6-Substituted amiloride derivatives as inhibitors of the urokinase-type plasminogen activator for use in metastatic disease

Bioorg Med Chem Lett. 2019 Dec 15;29(24):126753. doi: 10.1016/j.bmcl.2019.126753. Epub 2019 Oct 28.


The oral K+-sparing diuretic amiloride shows anti-cancer side-activities in multiple rodent models. These effects appear to arise, at least in part, through moderate inhibition of the urokinase-type plasminogen activator (uPA, Ki = 2.4 µM), a pro-metastatic trypsin-like serine protease that is upregulated in many aggressive solid malignancies. In applying the selective optimization of side-activity (SOSA) approach, a focused library of twenty two 6-substituted amiloride derivatives were prepared, with multiple examples displaying uPA inhibitory potencies in the nM range. X-ray co-crystal structures revealed that the potency increases relative to amiloride arise from increased occupancy of uPA's S1β subsite by the appended 6-substituents. Leading compounds were shown to have high selectivity over related trypsin-like serine proteases and no diuretic or anti-kaliuretic effects in rats. Compound 15 showed anti-metastatic effects in a xenografted mouse model of late-stage lung metastasis.

Keywords: Amiloride; Anti-metastatic; Cancer; Metastasis; Selective optimisation of side-activity; Trypsin-like serine protease; Urokinase plasminogen activator; uPA.

Publication types

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

MeSH terms

  • Amiloride / analogs & derivatives*
  • Amiloride / pharmacology
  • Amiloride / therapeutic use*
  • Diuretics / pharmacology
  • Diuretics / therapeutic use*
  • Humans
  • Neoplasm Metastasis / drug therapy*
  • Structure-Activity Relationship
  • Urokinase-Type Plasminogen Activator / antagonists & inhibitors*


  • Diuretics
  • Amiloride
  • Urokinase-Type Plasminogen Activator