Inhibition of clathrin by pitstop 2 activates the spindle assembly checkpoint and induces cell death in dividing HeLa cancer cells

Mol Cancer. 2013 Jan 17;12:4. doi: 10.1186/1476-4598-12-4.


Background: During metaphase clathrin stabilises the mitotic spindle kinetochore (K)-fibres. Many anti-mitotic compounds target microtubule dynamics. Pitstop 2™ is the first small molecule inhibitor of clathrin terminal domain and inhibits clathrin-mediated endocytosis. We investigated its effects on a second function for clathrin in mitosis.

Results: Pitstop 2 did not impair clathrin recruitment to the spindle but disrupted its function once stationed there. Pitstop 2 trapped HeLa cells in metaphase through loss of mitotic spindle integrity and activation of the spindle assembly checkpoint, phenocopying clathrin depletion and aurora A kinase inhibition.

Conclusions: Pitstop 2 is therefore a new tool for investigating clathrin spindle dynamics. Pitstop 2 reduced viability in dividing HeLa cells, without affecting dividing non-cancerous NIH3T3 cells, suggesting that clathrin is a possible novel anti-mitotic drug target.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Centrioles / metabolism
  • Clathrin / antagonists & inhibitors
  • Clathrin / metabolism*
  • HeLa Cells
  • Humans
  • M Phase Cell Cycle Checkpoints / drug effects*
  • Mice
  • Microtubules / metabolism
  • Mitosis / drug effects
  • Molecular Targeted Therapy
  • NIH 3T3 Cells
  • Spindle Apparatus / drug effects
  • Sulfonamides / pharmacology*
  • Thiazolidines / pharmacology*


  • Antineoplastic Agents
  • Clathrin
  • Sulfonamides
  • Thiazolidines
  • pitstop 2