Akt associates with nuclear factor kappaB and plays an important role in chemoresistance of gastric cancer cells

Oncol Rep. 2010 Jul;24(1):113-9. doi: 10.3892/or_00000835.

Abstract

The ubiquitously expressed serine-threonine kinase Akt and the transcription factor NF-kappaB both are involved in cell proliferation and apoptosis. Furthermore, the activation of Akt or NF-kappaB has been suggested to associate with chemo-resistance of human tumors. The exact mechanism and interreaction of Akt and NF-kappaB pathway on chemoresistance in gastric cancer is still unknown. We explored the function of Akt and NF-kappaB pathway on chemoresistance in human gastric cancer cells. MTT method was used to analyze the influence of chemotherapeutics and the combined use of wortmannin or MG-132 on the growth of SGC-7901 cells. Apoptosis of SGC-7901 was detected by TUNEL and Annexin V/PI methods. The protein level of NF-kappaB was analyzed by immunocytochemical staining. EMSA was used to confirm the increased nuclear translocation of RelA. The protein level of p-Akt and p-IkappaBalpha were analyzed by Western blotting. Etoposide and doxorubicin suppressed the growth of SGC-7901 time and dose-dependently. Combined use of wortmannin or MG-132 can suppress growth further. Chemotherapeutics induced apoptosis of SGC-7901 and activated Akt and NF-kappaB, combined use of wortmannin or MG-132 induced apoptosis further and attenuated the activation of NF-kappaB. The combined use of wortmannin attenuated the activation of Akt, but combined use of MG-132 did not attenuate the activation of Akt. The activation of NF-kappaB is a branch mechanism of Akt anti-apoptosis effects. The chemotherapeutics induced apoptosis and induced the activation of Akt and NF-kappaB in SGC-7901 cell, suppression the activation of Akt or NF-kappaB can increase the effects of chemotherapeutics. NF-kappaB is a downstream target of Akt.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Androstadienes / administration & dosage
  • Androstadienes / pharmacology
  • Antineoplastic Combined Chemotherapy Protocols / pharmacology
  • Carcinoma / drug therapy
  • Carcinoma / metabolism*
  • Carcinoma / pathology
  • Cell Proliferation / drug effects
  • DNA / metabolism
  • Drug Evaluation, Preclinical
  • Drug Resistance, Neoplasm* / drug effects
  • Drug Resistance, Neoplasm* / physiology
  • Enzyme Inhibitors / administration & dosage
  • Enzyme Inhibitors / pharmacology
  • Humans
  • I-kappa B Proteins / metabolism
  • Leupeptins / administration & dosage
  • Leupeptins / pharmacology
  • NF-KappaB Inhibitor alpha
  • NF-kappa B / metabolism*
  • NF-kappa B / physiology
  • Oncogene Protein v-akt / antagonists & inhibitors
  • Oncogene Protein v-akt / metabolism*
  • Oncogene Protein v-akt / physiology*
  • Protein Binding / physiology
  • Stomach Neoplasms / drug therapy
  • Stomach Neoplasms / metabolism*
  • Stomach Neoplasms / pathology
  • Tumor Cells, Cultured
  • Wortmannin

Substances

  • Androstadienes
  • Enzyme Inhibitors
  • I-kappa B Proteins
  • Leupeptins
  • NF-kappa B
  • NFKBIA protein, human
  • NF-KappaB Inhibitor alpha
  • DNA
  • Oncogene Protein v-akt
  • benzyloxycarbonylleucyl-leucyl-leucine aldehyde
  • Wortmannin