Detailed analysis of 6p and 1q amplifications in urothelial carcinoma reveals SOX4 as an auxiliary target on 6p, and BCL9, CHDL1, MCL1, SETDB1, and HIF1B as putative targets on 1q.

ABSTRACT: Background: Previous array CGH analyses have revealed several recurring genomic alterations in urothelial carcinoma. The most common genomic amplifications occur at 6p22 and 1q21-24. The main target gene at 6p22 is believed to be E2F3. This gene is frequently co-amplified with CDKAL1 and SOX4 and there are reports on 6p22 amplifications that do not include the E2F3 locus. Previous array CGH analyses have indicated multiple possible target regions at 1q21-24. However, due to complex rearrangements it has been difficult to identify specific 1q21-24 target regions and target genes. Results: We show that the most commonly amplified gene at 6p22 is SOX4 and that SOX4 can be amplified and over expressed without E2F3 or CDKAL1 being included in the amplicon. Hence, our data point to SOX4 as an auxiliary amplification target at 6p22. We further show that at least three amplified regions are observed at 1q21-24. Copy number data, combined with gene expression data, highlighted BCL9 and CHD1L as possible targets in the most proximal region and MCL1, SETDB1, and HIF1B as targets in the middle region, whereas no obvious gene targets could be determined in the most distal amplicon. We also highlight the enrichment of G4 quadruplex sequence motifs and the high number of intraregional sequence duplications, both known to contribute to genomic instability, as prominent features of the 1q21-24 region. Conclusions: Our detailed analyses of the 6p22 amplicon in urothelial carcinomas suggest SOX4 as an auxiliary target gene for amplification. We further demonstrate three separate target regions for amplification at 1q21-24 and identified BCL9, CHD1L, MCL1, SETDB1, and HIF1B as likely target genes within these regions.

ORGANISM(S): Homo sapiens

PROVIDER: GSE40938 | GEO | 2013/08/30

SECONDARY ACCESSION(S): PRJNA175405

REPOSITORIES: GEO