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PKCα inhibited apoptosis by decreasing the activity of JNK in MCF-7/ADR cells

Na Wang1, Zhihua Li, Fen Tian

  • 1Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong Province 510080, PR China.

Experimental and Toxicologic Pathology : Official Journal of the Gesellschaft Fur Toxikologische Pathologie
|November 26, 2010
PubMed

Insights

Multidrug resistance (MDR) in breast cancer involves the PKCα and c-Jun N-terminal kinase (JNK) pathway. PKCα regulates JNK, impacting apoptosis in tamoxifen-resistant breast cancer cells.

Area of Science:

  • Oncology
  • Molecular Biology
  • Signal Transduction

Background:

  • Multidrug resistance (MDR) poses a significant challenge in breast cancer treatment.
  • Signal transduction pathways are increasingly recognized for their role in MDR development.

Purpose of the Study:

  • To investigate the role of the c-Jun N-terminal kinase (JNK) pathway, regulated by protein kinase C alpha (PKCα), in MDR within breast cancer.
  • To elucidate the relationship between PKCα and JNK in tamoxifen-resistant MCF-7/ADR cells.

Main Methods:

  • Cell viability assays (MTT) and apoptosis detection (DNA ladder, flow cytometry) were employed.
  • Western blotting was used to assess protein activation.
  • Specific inhibitors (sp600125 for JNK, Go6976 for PKCα) were utilized.

Main Results:

  • MCF-7/ADR cells exhibited higher PKCα expression and resistance to tamoxifen-induced apoptosis compared to MCF-7 cells.
  • Tamoxifen activated JNK in MCF-7 cells but not in MCF-7/ADR cells.
  • PKCα inhibition suggested it acts upstream of JNK in regulating apoptosis.

Conclusions:

  • PKCα and JNK are critical regulators of apoptosis in tamoxifen-resistant breast cancer cells (MCF-7/ADR).
  • PKCα appears to be an upstream regulator of JNK, influencing MDR in this cellular context.

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