Blocking 17β-hydroxysteroid dehydrogenase type 1 in endometrial cancer: a potential novel endocrine therapeutic approach

J Pathol. 2018 Feb;244(2):203-214. doi: 10.1002/path.5004. Epub 2018 Jan 3.


The enzyme type 1 17β-hydroxysteroid dehydrogenase (17β-HSD-1), responsible for generating active 17β-estradiol (E2) from low-active estrone (E1), is overexpressed in endometrial cancer (EC), thus implicating an increased intra-tissue generation of E2 in this estrogen-dependent condition. In this study, we explored the possibility of inhibiting 17β-HSD-1 and impairing the generation of E2 from E1 in EC using in vitro, in vivo, and ex vivo models. We generated EC cell lines derived from the well-differentiated endometrial adenocarcinoma Ishikawa cell line and expressing levels of 17β-HSD-1 similar to human tissues. In these cells, HPLC analysis showed that 17β-HSD-1 activity could be blocked by a specific 17β-HSD-1 inhibitor. In vitro, E1 administration elicited colony formation similar to E2, and this was impaired by 17β-HSD-1 inhibition. In vivo, tumors grafted on the chicken chorioallantoic membrane (CAM) demonstrated that E1 upregulated the expression of the estrogen responsive cyclin A similar to E2, which was impaired by 17β-HSD-1 inhibition. Neither in vitro nor in vivo effects of E1 were observed using 17β-HSD-1-negative cells (negative control). Using a patient cohort of 52 primary ECs, we demonstrated the presence of 17β-HSD-1 enzyme activity (ex vivo in tumor tissues, as measured by HPLC), which was inhibited by over 90% in more than 45% of ECs using the 17β-HSD-1 inhibitor. Since drug treatment is generally indicated for metastatic/recurrent and not primary tumor, we next demonstrated the mRNA expression of the potential drug target, 17β-HSD-1, in metastatic lesions using a second cohort of 37 EC patients. In conclusion, 17β-HSD-1 inhibition efficiently blocks the generation of E2 from E1 using various EC models. Further preclinical investigations and 17β-HSD-1 inhibitor development to make candidate compounds suitable for the first human studies are awaited. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Keywords: 17β-estradiol; 17β-hydroxysteroid dehydrogenase type 1; endometrial cancer; estrogen metabolism; estrone.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Animals
  • Antineoplastic Agents / pharmacology*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects*
  • Chick Embryo
  • Cyclin A / metabolism
  • Endometrial Neoplasms / drug therapy*
  • Endometrial Neoplasms / enzymology
  • Endometrial Neoplasms / genetics
  • Endometrial Neoplasms / pathology
  • Enzyme Inhibitors / pharmacology*
  • Estradiol / metabolism
  • Estradiol / pharmacology
  • Estradiol Dehydrogenases / antagonists & inhibitors*
  • Estradiol Dehydrogenases / genetics
  • Estradiol Dehydrogenases / metabolism
  • Estrone / metabolism
  • Estrone / pharmacology
  • Female
  • Humans
  • Middle Aged
  • Molecular Targeted Therapy
  • Signal Transduction / drug effects


  • Antineoplastic Agents
  • Cyclin A
  • Enzyme Inhibitors
  • Estrone
  • Estradiol
  • Estradiol Dehydrogenases
  • HSD17B1 protein, human