It's Not What You Say But How You Say It: Targeting RNA Methylation in AML. Olsen Sarah Naomi,Armstrong Scott A Molecular cell In this month's issue of Cancer Cell, Su et al. (2020) describe two small-molecule inhibitors of the RNA demethylase FTO that demonstrate significant anti-tumor effects in various models of acute myeloid leukemia. 10.1016/j.molcel.2020.05.027
    The role of chlorine atom on the binding between acrylonitrile derivatives and fat mass and obesity-associated protein. Bai Ning,Gan Ya,Li Xitong,Gao Shuting,Yu Wenquan,Wang Ruiyong,Chang Junbiao Journal of molecular recognition : JMR In this work, seven acrylonitrile derivatives were selected as potential inhibitors of fat and obesity-related proteins (FTO) by the aid of fluorescence spectroscopy, ultraviolet visible spectroscopy, molecular docking, and cytotoxicity methods. Results show that the interaction between 3-amino-2-(4-chlorophenyl)-3-phenylacrylonitrile (1a) and FTO was the strongest among these derivatives. Thermodynamic analysis and molecular modeling show that the main force between 1a and FTO is hydrophobic interaction. The cytotoxicity test showed that the IC value of 1a was 46.64 μmol/L, which indicated 1a had the smallest IC value and had the best inhibitory effect on the proliferation of leukemia K562 cells among the seven derivatives. Both our previous results and this work show that chlorine atoms play important role in the binding of small molecules and FTO. This work brings new information for the study of FTO inhibitors. 10.1002/jmr.2880
    The role of chlorine atom on the binding between 2-phenyl-1H-benzimidazole analogues and fat mass and obesity-associated protein. Li Junya,Wang Ying,Han Xinxin,Wang Ning,Yu Wenquan,Wang Ruiyong,Chang Junbiao Journal of molecular recognition : JMR In this work, nine 2-phenyl-1H-benzimidazole structural analogues were screened for potential inhibitor of the fat mass and obesity-associated protein (FTO) by isothermal titration calorimetry (ITC). The results show that the binding between 6-chloro-2-phenyl-1H-benzimidazole (1d) and FTO was dominated by entropy. Results of enzymatic activity assays provided an IC value of 24.65 μM for 1d. Our previous results and comparison of nine structural analogues indicated that the chlorine atom was crucial for the binding of small molecules with FTO. The identification of novel small molecules may provide information for the design of FTO inhibitors and the treatment of leukemia. 10.1002/jmr.2774
    The Yin and Yang of RNA Methylation: An Imbalance of Erasers Enhances Sensitivity to FTO Demethylase Small-Molecule Targeting in Leukemia Stem Cells. Van Der Werf Inge,Jamieson Catriona Cancer cell A prevalent eukaryotic N-methyladensosine (mA) post-transcriptional mark can be "erased" by the mA demethylase FTO, which is commonly deregulated in acute myeloid leukemia (AML). In this issue of Cancer Cell, Huang et al. design small-molecule FTO inhibitors, FB23 and FB23-2, and demonstrate their potent inhibitory impact in AML models. 10.1016/j.ccell.2019.03.011
    Development of cell-active N6-methyladenosine RNA demethylase FTO inhibitor. Chen Baoen,Ye Fei,Yu Lu,Jia Guifang,Huang Xiaotian,Zhang Xueju,Peng Shuying,Chen Kai,Wang Meining,Gong Shouze,Zhang Ruihan,Yin Jinya,Li Haiyan,Yang Yiming,Liu Hong,Zhang Jiwen,Zhang Haiyan,Zhang Ao,Jiang Hualiang,Luo Cheng,Yang Cai-Guang Journal of the American Chemical Society The direct nucleic acid repair dioxygenase FTO is an enzyme that demethylates N(6)-methyladenosine (m(6)A) residues in mRNA in vitro and inside cells. FTO is the first RNA demethylase discovered that also serves a major regulatory function in mammals. Together with structure-based virtual screening and biochemical analyses, we report the first identification of several small-molecule inhibitors of human FTO demethylase. The most potent compound, the natural product rhein, which is neither a structural mimic of 2-oxoglutarate nor a chelator of metal ion, competitively binds to the FTO active site in vitro. Rhein also exhibits good inhibitory activity on m(6)A demethylation inside cells. These studies shed light on the development of powerful probes and new therapies for use in RNA biology and drug discovery. 10.1021/ja3064149
