title: [Radio-labeling of T7 peptide with 99mTc and its biodistribution in nude mice bearing non-small cell lung cancer].
abstract: BACKGROUND
  Lung cancer is a malignant tumor with high mortality rates. This study aims to develop potential candidates of integrin αvβ3 imaging agents, which can facilitate the diagnosis and treatment of lung cancer.
  
  
  METHODS
  The T7 peptide was labeled with carbonyl technetium. The thin layer chromatography with acetone as the development system was performed to investigate the purity and stability of (99m)Tc-T7. The binding affinity of (99m)Tc-T7 with NCI-H157 tumor cells was determined. The biodistribution of (99m)Tc-T7 in nude mice bearing non-small cell lung carcinoma was observed after injection of (99m)Tc-T7 at 0.5 h, 1 h, 2 h, 4 h, and 8 h, and the radioactive ratio of tumor (T) and non-tumor tissues (NT) was calculated.
  
  
  RESULTS
  99mTc labeled T7 had high radiochemical purity of more than 90%, which does not require further purification, with good stability in vitro. The association and dissociation constant (KD) of (99m)Tc-T7 with NCI-H157 tumor cells was 196.1 nM. (99m)Tc-T7 was mainly metabolism through the internal organs with rapid blood removal. Moreover, the uptake in tumor tissue was significantly higher than the muscle with tumor/muscle ratio of 5.8. In addition, the (99m)Tc-T7 exhibited a transient accumulation in the lungs.
  
  
  CONCLUSIONS
  The (99m)Tc-T7 could be prepared using a simple method, had high labeling rate and good stability, and could be accumulated at tumor site. Thus, (99m)Tc-T7 is a potential lung cancer SPECT/CT imaging agent.
authors.affiliation: Department of Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Peking Union Medical College, Chinese Academy of Medical Sciences, Tianjin 300192, China.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Department of Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Peking Union Medical College, Chinese Academy of Medical Sciences, Tianjin 300192, China.
authors.forename: Xin
authors.initials: X
authors.lastname: He
authors.affiliation: Department of Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Peking Union Medical College, Chinese Academy of Medical Sciences, Tianjin 300192, China.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Peking Union Medical College, Chinese Academy of Medical Sciences, Tianjin 300192, China.
authors.forename: Aimin
authors.initials: A
authors.lastname: Meng
authors.affiliation: Department of Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Peking Union Medical College, Chinese Academy of Medical Sciences, Tianjin 300192, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Peking Union Medical College, Chinese Academy of Medical Sciences, Tianjin 300192, China.
authors.forename: Jinjian
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Peking Union Medical College, Chinese Academy of Medical Sciences, Tianjin 300192, China.
authors.forename: Naling
authors.initials: N
authors.lastname: Song
mesh_terms: D000818:Animals; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000000981:diagnostic imaging*; D006801:Humans; D007553:Isotope Labeling; D008175:Lung Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D015609:Organotechnetium Compounds / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry / Q000493:pharmacokinetics*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000737:chemistry*; D014018:Tissue Distribution
chemical_list: D015609:Organotechnetium Compounds; D010455:Peptides; D019275:Radiopharmaceuticals