Development of [F-18]fluorine-substituted tanaproget as a progesterone receptor imaging agent for positron emission tomography

Jae Hak Lee, Hai Bing Zhou, Carmen S. Dence, Kathryn E. Carlson, Michael J. Welch, John A. Katzenellenbogen

Research output: Contribution to journalArticlepeer-review


The level of progesterone receptors (PRs) in breast tumors can be used to guide the selection of endocrine therapies for breast cancer patients. To this end, we have prepared a fluorine-18 labeled analogue of Tanaproget, a nonsteroidal progestin with very high PR binding affinity and low affinity for androgen and glucocorticoid receptors, and have studied its tissue distribution in estrogen-primed rats to evaluate its potential for imaging PR levels by positron emission tomography. 4-[18F]Fluoropropyl-Tanaproget ([ 18F]9, FPTP) was prepared in three steps, within 140 min at an overall decay-corrected yield of 5% and effective specific activity of >550 Ci/mmol. In biodistribution studies, [18F]9 uptake was high in target tissues at both 1 and 3 h (uterus, 4.55 and 5.26%ID/g; ovary, 2.32 and 2.20%ID/g, respectively) and was cleanly blocked by coinjection of excess unlabeled compound. Uterus to blood and muscle activity ratios were 9.2 and 5.2 at 1 h and 32 and 26 at 3 h, respectively. The biodistribution of [ 18F]9 compares favorably to that of previously prepared F-18 labeled steroidal progestins, FENP and FFNP. Its high target tissue uptake efficiency and selectivity, and prolonged retention, suggest that it has excellent promise as a PET imaging agent for PR-positive breast tumors.

Original languageEnglish (US)
Pages (from-to)1096-1104
Number of pages9
JournalBioconjugate Chemistry
Issue number6
StatePublished - Jun 16 2010

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Biomedical Engineering
  • Pharmacology
  • Pharmaceutical Science
  • Organic Chemistry


Dive into the research topics of 'Development of [F-18]fluorine-substituted tanaproget as a progesterone receptor imaging agent for positron emission tomography'. Together they form a unique fingerprint.

Cite this