Mouse Model Of Hepatocellular Carcinoma Research Articles

Cholecystohepatic shunt pathway reduces secondary bile acid accumulation to enhance natural killer T cell-mediated anti-hepatocellular carcinoma immunity.

The impact of cholecystectomy, which blocks the cholecystohepatic shunt pathway (CHSP), on the prognosis of patients with hepatocellular carcinoma (HCC) is unclear. Hepatic secondary bile acids (BAs) inhibit natural killer T (NKT) cell-mediated immunity against HCC, and the regulation of homeostasis of hepatic secondary BAs is controlled by the CHSP. However, the influence of CHSP on NKT cell-mediated immunity against HCC remains unclear. The clinical data of hospitalized patients undergoing HCC resection were collected. Meanwhile, an in situ HCC mouse model was established, and the CHSP was augmented using oleanolic acid (OA). After 1:1 propensity score matching, Cox regression analysis revealed that cholecystectomy was an independent risk factor for HCC recurrence after hepatectomy (P=0.027, hazard ratio: 1.599, 95% confidence interval: 1.055-2.422). Experimentally, when OA enhanced CHSP, a significant decrease was observed in the accumulation of secondary BAs in the livers of mice. Additionally, a significant increase was observed in the levels of C-X-C ligand 16 and interferon γ in the serum and tumor tissues. Further, the percentage of C-X-C receptor 6 (+) NKT cells in the tumor tissues increased significantly, and the growth of liver tumors was inhibited. This clinical study revealed that cholecystectomy promoted the recurrence after radical hepatectomy in patients with HCC. Preserving the normal-functioning gallbladder as much as possible during surgery may be beneficial to the patient's prognosis. Further investigation into the mechanism revealed that CHSP enhanced NKT cell-mediated immunity against HCC by reducing the hepatic accumulation of secondary BAs.

Interleukin-21 receptor signaling promotes metabolic dysfunction-associated steatohepatitis-driven hepatocellular carcinoma by inducing immunosuppressive IgA+ B cells

BackgroundDysregulation of immune surveillance is tightly linked to the development of metabolic dysfunction-associated steatohepatitis (MASH)-driven hepatocellular carcinoma (HCC); however, its underlying mechanisms remain unclear. Herein, we aimed to determine the role of interleukin-21 receptor (IL-21R) in MASH-driven HCC.MethodsThe clinical significance of IL-21R was assessed in human HCC specimens using immunohistochemistry staining. Furthermore, the expression of IL-21R in mice was assessed in the STAM model. Thereafter, two different MASH-driven HCC mouse models were applied between IL-21R-deficient mice and wild type controls to explore the role of IL-21R in MASH-driven HCC. To further elucidate the potential mechanisms by which IL-21R affected MASH-driven HCC, whole transcriptome sequencing, flow cytometry and adoptive lymphocyte transfer were performed. Finally, flow cytometry, enzyme-linked immunosorbent assay, immunofluorescent staining, chromatin immunoprecipitation assay and western blotting were conducted to explore the mechanism by which IL-21R induced IgA+ B cells.ResultsHCC patients with high IL-21R expression exhibited poor relapse-free survival, advanced TNM stage and severe steatosis. Additionally, IL-21R was demonstrated to be upregulated in mouse liver tumors. Particularly, ablation of IL-21R impeded MASH-driven hepatocarcinogenesis with dramatically reduction of lipid accumulation. Moreover, cytotoxic CD8+ T lymphocyte activation was enhanced in the absence of IL-21R due to the reduction of immunosuppressive IgA+ B cells. Mechanistically, the IL-21R-STAT1-c-Jun/c-Fos regulatory axis was activated in MASH-driven HCC and thus promoted the transcription of Igha, resulting in the induction of IgA+ B cells.ConclusionsIL-21R plays a cancer-promoting role by inducing IgA+ B cells in MASH-driven hepatocarcinogenesis. Targeting IL-21R signaling represents a potential therapeutic strategy for cancer therapy.

