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Ultrasound-Guided Orthotopic Implantation of Murine Pancreatic Ductal Adenocarcinoma
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A subset of metastatic pancreatic ductal adenocarcinomas depends quantitatively on oncogenic Kras/Mek/Erk-induced

Bo Kong1, Weiwei Wu1, Tao Cheng1

  • 1Department of Surgery, Technische Universität München (TUM), Munich, Germany.

Gut
|January 21, 2015
PubMed
Abstract

Insights

Targeting both Mek and PI3K pathways simultaneously, along with Aldh1a3, shows promise for treating aggressive pancreatic ductal adenocarcinoma (PDAC). This dual inhibition strategy overcomes resistance seen with single-agent therapies in Kras-driven PDAC.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cancer Research

Background:

  • Oncogenic Kras in pancreatic ductal adenocarcinoma (PDAC) activates Mek/Erk signaling, inhibiting the tuberous sclerosis complex (Tsc) and mammalian target of rapamycin (mTOR).
  • Single-agent Mek or mTOR inhibitors show limited efficacy in PDAC due to feedback activation of compensatory pathways.

Purpose of the Study:

  • To investigate the mechanisms of Mek/Erk-driven mTOR activation in PDAC.
  • To identify effective therapeutic strategies targeting this pathway.
  • To explore the role of Aldh1a3 as a biomarker and therapeutic target in PDAC.

Main Methods:

  • Generated transgenic mouse models with hyperactivated mTOR via Kras/Mek/Erk, Pten loss, or Tsc1 haploinsufficiency.
  • Assessed oncogenic signaling in primary cancer cells in vitro and in vivo under targeted inhibition.
  • Utilized transcriptional profiling to identify predictive biomarkers for therapeutic response.
  • Validated preclinical findings in human PDAC samples.

Main Results:

  • Reduced Tsc1 function promoted Kras/Mek/Erk-mediated mTOR signaling and metastatic PDAC development.
  • Single inhibition of mTOR or Mek led to feedback activation of Erk or Akt, respectively.
  • Dual inhibition of Mek and PI3K effectively reduced mTOR activity and induced apoptosis.
  • The Mek/Erk/Tsc/mTOR axis oncogenic activity depended on Aldh1a3, which identified an aggressive PDAC subtype in clinical samples.

Conclusions:

  • Dual inhibition of Mek and PI3K is a promising strategy for PDAC treatment.
  • Aldh1a3 is a key downstream target and a potential biomarker for aggressive PDAC.
  • These findings provide a rationale for targeting Aldh1a3-positive PDAC.
Keywords:
ONCOGENESPANCREATIC CANCERPANCREATIC PATHOLOGY

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