    Omeprazole improves chemosensitivity of gastric cancer cells by m6A demethylase FTO-mediated activation of mTORC1 and DDIT3 up-regulation. Feng Shuitu,Qiu Guoqin,Yang Lihong,Feng Lihua,Fan Xin,Ren Fang,Huang Kaida,Chen Yide Bioscience reports The curative effect for patients with advanced gastric cancer is still unsatisfactory. Proton pump inhibitors could be a promising treatment strategy that could sensitize gastric cancer cells to antitumor drugs further; however, the underlying molecular mechanism remains to be further elucidated. In this research, it was found that omeprazole pretreatment could enhance the inhibitory effect of 5-Fu, DDP and TAX on gastric cancer cells. Interestingly, omeprazole pretreatment enhanced the total m6A level of cells due to the decreased FTO. TCGA analysis showed that FTO expression is up-regulated in GC tissues and is negatively correlated with disease-free survival of GC patients. It was also found that FTO inhibition induced by omeprazole enhanced the activation of mTORC1 signal pathway that inhibited the prosurvival autophagy so as to improve the antitumor efficiency of chemotherapeutic drugs on GC cells. Meanwhile, transcript level of DDIT3, which is an apoptosis-related tumor suppressor gene downstream of mTORC1, was regulated by omeprazole-induced FTO silence through an m6A-dependent mechanism. The present study, for the first time, found that m6A modification and its eraser FTO may play a role in the improvement of chemosensitivity mediated by proton pump inhibitor omeprazole. 10.1042/BSR20200842
    Identification of entacapone as a chemical inhibitor of FTO mediating metabolic regulation through FOXO1. Peng Shiming,Xiao Wen,Ju Dapeng,Sun Baofa,Hou Nannan,Liu Qianlan,Wang Yanli,Zhao Haijiao,Gao Chunchun,Zhang Song,Cao Ran,Li Pengfei,Huang Huanwei,Ma Yongfen,Wang Yankai,Lai Weiyi,Ma Zhixiong,Zhang Wei,Huang Song,Wang Hailin,Zhang Zhiyuan,Zhao Liping,Cai Tao,Zhao Yong-Liang,Wang Fengchao,Nie Yongzhan,Zhi Gang,Yang Yun-Gui,Zhang Eric Erquan,Huang Niu Science translational medicine Recent studies have established the involvement of the fat mass and obesity-associated gene () in metabolic disorders such as obesity and diabetes. However, the precise molecular mechanism by which FTO regulates metabolism remains unknown. Here, we used a structure-based virtual screening of U.S. Food and Drug Administration-approved drugs to identify entacapone as a potential FTO inhibitor. Using structural and biochemical studies, we showed that entacapone directly bound to FTO and inhibited FTO activity in vitro. Furthermore, entacapone administration reduced body weight and lowered fasting blood glucose concentrations in diet-induced obese mice. We identified the transcription factor forkhead box protein O1 () mRNA as a direct substrate of FTO, and demonstrated that entacapone elicited its effects on gluconeogenesis in the liver and thermogenesis in adipose tissues in mice by acting on an regulatory axis. 10.1126/scitranslmed.aau7116
    Computational insights into the origin of decrease/increase in potency of N-CDPCB analogues toward FTO. Qiao Yan,Yang Qinghua,Song Chuanjun,Chang Junbiao Journal of biomolecular structure & dynamics 10.1080/07391102.2016.1193445
