Long read sequencing reveals sequential complex rearrangements driven by Hepatitis B virus integration

Integration of Hepatitis B virus (HBV) into human genome disrupts genetic structures and cellular functions. Here, we conducted multiplatform long read sequencing on two cell lines and five clinical samples of HBV-infected hepatocellular carcinomas (HCC). We resolved three types of viral integration-induced complex genome rearrangements (CGR) and proposed a model of multi-hits and sequential-breaks to depict their formation process by differentiating inserted HBV copies with HiFi long reads. We deduced that all three complex types were initialized from focal replacement and fragile virus-human junctions triggered subsequent rearrangements. We further revealed that such rearrangements caused a prevalent loss-of-heterozygosity at chr4q, accounting for 19.5% of HCC samples in ICGC cohort and contributing to immune and metabolic dysfunction. Overall, our long read based analysis reveals novel sequential rearrangement processes initiated by HBV integration, hinting its structural and functional impact on HCC.