Expression data from human Esophageal squamous cell carcinoma (ESCC)

Downregulation is a common feature of tumor suppressor gene (TSG), which can be caused by allele deletion, promoter hypermethylation, histone deacetylation and posttranscriptional silencing by microRNA. Therefore, comparison of expression profiles by cDNA microarray between tumor and non-tumor tissues and characterization of downregulated genes in tumor specimens is a useful strategy to identify TSGs. To identify deregulated genes during ESCC development, Affemetrix cDNA microarray was applied to compare differentially expressed genes between 4 pairs of ESCC tumors and corresponding adjacent non-tumor tissues (#301, #327, #351 and #363), and one pair of esophageal dysplasia tissue and adjacent normal tissue (#314). Clinical specimens were collected from patients with ESCCs who underwent surgical resection of tumor tissues. Paired adjacent nontumor tissues from the proximal resection margins (>5 cm away from the ESCC sample) were also collected for RNA extraction and hybridization on affymetrix microarrays.