About 50%–75% of hepatocellular carcinoma (HCC) cases present with multiple intrahepatic foci in the liver at diagnosis, with poor prognosis and limited therapeutic options available. In this study, we aimed to identify recurrent genetic alterations of multifocal HCC.Methods
Whole genome sequencing and RNA sequencing were performed in 12 tumours and six matched non-tumour liver tissue samples to screen recurrent alterations in multifocal tumours. The selected genes were then analysed using data from The Cancer Genome Atlas (TCGA). Their biological functions were explored by in vitro experiments. Clinical impact of targeted genes was assessed in 60 patients with multifocal HCC in our medical centre.Results
ZNF687, ANXA9 and RABIF were identified as top candidates for their copy number gain and upregulated transcriptional activity in 10 tumours. The mRNA expression of these genes was upregulated in tumour tissues, with a positive correlation with gene amplification in 370 HCC cases from TCGA. Functional studies of ZNF687, ANXA9 and RABIF revealed that they could significantly increase cell proliferation and migration. Furthermore, the protein expression of ZNF687 was significantly higher in tumour tissues as compared with their adjacent normal tissues and overexpression of ZNF687 was significantly associated with shortened recurrence-free survival and overall survival in patients with multifocal HCC.Conclusions
We have identified three recurrent genetic alterations of multifocal HCC - the amplification and overexpression of ZNF687, ANXA9 and RABIF, which were highly associated with intrahepatic metastasis. Our findings may inspire innovative therapeutic approaches for multifocal HCC.