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Purification of Ubiquitinated p53 Proteins from Mammalian Cells
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Purification of Ubiquitinated p53 Proteins from Mammalian Cells

Published on: March 21, 2022

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Cell type-dependent bimodal p53 activation engenders a dynamic mechanism of chemoresistance

Ruizhen Yang1, Bo Huang1,2, Yanting Zhu1

  • 1Center for Quantitative Systems Biology, Department of Physics and Department of Biology, Hong Kong Baptist University, Hong Kong, China.

Science Advances
|December 27, 2018
PubMed

Insights

We discovered a new mechanism of cancer drug resistance involving the protein p53. Modulating p53

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Systems Biology

Background:

  • Phenotypic mechanisms of drug resistance are less understood than genetic mutations.
  • p53 protein is crucial for chemotherapy response, but its wild-type cells show variable drug sensitivity.
  • Understanding quantitative phenotypic resistance is vital for effective cancer treatment.

Purpose of the Study:

  • To elucidate a novel phenotypic mechanism of chemoresistance mediated by bimodal p53 activation dynamics.
  • To quantitatively characterize the regulatory network governing p53 activation in response to DNA-damaging agents.
  • To identify potential therapeutic strategies targeting p53 dynamics for overcoming drug resistance.

Main Methods:

  • Single-cell imaging techniques to observe p53 dynamics in real-time.
  • Computational modeling to analyze a four-component regulatory module of p53.
  • Quantitative analysis of inhibitory interactions between ATM and Mdm2.
  • Assessment of combinatorial inhibition of Mdm2 and Wip1 in resistant cancer cells.

Main Results:

  • A four-component regulatory module generating bimodal p53 activation dynamics was characterized.
  • The inhibitory strength between ATM and Mdm2 was identified as a key determinant of differential p53 output in sensitive versus resistant cells.
  • Combinatorial inhibition of Mdm2 and Wip1 effectively altered p53 dynamics and sensitized resistant cells to apoptosis.

Conclusions:

  • p53 pulsing represents a druggable mechanism underlying chemoresistance.
  • Targeting p53 activation dynamics offers a promising strategy to overcome drug resistance in cancer.
  • Quantitative analysis of cellular regulatory modules can reveal novel therapeutic targets.

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