Airway gene expression is dynamic with corticosteroid treatment and reflects disease activity

ABSTRACT: Introduction: In the recently completed Dutch GLUCOLD study, treatment of COPD patients with fluticasone ± salmeterol reduced the rate of decline in FEV1. These results indicate that ICS can have therapeutic efficacy in COPD. Aim: To explore the molecular mechanisms by which ICS exert their effects, we performed genome-wide gene expression profiling on bronchial biopsies from COPD patients who participated in the GLUCOLD study. Methods: An Affymetrix Human Gene Array ST version 1.0 was performed in a total of 221 bronchial biopsies that were available from 90 COPD patients at baseline and after 6 and 30 months of therapy. Linear mixed effects modeling was used to analyze treatment-specific changes in gene expression. A validation set was included and pathway analysis was performed with Gene Set Enrichment Analysis (GSEA). Results: The expression of 138 genes significantly decreased after both 6 and 30 months of treatment with fluticasone ± salmeterol versus placebo, whereas the expression of 140 genes increased. A more pronounced treatment-induced change in expression of 51 of these 278 genes was associated with a slower rate of decline in FEV1. Genes that decreased with treatment were involved in pathways related to cell cycle, oxidative phosphorylation, epithelial cell signaling, p53 signaling and T cell signaling. Genes that increased with treatment were involved in pathways related to focal adhesion, gap junction and extracellular matrix deposition. Conclusion: The present study suggests that gene expression in biological pathways of COPD is dynamic with treatment and reflects disease activity. This study opens the gate to targeted and phenotype-driven therapy of COPD. First, a total of 162 samples were analysed (RNA derived from bronchial biopsies from COPD patients before and after treatment with fluticasone +/- salmeterol or placebo [GLUCOLD study]), 107 samples before and after 6 and 30 months of treatment with fluticasone +/- salmeterol and 55 samples before and after treatment with placebo. A total of 278 genes were found that changed in expression after both 6 and 30 months of treatment with fluticasone +/- salmeterol versus placebo. Next, an additional number of 59 samples from the fouth GLUCOLD treatment were put on array. In this study arm, COPD patients were treated for 6 months with fluticasone and then fluticasone was discontinued and patients switched to placebo for the remaining 24 months of the study.

ORGANISM(S): Homo sapiens

SUBMITTER: Maarten van den Berge 

PROVIDER: E-GEOD-36221 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress