Clinical and demographic predictors of survival for fibrolamellar carcinoma patients-A patient community, registry-based study

A novel high-throughput screening platform to identify inhibitors of DNAJB1-PRKACA-driven transcriptional activity in fibrolamellar carcinoma

Fibrolamellar carcinoma (FLC) is a primary liver cancer with a poor prognosis, primarily due to the lack of effective chemotherapeutic options. The DNAJB1-PRKACA (DP) gene fusion is recognized as the key oncogenic driver in FLC. This fusion arises from a ∼400 kb heterozygous deletion on chromosome 19, which fuses exon 1 of DNAJB1 with exons 2-10 of PRKACA, the gene encoding the catalytic subunit of protein kinase A (PKA). While targeting DP is considered a promising therapeutic approach, attempts to inhibit the kinase function of the DP fusion protein have been largely unsuccessful due to off-target effects on wild-type PKA. In response to this challenge, we developed a high-throughput screening (HTS) assay to identify inhibitors of DP's downstream signaling pathways involved in transcriptional regulation. Our previous research identified LINC00473 as a transcriptional marker for DP protein expression, and LINC00473 is known to be upregulated in FLC tumors. Additionally, evidence suggests that LINC00473 promotes FLC tumor growth. Based on the relationship between DP and LINC00473 expression, we engineered the HEK-DP-Luc reporter cell line by modifying HEK293 cells to express DP at the endogenous locus and to express the NanoLuc luciferase gene under the control of the LINC00473 promoter and enhancer. We have optimized the HEK-DP-Luc cells for HTS, and here we present our pipeline for primary screening and counter-screening to identify compounds that inhibit DP's downstream transcriptional activity. This HTS platform provides a novel approach for therapeutic drug discovery in FLC.

Evolving Global Etiology of Hepatocellular Carcinoma (HCC): Insights and Trends for 2024

The epidemiology of HCC is changing all over the world and the incidence of HCC is expected to continue increasing over the next 30 years. The changes are in the predisposing factors. Hepatitis B and hepatitis C as predisposing etiologies are decreasing while NAFLD/MAFLD is increasing. The increase in MAFLD is so great that despite the decrease in hepatitis B and C, the overall incidence of HCC is increasing. HCC in persons below the age of 20 years has distinct characteristics different from that of HCC in adults. The changing etiology of hepatocellular carcinoma has implications for the early detection, prevention, the stage of HCC at time of detection and in the treatment of HCC. The extent of these changes and their significance are discussed.

Liver cancer multiomics reveals diverse protein kinase A disruptions convergently produce fibrolamellar hepatocellular carcinoma

Fibrolamellar Hepatocellular Carcinoma (FLC) is a rare liver cancer characterized by a fusion oncokinase of the genes DNAJB1 and PRKACA, the catalytic subunit of protein kinase A (PKA). A few FLC-like tumors have been reported showing other alterations involving PKA. To better understand FLC pathogenesis and the relationships among FLC, FLC-like, and other liver tumors, we performed a massive multi-omics analysis. RNA-seq data of 1412 liver tumors from FLC, hepatocellular carcinoma, hepatoblastoma and intrahepatic cholangiocarcinoma are analyzed, obtaining transcriptomic signatures unrestricted by experimental processing methods. These signatures reveal which dysregulations are unique to specific tumors and which are common to all liver cancers. Moreover, the transcriptomic FLC signature identifies a unifying phenotype for all FLC tumors regardless of how PKA was activated. We study this signature at multi-omics and single-cell levels in the first spatial transcriptomic characterization of FLC, identifying the contribution of tumor, normal, stromal, and infiltrating immune cells. Additionally, we study FLC metastases, finding small differences from the primary tumors.

Liver-directed therapies for fibrolamellar carcinoma: A single-center experience

Background

This article aims to present the single-institution outcomes of patients with Fibrolamellar Carcinoma (FLC) treated with liver-directed therapies (LDT).

Methods

In this single-center retrospective study, all patients diagnosed with FLC who underwent LDT were identified. Between July 2012 and July 2023, six patients were identified. One patient was excluded due to bleeding. Demographic and clinical parameters were recorded. Complications within 30 days of the LDT were evaluated. Radiological treatment responses at 1, 6, and 12 months were assessed per mRECIST.

