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3-D Cell Culture System for Studying Invasion and Evaluating Therapeutics in Bladder Cancer
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3-D Cell Culture System for Studying Invasion and Evaluating Therapeutics in Bladder Cancer

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Dual inhibition by S6K1 and Elf4E is essential for controlling cellular growth and invasion in bladder cancer

Jong Kyou Kwon1, Soon-Ja Kim2, Jung Hoon Kim3

  • 1Department of Urology, Chung-Ang University College of Medicine, Seoul, Republic of Korea.

Urologic Oncology
|November 19, 2013
PubMed
Abstract

Insights

Dual inhibition of mTOR pathway components S6K1 and eukaryotic initiation factor 4E (eIF4E) suppressed urothelial carcinoma cell proliferation. High-dose rapamycin effectively blocked these targets, suggesting a potential strategy for preventing bladder cancer recurrence.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cell Biology

Background:

  • The mammalian target of rapamycin (mTOR) pathway plays a crucial role in cell growth and proliferation.
  • Dysregulation of the mTOR pathway is implicated in the progression of various cancers, including urothelial carcinoma.
  • Targeting key downstream effectors like S6K1 and eukaryotic initiation factor 4E (eIF4E) is a potential therapeutic strategy.

Purpose of the Study:

  • To investigate the effects of dual inhibition of S6K1 and eIF4E on urothelial carcinoma cell proliferation and progression.
  • To elucidate the molecular mechanisms underlying the suppression of urothelial carcinoma by targeting the mTOR pathway.
  • To evaluate the efficacy of rapamycin and siRNA technology in inhibiting these targets.

Main Methods:

  • Utilized T24 and 5637 urothelial carcinoma cell lines.
  • Interfered with mTOR pathway components using rapamycin and small interfering RNA (siRNA) targeting S6K1 or eIF4E.
  • Analyzed molecular activation status, cell growth, proliferation, viability, migration, and invasion.

Main Results:

  • High-dose rapamycin (10 μM) inhibited both S6K1 and eIF4E phosphorylation, leading to suppressed cell proliferation in T24 and 5637 cells.
  • Dual inhibition by rapamycin demonstrated greater efficacy in reducing cell viability and proliferation compared to individual siRNA-mediated silencing of S6K1 or eIF4E.
  • Silencing S6K1 or eIF4E significantly reduced cell migration and invasion, with rapamycin showing a more pronounced effect than siRNA.

Conclusions:

  • Dual inhibition of the mTOR pathway downstream of S6K1 and eIF4E effectively suppresses urothelial carcinoma cell proliferation, migration, and invasion.
  • High-dose rapamycin can be a potential therapeutic agent for preventing bladder cancer recurrence by simultaneously inhibiting S6K1 and eIF4E.
  • The findings suggest that 4E-BP1 may remain under mTORC1 regulation, warranting further investigation.
Keywords:
BladderCancerRapamycinS6K1eIF4EmTOR

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