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Cell-permeable carboxyl-terminal p27(Kip1) peptide exhibits anti-tumor activity by inhibiting Pim-1 kinase

Daisuke Morishita1, Miho Takami, Seiko Yoshikawa

  • 1Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan.

The Journal of Biological Chemistry
|November 11, 2010
PubMed

Insights

A novel peptide targeting Pim-1 kinase offers a promising new treatment for prostate cancer. This peptide inhibits tumor growth and overcomes chemotherapy resistance, showing potential as an effective anti-cancer drug.

Area of Science:

  • Oncology
  • Molecular Biology
  • Drug Discovery

Background:

  • Prostate cancer incidence and mortality are rising, with limited chemotherapy efficacy.
  • Serine/threonine kinase Pim-1 is crucial in prostate tumorigenesis, making it a therapeutic target.
  • Existing small molecule Pim-1 inhibitors lack specificity, hindering clinical application.

Purpose of the Study:

  • To develop a specific and effective Pim-1 inhibitor for prostate cancer treatment.
  • To investigate a novel cell-permeable p27(Kip1) peptide as a potential anti-cancer drug.
  • To evaluate the peptide's efficacy in vitro and in vivo, including its ability to overcome drug resistance.

Main Methods:

  • Designed and synthesized a cell-permeable p27(Kip1) peptide targeting Pim-1.
  • Assessed peptide's ability to inhibit Pim-1 phosphorylation of substrates (p27(Kip1), Bad) in vitro.
  • Evaluated peptide's effects on prostate cancer cell cycle (G1 arrest) and apoptosis in vitro.
  • Tested peptide's efficacy in inhibiting tumor growth in prostate cancer xenograft models in vivo.
  • Investigated peptide's ability to overcome taxol resistance and its synergistic effect with taxol.

Main Results:

  • The peptide specifically binds to Pim-1, inhibiting phosphorylation of its substrates.
  • In vitro treatment induced G1 arrest and apoptosis in prostate cancer cells, sparing normal cells.
  • The peptide demonstrated significant inhibition of tumor growth in vivo.
  • Treatment with the peptide overcame taxol resistance and showed synergistic effects with taxol in combination therapy.

Conclusions:

  • A Pim-1 inhibitory p27(Kip1) peptide is a potent anti-cancer agent against prostate cancer.
  • The peptide exhibits high specificity, targeting cancer cells while sparing normal cells.
  • This peptide holds promise for overcoming chemotherapy resistance and improving treatment outcomes for prostate cancer.

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