Induction of apoptosis by cryptophycin 1, a new antimicrotubule agent

Int J Cancer. 1997 Nov 4;73(3):440-8. doi: 10.1002/(sici)1097-0215(19971104)73:3<440::aid-ijc20>;2-f.


The ability of cryptophycin 1, a new potent cytotoxic antimicrotubule agent, to initiate apoptosis was studied. Treatment of cells with cryptophycin 1 (50 pM) rapidly caused morphological changes consistent with the induction of apoptosis. DNA strand breakage and fragmentation of the DNA into oligonucleosome-sized fragments was observed, and this coincided with the loss of cellular DNA. Activation of the cysteine protease CPP32 (caspase 3, YAMA, apopain), a member of the ICE/CED-3-like protease family of apoptosis effectors, was consistent with the execution of cell death by a coordinated sequence of events. Low concentrations of cryptophycin 1 caused mitotic arrest with the formation of abnormal mitotic spindles without affecting interphase microtubule structures. Unlike other microtubule active agents, cryptophycin-induced mitotic arrest persisted for only a brief period before the onset of apoptosis. There was no evidence of release from G2/M cell cycle arrest. Our results show that low concentrations of cryptophycin 1 (50 pM) initiated cell death consistent with apoptosis. These data suggest that the cytotoxic effects of cryptophycin 1 are due in part to its ability to initiate apoptosis rapidly.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology*
  • Apoptosis* / genetics
  • Caspase 3
  • Caspases*
  • Cysteine Endopeptidases / metabolism*
  • DNA Fragmentation
  • DNA, Neoplasm / drug effects*
  • Depsipeptides
  • Enzyme Activation / drug effects
  • Humans
  • Microtubules / drug effects
  • Mitosis / drug effects
  • Peptides, Cyclic / pharmacology*
  • Poly(ADP-ribose) Polymerases / metabolism
  • Tumor Cells, Cultured / drug effects


  • Antineoplastic Agents
  • DNA, Neoplasm
  • Depsipeptides
  • Peptides, Cyclic
  • cryptophycin
  • Poly(ADP-ribose) Polymerases
  • CASP3 protein, human
  • Caspase 3
  • Caspases
  • Cysteine Endopeptidases