title: Noninvasive visualization of microRNA-155 in multiple kinds of tumors using a radiolabeled anti-miRNA oligonucleotide.
abstract: OBJECTIVE
  We investigated whether a (99m)Tc radiolabeled anti-miRNA-155 oligonucleotide (AMO-155) could visualize the expression of miR-155 in multiple kinds of tumors in vivo.
  
  
  METHODS
  AMO-155 was chemically synthesized and modified with 2'-O-methyl (2'-OMe) and phosphorothioate (PS). It was radiolabeled with (99m)Tc via the conjugation with NHS-MAG3 at 5' end. The characterization of radiolabeling and serum stability was evaluated using high performance liquid chromatography (HPLC) and agarose gel electrophoresis. The expression of C/EBPβ, one of the miR-155 target proteins, was assessed using Western blot. The cellular uptake and delivery of AMO-155 was further evaluated in tumor cells. (99m)Tc-AMO-155 was tested in vivo in multiple tumor models, including miR-155 over-expressed and low-expressed tumor models. Finally, biodistribution of (99m)Tc-AMO-155 was evaluated.
  
  
  RESULTS
  (99m)Tc-AMO-155 was prepared with high yield and radiochemical purity. It showed high stability in fresh human serum for 10h. (99m)Tc-AMO-155 displayed comparable capacity as unlabeled AMO-155 to increase the expression of C/EBPβ protein in MCF-7 cells. (99m)Tc-AMO-155 showed an increased radioactive uptake in MCF-7 cells after 8h of incubation, whereas no change of (99m)Tc-pertechnetate uptake was observed. Carboxyfluorescein (FAM) labeled AMO-155 had higher fluorescent delivery than Control in HeLa and HepG2 cells by confocal microscopy. In miR-155 over-expressed tumor models, (99m)Tc-AMO-155 showed significantly higher tumor accumulation than (99m)Tc-Control. Furthermore, (99m)Tc-AMO-155 was capable of discriminating between MCF-7 and MDA-MB-231 tumors based on their expression of miR-155.
  
  
  CONCLUSIONS
  Our study successfully prepared and proved (99m)Tc-AMO-155 as a prospective imaging agent for the noninvasive visualization of miR-155 expression in vivo.
authors.affiliation: Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Kang
authors.affiliation: Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huo
authors.affiliation: Department of Orthopedics, PLA General Hospital, Beijing 100853, China.
authors.forename: Quanbo
authors.initials: Q
authors.lastname: Ji
authors.affiliation: Laboratory of Computer-Aided Drug Design and Discovery, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
authors.forename: Shiyong
authors.initials: S
authors.lastname: Fan
authors.affiliation: Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yan
authors.affiliation: Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China.
authors.forename: Chunli
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Ma
authors.affiliation: Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China.
authors.forename: Pan
authors.initials: P
authors.lastname: Hao
authors.affiliation: Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Sun
authors.affiliation: Laboratory of Computer-Aided Drug Design and Discovery, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China. Electronic address: zzbcaptain@yahoo.com.cn.
authors.forename: Zhibing
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Department of Medical Molecular Biology, Beijing Institute of Biotechnology, Beijing 100850, China. Electronic address: miraclexxj@126.com.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Nuclear Medicine, Peking University First Hospital, Beijing 100034, China. Electronic address: rongfu_wang2003@163.com.
authors.forename: Rongfu
authors.initials: R
authors.lastname: Wang
mesh_terms: D001692:Biological Transport; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000235:genetics; D045744:Cell Line, Tumor; D004355:Drug Stability; D006801:Humans; D007553:Isotope Labeling; D035683:MicroRNAs / Q000235:genetics*; D057054:Molecular Imaging / Q000379:methods*; D016376:Oligonucleotides, Antisense / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism / Q000493:pharmacokinetics; D013667:Technetium / Q000737:chemistry*; D014018:Tissue Distribution; D015854:Up-Regulation / Q000235:genetics
chemical_list: D022782:CCAAT-Enhancer-Binding Protein-beta; C524942:MIRN155 microRNA, human; D035683:MicroRNAs; D016376:Oligonucleotides, Antisense; D013667:Technetium
keywords: (99m)Tc; Anti-miRNA oligonucleotide; MicroRNA-155; Molecular imaging; Radiolabel