    Synthesis of a FTO inhibitor with anticonvulsant activity. Zheng Guanqun,Cox Thomas,Tribbey Leah,Wang Gloria Z,Iacoban Paulina,Booher Matthew E,Gabriel Gregory J,Zhou Lu,Bae Nancy,Rowles Joie,He Chuan,Olsen Mark J ACS chemical neuroscience We describe the rationale for and the synthesis of a new class of compounds utilizing a modular approach that are designed to mimic ascorbic acid and to inhibit 2-oxoglutarate-dependent hydroxylases. Preliminary characterization of one of these compounds indicates in vivo anticonvulsant activity (6 Hz mouse model) at nontoxic doses, inhibition of the 2-oxoglutarate-dependent hydroxylase FTO, and expected increase in cellular N(6)-methyladenosine. This compound is also able to modulate various microRNA, an interesting result in light of the recent view that modulation of microRNAs may be useful for the treatment of CNS disease. 10.1021/cn500042t
    Pharmacological inhibition of FTO. McMurray Fiona,Demetriades Marina,Aik WeiShen,Merkestein Myrte,Kramer Holger,Andrew Daniel S,Scudamore Cheryl L,Hough Tertius A,Wells Sara,Ashcroft Frances M,McDonough Michael A,Schofield Christopher J,Cox Roger D PloS one In 2007, a genome wide association study identified a SNP in intron one of the gene encoding human FTO that was associated with increased body mass index. Homozygous risk allele carriers are on average three kg heavier than those homozygous for the protective allele. FTO is a DNA/RNA demethylase, however, how this function affects body weight, if at all, is unknown. Here we aimed to pharmacologically inhibit FTO to examine the effect of its demethylase function in vitro and in vivo as a first step in evaluating the therapeutic potential of FTO. We showed that IOX3, a known inhibitor of the HIF prolyl hydroxylases, decreased protein expression of FTO (in C2C12 cells) and reduced maximal respiration rate in vitro. However, FTO protein levels were not significantly altered by treatment of mice with IOX3 at 60 mg/kg every two days. This treatment did not affect body weight, or RER, but did significantly reduce bone mineral density and content and alter adipose tissue distribution. Future compounds designed to selectively inhibit FTO's demethylase activity could be therapeutically useful for the treatment of obesity. 10.1371/journal.pone.0121829
    Identification of Natural Compound Radicicol as a Potent FTO Inhibitor. Wang Ruiyong,Han Zhifu,Liu Bingjie,Zhou Bin,Wang Ning,Jiang Qingwei,Qiao Yan,Song Chuanjun,Chai Jijie,Chang Junbiao Molecular pharmaceutics The fat mass and obesity-associated protein (FTO), as an mA demethylase, is involved in many human diseases. Virtual screening and similarity search in combination with bioactivity assay lead to the identification of the natural compound radicicol as a potent FTO inhibitor, which exhibits a dose-dependent inhibition of FTO demethylation activity with an IC value of 16.04 μM. Further ITC experiments show that the binding between radicicol and FTO was mainly entropy-driven. Crystal structure analysis reveals that radicicol adopts an L-shaped conformation in the FTO binding site and occupies the same position as N-CDPCB, a previously identified small molecular inhibitor of FTO. Unexpectedly, however, the 1,3-diol group conserved in radicicol and N-CDPCB assumes strikingly different orientations for interaction with FTO. The identification of radicicol as an FTO inhibitor and revelation of its recognition mechanism not only opens the possibility of developing new therapeutic strategies for treatment of leukemia but also provide clues for elucidation of the acting mechanisms of radicicol, which is a possible clinical candidate worth in-depth study. 10.1021/acs.molpharmaceut.8b00522
