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Activation of the PIK3CA/AKT pathway suppresses senescence induced by an activated RAS oncogene to promote

Alyssa L Kennedy1, Jennifer P Morton, Indrani Manoharan

  • 1Drexel University College of Medicine, Philadelphia, PA 19129, USA; Fox Chase Cancer Center, Philadelphia, PA 19111, USA.

Molecular Cell
|April 9, 2011
PubMed

Insights

Concurrent mutations in RAS and PIK3CA/AKT pathways suppress tumor-suppressing senescence. This finding reveals a selective advantage for cancer growth and suggests new therapeutic strategies targeting senescence.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cellular Senescence

Background:

  • Mutations in RAS and the PTEN/PIK3CA/AKT pathway frequently co-occur in human tumors.
  • The functional consequence of co-occurring mutations in this shared signaling pathway remains poorly understood.
  • RAS and PIK3CA/AKT are key regulators of cell growth and survival, and their mutations are common in cancer.

Purpose of the Study:

  • To investigate the comparative ability of RAS and PIK3CA/AKT to induce cellular senescence.
  • To determine how concurrent activation of RAS and PIK3CA/AKT affects RAS-induced senescence.
  • To elucidate the role of senescence suppression in tumorigenesis driven by these mutations.

Main Methods:

  • Comparative molecular analysis of senescence induction by RAS and PIK3CA/AKT.
  • In vivo studies to assess the impact of pathway activation on tumor development.
  • Assessment of senescence as a tumor suppressor mechanism.

Main Results:

  • Activated PIK3CA/AKT is a weaker inducer of senescence compared to activated RAS.
  • Concomitant activation of RAS and PIK3CA/AKT inhibits RAS-induced senescence.
  • Bypass of RAS-induced senescence by PIK3CA/AKT correlates with accelerated tumor growth in vivo.
  • A weak senescence inducer (PIK3CA/AKT) can dominate over a strong inducer (RAS).

Conclusions:

  • Suppression of RAS-induced senescence provides a selective advantage for tumor growth when both RAS and PTEN/PIK3CA/AKT are concurrently mutated.
  • Oncogene-induced senescence potency varies, with implications for cancer progression.
  • This research offers insights for developing targeted pro-senescence cancer therapies.

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