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Enhancement of Apoptotic and Autophagic Induction by a Novel Synthetic C-1 Analogue of 7-deoxypancratistatin in Human Breast Adenocarcinoma and Neuroblastoma Cells with Tamoxifen
19:44

Enhancement of Apoptotic and Autophagic Induction by a Novel Synthetic C-1 Analogue of 7-deoxypancratistatin in Human Breast Adenocarcinoma and Neuroblastoma Cells with Tamoxifen

Published on: May 30, 2012

Phospholipase C-protein kinase C mediated phospholipase D activation pathway is involved in tamoxifen induced

Soo-Jung Ahn1, Mee-Sup Yoon, Shin Hyuk

  • 1Cancer Research Institute, College of Medicine, Seoul National University, Seoul 110-744, Korea.

Journal of Cellular Biochemistry
|May 23, 2003
PubMed

Insights

Tamoxifen (TAM) triggers breast cancer cell death via apoptosis. This study reveals a non-estrogen receptor pathway involving phospholipase D (PLD), phospholipase C (PLC), and protein kinase C (PKC) in TAM

Area of Science:

  • Biochemistry
  • Cell Biology
  • Pharmacology

Background:

  • Tamoxifen (TAM) is a primary endocrine therapy for breast cancer, mainly acting via estrogen receptor (ER) pathways to induce apoptosis.
  • Understanding non-ER mediated mechanisms of TAM is crucial for comprehensive treatment strategies.

Purpose of the Study:

  • To investigate the non-ER mediated signaling pathway involving phospholipase D (PLD), phospholipase C (PLC), and protein kinase C (PKC) in TAM-induced apoptosis of breast cancer cells.
  • To elucidate the role of PLD activation in TAM's mechanism of action.

Main Methods:

  • Utilized multimodality methods to analyze protein and mRNA levels of PLC and PLD in TAM-treated MCF7 cells.
  • Measured phosphatidylethanol (PEt) and diacylglycerol (DAG) generation to assess PLD and PLC activity.
  • Observed PKCalpha translocation using cellular imaging techniques.
  • Employed specific inhibitors for PLC and PKC to confirm their regulatory roles in PLD activation.

Main Results:

  • TAM treatment increased PLC and PLD protein and mRNA levels in MCF7 cells.
  • Elevated PEt and DAG generation indicated increased PLD and PLCgamma1 activity.
  • PKCalpha translocated from the cytosol to the membrane in TAM-treated cells.
  • Inhibitors of PKC and PLC attenuated TAM-induced PLD activation, confirming their upstream regulatory roles.
  • TAM treatment reduced MCF7 cell viability and induced rapid cell death.

Conclusions:

  • TAM induces apoptosis in breast cancer cells through a non-ER mediated pathway.
  • The signal transduction pathway involving PLD, PLC, and PKC is a key mechanism underlying TAM's non-ER mediated effects.
  • This pathway represents a potential therapeutic target for breast cancer treatment.

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