The global gene expression in Barrett's esophagus in comparison to adjacent or histologically similar tissues has not been extensively studied.
Dr Hashem El-Serag and colleagues from Texas tested the feasibility of conducting gene arrays in endoscopically obtained mucosal specimens.
The investigators collected endoscopic biopsies from Barrett's esophagus, normal esophagus, antrum, duodenum, and sigmoid colon from 5 patients with Barrett's.
RNA was extracted and subjected to cDNA microarrays and gene expression was compared between Barrett's and control tissues.
Reverse transcription-polymerase chain reaction was conducted to confirm some of the findings.
The investigative team's main outcome was gene expression profiles in Barrett's tissues and 4 control sites.
|246 of 587 genes with different expression between Barrett's and duodenum were upregulated|
The 4 sites were squamous esophagus, antrum, duodenum, sigmoid colon.
On average, 2 biopsies by disposable jumbo biopsy forceps provided approximately 5 μg required for microarrays.
From the original number of 22,283 gene probes, 13,805 genes had a significant quality score and were subjected to further comparison.
Barrett's gene expression clustered most closely with that of antrum and least closely with squamous esophagus.
The team found that of the 587 genes that had different expression between Barrett's and duodenum, 246 were upregulated and 341 were downregulated.
The expression of genes involved in apoptosis, negative regulation of apoptosis, and inflammatory response was lower in Barrett's compared to squamous esophagus.
The investigators observed that none of the gene groups were significantly overexpressed in Barrett's compared to squamous esophagus or antrum.
The reverse transcription-polymerase chain reaction confirmed the results of microarrays.
Dr El-Serag's team concludes, “Microarray-based studies are feasible in endoscopically obtained tissues.”
“Differences in gene expression could identify potential markers, and shed light on the pathogenesis of Barrett's esophagus.”