IL-12 improves the anti-HCC efficacy of dendritic cells loaded with exosomes from overexpressing Rab27a tumor cells

Determining the appropriate source of antigens for optimal antigen presentation to T cells is a major challenge in designing dendritic cell (DC) -based therapeutic strategies against hepatocellular carcinoma (HCC). Tumor-derived exosomes (Tex) express a wide range of tumor antigens, making them a promising source of antigens for DC vaccines. As reported, the exosomes secreted by tumor cells can inhibit the antitumor function of immune cells. In this study, we transfected hepatocellular carcinoma cells with Rab27a to enhance the yield of exosomes, which were characterized using transmission electron microscopy and Western blot analysis. We found that Tex secreted by overexpressing Rab27a Hepatocellular carcinoma cell lines pulsed DC is beneficial for the differentiation and maturation of DCs but inhibits the secretion of the IL-12 cytokine. Consequently, we developed a complementary immunotherapy approach by using Tex as an antigen loaded onto DCs, in combination with the cytokine IL-12 to induce antigen-specific cytotoxic T lymphocytes （CTLs）. The results indicated that the combination of DC-Tex and IL-12 was more effective in stimulating T lymphocyte proliferation, releasing IFN-γ， and enhancing cytotoxicity compared to using exosomes or IL-12 alone. Additionally, the inclusion of IL-12 also compensated for the reduced IL-2 secretion by DCs caused by Tex. Moreover, in a BALB/c nude mice model of hepatocellular carcinoma, CTLs induced by DC-Tex combined with IL-12 maximized the tumor-specific T-cell immune effect and suppressed tumor growth. Thus, Tex provides a novel and promising source of antigens, with cytokines compensating for the shortcomings of Tex as a tumor antigen. This work helps to clarify the role of exosomes in tumor immunotherapy and may offer a safe and effective prospective strategy for the clinical application of exosome-based cellular immunotherapy.

Macrophage hitchhiking for systematic suppression in postablative multifocal hepatocellular carcinoma.

Hepatocellular carcinoma (HCC), particularly the multifocal HCC, features aggressive invasion and dismal prognosis. Locoregional treatments were often refractory to eliminate tumor tissue, resulting in residual tumor cells persisting and subsequent progression. Owing to problematic delivery to the tumor tissue, systemic therapies, such as lenvatinib (LEN) therapy, show limited clinical benefit in preventing residual tumor progression. Therefore, more advanced strategies for postablative multifocal HCC are urgently needed. Motivated by the chemotaxis in tumor penetration of macrophages, we report a strategy named microinvasive ablation-guided macrophage hitchhiking (MAMH) for the targeted therapy toward HCC. In this study, the strategy leverages the natural inflammatory gradient induced by ablation to guide LEN-loaded macrophages toward tumor targeting, which increased by ~10-fold the delivery efficiency of LEN in postablative HCC in vivo. MAMH has demonstrated significant antitumor activity in various HCC models, including the hydrodynamic tail vein injection multifocal HCC mouse model and the orthotopic xenograft HCC rabbit model, systematically inhibiting residual tumor progression after ablation and prolonging the median survival of tumor-bearing mice. The potential antitumor mechanism was explored using techniques such as flow cytometry, enzyme-linked immunosorbent assay, and immunohistochemistry. We found that the strategy significantly suppressed tumor cell proliferation and neovascularization, and such enhanced delivery of LEN stimulated systemic immune responses and induced durable immune memory. The macrophage hitchhiking strategy demonstrates exceptional therapeutic efficacy and biosafety across various species, offering promising prospects for clinical translation in controlling residual tumor progression and improving outcomes following HCC ablation.

Deficiency of betaine-homocysteine methyltransferase activates glucose-6-phosphate dehydrogenase (G6PD) by decreasing arginine methylation of G6PD in hepatocellular carcinogenesis.

Betaine-homocysteine methyltransferase (BHMT) regulates protein methylation and is correlated with tumorigenesis; however, the effects and regulation of BHMT in hepatocarcinogenesis remain largely unexplored. Here, we determined the clinical significance of BHMT in the occurrence and progression of hepatocellular carcinoma (HCC) using tissue samples from 198 patients. BHMT was to be frequently found (86.6%) expressed at relatively low levels in HCC tissues and was positively correlated with the overall survival of patients with HCC. Bhmt overexpression effectively suppressed several malignant phenotypes in hepatoma cells in vitro and in vivo, whereas complete knockout of Bhmt (Bhmt-/-) produced the opposite effect. We combined proteomics, metabolomics, and molecular biological strategies and detected that Bhmt-/- promoted hepatocarcinogenesis and tumor progression by enhancing the activity of glucose-6-phosphate dehydrogenase (G6PD) and PPP metabolism in DEN-induced HCC mouse and subcutaneous tumor-bearing models. In contrast, restoration of Bhmt with an AAV8-Bhmt injection or pharmacological inhibition of G6PD attenuated hepatocarcinogenesis. Additionally, coimmunoprecipitation identified monomethylated modifications of the G6PD, and BHMT regulated the methylation of G6PD. Protein sequence analysis, generation and application of specific antibodies, and site-directed mutagenesis indicated G6PD methylation at the arginine residue 246. Furthermore, we established bidirectionally regulated BHMT cellular models combined with methylation-deficient G6PD mutants to demonstrate that BHMT potentiated arginine methylation of G6PD, thereby inhibiting G6PD activity, which in turn suppressed hepatocarcinogenesis. Taken together, this study reveals a new methylation-regulatory mechanism in hepatocarcinogenesis owing to BHMT deficiency, suggesting a potential therapeutic strategy for HCC treatment.

