A new specific gene expression in squamous cell carcinoma of the esophagus detected using representational difference analysis and cDNA microarray.

OBJECTIVES To detect new specific gene expressions in squamous cell carcinoma of the esophagus. METHODS Representational difference analysis of cDNA (cDNA RDA) was applied to a human esophageal cancer cell line (KYSE170) and a human esophageal epithelial cell line (HEEC-1). RESULTS LAGE-1 was expressed specifically in KYSE170, but not in HEEC-1. It is also expressed in 27% of esophageal cancer cell lines (3/11) and 33% of esophageal cancer tissues (10/30), but not in other HEECs, normal esophageal epithelium, or other normal tissues except testis, ovary and kidney. The expression of LAGE-1 is strongly correlated with that of MAGE-A1 (p = 0.013, Fisher's exact probability test). Fibronectin, cytokeratin 6B, cytokeratin 19, cyclin D2 and Ten-m2 were detected as candidates for downregulated genes. Reduced expression profiles of them were also identified using cDNA microarrays. The expression of LAGE-1 was induced by 5'-aza-2'-deoxycytidine (5Aza-dC) and trichostatin A (TSA) in esophageal cancer cell lines, which did not express LAGE-1. In HEECs, 5Aza-dC induced LAGE-1 expression, but TSA did not. CONCLUSIONS LAGE-1 expression was detected in esophageal cancer by cDNA RDA. LAGE-1 might have the potential to be a target antigen for anti-tumoral immunotherapy in esophageal cancers because of its tumor-specific expression similar to that of MAGE-A1.