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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

Essential role of PI3-kinase pathway in p53-mediated transcription: Implications in cancer chemotherapy

R Suvasini1, K Somasundaram

  • 1Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.

Oncogene
|April 27, 2010
PubMed

Insights

Inhibiting the PI3-kinase pathway affects p53

Area of Science:

  • Oncology
  • Molecular Biology
  • Pharmacology

Background:

  • The PI3-kinase (phosphatidylinositol 3-kinase) pathway is crucial in cancer development and a target for chemotherapy.
  • p53 is a tumor suppressor protein that regulates cell cycle arrest and apoptosis in response to DNA damage.

Purpose of the Study:

  • To investigate the intricate relationship between PI3-kinase signaling and p53-mediated transcriptional activity.
  • To elucidate how PI3-kinase inhibition impacts cellular responses to DNA damage and chemotherapy.

Main Methods:

  • Utilized pharmacological PI3-kinase inhibitors (LY294002) and dominant-negative/constitutively active PI3-kinase mutants.
  • Assessed p53 post-translational modifications, sub-cellular localization, and target gene expression.
  • Evaluated cellular chemosensitivity to adriamycin under varying drug concentrations and PI3-kinase inhibition.

Main Results:

  • PI3-kinase inhibition, via LY294002, altered p53 modifications and localization.
  • LY294002 increased sensitivity to low-dose adriamycin but conferred protection against high-dose adriamycin in a p53-dependent manner.
  • PI3-kinase inhibition differentially modulated p53 target genes, abolishing pro-apoptotic gene activation under high adriamycin stress while activating specific genes under low-dose conditions.

Conclusions:

  • PI3-kinase signaling plays a differential role in regulating p53-mediated DNA damage responses and cytotoxicity.
  • The p53 status is critical for predicting outcomes when combining PI3-kinase inhibitors with chemotherapy agents like adriamycin.
  • Findings are relevant for optimizing combination chemotherapy strategies involving PI3-kinase pathway inhibitors.

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