    Identification of Clausine E as an inhibitor of fat mass and obesity-associated protein (FTO) demethylase activity. Wang Ying,Li Junya,Han Xinxin,Wang Ning,Song Chuanjun,Wang Ruiyong,Chang Junbiao Journal of molecular recognition : JMR The alkaloids containing a carbazole nucleus are an established class of natural products with wide range of biological activities. A combination of thermodynamic and enzymatic activity studies provides an insight into the recognition of Clausine E by the fat mass and obesity-associated protein (FTO). The binding of Clausine E to FTO was driven by positive entropy and negative enthalpy changes. Results also indicated that the hydroxyl group was crucial for the binding of small molecules with FTO. The structural and thermodynamic information provides the basis for the design of more effective inhibitors for FTO demethylase activity. 10.1002/jmr.2800
    Structure-based design and evaluation of novel N-phenyl-1H-indol-2-amine derivatives for fat mass and obesity-associated (FTO) protein inhibition. Padariya Monikaben,Kalathiya Umesh Computational biology and chemistry Fat mass and obesity-associated (FTO) protein contributes to non-syndromic human obesity which refers to excessive fat accumulation in human body and results in health risk. FTO protein has become a promising target for anti-obesity medicines as there is an immense need for the rational design of potent inhibitors to treat obesity. In our study, a new scaffold N-phenyl-1H-indol-2-amine was selected as a base for FTO protein inhibitors by applying scaffold hopping approach. Using this novel scaffold, different derivatives were designed by extending scaffold structure with potential functional groups. Molecular docking simulations were carried out by using two different docking algorithm implemented in CDOCKER (flexible docking) and AutoDock programs (rigid docking). Analyzing results of rigid and flexible docking, compound MU06 was selected based on different properties and predicted binding affinities for further analysis. Molecular dynamics simulation of FTO/MU06 complex was performed to characterize structure rationale and binding stability. Certainly, Arg96 and His231 residue of FTO protein showed stable interaction with inhibitor MU06 throughout the production dynamics phase. Three residues of FTO protein (Arg96, Asp233, and His231) were found common in making H-bond interactions with MU06 during molecular dynamics simulation and CDOCKER docking. 10.1016/j.compbiolchem.2016.09.008
    mA-RNA Demethylase FTO Inhibitors Impair Self-Renewal in Glioblastoma Stem Cells. Huff Sarah,Tiwari Shashi Kant,Gonzalez Gwendolyn M,Wang Yinsheng,Rana Tariq M ACS chemical biology -methyladenosine (mA) has emerged as the most abundant mRNA modification that regulates gene expression in many physiological processes. mA modification in RNA controls cellular proliferation and pluripotency and has been implicated in the progression of multiple disease states, including cancer. RNA mA methylation is controlled by a multiprotein "writer" complex including the enzymatic factor methyltransferase-like protein 3 (METTL3) that regulates methylation and two "eraser" proteins, RNA demethylase ALKBH5 (ALKBH5) and fat mass- and obesity-associated protein (FTO), that demethylate mA in transcripts. FTO can also demethylate ,2'--dimethyladenosine (mA), which is found adjacent to the mG cap structure in mRNA. FTO has recently gained interest as a potential cancer target, and small molecule FTO inhibitors such as meclofenamic acid have been shown to prevent tumor progression in both acute myeloid leukemia and glioblastoma models. However, current FTO inhibitors are unsuitable for clinical applications due to either poor target selectivity or poor pharmacokinetics. In this work, we describe the structure-based design, synthesis, and biochemical evaluation of a new class of FTO inhibitors. Rational design of 20 small molecules with low micromolar IC's and specificity toward FTO over ALKBH5 identified two competitive inhibitors FTO-02 and FTO-04. Importantly, FTO-04 prevented neurosphere formation in patient-derived glioblastoma stem cells (GSCs) without inhibiting the growth of healthy neural stem cell-derived neurospheres. Finally, FTO-04 increased mA and mA levels in GSCs consistent with FTO inhibition. These results support FTO-04 as a potential new lead for treatment of glioblastoma. 10.1021/acschembio.0c00841
