title: Identification of a fluorescent small-molecule enhancer for therapeutic autophagy in colorectal cancer by targeting mitochondrial protein translocase TIM44.
abstract: As the modulation of autophagic processes can be therapeutically beneficial to cancer treatment, the identification of novel autophagic enhancers is highly anticipated. However, current autophagy-inducing anticancer agents exert undesired side effects owing to their non-specific biodistribution in off-target tissues. This study aims to develop a multifunctional agent to integrate cancer targeting, imaging and therapy and to investigate its mechanism.
  
  
  
  A series of mitochondria-targeting near-infrared (NIR) fluorophores were synthesised, screened and identified for their autophagy-enhancing activity. The optical properties and biological effects were tested both in vitro and in vivo. The underlying mechanism was investigated using inhibitors, small interfering RNA (siRNA), RNA sequencing, mass spectrometry and human samples.
  
  
  
  We have screened and identified a new NIR autophagy-enhancer, IR-58, which exhibits significant tumour-selective killing effects. IR-58 preferentially accumulates in the mitochondria of colorectal cancer (CRC) cells and xenografts, a process that is glycolysis-dependent and organic anion transporter polypeptide-dependent. IR-58 kills tumour cells and induces apoptosis via inducing excessive autophagy, which is mediated through the reactive oxygen species (ROS)-Akt-mammalian target of rapamycin (mTOR) pathway. RNA sequencing, mass spectrometry and siRNA interference studies demonstrate that translocase of inner mitochondrial membrane 44 (TIM44)-superoxide dismutase 2 (SOD2) pathway inhibition is responsible for the excessive ROS, autophagy and apoptosis induced by IR-58. TIM44 expression correlates positively with CRC development and poor prognosis in patients.
  
  
  
  A novel NIR small-molecule autophagy-enhancer, IR-58, with mitochondria-targeted imaging and therapy capabilities was developed for CRC treatment. Additionally, TIM44 was identified for the first time as a potential oncogene, which plays an important role in autophagy through the TIM44-SOD2-ROS-mTOR pathway.
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Oncology, Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Shenglin
authors.initials: S
authors.lastname: Luo
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Jintao
authors.initials: J
authors.lastname: He
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Luo
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Zelin
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Tan
authors.affiliation: Department of Oncology, Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Ou
authors.affiliation: Department of Oncology, Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Hongming
authors.initials: H
authors.lastname: Miao
authors.affiliation: Department of Oncology, Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Houjie
authors.initials: H
authors.lastname: Liang
authors.affiliation: Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Chunmeng
authors.initials: C
authors.lastname: Shi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects*; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000494:pharmacology* / Q000627:therapeutic use; D045325:HCT116 Cells; D019073:HT29 Cells; D056945:Hep G2 Cells; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D008928:Mitochondria / Q000201:enzymology*; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism*; D055620:Optical Phenomena; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D013482:Superoxide Dismutase / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays; D000099156:Superoxide Dismutase 2
chemical_list: D002352:Carrier Proteins; D005456:Fluorescent Dyes; D008565:Membrane Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D051057:Proto-Oncogene Proteins c-akt; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D058570:TOR Serine-Threonine Kinases; D000099156:Superoxide Dismutase 2; C489671:TIMM44 protein, human; C546842:MTOR protein, human
keywords: COLORECTAL CANCER; MOLECULAR MECHANISMS; PHARMACOTHERAPY