A targeted low molecular weight near-infrared fluorescent probe for prostate cancer

Bioorg Med Chem Lett. 2010 Dec 1;20(23):7124-6. doi: 10.1016/j.bmcl.2010.09.057. Epub 2010 Sep 17.


Prostate-specific membrane antigen (PSMA) remains an active target for imaging and therapeutic applications for prostate cancer. Although radionuclide-based imaging is generally more sensitive and also has been deeply explored, near-infrared fluorescence imaging agents are simple to prepare and compatible with long-term storage conditions. In the present study, a near-infrared fluorescent imaging probe (Cy5.5-CTT-54.2) has been developed by chemical conjugation of Cy5.5N-hydroxysuccinimide ester (Cy5.5-NHS) with a potent PSMA inhibitor CTT-54.2 (IC(50)=144 nM). The probe displays a highly potency (IC(50)=0.55 nM) against PSMA and has demonstrated successful application for specifically labeling PSMA-positive prostate cancer cells in both two and three-dimensional cell culture conditions. These results suggest that the potent, near-infrared Cy5.5-PSMA inhibitor conjugate may be useful for the detection of prostate tumor cells by optical in vivo imaging.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbocyanines
  • Fluorescent Dyes*
  • Humans
  • Infrared Rays
  • Male
  • Molecular Weight
  • Prostate-Specific Antigen / antagonists & inhibitors*
  • Prostatic Neoplasms / diagnosis*
  • Tumor Cells, Cultured


  • CY5.5 cyanine dye
  • Carbocyanines
  • Fluorescent Dyes
  • Prostate-Specific Antigen