Liang-Qing Dong1, Li-Hua Peng2, Li-Jie Ma1, Dong-Bing Liu3, Shu Zhang1, Shu-Zhen Luo2, Jun-Hua Rao2, Hong-Wen Zhu4, Shuai-Xi Yang1, Shui-Jun Xi1, Min Chen5, Fan-Fan Xie2, Fu-Qiang Li2, Wen-Hui Li2, Chen Ye2, Li-Ya Lin2, Yu-Jue Wang2, Xiao-Ying Wang1, Da-Ming Gao5, Hu Zhou4, Huan-Ming Yang6, Jian Wang6, Shi-da Zhu7, Xiang-Dong Wang8, Ya Cao9, Jian Zhou10, Jia Fan11, Kui Wu12, Qiang Gao13. 1. Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai 200032, China. 2. BGI-Shenzhen, Shenzhen 518083, China. 3. BGI-Shenzhen, Shenzhen 518083, China; Guangdong Provincial Key Laboratory of Human Disease Genomics, Shenzhen Key Laboratory of Genomics, BGI-Shenzhen, Shenzhen 518083, China. 4. Department of Analytical Chemistry and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China. 5. CAS Key Laboratory of Systems Biology, Innovation Center for Cell Signaling Network, CAS enter for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China. 6. BGI-Shenzhen, Shenzhen 518083, China; James D. Watson Institute of Genome Sciences, Hangzhou 310058, China. 7. BGI-Shenzhen, Shenzhen 518083, China; Department of Biology, University of Copenhagen, Copenhagen N DK-2200, Denmark. 8. Shanghai Institute of Clinical Bioinformatics, Zhongshan Hospital, Fudan University, Shanghai 200032, China. 9. Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha 410078, China. 10. Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai 200032, China; Key Laboratory of Medical Epigenetics and Metabolism, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China. 11. Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai 200032, China; Key Laboratory of Medical Epigenetics and Metabolism, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China; State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200433, China. 12. BGI-Shenzhen, Shenzhen 518083, China; Guangdong Provincial Key Laboratory of Human Disease Genomics, Shenzhen Key Laboratory of Genomics, BGI-Shenzhen, Shenzhen 518083, China; Department of Biology, University of Copenhagen, Copenhagen N DK-2200, Denmark. Electronic address: wukui@genomics.cn. 13. Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, and Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Fudan University, Shanghai 200032, China; Key Laboratory of Medical Epigenetics and Metabolism, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China. Electronic address: gaoqiang@fudan.edu.cn.
Abstract
BACKGROUND & AIMS: The presence of multifocal tumors, developed either from intrahepatic metastasis (IM) or multicentric occurrence (MO), is a distinct feature of hepatocellular carcinoma (HCC). Immunogenomic characterization of multifocal HCC is important for understanding immune escape in different lesions and developing immunotherapy. METHODS: We combined whole-exome/transcriptome sequencing, multiplex immunostaining, immunopeptidomes, T cell receptor (TCR) sequencing and bioinformatic analyses of 47 tumors from 15 patients with HCC and multifocal lesions. RESULTS: IM and MO demonstrated distinct clonal architecture, mutational spectrum and genetic susceptibility. The immune microenvironment also displayed spatiotemporal heterogeneity, such as less T cell and more M2 macrophage infiltration in IM and higher expression of inhibitory immune checkpoints in MO. Similar to mutational profiles, shared neoantigens and TCR repertoires among tumors from the same patients were abundant in IM but scarce in MO. Combining neoantigen prediction and immunopeptidomes identified T cell-specific neoepitopes and achieved a high verification rate in vitro. Immunoediting mainly occurred in MO but not IM, due to the relatively low immune infiltration. Loss of heterozygosity of human leukocyte antigen (HLA) alleles, identified in 17% of multifocal HCC, hampered the ability of major histocompatibility complex to present neoantigens, especially in IM. An integrated analysis of Immunoscore, immunoediting, TCR clonality and HLA loss of heterozygosity in each tumor could stratify patients into 2 groups based on whether they have a high or low risk of recurrence (p = 0.038). CONCLUSION: Our study comprehensively characterized the genetic structure, neoepitope landscape, T cell profile and immunoediting status that collectively shape tumor evolution and could be used to optimize personalized immunotherapies for multifocal HCC. LAY SUMMARY: Immunogenomic features of multifocal hepatocellular carcinoma (HCC) are important for understanding immune-escape mechanisms and developing more effective immunotherapy. Herein, comprehensive immunogenomic characterization showed that diverse genomic structures within multifocal HCC would leave footprints on the immune landscape. Only a few tumors were under the control of immunosurveillance, while others evaded the immune system through multiple mechanisms that led to poor prognosis. Our study revealed heterogeneous immunogenomic landscapes and immune-constrained tumor evolution, the understanding of which could be used to optimize personalized immunotherapies for multifocal HCC.
BACKGROUND & AIMS: The presence of multifocal tumors, developed either from intrahepatic metastasis (IM) or multicentric occurrence (MO), is a distinct feature of hepatocellular carcinoma (HCC). Immunogenomic characterization of multifocal HCC is important for understanding immune escape in different lesions and developing immunotherapy. METHODS: We combined whole-exome/transcriptome sequencing, multiplex immunostaining, immunopeptidomes, T cell receptor (TCR) sequencing and bioinformatic analyses of 47 tumors from 15 patients with HCC and multifocal lesions. RESULTS: IM and MO demonstrated distinct clonal architecture, mutational spectrum and genetic susceptibility. The immune microenvironment also displayed spatiotemporal heterogeneity, such as less T cell and more M2 macrophage infiltration in IM and higher expression of inhibitory immune checkpoints in MO. Similar to mutational profiles, shared neoantigens and TCR repertoires among tumors from the same patients were abundant in IM but scarce in MO. Combining neoantigen prediction and immunopeptidomes identified T cell-specific neoepitopes and achieved a high verification rate in vitro. Immunoediting mainly occurred in MO but not IM, due to the relatively low immune infiltration. Loss of heterozygosity of human leukocyte antigen (HLA) alleles, identified in 17% of multifocal HCC, hampered the ability of major histocompatibility complex to present neoantigens, especially in IM. An integrated analysis of Immunoscore, immunoediting, TCR clonality and HLA loss of heterozygosity in each tumor could stratify patients into 2 groups based on whether they have a high or low risk of recurrence (p = 0.038). CONCLUSION: Our study comprehensively characterized the genetic structure, neoepitope landscape, T cell profile and immunoediting status that collectively shape tumor evolution and could be used to optimize personalized immunotherapies for multifocal HCC. LAY SUMMARY: Immunogenomic features of multifocal hepatocellular carcinoma (HCC) are important for understanding immune-escape mechanisms and developing more effective immunotherapy. Herein, comprehensive immunogenomic characterization showed that diverse genomic structures within multifocal HCC would leave footprints on the immune landscape. Only a few tumors were under the control of immunosurveillance, while others evaded the immune system through multiple mechanisms that led to poor prognosis. Our study revealed heterogeneous immunogenomic landscapes and immune-constrained tumor evolution, the understanding of which could be used to optimize personalized immunotherapies for multifocal HCC.