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Edward R Kastenhuber,1,2 John Craig,3 Jon Ramsey,4 Kevin M Sullivan,5 Julien Sage,6,7 Sofia de Oliveira,8 Kimberly J Riehle,5 John D Scott,5 John D Gordan,9 Nabeel Bardeesy,10,11 Ghassan K Abou-Alfa1,12 1Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; 2Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA; 3Fibrolamellar Cancer Foundation, Greenwich, CT, USA; 4Department of Biochemistry, University of Vermont Cancer Center, Burlington, VT, USA; 5Northwest Liver Research Program, University of Washington, Seattle, WA, USA; 6Department of Pediatrics, Stanford University, Stanford, CA, USA; 7Department of Genetics, Stanford University, Stanford, CA, USA; 8Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, USA; 9Department of Medicine, University of California, San Francisco, San Francisco, CA, USA; 10Center for Cancer Research, Massachusetts General Hospital, Boston, MA, USA; 11Department of Medicine, Harvard Medical School, Boston, MA, USA; 12Department of Medicine, Weill Cornell School of Medicine, New York, NY, USA Abstract: Fibrolamellar carcinoma is a rare liver cancer, which primarily afflicts adolescents and young adults worldwide and is frequently lethal. Given the rarity of this disease, patient recruitment for clinical trials remains a challenge. In November 2017, the Second Fibrolamellar Cancer Foundation Scientific Summit (Stamford, CT, USA) provided an opportunity for investigators to discuss recent advances in the characterization of the disease and its surrounding liver and immune context. The Fibrolamellar Cancer Foundation has thus set out a road map to identify and test therapeutic targets in the most efficient possible manner. Keywords: fibrolamellar carcinoma, liver cancer, adolescent, young adult, fusion oncogene, cyclic AMP-dependent protein kinase catalytic subunit, heat shock protein 40

Adhesion to the extracellular matrix (ECM) is critical for epithelial tissue homeostasis and function. ECM detachment induces metabolic stress and programmed cell death via anoikis. ECM-detached mammary epithelial cells are able to rapidly activate autophagy allowing for survival and an opportunity for re-attachment. However, the mechanisms controlling detachment-induced autophagy remain unclear. Here we uncover that the kinase PERK rapidly promotes autophagy in ECM-detached cells by activating AMP-activated protein kinase (AMPK), resulting in downstream inhibition of mTORC1-p70(S6K) signaling. LKB1 and TSC2, but not TSC1, are required for PERK-mediated inhibition of mammalian target of rapamycinin MCF10A cells and mouse embryo fibroblast cells. Importantly, this pathway shows fast kinetics, is transcription-independent and is exclusively activated during ECM detachment, but not by canonical endoplasmic reticulum stressors. Moreover, enforced PERK or AMPK activation upregulates autophagy and causes luminal filling during acinar morphogenesis by perpetuating a population of surviving autophagic luminal cells that resist anoikis. Hence, we identify a novel pathway in which suspension-activated PERK promotes the activation of LKB1, AMPK and TSC2, leading to the rapid induction of detachment-induced autophagy. We propose that increased autophagy, secondary to persistent PERK and LKB1-AMPK signaling, can robustly protect cells from anoikis and promote luminal filling during early carcinoma progression.

The mechanisms controlling mammalian organ size have long been a source of fascination for biologists. These controls are needed to both ensure the integrity of the body plan and to restrict inappropriate proliferation that could lead to cancer. Regulation of liver size is of particular interest inasmuch as this organ maintains the capacity for regeneration throughout life, and is able to regain precisely its original mass after partial surgical resection. Recent studies using genetically engineered mouse strains have shed new light on this problem; the Hippo signalling pathway, first elucidated as a regulator of organ size in Drosophila, has been identified as dominant determinant of liver growth. Defects in this pathway in mouse liver lead to sustained liver overgrowth and the eventual development of both major types of liver cancer, hepatocellular carcinoma and cholangiocarcinoma. In this review, we discuss the role of Hippo signalling in liver biology and the contribution of this pathway to liver cancer in humans. [ABSTRACT FROM AUTHOR]

The mechanisms controlling mammalian organ size have long been a source of fascination for biologists. These controls are needed to both ensure the integrity of the body plan and to restrict inappropriate proliferation that could lead to cancer. Regulation of liver size is of particular interest inasmuch as this organ maintains the capacity for regeneration throughout life, and is able to regain precisely its original mass after partial surgical resection. Recent studies using genetically engineered mouse strains have shed new light on this problem; the Hippo signalling pathway, first elucidated as a regulator of organ size in \(Drosophila\), has been identified as dominant determinant of liver growth. Defects in this pathway in mouse liver lead to sustained liver overgrowth and the eventual development of both major types of liver cancer, hepatocellular carcinoma and cholangiocarcinoma. In this review, we discuss the role of Hippo signalling in liver biology and the contribution of this pathway to liver cancer in humans.