Time-Restricted Feeding Attenuates Metabolic Dysfunction-Associated Steatohepatitis and Hepatocellular Carcinoma in Obese Male Mice.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has surpassed the hepatitis B virus and hepatitis C virus as the leading cause of chronic liver disease in most parts of the Western world. MASLD (formerly known as NAFLD) encompasses both simple steatosis and more aggressive metabolic dysfunction-associated steatohepatitis (MASH), which is accompanied by inflammation, fibrosis, and cirrhosis, and ultimately can lead to hepatocellular carcinoma (HCC). There are currently very few approved therapies for MASH. Weight loss strategies such as caloric restriction can ameliorate the harmful metabolic effect of MASH and inhibit HCC; however, it is difficult to implement and maintain in daily life, especially in individuals diagnosed with HCC. In this study, we tested a time-restricted feeding (TRF) nutritional intervention in mouse models of MASH and HCC. We show that TRF abrogated metabolic dysregulation induced by a Western diet without any calorie restriction or weight loss. TRF improved insulin sensitivity and reduced hyperinsulinemia, liver steatosis, inflammation, and fibrosis. Importantly, TRF inhibited liver tumors in two mouse models of obesity-driven HCC. Our data suggest that TRF is likely to be effective in abrogating MASH and HCC and warrant further studies of time-restricted eating in humans with MASH who are at higher risk of developing HCC.

Chemically engineered mTOR-nanoparticle blockers enhance antitumour efficacy

Hepatocellular carcinoma (HCC) is a highly prevalent and deadly type of cancer, and although pharmacotherapy remains the cornerstone of treatment, therapeutic outcomes are often unsatisfactory. Pharmacological inhibition of mammalian target of rapamycin (mTOR) has been closely associated with HCC regression. Herein, we covalently conjugated AZD8055, a potent mTORC1/2 blocker, with a small panel of unsaturated fatty acids via a dynamically activating linkage to enable aqueous self-assembly of prodrug conjugates to form mTOR nanoblockers. Cell-based experiments were carried out to evaluate the effects of the nanoblocker against hepatocellular carcinoma (HCC) cells. The orthotopic and subcutaneous HCC mouse models were established to examine its antitumour activity. Among several fatty acids as promoieties, linoleic acid-conjugated self-assembling nanoblocker exhibited optimal size distribution and superior physiochemical properties. Compared with free agents, PEGylated AZD8055 nanoblocker (termed AZD NB) was pharmacokinetically optimized after intravenous administration. Invivo investigations confirmed that AZD NB significantly suppressed tumour outgrowth in subcutaneous HCCLM3 xenograft, Hepatoma-22, and orthotopic Hepa1-6 liver tumour models. Strikingly, treatment with AZD NB, but not free agent, increased intratumour infiltration of IFN-γ+CD8+ T cells and CD8+ memory T cells, suggesting a potential role of the mTOR nanoblocker to remodel the tumour microenvironment. Overall, a single conjugation with fatty acid transformed a hydrophobic mTOR blocker into a systemically injectable nanomedicine, representing a facile and generalizable strategy for improving the therapeutic index of mTOR inhibition-based cancer therapy. The mTOR inhibition by chemically engineered nanoblocker presented here had enhanced efficacy against tumours compared with the pristine drug and thus has the potential to improve the survival outcomes of patients with HCC. Additionally, this new nanosystem derived from co-assembling of small-molecule prodrug entities can serve as a delivery platform for the synergistic co-administration of distinct pharmaceutical agents. This work was supported by the National Natural Science Foundation of China (32171368,81721091), the Zhejiang Provincial Natural Science Foundation of China (LZ21H180001), the Jinan Provincial Laboratory Research Project of Microecological Biomedicine (JNL-2022039c and JNL-2022010B), State Key Laboratory for Diagnosis and Treatment of Infectious Diseases (zz202310), and Natural Science Foundation of Shandong Province (ZR2023ZD59).

Proteomic analysis of DEN and CCl4-induced hepatocellular carcinoma mouse model.

