Discovery of new pyridoacridine alkaloids from Lissoclinum cf. badium that inhibit the ubiquitin ligase activity of Hdm2 and stabilize p53

Bioorg Med Chem. 2008 Dec 1;16(23):10022-8. doi: 10.1016/j.bmc.2008.10.024. Epub 2008 Oct 14.

Abstract

Compounds that stabilize p53 could suppress tumors providing a additional tool to fight cancer. Mdm2, and the human ortholog, Hdm2 serve as ubiquitin E3 ligases and target p53 for ubiquitylation and degradation. Inhibition of Hdm2 stabilizes p53, inhibits cell proliferation and induces apoptosis. Using HTS to discover inhibitors, we identified three new alkaloids, isolissoclinotoxin B, diplamine B, and lissoclinidine B from Lissoclinum cf. badium. Lissoclinidine B inhibited ubiquitylation and degradation of p53, and selectively killed transformed cells harboring wild-type p53, suggesting this compound could be used to develop new treatments.

Publication types

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

MeSH terms

  • Acridines / chemistry
  • Acridines / isolation & purification
  • Acridines / metabolism
  • Alkaloids / chemistry
  • Alkaloids / isolation & purification
  • Alkaloids / pharmacology*
  • Animals
  • Cell Line, Transformed
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / isolation & purification
  • Enzyme Inhibitors / pharmacology*
  • Humans
  • Inhibitory Concentration 50
  • Phenanthrolines / chemistry
  • Phenanthrolines / isolation & purification
  • Phenanthrolines / metabolism
  • Proto-Oncogene Proteins c-mdm2 / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-mdm2 / metabolism
  • Tumor Suppressor Protein p53 / metabolism*
  • Ubiquitin / metabolism
  • Urochordata / chemistry*

Substances

  • Acridines
  • Alkaloids
  • Enzyme Inhibitors
  • Phenanthrolines
  • Tumor Suppressor Protein p53
  • Ubiquitin
  • pyridoacridine
  • MDM2 protein, human
  • Proto-Oncogene Proteins c-mdm2