Abstract Background The genetics of advanced biliary tract cancers (BTC), which encompass intra- and extra-hepatic cholangiocarcinomas as well as gallbladder carcinomas, are heterogeneous and remain to be fully defined. Methods To better characterize mutations in established known oncogenes and tumor suppressor genes we tested a mass spectrometric based platform to interrogate common cancer associated mutations across a panel of 77 formalin fixed paraffin embedded archived BTC cases. Results Mutations among three genes, KRAS, NRAS and PIK3CA were confirmed in this cohort. Activating mutations in PIK3CA were identified exclusively in GBC (4/32, 12.5%). KRAS mutations were identified in 3 (13%) intra-hepatic cholangiocarcinomas and 1 (33%) perihillar cholangiocarcinoma but were not identified in gallbladder carcinomas and extra-hepatic cholangiocarcinoma. Conclusions The presence of activating mutations in PIK3CA specifically in GBC has clinical implications in both the diagnosis of this cancer type, as well as the potential utility of targeted therapies such as PI3 kinase inhibitors.

Novel therapeutic strategies are needed to improve the efficacy of chimeric antigen receptor (CAR) T cells as a treatment of solid tumors. Multiple tumor microenvironmental factors are thought to contribute to resistance to CAR T-cell therapy in solid tumors, and appropriate model systems to identify and examine these factors using clinically relevant biospecimens are limited. In this study, we examined the activity of B7-H3-directed CAR T cells (B7-H3.CAR-T) using 3D microfluidic cultures of patient-derived organotypic tumor spheroids (PDOTS) and then confirmed the activity of B7-H3.CAR T cells in PDOTS. Although B7-H3 expression in PDOTS was associated with B7-H3.CAR-T sensitivity, mechanistic studies revealed dynamic upregulation of co-inhibitory receptors on CAR T-cells following target cell encounter that led to CAR T-cell dysfunction and limited efficacy against B7-H3-expressing tumors. PD-1 blockade restored CAR T-cell activity in monotypic and organotypic tumor spheroids with improved tumor control and upregulation of effector cytokines. Given the emerging role of TANK-binding kinase 1 (TBK1) as an immune evasion gene, we examined the effect of TBK1 inhibition on CAR T-cell efficacy. Similar to PD-1 blockade, TBK1 inhibition restored CAR T-cell activity in monotypic and organotypic tumor spheroids, prevented CAR T-cell dysfunction, and enhanced CAR T-cell proliferation. Inhibition or deletion of TBK1 also enhanced the sensitivity of cancer cells to immune-mediated killing. Taken together, our results demonstrate the feasibility and utility of ex vivo profiling of CAR T cells using PDOTS and suggest that targeting TBK1 could be used to enhance CAR T-cell efficacy by overcoming tumor-intrinsic and -extrinsic resistance mechanisms., (©2025 American Association for Cancer Research.)

Pancreatic ductal adenocarcinoma (PDAC) poses a grim prognosis for patients. Recent multidisciplinary research efforts have provided critical insights into its genetics and tumor biology, creating the foundation for rational development of targeted and immune therapies. Here, we review the PDAC genomic landscape and the role of specific oncogenic events in tumor initiation and progression, as well as their contributions to shaping its tumor biology. We further summarize and synthesize breakthroughs in single-cell and metabolic profiling technologies that have illuminated the complex cellular composition and heterotypic interactions of the PDAC tumor microenvironment, with an emphasis on metabolic cross-talk across cancer and stromal cells that sustains anabolic growth and suppresses tumor immunity. These conceptual advances have generated novel immunotherapy regimens, particularly cancer vaccines, which are now in clinical testing. We also highlight the advent of KRAS targeted therapy, a milestone advance that has transformed treatment paradigms and offers a platform for combined immunotherapy and targeted strategies. This review provides a perspective summarizing current scientific and therapeutic challenges as well as practice-changing opportunities for the PDAC field at this major inflection point., (© 2025 Ying et al.; Published by Cold Spring Harbor Laboratory Press.)

