Imaging of Fibroblast Activation Protein in Cancer Xenografts Using Novel (4-Quinolinoyl)-glycyl-2-cyanopyrrolidine-Based Small Molecules Academic Article uri icon

  • Overview
  • Research
  • Identity
  • Additional Document Info
  • View All


  • Fibroblast activation protein (FAP) has become a favored target for imaging and therapy of malignancy. We have synthesized and characterized two new (4-quinolinoyl)-glycyl-2-cyanopyrrolidine-based small molecules for imaging of FAP, QCP01 and [111In]QCP02, using optical and single-photon computed tomography/CT, respectively. Binding of imaging agents to FAP was assessed in six human cancer cell lines of different cancer types: glioblastoma (U87), melanoma (SKMEL24), prostate (PC3), NSCLC (NCIH2228), colorectal carcinoma (HCT116), and lung squamous cell carcinoma (NCIH226). Mouse xenograft models were developed with FAP-positive U87 and FAP-negative PC3 cells to test pharmacokinetics and binding specificity in vivo. QCP01 and [111In]QCP02 demonstrated nanomolar inhibition of FAP at Ki values of 1.26 and 16.20 nM, respectively. Both were selective for FAP over DPP-IV, a related serine protease. Both enabled imaging of FAP-expressing tumors specifically in vivo. [111In]QCP02 showed high uptake at 18.2 percent injected dose per gram in the U87 tumor at 30 min post-administration.


  • Slania, Stephanie L
  • Das, Deepankar
  • Lisok, Ala
  • Du, Yong
  • Jiang, Zirui
  • Mease, Ronnie C
  • Rowe, Steven P
  • Nimmagadda, Sridhar
  • Yang, Xing
  • Pomper, Martin G

publication date

  • April 8, 2021

has subject area