CaSiR-1 AM, which is mainly localized in lysosomes as well as cytosol in living cells. CaPR-1 showed longer-wavelength absorption and emission (up to 712 nm) than CaSiR-1. The new probe was able to image Ca2+ at dendrites and spines in brain slices, and should be a useful tool in neuroscience research.

Access to Document (DOI)

Metabolic-Pathway-Oriented Screening Targeting S-Adenosyl- l -methionine Reveals the Epigenetic Remodeling Activities of Naturally Occurring Catechols

Ogihara S., Komatsu T., Itoh Y., Miyake Y., Suzuki T., Yanagi K., Kimura Y., Ueno T., Hanaoka K., Kojima H., Okabe T., Nagano T., Urano Y.

Journal of the American Chemical Society (Journal of the American Chemical Society) 142 ( 1 ) 21 - 26 2020.01

Research paper (scientific journal), Accepted, ISSN 00027863

Methyl transfer reactions play important roles in many biological phenomena, wherein the methylation cofactor S-adenosyl-l-methionine (SAM) serves as the important currency to orchestrate those reactions. We have developed a fluorescent-probe-based high-throughput screening (HTS) system to search for the compounds that control cellular SAM levels. HTS with a drug repositioning library revealed the importance of catechol-O-methyltransferase (COMT) and its substrates in controlling the SAM concentrations and histone methylation levels in colorectal tumor cells.

Access to Document (DOI)

　 Previous page - Next page 　