Project description:The DNAJB1-PRKACA fusion transcript is the oncogenic driver in fibrolamellar hepatocellular carcinoma, a lethal disease lacking specific therapies. This study reports on the identification, characterization, and immunotherapeutic application of HLA-presented neoantigens specific for the DNAJB1-PRKACA fusion transcript in fibrolamellar hepatocellular carcinoma. DNAJB1-PRKACA-derived HLA class I and HLA class II ligands induce multifunctional cytotoxic CD8+ and T-helper 1 CD4+ T cells, and their cellular processing and presentation in DNAJB1-PRKACA expressing tumor cells is demonstrated by mass spectrometry-based immunopeptidome analysis. Single-cell RNA sequencing further identifies multiple T cell receptors from DNAJB1-PRKACA-specific T cells. Vaccination of a fibrolamellar hepatocellular carcinoma patient, suffering from recurrent short interval disease relapses, with DNAJB1-PRKACA-derived peptides under continued Poly (ADP-ribose) polymerase inhibitor therapy induces multifunctional CD4+ T cells, with an activated T-helper 1 phenotype and high T cell receptor clonality. Vaccine-induced DNAJB1-PRKACA-specific T cell responses persist over time and, in contrast to various previous treatments, are accompanied by durable relapse free survival of the patient for more than 21 months post vaccination. Our preclinical and clinical findings identify the DNAJB1-PRKACA protein as source for immunogenic neoepitopes and corresponding T cell receptors and provide efficacy in a single-patient study of T cell-based immunotherapy specifically targeting this oncogenic fusion.
Project description:The DNAJB1-PRKACA fusion transcript is the oncogenic driver in fibrolamellar hepatocellular carcinoma (FL-HCC), a lethal disease lacking specific therapies. Here, we report on the identification, characterization and first immunotherapeutic application of HLA-presented neoantigens specific for the DNAJB1-PRKACA fusion transcript in FL-HCC. To characterize the T cell response against DNAJB1-PRKACA-derived HLA class I and HLA class II ligands, single cell RNA sequencing (scRNA-seq) and single cell TCR profiling from CD4+ and CD8+ T cells were performed using 10x Genomics single cell immune profiling.
Project description:Most fibrolamellar carcinoma (FLC) is driven by a fusion of DNAJB1 and PRKACA, the catalytic subunit of protein kinase A (PKA). Overexpression of DNAJB1::PRKACA, ATP1B1::PRKACA or PRKACA, but not catalytically inactive kinase, caused similar transcriptomic changes of primary human hepatocytes; these recapitulated most changes observed in FLC. This is consistent with the observation that FLC is found in patients missing a regulatory subunit or with a ATP1B1::PRKACA fusion. Thus, the DNAJB1 domain is not required for FLC.
Project description:Fibrolamellar carcinoma (FLC) is a liver cancer of adolescents and young adults defined by fusion of the DNAJB1 heat shock protein and protein kinase A (PKA) catalytic subunit (DNAJB1-PRKACA). The resulting chimeric protein has increased kinase activity and is essential for FLC xenograft growth. However, the critical oncogenic pathways controlled by DNAJB1-PRKACA have not been defined. Here, we explored this question by studying patient-derived FLC models and engineered systems and analyzing patient samples. We show that the core function of DNAJB1-PRKACA is the direct phosphorylation and inactivation of the Salt-inducible kinases. This leads to deregulation of the CRTC2 co-activator and p300 acetyltransferase, resulting in transcriptional reprogramming and global increases in histone acetylation necessary for malignant growth. Our studies establish a central oncogenic mechanism of DNAJB1-PRKACA and suggest opportunities for therapeutic targeting of CRTC2/p300 in FLC. Notably, these findings link this signature fusion oncoprotein of a rare cancer type to more common cancer gene alterations involving the STK11 tumor suppressor and GNAS oncogene, which also function via SIK suppression.
Project description:Most fibrolamellar carcinoma (FLC) is driven by a fusion of DNAJB1 and PRKACA, the catalytic subunit of protein kinase A (PKA). PKA holoenzyme activity is controlled through a regulatory protein (R) that both inhibits and localizes catalytic activity. An excess of regulatory subunits ensures PRKACA activity is normally inhibited. In FLC patient tumors driven by DNAJB1::PRKACA we find an increase in the ratio of catalytic to regulatory units by mass spectrometry, biochemistry and immunofluorescence, with increased kinase in the nucleus. Overexpression of DNAJB1::PRKACA, ATP1B1::PRKACA or PRKACA, but not catalytically inactive kinase, caused similar transcriptomic changes of primary human hepatocytes; these recapitulated most changes observed in FLC. This is consistent with the observation that FLC is found in patients missing a regulatory subunit or with a ATP1B1::PRKACA fusion. Thus, the DNAJB1 domain is not required for FLC. Instead, changes in PKA quantity and localization determine the FLC phenotype.
