Cancer Immunology, Immunotherapy

, Volume 57, Issue 3, pp 347–358

Cyclooxygenase-2 independent effects of cyclooxygenase-2 inhibitors on oxidative stress and intracellular glutathione content in normal and malignant human B-cells

  • Elizabeth P. Ryan
  • Timothy P. Bushnell
  • Alan E. Friedman
  • Irfan Rahman
  • Richard P. Phipps
Original Article

DOI: 10.1007/s00262-007-0374-4

Cite this article as:
Ryan, E.P., Bushnell, T.P., Friedman, A.E. et al. Cancer Immunol Immunother (2008) 57: 347. doi:10.1007/s00262-007-0374-4

Abstract

We recently reported that inhibition of Cyclooxygenase-2 (Cox-2) reduced human B-CLL proliferation and survival. Herein, we investigated the mechanisms whereby small molecule Cox-2 selective inhibitors, SC-58125 (a Celebrex analog) and CAY10404 blunt survival of human B-cell lymphomas and chronic lymphocytic leukemia B-cells. SC-58125 and OSU03012 (a Celebrex analog that lacks Cox-2 inhibitory activity) both decreased intracellular glutathione (GSH) content in malignant human B-cells, as well as in Cox-2 deficient mouse B-cells. This new finding supports Cox-2 independent effects of SC-58125. Interestingly, SC-58125 also significantly increased B-cell reactive oxygen species (ROS) production, suggesting that ROS are a pathway that reduces malignant cell survival. Addition of GSH ethyl ester protected B lymphomas from the increased mitochondrial membrane permeability and reduced survival induced by SC-58125. Moreover, the SC-58125-mediated GSH depletion resulted in elevated steady-state levels of the glutamate cysteine ligase catalytic subunit mRNA and protein. These new findings of increased ROS and diminished GSH levels following SC-58125 exposure support novel mechanisms whereby a Cox-2 selective inhibitor reduces malignant B-cell survival. These observations also support the concept that certain Cox-2 selective inhibitors may have therapeutic value in combination with other drugs to kill malignant B lineage cells.

Keywords

Cox-2Oxidative stressGlutathioneLymphomaB-cells

Abbreviations

Cox-2

Cyclooxygenase-2

GSH

Glutathione

ROS

Reactive oxygen species

GCL

Glutamate cysteine ligase

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Elizabeth P. Ryan
    • 1
  • Timothy P. Bushnell
    • 2
  • Alan E. Friedman
    • 1
  • Irfan Rahman
    • 1
  • Richard P. Phipps
    • 1
  1. 1.Department of Environmental Medicine, Lung Biology and Disease ProgramUniversity of Rochester School of Medicine and DentistryRochesterUSA
  2. 2.Department of Pediatrics, Center for Pediatric Biomedical ResearchUniversity of Rochester School of Medicine and DentistryRochesterUSA