SNO is a probable target for gene amplification at 3q26 in squamous-cell carcinomas of the esophagus

Amplification of the 3q26 region appears to occur frequently among esophageal squamous cell carcinomas (ESCs). We examined ESC cell lines for amplification and expression levels of four genes in this region: SNO and EVI1, which encode proteins antagonizing transforming growth factor-beta signaling, and two other putative target genes, TERC and PIK3CA Amplification of SNO was accompanied by significant increases in its expression level, suggesting that this gene is activated in an amplification-dependent manner. SNO was also amplified in 5 of 44 primary ESCs (11.4%). However, expression levels of EVI1, TERC, and PIK3CA did not correlate with their copy-numbers, even though EVI1 and TERC showed the same amplification pattern as SNO. Taken together, the data suggest that of the four candidates, SNO is the most probable target in the 3q26 amplicon for involvement in the progression of ESC. (C) 2001 Academic Press.