Examining Smoking-Induced Differential Gene Expression Changes in Buccal Mucosa

Gene expression changes resulting from conditions such as disease, environmental stimuli, and drug use can be monitored in the blood. However, a less invasive method of sample collection is of interest because of the discomfort and specialized personnel necessary for blood sampling, especially if multiple samples are being collected. Buccal mucosa (cheek swabs) are easily collected and may be an alternative sample material for biomarker testing. A limited number of studies, primarily in the smoker/oral cancer literature, address this tissue’s efficacy as an RNA source for expression analysis. The current study was undertaken to determine if total RNA isolated from buccal mucosa could be used as an alternative tissue source to assay relative gene expression. In this study, qPCR and microarray analyses were used to evaluate gene expression in buccal cells. Initially, qPCR was used to assess relative transcript levels of four genes from whole blood and buccal cells collected from the same seven individuals at the same time. The RNA isolated from buccal cells was degraded but was of sufficient quality to be used with RT-qPCR to detect expression of specific genes. Second, buccal cell RNA was used for microarray-based differential gene expression studies by comparing gene expression between smokers and nonsmokers. An amplification protocol allowed use of 150-fold less buccal cell RNA than had been reported previously with human microarrays. The authors report here the finding of a small number of statistically significant differentially expressed genes between smokers and nonsmokers, using buccal cells as starting material. Gene Set Enrichment Analysis confirmed that these genes had a similar expression pattern as results from another study. The results suggest that despite a high degree of degradation, RNA from buccal cells from cheek mucosa could be used to detect differential gene expression between smokers and nonsmokers. However, the RNA degradation, increase in sample variability, and microarray failure rate show that buccal samples should be used with caution as source material in expression studies.

Language

  • English

Media Info

  • Media Type: Print
  • Edition: Final Report
  • Features: Figures; References; Tables;
  • Pagination: 30p

Subject/Index Terms

Filing Info

  • Accession Number: 01155057
  • Record Type: Publication
  • Files: NTL, TRIS, USDOT
  • Created Date: Apr 12 2010 12:03PM