Journal of Cancer Research and Clinical Oncology

, Volume 131, Issue 6, pp 347–354

Evaluation of glucocorticoid sensitivity in 697 pre-B acute lymphoblastic leukemia cells after overexpression or silencing of MAP kinase phosphatase-1

Authors

  • Marc T. Abrams
    • Department of Biochemistry and Molecular PharmacologyThomas Jefferson University
  • Noreen M. Robertson
    • A.J. Drexel Institute of Basic and Applied Protein ScienceDrexel University School of Medicine
  • Gerald Litwack
    • Department of Biochemistry and Molecular PharmacologyThomas Jefferson University
    • Department of Biochemistry and Molecular PharmacologyThomas Jefferson University
Original Paper

DOI: 10.1007/s00432-004-0659-3

Cite this article as:
Abrams, M.T., Robertson, N.M., Litwack, G. et al. J Cancer Res Clin Oncol (2005) 131: 347. doi:10.1007/s00432-004-0659-3

Abstract

Purpose

To determine the effect of modulating MAP kinase phosphatase-1 (MKP-1) expression levels on cell death induced by glucocorticoid (GC) or hydroxyurea (HU) treatment in the human pre-B acute lymphoblastic leukemia cell line 697.

Methods

Stable MKP-1 overexpressing transformants of the 697 pre-B acute lymphoblastic leukemia cell line were created and tested for sensitivity to the GC triamcinolone acetonide (TA) and HU, and compared to a control 697 cell line containing normal MKP-1 expression levels. Small interfering RNAs (siRNAs) were designed to inhibit MKP-1 expression and evaluated for their effect on GC-mediated cell death.

Results

MKP-1 overexpression caused a phenotype of partial resistance to HU-induced apoptosis but not to GC-induced apoptosis. Electroporation of siRNAs effectively silenced MKP-1 expression, and increased sensitivity to TA by 9.6±1.9%.

Conclusions

Because MKP-1 protects certain tumor cells from chemotherapy-induced apoptosis, its inhibition is being considered as a possible strategy for combination cancer therapy. However, this study suggests that while MKP-1 inhibition may improve the efficacy of DNA damaging agents, it may have only limited utility in combination with glucocorticoids.

Keywords

GlucocorticoidApoptosisMKP-1siRNAALL

Abbreviations

GC

Glucocorticoid

ALL

Acute lymphoblastic leukemia

GR

Glucocorticoid receptor

MKP-1

MAP kinase phosphatase-1

RNAi

RNA interference

siRNA

Small-interfering RNA

FITC

Fluorescein isothiocyanate

μF

Microfarads

TA

Triamcinolone acetonide

HU

Hydroxyurea

RT-PCR

Reverse transcriptase-polymerase chain reaction

7-AAD

7-aminoactinomycin D.

Copyright information

© Springer-Verlag 2005