Results

A total of five patients, which included three females and two males, were reviewed. Three patients were treated with transarterial hepatic embolization (TAE; n = 3), transarterial radioembolization (TARE; n = 1), and combined TAE + radiofrequency ablation (n = 1). The objective response rate at one month was 80% [CR = 2 (40%), PR = 2 (40%), and SD = 1 (20%)]. At 12 months (n = 4), two patients demonstrated CR (50%) and two demonstrated PR (50%). Overall survival from LDT at five years was 50%. There was no 30-day mortality among this group of patients or any adverse event attributable to the LDT.

Conclusion

TAE, TARE, and ablation are safe and effective therapeutic options for FLC. Based on this study and previously published case reports, ablation and TARE yielded the most favorable results.

DNAJB1-PRKACA fusion neoantigens elicit rare endogenous T cell responses that potentiate cell therapy for fibrolamellar carcinoma

Fibrolamellar carcinoma (FLC) is a liver tumor with a high mortality burden and few treatment options. A promising therapeutic vulnerability in FLC is its driver mutation, a conserved DNAJB1-PRKACA gene fusion that could be an ideal target neoantigen for immunotherapy. In this study, we aim to define endogenous CD8 T cell responses to this fusion in FLC patients and evaluate fusion-specific T cell receptors (TCRs) for use in cellular immunotherapies. We observe that fusion-specific CD8 T cells are rare and that FLC patient TCR repertoires lack large clusters of related TCR sequences characteristic of potent antigen-specific responses, potentially explaining why endogenous immune responses are insufficient to clear FLC tumors. Nevertheless, we define two functional fusion-specific TCRs, one of which has strong anti-tumor activity in vivo. Together, our results provide insights into the fragmented nature of neoantigen-specific repertoires in humans and indicate routes for clinical development of successful immunotherapies for FLC.

Reversing immunosuppression in the tumor microenvironment of fibrolamellar carcinoma via PD-1 and IL-10 blockade

Fibrolamellar carcinoma (FLC) is a rare liver tumor driven by the DNAJ-PKAc fusion protein that affects healthy young patients. Little is known about the immune response to FLC, limiting rational design of immunotherapy. Multiplex immunohistochemistry and gene expression profiling were performed to characterize the FLC tumor immune microenvironment and adjacent non-tumor liver (NTL). Flow cytometry and T cell receptor (TCR) sequencing were performed to determine the phenotype of tumor-infiltrating immune cells and the extent of T cell clonal expansion. Fresh human FLC tumor slice cultures (TSCs) were treated with antibodies blocking programmed cell death protein-1 (PD-1) and interleukin-10 (IL-10), with results measured by cleaved caspase-3 immunohistochemistry. Immune cells were concentrated in fibrous stromal bands, rather than in the carcinoma cell compartment. In FLC, T cells demonstrated decreased activation and regulatory T cells in FLC had more frequent expression of PD-1 and CTLA-4 than in NTL. Furthermore, T cells had relatively low levels of clonal expansion despite high TCR conservation across individuals. Combination PD-1 and IL-10 blockade signficantly increased cell death in human FLC TSCs. Immunosuppresion in the FLC tumor microenvironment is characterized by T cell exclusion and exhaustion, which may be reversible with combination immunotherapy.

Current Advances in the Treatment of Fibrolamellar Carcinoma of Liver

Fibrolamellar carcinoma (FLC) of the liver is a rare type of liver cancer that is prevalent in children and young adults, often less than 40 years old. The etiology is unclear. It presents without underlying liver disease with distinctive histological features such as fibrous collagen bands surrounding the tumor cells. Fusion protein DNAJB1-PRKACA is found in most of the cases. The prognosis of FLC is poor. Even though curative treatment option is surgery for a certain patient population, other treatment modalities including radiation, chemotherapy are currently being used without significant improvement of overall survival. Recently, targeted therapy and immunotherapy have been studied which may provide survival advantage in the future. This review sought to compile data from clinical trials and case reports/series to outline the current state of FLC treatment.

Fighting rare cancers: lessons from fibrolamellar hepatocellular carcinoma

The fight against rare cancers faces myriad challenges, including missed or wrong diagnoses, lack of information and diagnostic tools, too few samples and too little funding. Yet many advances in cancer biology, such as the realization that there are tumour suppressor genes, have come from studying well-defined, albeit rare, cancers. Fibrolamellar hepatocellular carcinoma (FLC), a typically lethal liver cancer, mainly affects adolescents and young adults. FLC is both rare, 1 in 5 million, and problematic to diagnose. From the paucity of data, it was not known whether FLC was one cancer or a collection with similar phenotypes, or whether it was genetically inherited or the result of a somatic mutation. A personal journey through a decade of work reveals answers to these questions and a road map of steps and missteps in our fight against a rare cancer.