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Updated: Jul 31, 2026

Yeast As a Chassis for Developing Functional Assays to Study Human P53
14:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

Topoisomerase IIalpha mediates E2F-1-induced chemosensitivity and is a target for p53-mediated transcriptional

J Nip1, S W Hiebert

  • 1Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.

Cell Biochemistry and Biophysics
|April 28, 2001
PubMed

Insights

Targeting the retinoblastoma (pRb) pathway with E2F-1 overexpression sensitizes cells to apoptosis. Topoisomerase II inhibition and DNA damage synergize to induce apoptosis in pRb-mutated cells, offering therapeutic potential.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • Mutations in the retinoblastoma tumor suppressor (pRb) pathway lead to uncontrolled cell cycle progression.
  • Overexpression of E2F-1, a key regulator in this pathway, can sensitize cells to apoptosis, suggesting therapeutic potential.

Purpose of the Study:

  • To investigate the therapeutic implications of targeting the pRb/E2F pathway.
  • To determine the role of topoisomerase II inhibitors and DNA damage in inducing apoptosis in cells with pRb pathway alterations.

Main Methods:

  • Enforced expression of E2F-1 in interleukin-3-dependent myeloid cells.
  • Treatment with topoisomerase II inhibitors (etoposide and ICRF-193) and other DNA-damaging agents.
  • Assessment of apoptosis induction and p53 protein accumulation.

Main Results:

  • E2F-1 overexpression sensitized cells to etoposide-induced apoptosis, independent of p53 accumulation.
  • ICRF-193 protected against etoposide but cooperated with other DNA-damaging agents to induce apoptosis.
  • E2F-1 expression led to p53 accumulation, suggesting a direct response to E2F, not cell cycle progression defects.

Conclusions:

  • Topoisomerase II inhibition and DNA damage cooperate to selectively induce apoptosis in cells with pRb pathway mutations.
  • Targeting the pRb/E2F pathway in conjunction with DNA-damaging agents represents a potential therapeutic strategy for cancer.

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