Peloruside- and laulimalide-resistant human ovarian carcinoma cells have βI-tubulin mutations and altered expression of βII- and βIII-tubulin isotypes Academic Article uri icon


MeSH Major

  • Antineoplastic Agents
  • Bridged Bicyclo Compounds, Heterocyclic
  • Lactones
  • Macrolides
  • Mutation
  • Ovarian Neoplasms
  • Tubulin


  • Peloruside A and laulimalide are potent microtubule-stabilizing natural products with a mechanism of action similar to that of paclitaxel. However, the binding site of peloruside A and laulimalide on tubulin remains poorly understood. Drug resistance in anticancer treatment is a serious problem. We developed peloruside A- and laulimalide-resistant cell lines by selecting 1A9 human ovarian carcinoma cells that were able to grow in the presence of one of these agents. The 1A9-laulimalide resistant cells (L4) were 39-fold resistant to the selecting agent and 39-fold cross-resistant to peloruside A, whereas the 1A9-peloruside A resistant cells (R1) were 6-fold resistant to the selecting agent while they remained sensitive to laulimalide. Neither cell line showed resistance to paclitaxel or other drugs that bind to the taxoid site on β-tubulin nor was there resistance to microtubule-destabilizing drugs. The resistant cells exhibited impaired peloruside A/laulimalide-induced tubulin polymerization and impaired mitotic arrest. Tubulin mutations were found in the βI-tubulin isotype, R306H or R306C for L4 and A296T for R1 cells. This is the first cell-based evidence to support a β-tubulin-binding site for peloruside A and laulimalide. To determine whether the different resistance phenotypes of the cells were attributable to any other tubulin alterations, the β-tubulin isotype composition of the cells was examined. Increased expression of βII- and βIII-tubulin was observed in L4 cells only. These results provide insight into how alterations in tubulin lead to unique resistance profiles for two drugs, peloruside A and laulimalide, that have a similar mode of action.

publication date

  • August 2011



  • Academic Article



  • eng

PubMed Central ID

  • PMC3158586

Digital Object Identifier (DOI)

  • 10.1158/1535-7163.MCT-10-1057

PubMed ID

  • 21653684

Additional Document Info

start page

  • 1419

end page

  • 29


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