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Identification of nuclear export inhibitors with potent anticancer activity in vivo

Sarah C Mutka1, Wen Qing Yang, Steven D Dong

  • 1Kosan Biosciences, Inc, Hayward, California 92121, USA. sarah.mutka@n30pharma.com

Cancer Research
|January 17, 2009
PubMed

Insights

New nuclear export inhibitors derived from Leptomycin B (LMB) effectively target cancer cells, inducing apoptosis while sparing normal cells. These potent CRM1 inhibitors demonstrate improved in vivo tolerability and efficacy in preclinical models.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pharmacology

Background:

  • CRM1 (exportin 1) is crucial for nuclear export of key cancer-related proteins like p53, c-Abl, and FOXO-3A.
  • Leptomycin B (LMB) inhibits CRM1 but has limited in vivo use due to toxicity.

Purpose of the Study:

  • To develop novel CRM1 inhibitors with improved therapeutic windows and in vivo efficacy.
  • To evaluate the anticancer potential of semisynthetic LMB derivatives.

Main Methods:

  • Synthesis of novel LMB derivatives.
  • In vitro assessment of nuclear export inhibition and apoptosis induction in cancer cells.
  • Evaluation of cell cycle effects in normal lung fibroblasts.
  • In vivo efficacy studies using mouse xenograft models.

Main Results:

  • Semisynthetic LMB derivatives demonstrated potent and prolonged inhibition of nuclear export.
  • These compounds induced apoptosis in cancer cells but only cell cycle arrest in normal fibroblasts.
  • The new inhibitors showed up to 16-fold better in vivo tolerability compared to LMB.
  • Significant efficacy was observed in multiple mouse xenograft models.

Conclusions:

  • Semisynthetic LMB derivatives represent a promising class of novel nuclear export inhibitors (NEIs).
  • These NEIs offer a favorable therapeutic window and potent anticancer activity.
  • CRM1 inhibitors hold significant potential as novel therapeutic agents for cancer treatment.

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