, Volume 19, Issue 1, pp 241–258 | Cite as

Targeting elongation factor-2 kinase (eEF-2K) induces apoptosis in human pancreatic cancer cells

  • Ahmed A. Ashour
  • Abdel-Aziz H. Abdel-Aziz
  • Ahmed M. Mansour
  • S. Neslihan Alpay
  • Longfei Huo
  • Bulent OzpolatEmail author
Original Paper


Pancreatic cancer (PaCa) is one of the most aggressive, apoptosis-resistant and currently incurable cancers with a poor survival rate. Eukaryotic elongation factor-2 kinase (eEF-2K) is an atypical kinase, whose role in PaCa survival is not yet known. Here, we show that eEF-2K is overexpressed in PaCa cells and its down-regulation induces apoptotic cell death. Rottlerin (ROT), a polyphenolic compound initially identified as a PKC-δ inhibitor, induces apoptosis and autophagy in a variety of cancer cells including PaCa cells. We demonstrated that ROT induces intrinsic apoptosis, with dissipation of mitochondrial membrane potential (ΔΨm), and stimulates extrinsic apoptosis with concomitant induction of TNF-related apoptosis inducing ligand (TRAIL) receptors, DR4 and DR5, with caspase-8 activation, in PANC-1 and MIAPaCa-2 cells. Notably, while none of these effects were dependent on PKC-δ inhibition, ROT down-regulates eEF-2K at mRNA level, and induce eEF-2K protein degradation through ubiquitin–proteasome pathway. Down-regulation of eEF-2K recapitulates the events observed after ROT treatment, while its over-expression suppressed the ROT-induced apoptosis. Furthermore, eEF-2K regulates the expression of tissue transglutaminase (TG2), an enzyme previously implicated in proliferation, drug resistance and survival of cancer cells. Inhibition of eEF-2K/TG2 axis leads to caspase-independent apoptosis which is associated with induction of apoptosis-inducing factor (AIF). Collectively, these results indicate, for the first time, that the down-regulation of eEF-2K leads to induction of intrinsic, extrinsic as well as AIF-dependent apoptosis in PaCa cells, suggesting that eEF-2K may represent an attractive therapeutic target for the future anticancer agents in PaCa.


eEF-2K TG2 PKC delta Rottlerin Pancreatic cancer Apoptosis 



The authors would like to thank Dr. Kevin N. Dalby, and his laboratory members, Division of Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, for helpful discussions and critically reading the manuscript.

Supplementary material

10495_2013_927_MOESM1_ESM.docx (164 kb)
Supplementary material 1 (DOCX 163 kb)
10495_2013_927_MOESM2_ESM.docx (12 kb)
Supplementary material 2 (DOCX 11 kb)


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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Ahmed A. Ashour
    • 1
    • 2
  • Abdel-Aziz H. Abdel-Aziz
    • 2
  • Ahmed M. Mansour
    • 2
  • S. Neslihan Alpay
    • 2
  • Longfei Huo
    • 3
  • Bulent Ozpolat
    • 1
    • 4
    Email author
  1. 1.Department of Experimental Therapeutics, Unit 422The University of Texas, M.D. Anderson Cancer CenterHoustonUSA
  2. 2.Department of Pharmacology and Toxicology, Faculty of PharmacyAl-Azhar UniversityCairoEgypt
  3. 3.Department of Molecular & Cellular OncologyThe University of Texas, M.D. Anderson Cancer CenterHoustonUSA
  4. 4.Non-Coding RNAThe University of Texas, M.D. Anderson Cancer CenterHoustonUSA

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