title: Evaluation of Tc-99 m Labeled Dimeric GX1 Peptides for Imaging of Colorectal Cancer Vasculature.
abstract: OBJECTIVE
  This study aimed to evaluate the potential of PEGylated dimeric GX1 peptide as a radiotracer for imaging of colorectal cancer vasculature in a LoVo tumor xenografted mouse model.
  
  
  METHODS
  The [(99m)Tc]PEG-(GX1)2 peptide was synthesized and identified. Confocal immunofluorescence analysis, receptor binding assay, and competitive inhibition assay were performed to evaluate the binding specificity and the receptor binding affinity of PEG-(GX1)2 to Co-human umbilical vein endothelial cells (HUVECs). Single photon emission computed tomography imaging and biodistribution were performed to evaluate the targeting ability of PEG-(GX1)2 to colorectal cancer.
  
  
  RESULTS
  The studies in vitro suggested that PEG-(GX1)2 co-localized with Factor VIII in the perinuclear cytoplasm of Co-HUVECs and bound specifically to Co-HUVECs with a high affinity. The studies in vivo demonstrated that the targeting efficacy of PEG-(GX1)2 was superior to GX1.
  
  
  CONCLUSIONS
  PEGylation improved the affinity and the targeting ability of the GX1 peptide. PEG-(GX1)2 is a more promising probe for imaging of colorectal vasculature than GX1.
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Jipeng
authors.initials: J
authors.lastname: Yin
authors.affiliation: First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Hui
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: The 88th Hospital of PLA, Taian, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Xin
authors.affiliation: School of Life Science, Dalian Nationalities University, Dalian, China.
authors.forename: Minglei
authors.initials: M
authors.lastname: He
authors.affiliation: Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Yongzhan
authors.initials: Y
authors.lastname: Nie
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China. kaicwu@fmmu.edu.cn.
authors.forename: Kaichun
authors.initials: K
authors.lastname: Wu
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000098:blood supply* / Q000473:pathology*; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D057054:Molecular Imaging / Q000379:methods*; D019275:Radiopharmaceuticals / Q000737:chemistry / Q000493:pharmacokinetics*; D012680:Sensitivity and Specificity; D013667:Technetium / Q000737:chemistry / Q000493:pharmacokinetics*; D014018:Tissue Distribution
chemical_list: D019275:Radiopharmaceuticals; D013667:Technetium
keywords: Angiogenesis; Molecular imaging; Molecular tracer; PEGylation; Tumor vascular targeting
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