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Comparative effects of PP242 and rapamycin on mTOR signalling and NOTCH signalling in leukemia cells

Aya Ono1, Ryo Oike, Yuki Okuhashi

  • 1Department of Laboratory Medicine, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-Ku, Tokyo 113-8519, Japan.

Anticancer Research
|March 14, 2013
PubMed
Abstract

Insights

PP242 effectively inhibits leukemia cell growth, showing promise for targeted therapy. This study reveals crosstalk between mTOR and NOTCH signaling pathways, crucial for understanding treatment responses.

Area of Science:

  • Oncology
  • Molecular Biology
  • Signal Transduction

Background:

  • Mammalian target of rapamycin (mTOR) signaling is dysregulated in various cancers, including leukemia.
  • Dual inhibitors of mTORC1 and mTORC2, like PP242, offer potential therapeutic advantages over selective inhibitors.
  • The interplay between mTOR and NOTCH signaling in leukemia remains incompletely understood.

Purpose of the Study:

  • To investigate the efficacy of PP242 and rapamycin in inhibiting leukemia cell growth.
  • To elucidate the impact of these inhibitors on mTOR signaling pathways.
  • To explore potential crosstalk between mTOR and NOTCH signaling in leukemia cell lines.

Main Methods:

  • Treatment of eight leukemia cell lines with PP242 and rapamycin.
  • Assessment of cell growth inhibition.
  • Analysis of key protein phosphorylation events in mTOR and AKT pathways.
  • Evaluation of NOTCH1 expression and activation.

Main Results:

  • PP242 demonstrated superior growth suppression compared to rapamycin.
  • Differential inhibition of AKT phosphorylation by PP242 was observed, correlating with sensitivity.
  • mTOR phosphorylation suppression varied, particularly in myeloid cell lines.
  • Rapamycin induced 4E-BP1 hyperphosphorylation in some lines; S6K phosphorylation was differentially affected.
  • NOTCH1 expression and activation showed varied responses to PP242.

Conclusions:

  • PP242 is a potential candidate for molecular-targeted leukemia therapy, necessitating individualized treatment evaluation.
  • Significant crosstalk exists between the mTOR and NOTCH signaling pathways in leukemia.
  • Understanding pathway crosstalk is essential for optimizing PP242 efficacy in leukemia treatment.

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