Sampling-dependent up-regulation of gene expression in sequential samples of human airway epithelial cells.

Publication Type	Academic Article
Authors	Heguy A, Harvey B, O'Connor T, Hackett N, Crystal R
Journal	Mol Med
Volume	9
Issue	9-12
Pagination	200-8
Date Published	01/01/2003
ISSN	1076-1551
Keywords	Epithelial Cells, Gene Expression, Respiratory System, Up-Regulation
Abstract	As part of a study of in vivo gene expression levels in the human airway epithelium in response to chronic cigarette smoking, we have identified a number of genes whose expression levels are altered in a time-dependent fashion resulting from the procedure used to sample epithelial cells. Fiberoptic bronchoscopy and airway epithelium brushing were used to obtain independent samples from a single individual, 1st from the right lung, followed by sampling of the left lung. We observed that a specific subset of early response genes encoding proteins involved in transcription, signal transduction, cell cycle/growth, and apoptosis were significantly up-regulated in the left lung samples (the 2nd region to be sampled) compared with the right lung samples (the 1st region to be sampled). This response was due to the temporal nature of the sampling procedure and not to inherent gene expression differences between airway epithelium of the right and left lungs. When the order of sampling was reversed, with the left airway epithelium sampled 1st, the same subset of genes were up-regulated in the samples obtained from the right airway epithelium. The time-dependent up-regulation of these genes was likely in response to the stress of the procedure and/or the anesthesia used. Sampling-dependent uncertainty of gene expression is likely a general phenomenon relevant to the procedures used for obtaining biological samples, particularly in humans where the sampling procedures are dependent on ensuring comfort and safety.
DOI	10.2119/2003-00051.crystal
PubMed ID	15208741
PubMed Central ID	PMC1430986