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PAC1 is a direct transcription target of E2F-1 in apoptotic signaling

J Wu1, Y J Jin, G M Calaf

  • 1Department of Radiation Oncology, Center for Radiological Research, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.

Oncogene
|May 2, 2007
PubMed

Insights

The transcription factor E2F-1 directly targets PAC1 phosphatase, initiating apoptosis in cancer cells. This E2F-1-PAC1 pathway suppresses ERK signaling, leading to cancer cell death and offering therapeutic insights.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • E2F-1 regulates cellular activities and mediates apoptosis.
  • The precise mechanism of E2F-1 in cancer cell killing remains unclear.

Purpose of the Study:

  • To elucidate the mechanism by which E2F-1 induces cancer cell death.
  • To identify direct transcriptional targets of E2F-1 involved in apoptosis signaling.

Main Methods:

  • Investigated the transcriptional regulation of PAC1 by E2F-1 in breast cancer cells.
  • Analyzed E2F-1 interaction with the PAC1 promoter using chromatin immunoprecipitation assays.
  • Assessed the role of PAC1 and ERK phosphorylation in E2F-1-mediated apoptosis via Western blotting and cell viability assays.

Main Results:

  • Ectopic E2F-1 upregulates PAC1 expression transcriptionally and translationally.
  • E2F-1 directly binds to the PAC1 promoter, enhancing its transcription.
  • E2F-1, via PAC1, suppresses ERK phosphorylation, inducing apoptosis in response to 4-HPR.

Conclusions:

  • PAC1 phosphatase is a direct transcriptional target of E2F-1, crucial for apoptosis.
  • The E2F-1-PAC1 cascade suppresses ERK signaling, mediating cancer cell death.
  • This pathway provides a potential molecular target for cancer therapeutic interventions.

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