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Updated: Jun 21, 2026

Generation of Prostate Cancer Cell Models of Resistance to the Anti-mitotic Agent Docetaxel
06:44

Generation of Prostate Cancer Cell Models of Resistance to the Anti-mitotic Agent Docetaxel

Published on: September 8, 2017

PF-00477736 mediates checkpoint kinase 1 signaling pathway and potentiates docetaxel-induced efficacy in xenografts

Cathy Zhang1, Zhengming Yan, Cory L Painter

  • 1Oncology Research Unit, Pfizer Global Research and Development, La Jolla Laboratories, San Diego, California, USA. cathy.zhang@pfizer.com

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research
|July 9, 2009
PubMed
Abstract

Insights

The Chk1 inhibitor PF-00477736 enhances docetaxel efficacy by abrogating DNA damage and mitotic checkpoints, sensitizing cancer cells to apoptosis. This combination therapy shows therapeutic potential for improving taxane treatments.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pharmacology

Background:

  • Checkpoint kinase 1 (Chk1) is crucial for mitotic spindle and DNA damage checkpoint activation.
  • Docetaxel efficacy can be limited by cellular resistance mechanisms.
  • Targeting Chk1 offers a potential strategy to overcome docetaxel resistance.

Purpose of the Study:

  • To evaluate the preclinical efficacy of the Chk1 inhibitor PF-00477736 as a docetaxel-sensitizing agent.
  • To investigate the correlation between PF-00477736-mediated biomarker modulation and docetaxel sensitization.

Main Methods:

  • In vitro and in vivo studies using various cell lines, including COLO205.
  • Assessment of PF-00477736-induced enhancement of docetaxel efficacy and effects on key biomarkers.
  • Utilized [18F]FLT-PET and bioluminescence imaging for in vivo assessment.

Main Results:

  • PF-00477736 significantly enhanced docetaxel efficacy in tumor cells and xenografts.
  • Docetaxel induced dose- and time-dependent increases in phosphorylated Chk1, histone H3, and gammaH2AX.
  • PF-00477736 cotreatment suppressed docetaxel-induced checkpoint activation and sensitized apoptosis, improving tumor survival suppression.

Conclusions:

  • Docetaxel activates mitotic and DNA damage checkpoints at varying concentrations.
  • PF-00477736 abrogates these checkpoints, leading to sensitization to docetaxel.
  • Chk1 inhibition with PF-00477736 demonstrates therapeutic potential for enhancing taxane-based chemotherapy.

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