Coexistence of copy number increases of ZNF217 and CYP24A1 in colorectal cancers in a Chinese population

Evidence suggests that the amplification of chromosome 20q13 is common in colorectal cancers (CRCs). Certain candidate oncogenes located in this region are reported to be associated with tumorigenesis of the gastrointestinal tract. The functional impact of such regions should be extensively investigated in a large number of clinical samples. In this study, 145 CRC samples with matched adjacent normal tissues were collected from a Chinese population for copy number variation (CNV) analysis. Our results showed that both the copy numbers of 25-hydroxy vitamin D3 24-hydroxylase (CYP24A1) and zinc-finger protein 217 (ZNF217) were amplified in a relatively high percentage of CRC samples (51.1 and 60%, respectively). The mRNA expression levels of both CYP24A1 and ZNF217 were found to have increased in the collected CRC samples as compared to the matched adjacent normal tissues. ZNF217, but not CYP24A1, showed a positive correlation between copy number increases and mRNA overexpression. These findings suggest the potential role of CNVs of certain oncogenes in CRCs.