    Identification of nafamostat mesilate as an inhibitor of the fat mass and obesity-associated protein (FTO) demethylase activity. Han Xinxin,Wang Ning,Li Junya,Wang Ying,Wang Ruiyong,Chang Junbiao Chemico-biological interactions Nafamostat mesilate is a serine protease inhibitor and used for the treatment of pancreatitis and cancers. The fat mass and obesity-associated protein (FTO) was identified to be a demethylase and played an important role in physiological processes. The aim of this study was to examine the inhibition of Nafamostat mesilate on FTO demethylase activity. A combination of thermodynamic and enzymatic activity studies provides an insight into the recognition of Nafamostat mesilate by FTO. The binding of Nafamostat mesilate to FTO was driven by higher positive entropy changes and smaller negative enthalpy changes. The structural and thermodynamic information provides the basis for the design of more effective inhibitors for FTO. Our results might provide a novel target protein for Nafamostat mesilate. 10.1016/j.cbi.2018.10.023
    Small-Molecule Targeting of Oncogenic FTO Demethylase in Acute Myeloid Leukemia. Huang Yue,Su Rui,Sheng Yue,Dong Lei,Dong Ze,Xu Hongjiao,Ni Tengfeng,Zhang Zijie Scott,Zhang Tao,Li Chenying,Han Li,Zhu Zhenyun,Lian Fulin,Wei Jiangbo,Deng Qiangqiang,Wang Yungui,Wunderlich Mark,Gao Zhiwei,Pan Guoyu,Zhong Dafang,Zhou Hu,Zhang Naixia,Gan Jianhua,Jiang Hualiang,Mulloy James C,Qian Zhijian,Chen Jianjun,Yang Cai-Guang Cancer cell FTO, an mRNA N-methyladenosine (mA) demethylase, was reported to promote leukemogenesis. Using structure-based rational design, we have developed two promising FTO inhibitors, namely FB23 and FB23-2, which directly bind to FTO and selectively inhibit FTO's mA demethylase activity. Mimicking FTO depletion, FB23-2 dramatically suppresses proliferation and promotes the differentiation/apoptosis of human acute myeloid leukemia (AML) cell line cells and primary blast AML cells in vitro. Moreover, FB23-2 significantly inhibits the progression of human AML cell lines and primary cells in xeno-transplanted mice. Collectively, our data suggest that FTO is a druggable target and that targeting FTO by small-molecule inhibitors holds potential to treat AML. 10.1016/j.ccell.2019.03.006
    Targeting FTO Suppresses Cancer Stem Cell Maintenance and Immune Evasion. Su Rui,Dong Lei,Li Yangchan,Gao Min,Han Li,Wunderlich Mark,Deng Xiaolan,Li Hongzhi,Huang Yue,Gao Lei,Li Chenying,Zhao Zhicong,Robinson Sean,Tan Brandon,Qing Ying,Qin Xi,Prince Emily,Xie Jun,Qin Hanjun,Li Wei,Shen Chao,Sun Jie,Kulkarni Prakash,Weng Hengyou,Huang Huilin,Chen Zhenhua,Zhang Bin,Wu Xiwei,Olsen Mark J,Müschen Markus,Marcucci Guido,Salgia Ravi,Li Ling,Fathi Amir T,Li Zejuan,Mulloy James C,Wei Minjie,Horne David,Chen Jianjun Cancer cell Fat mass and obesity-associated protein (FTO), an RNA N-methyladenosine (mA) demethylase, plays oncogenic roles in various cancers, presenting an opportunity for the development of effective targeted therapeutics. Here, we report two potent small-molecule FTO inhibitors that exhibit strong anti-tumor effects in multiple types of cancers. We show that genetic depletion and pharmacological inhibition of FTO dramatically attenuate leukemia stem/initiating cell self-renewal and reprogram immune response by suppressing expression of immune checkpoint genes, especially LILRB4. FTO inhibition sensitizes leukemia cells to T cell cytotoxicity and overcomes hypomethylating agent-induced immune evasion. Our study demonstrates that FTO plays critical roles in cancer stem cell self-renewal and immune evasion and highlights the broad potential of targeting FTO for cancer therapy. 10.1016/j.ccell.2020.04.017