Cholangiocarcinoma is an aggressive bile duct malignancy with heterogeneous genomic features. Although most patients receive standard-of-care chemotherapy/immunotherapy, genomic changes that can be targeted with established or emerging therapeutics are common. Accordingly, precision medicine strategies are transforming the next-line treatment for patient subsets. Hotspot IDH1 mutations and activating fibroblast growth factor receptor 2 fusions occur frequently, and small-molecule inhibitors against these alterations are US Food and Drug Administration approved. Translational and basic science studies have elucidated the mechanisms of response and resistance in cholangiocarcinoma, providing insights into these targets that extend to other cancers. Additional US Food and Drug Administration-approved and National Comprehensive Cancer Network guideline-recommended treatments for recurrent genomic changes include BRAF inhibition (BRAF-V600E) and trastumazab deruxtecan (human epidermal growth factor receptor 2 amplification). Furthermore, ongoing clinical trials show promising results with KRAS inhibition (KRAS-codon 12 mutations), PRTM5 inhibition, alone or with methylthioadenosine inhibition (5-methylthioadenosine phosphorylase deletion), and murine double minute 2 inhibition (murine double minute 2 amplification). Despite these advances, the rate, depth, and duration of response to each treatment need improvement. Moreover, many patients do not have currently targetable genotypes. In this review, we examine the clinical efficacy and mechanisms of resistance associated with these treatments, as well as insights into the molecular and biological effects of pathway activation and inhibition, based on study of patient samples and preclinical models. We also explore strategies to overcome resistance and possible precision medicine approaches for additional patient subsets., Competing Interests: Disclosure Statement H.E. received honoraria as a speaker (Jazz Pharmaceuticals) and consultant (Cogent Biosciences and Jazz Pharmaceuticals). C.B. received honoraria as a speaker (AstraZeneca and Incyte) and consultant (Incyte, Servier, Boehringer Ingelheim, AstraZeneca, Jazz Therapeutics, and Taiho), received research funds (Avacta, Medannex, and Servier), and her spouse is an employee of AstraZeneca. J.W.V. received honoraria/served on advisory boards (personal: AstraZeneca, Incyte, Taiho Oncology, Servier, and Jazz Pharmaceuticals; institution: Redx Pharma, Cogent Biosciences, Owkin, Jazz Pharmaceuticals, and Ocosil)., (Copyright © 2024. Published by Elsevier Inc.)

Immune evasion by tumors is promoted by low T cell infiltration, ineffective T cell activity directed against the tumor, and reduced tumor antigen presentation. The TET2 DNA dioxygenase gene is frequently mutated in hematopoietic malignancies and loss of TET enzymatic activity is found in a variety of solid tumors. We showed previously that vitamin C (VC), a cofactor of TET2, enhances tumor-associated T cell recruitment and checkpoint inhibitor therapy responses in a TET2-dependent manner. Using single-cell RNA sequencing (scRNA-seq) analysis performed on B16-OVA melanoma tumors, we have shown here that an additional function for TET2 in tumors is to promote expression of certain antigen presentation machinery genes, which is potently enhanced by VC. Consistently, VC promoted antigen presentation in cell-based and tumor assays in a TET2-dependent manner. Quantifying intercellular signaling from the scRNA-seq dataset showed that T cell-derived IFN-γ-induced signaling within the tumor and tumor microenvironment requires tumor-associated TET2 expression, which is enhanced by VC treatment. Analysis of patient tumor samples indicated that TET activity directly correlates with antigen presentation gene expression and with patient outcomes. Our results demonstrate the importance of tumor-associated TET2 activity as a critical mediator of tumor immunity, which is augmented by high-dose VC therapy.

Fibrolamellar carcinoma (FLC) is a liver cancer of adolescents and young adults characterized by fusions of the genes encoding the protein kinase A catalytic subunit, PRKACA, and heat shock protein, DNAJB1. The chimeric DNAJB1-PRKACA protein has increased kinase activity and is essential for FLC xenograft growth. Here, we explore the critical oncogenic pathways controlled by DNAJB1-PRKACA using patient-derived FLC models, engineered systems, and patient samples. We show that a core function of DNAJB1-PRKACA is the phosphorylation and inactivation of Salt-inducible kinases (SIKs). This leads to deregulation of the CRTC2 transcriptional co-activator and p300 acetyltransferase, resulting in transcriptional reprogramming and increased global histone acetylation, driving malignant growth. Our studies establish a central oncogenic mechanism of DNAJB1-PRKACA and suggest the potential of targeting CRTC2/p300 in FLC. Notably, these findings link this rare cancer's signature fusion oncoprotein to more common cancer gene alterations involving STK11 and GNAS, which also function via SIK suppression.

Translocations involving FGFR2 gene fusions are common in cholangiocarcinoma and predict response to FGFR kinase inhibitors. However, the rate and durability of response are limited due to the emergence of resistance, typically involving acquired FGFR2 kinase domain mutations, and to sub-optimal dosing, relating to drug adverse effects. Here, we report the development of biparatopic antibodies targeting the FGFR2 extracellular domain (ECD), as candidate therapeutics. Biparatopic antibodies can overcome drawbacks of standard bivalent monoparatopic antibodies, which often show poor inhibitory or even agonist activity against oncogenic receptors. We show that oncogenic transformation by FGFR2 fusions requires an intact ECD. Moreover, by systematically generating biparatopic antibodies that target distinct epitope pairs along the FGFR2 ECD, we identified antibodies that effectively block signaling and malignant growth driven by FGFR2-fusions. Importantly, these antibodies demonstrate efficacy in vivo, synergy with FGFR inhibitors, and activity against FGFR2 fusions harboring kinase domain mutations. Thus, biparatopic antibodies may serve as new treatment options for patients with FGFR2-altered cholangiocarcinoma., Summary: We identify biparatopic FGFR2 antibodies that are effective against FGFR2 fusion driven cholangiocarcinoma.