title: Synthesis and biological evaluation of N-(2-[(18)F]Fluoropropionyl)-L-methionine for tumor imaging.
abstract: BACKGROUND
  N-position radiolabeled amino acids, such as N-(2-[(18)F]fluoropropionyl)-L-methionine ([(18)F]FPMET) as a derivative of L-methionine (MET), can potentially serve as a PET tracer for tumor imaging. In the current study, radiosynthesis and biological evaluation of [(18)F]FPMET as a new PET tumor agent are performed.
  
  
  METHODS
  [(18)F]FPMET was synthesized by reacting 4-nitrophenyl 2-[(18)F]fluoropropionate ([(18)F]NFP) with MET. In vitro competitive inhibition and protein incorporation experiments were performed with Hepa1-6 hepatoma cell lines. The biodistribution of [(18)F]FPMET was determined in S180 fibrosarcoma-bearing mice. PET/CT studies of [(18)F]FPMET were conducted in S180 fibrosarcoma-bearing mice, A549 lung adenocarcinoma-bearing nude mice, and PC-3 prostate cancer-bearing nude mice.
  
  
  RESULTS
  [(18)F]FPMET was synthesized in 72%± 4% uncorrected radiochemical yield (n=10) from [(18)F]NFP. In vitro experiments showed that [(18)F]FPMET was primarily transported through Na(+)-dependent system A, system ASC, and system B(0,+), and was not incorporated into protein. Biodistribution and PET/CT imaging studies indicated that [(18)F]FPMET could delineate S180 fibrosarcoma, A549 lung adenocarcinoma, and PC-3 prostate cancer.
  
  
  CONCLUSIONS
  An efficient synthesis of N-position [(18)F]labeled amino acids with a classic [(18)F]NFP prosthetic group is developed. The results support that [(18)F]FPMET seems to be a potential tracer for tumor imaging with PET.
authors.affiliation: PET-CT Center, Department of Nuclear Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510080, China.
authors.forename: Kong-Zhen
authors.initials: KZ
authors.lastname: Hu
authors.forename: Hongliang
authors.initials: H
authors.lastname: Wang
authors.forename: Tingting
authors.initials: T
authors.lastname: Huang
authors.forename: Ganghua
authors.initials: G
authors.lastname: Tang
authors.forename: Xiang
authors.initials: X
authors.lastname: Liang
authors.forename: Shanzhen
authors.initials: S
authors.lastname: He
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Tang
mesh_terms: D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor; D060326:Chemistry Techniques, Synthetic; D004355:Drug Stability; D005354:Fibrosarcoma / Q000000981:diagnostic imaging*; D008715:Methionine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics; D051379:Mice; D000442:Octanols / Q000737:chemistry; D049268:Positron-Emission Tomography / Q000379:methods*; D011854:Radiochemistry; D014867:Water / Q000737:chemistry
chemical_list: C587434:N-(2-fluoropropionyl)methionine; D000442:Octanols; D014867:Water; D008715:Methionine
keywords: Amino acid transport; N-(2-[(18)F]fluoropropionyl)-L-methionine; Positron emission tomography (PET); Tumor