Project description:Background & Aims: Fibrolamellar hepatocellular carcinoma (FLC) is a rare primary hepatic cancer usually developed in non-cirrhotic livers of children and young adults with unknown etiology. Treatment is limited to surgical intervention. To date, molecular pathogenesis of FLC has been poorly characterized. Herein, we aim to provide an integrative genomic analysis from a large series of FLC patients. Methods: A clinically annotated cohort of 77 FLCs was analyzed through wholetranscriptome, SNP-array and whole-exome sequencing. Non-negative matrix factorization was performed for class discovery, and GSEA, NTP, IPA and immunohistochemistry for functional annotation. GISTIC algorithm identified chromosomal aberrations; Mutect and VarScan2, somatic mutations, and Random survival forest the prognostic signature, validated in an independent cohort. Results: Unsupervised gene expression clustering revealed 3 robust molecular classes: Proliferation-51%, enriched with liver cancer proliferation signatures and mTOR signaling activation, Inflammation-26%, with pro-inflammatory cytokines signatures, and Unannotated-23%, with non-liver-related cancer signatures. Neuroendocrine genes and cholangiocyte and hepatocyte histological markers were present in all classes. FLC showed few copy number variations, being the most frequent: focal amplification at 8q24.3(12.5%), and deletions at 19p13(28%) and 22q13.32(25%). DNAJB1-PRKACA fusion transcript was observed in 79% of cases. FLC tumors had 32 damaging mutations on average, affecting uncommon genes in liver neoplasms (BRCA2, U2AF1). An 8-gene prognostic signature predicted survival in FLC patients. Conclusions: FLC genomic analysis reveals a unique molecular portrait characterized by uncommon damaging mutations and chromosomal aberrations, and a highly prevalent fusion protein. Three molecular classes, including Proliferation and Inflammation, define the biological behavior. Prognostic signature will allow better patient stratification. Gene-expression profiles of fresh frozen human fibrolamellar hepatocellular carcinoma
Project description:Background & Aims: Fibrolamellar hepatocellular carcinoma (FLC) is a rare primary hepatic cancer usually developed in non-cirrhotic livers of children and young adults with unknown etiology. Treatment is limited to surgical intervention. To date, molecular pathogenesis of FLC has been poorly characterized. Herein, we aim to provide an integrative genomic analysis from a large series of FLC patients. Methods: A clinically annotated cohort of 77 FLCs was analyzed through whole transcriptome, SNP-array and whole-exome sequencing. Non-negative matrix factorization was performed for class discovery, and GSEA, NTP, IPA and immunohistochemistry for functional annotation. GISTIC algorithm identified chromosomal aberrations; Mutect and VarScan2, somatic mutations, and Random survival forest the prognostic signature, validated in an independent cohort. Results: Unsupervised gene expression clustering revealed 3 robust molecular classes: Proliferation-51%, enriched with liver cancer proliferation signatures and mTOR signaling activation, Inflammation-26%, with pro-inflammatory cytokines signatures, and Unannotated-23%, with non-liver-related cancer signatures. Neuroendocrine genes and cholangiocyte and hepatocyte histological markers were present in all classes. FLC showed few copy number variations, being the most frequent: focal amplification at 8q24.3(12.5%), and deletions at 19p13(28%) and 22q13.32(25%). DNAJB1-PRKACA fusion transcript was observed in 79% of cases. FLC tumors had 32 damaging mutations on average, affecting uncommon genes in liver neoplasms (BRCA2, U2AF1). An 8-gene prognostic signature predicted survival in FLC patients. Conclusions: FLC genomic analysis reveals a unique molecular portrait characterized by uncommon damaging mutations and chromosomal aberrations, and a highly prevalent fusion protein. Three molecular classes, including Proliferation and Inflammation, define the biological behavior. Prognostic signature will allow better patient stratification. Gene-expression profiles of formalin-fixed, paraffin-embedded human fibrolamellar hepatocellular carcinoma
Project description:To identify targets in Fibrolamellar cancer (FLC), we introduced the FLC driver gene mutation (DNAJB1-PRKACA) into HepG2 cells to engineer FLC cell lines. We then performed gene expression profiling analysis using data obtained from RNA-seq of 6 different cell samples from HepG2, H33 (FLC cell line) and H12 (FLC cell line)