CD1d gene is a target for a novel amplicon at 1q22-23.1 in human hepatocellular carcinoma

Genome copy number variation (CNV) is one of the mechanisms to regulate the expression level of genes which contributes to the development and progression of cancer. In order to investigate the regions of high-level amplification and potential target genes within these amplicons in hepatocellular carcinoma (HCC), we analyzed HCC cell line (TJ3ZX-01) for CNV regions at the whole genome level using GeneChip Human Mapping 500K array, and also examined the relative copy number and expression levels of the related genes at candidate amplicons in 41 HCC tissues via real-time fluorescence quantitative PCR methods. Through analysis of sequence tag site(STS) markers by quantitative PCR, The two candidate amplicons at 1q found by SNP array were shown to occur in56.1% (23/41) HCC samples at 1q21 and 80.5% (33/41) at 1q22-23.1. Wilcoxon signed rank test showed expression of CD1d, which located at amplicon of 1q22-23.1 increased significantly within tumor tissues compared with paired nontumor tissues. Our study provides evidences that a novel, high-level amplicon at 1q22-23.1 occurs in both HCC cell line and tissues. CD1d is a potential target for this amplicon in HCC. The up-regulation of CD1d may be used as a novel molecular signature for diagnosis and prognosis of HCC.