ABSTRACT
Hepatocellular carcinoma (HCC) has well-defined environmental risk factors. In addition, epidemiologic studies have suggested hereditary risk factors. The goals of this study were to determine the rate of pathogenic and likely pathogenic (P/LP) germline variants in cancer predisposition genes in patients with HCC, possible enrichment of P/LP variants in particular genes, and potential impact on clinical management. MATERIALS AND METHODS: A prospective study at a tertiary medical center enrolled 217 patients with a personal history of HCC. Multigene panel testing was performed for 134 cancer predisposition genes in all patients. The rate of P/LP variants was compared with population rates. A separate retrospective cohort included 219 patients with HCC who underwent testing at a commercial laboratory. RESULTS: In the prospective cohort, P/LP germline variants were identified in 25 of 217 patients with HCC (11.5%). Four patients (1.8%) had P/LP variants in the highly penetrant cancer genes BRCA2 (n = 2), MSH6 (n = 1), and PMS2 (n = 1). In addition, multiple patients had P/LP variants in FANCA (n = 5) and BRIP1 (n = 4), which were significantly enriched in HCC compared with the general population. Detection of P/LP variants led to changes in clinical management in regard to therapy selection, screening recommendations, and cascade testing of relatives. In a separate retrospective analysis of 219 patients with HCC, 30 (13.7%) were positive for P/LP variants including 13 (5.9%) with highly penetrant genes APC (n = 2), BRCA1 (n = 1), BRCA2 (n = 6), MSH2 (n = 2), or TP53 (n = 2). CONCLUSION: P/LP germline variants in cancer predisposition genes were detected in 11%-14% of patients with HCC. Inherited genetics should not be overlooked in HCC as there are important implications for precision treatment, future risk of cancers, and familial cancer risk.
Subject(s)
Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/genetics , Genetic Testing/methods , Liver Neoplasms/diagnosis , Liver Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Genetic Variation , Germ Cells , Humans , Male , Middle Aged , Prospective Studies , Retrospective StudiesABSTRACT
Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 activation (CRISPRa) systems have enabled genetic screens in cultured cell lines to discover and characterize drivers and inhibitors of cancer cell growth. We adapted this system for use in vivo to assess whether modulating endogenous gene expression levels can result in functional outcomes in the native environment of the liver. We engineered the catalytically dead CRISPR-associated 9 (dCas9)-positive mouse, cyclization recombination-inducible (Cre) CRISPRa system for cell type-specific gene activation in vivo. We tested the capacity for genetic screening in live animals by applying CRISPRa in a clinically relevant model of liver injury and repopulation. We targeted promoters of interest in regenerating hepatocytes using multiple single guide RNAs (gRNAs), and employed high-throughput sequencing to assess enrichment of gRNA sequences during liver repopulation and to link specific gRNAs to the initiation of carcinogenesis. All components of the CRISPRa system were expressed in a cell type-specific manner and activated endogenous gene expression in vivo. Multiple gRNA cassettes targeting a proto-oncogene were significantly enriched following liver repopulation, indicative of enhanced division of cells expressing the proto-oncogene. Furthermore, hepatocellular carcinomas developed containing gRNAs that activated this oncogene, indicative of cancer initiation events. Also, we employed our system for combinatorial cancer genetics in vivo as we found that while clonal hepatocellular carcinomas were dependent on the presence of the oncogene-inducing gRNAs, they were depleted for multiple gRNAs activating tumor suppressors. CONCLUSION: The in vivo CRISPRa platform developed here allows for parallel and combinatorial genetic screens in live animals; this approach enables screening for drivers and suppressors of cell replication and tumor initiation. (Hepatology 2017).
Subject(s)
Carcinogenesis/genetics , Carcinoma, Hepatocellular/genetics , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , Genetic Testing/methods , Liver Neoplasms/genetics , Animals , Blotting, Western , Gene Expression Regulation, Neoplastic/genetics , High-Throughput Nucleotide Sequencing , Immunohistochemistry , Liver/metabolism , Liver/pathology , Mice , Oncogenes , RNA, Guide, Kinetoplastida/metabolism , Real-Time Polymerase Chain Reaction , Transcriptional ActivationABSTRACT
Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) of the colon is a very rare disease that in previously reported cases was often mistaken for inflammatory bowel disease because of similar clinical characteristics. In our review of the literature, we found a total of 15 cases described, generally featuring sigmoid and rectal colitis and symptoms of abdominal pain, diarrhea, and hematochezia refractory to treatment with immunosuppressants. In all previously reported cases, the diagnosis was achieved only after surgical resection of the affected area. Herein, we report a case of IMHMV that was diagnosed preoperatively based on clinical information and endoscopy with biopsies. This led to the withdrawal of immunosuppression before a carefully planned surgical resection, with confirmation of the diagnosis in the resected tissue. To our knowledge, our case of IMHMV is the first to be diagnosed preoperatively.