Glucocorticoid-induced glucocorticoid-receptor expression and promoter usage is not linked to glucocorticoid resistance in childhood ALL

Wim J. E. Tissing, Jules P. P. Meijerink*, Bas Brinkhof, Mathilde J. C. Broekhuis, Renee X. Menezes, Monique L. den Boer, Rob Pieters

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

58 Citations (Scopus)

Abstract

Glucocorticoid (GC) resistance is an adverse prognostic factor in childhood acute lymphoblastic leukemia (ALL), but little is known about causes of GC resistance. Up-regulation of the glucocorticoid receptor (GR) has been suggested as an essential step to the induction of apoplosis in leukemic cells. In this study we investigated whether baseline mRNA expression levels of the 5 different GR promoter transcripts (1A1, 1A2, 1A3, 1B, and 1C) or differences in the degree of regulation of the GR or GR promoter transcripts upon GC exposure are related to GC resistance. Therefore, mRNA levels of the 5 GR promoter transcripts and of the GR were measured by quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR; Taqman) technology in primary ALL cells prior to and after 3, 8, and 24 hours of prednisolone exposure. GR expression is induced upon GC expo- sure in primary ALL patient samples, which is opposite to what is found in tissues in which GCs do not induce apoptosis. GC resistance in childhood ALL cannot be attributed to an inability of resistant cells to up-regulate the expression of the GR upon GC exposure, nor to differences in GR promoter usage (at baseline and upon GC exposure).

Original languageEnglish
Pages (from-to)1045-1049
Number of pages5
JournalBlood
Volume108
Issue number3
DOIs
Publication statusPublished - 1-Aug-2006

Keywords

  • ACUTE LYMPHOBLASTIC-LEUKEMIA
  • INDUCED CELL-DEATH
  • INDUCED APOPTOSIS
  • DRUG-SENSITIVITY
  • 1A PROMOTER
  • LONG-TERM
  • T-CELLS
  • GENE
  • CHILDREN
  • LINES

Cite this