A Novel Amplicon at 9p23‐24 in Squamous Cell Carcinoma of the Esophagus That Lies Proximal to GASC1 and Harbors NFIB

Abstract

The non‐random amplification of DNA at 9p23‐24 observed in various types of human cancers, including esophageal squamous cell carcinomas (ESCs), may reflect the locations of important tumor‐associated genes. Our previous studies using ESC cell lines defined an amplicon in this region and identified a novel gene, GASC1, as a target of the amplification. Since different regions within the same chromosome arm are often involved in amplification in a syntenic or non‐syntenic manner, we characterized the amplicon at 9p23‐24 in 35 ESC cell lines (29 KYSE series and 6 YES series), and examined possible involvement of non‐syntenic amplifications at 9p23‐24 in 32 primary ESCs. Our results clearly indicated that two target regions for DNA amplification exist at 9p23‐24; the major amplicon contains GASC1, and the minor one harbors a transcription factor, NFIB, centromeric to the GASC1 locus.