Hepatocellular carcinoma (HCC) seriously threatens human health, mostly developed from liver fibrosis or cirrhosis. Since diethylnitrosamine (DEN) and carbon tetrachloride (CCl4)-induced HCC mouse model almost recapitulates the characteristic of HCC with fibrosis and inflammation, it is taken as an essential tool to investigate the pathogenesis of HCC. However, a comprehensive understanding of the protein expression profile of this model is little. In this study, we performed proteomic analysis of this model to elucidate its proteomic characteristics. Compared with normal liver tissues, 432 differentially expressed proteins (DEPs) were identified in tumor tissues, among which 365 were up-regulated and 67 were down-regulated. Through Gene Ontology (GO) analysis, Ingenuity Pathway Analysis (IPA), protein-protein interaction networks (PPI) analysis and Gene-set enrichment analysis (GSEA) analysis of DEPs, we identified two distinguishing features of DEN and CCl4-induced HCC mouse model in protein expression, the upregulation of actin cytoskeleton and branched-chain amino acids metabolic reprogramming. In addition, matching DEPs from the mouse model to homologous proteins in the human HCC cohort revealed that the DEN and CCl4-induced HCC mouse model was relatively similar to the subtype of HCC with poor prognosis. Finally, combining clinical information from the HCC cohort, we screened seven proteins with prognostic significance, SMAD2, PTPN1, PCNA, MTHFD1L, MBOAT7, FABP5, and AGRN. Overall, we provided proteomic data of the DEN and CCl4-induced HCC mouse model and highlighted the important proteins and pathways in it, contributing to the rational application of this model in HCC research.

Selective refueling of CAR T cells using ADA1 and CD26 boosts antitumor immunity

Chimeric antigen receptor (CAR) Tcell therapy is hindered in solid tumor treatment due to the immunosuppressive tumor microenvironment and suboptimal Tcell persistence. Current strategies do not address nutrient competition in the microenvironment. Hence, we present a metabolic refueling approach using inosine as an alternative fuel. CAR Tcells were engineered to express membrane-bound CD26 and cytoplasmic adenosine deaminase 1 (ADA1), converting adenosine to inosine. Autocrine secretion of ADA1 upon CD3/CD26 stimulation activates CAR Tcells, improving migration and resistance to transforming growth factor β1 suppression. Fusion of ADA1 with anti-CD3 scFv further boosts inosine production and minimizes tumor cell feeding. In mouse models of hepatocellular carcinoma and non-small cell lung cancer, metabolically refueled CAR Tcells exhibit superior tumor reduction compared to unmodified CAR Tcells. Overall, our study highlights the potential of selective inosine refueling to enhance CAR T therapy efficacy against solid tumors.

Abstract 3063: Defining oncogene-specific metabolic vulnerabilities in a mouse model of hepatocellular carcinoma

Abstract Despite the continued success of advanced cancer therapies, hepatocellular carcinoma (HCC) represents a substantial challenge to current treatment modalities that are not sufficiently effective for the management of advanced disease. Metabolic reprogramming is a hallmark of cancer and many oncogenic signaling pathways impact on cellular metabolism. Here, we are investigating changes in metabolism in different oncogene-driven mouse models of liver cancer to identify selective metabolic vulnerabilities associated with HCC that could be implicated in tumor initiation and progression to be exploited for cancer therapy. Transposon-based vectors coding for different combinations of oncogenes, either Myc and Akt1Myr (CaMIA) or Myc and NrasG12V (CaMIN), were transduced by hydrodynamic tail vein injected into C57BL/6 mice. The resulting liver tumors and control livers were subjected to a comprehensive profiling of polar metabolites (metabolomics) and lipids (lipidomics and total fatty acids) as well as changes in gene expression (transcriptomics). Despite similar overall survival, the two models display marked differences in the presentation of the tumors, with CaMIA showing larger aggressive tumors, while CaMIN livers contain numerous small tumor nodules. Both models also showed evidence for the deregulation of intermediate metabolism, indicating activation of aerobic glycolysis and deregulation of glutamine metabolism. Lipidomic analysis revealed substantial lipidome remodeling in both models. Oncogene-specific alterations included elevated levels of lysophosphatidylcholine (LPC) in CaMIN tumors, while CaMIA tumors displayed high levels of ether phospholipids compared to CaMIN and normal liver. Moreover, the fraction of polyunsaturated fatty acids (PUFAs) was enhanced in lipids from CaMIN tumors, while monounsaturated fatty acids (MUFAs) were enriched in CaMIA tumors. Furthermore, tumors from both genotypes produced higher levels of oxylipins, a class of lipid mediators involved in signaling and inflammation, compared to normal liver. Transcriptome analysis confirmed these metabolic alterations and revealed evidence for enhanced inflammatory signaling in CaMIN. In addition, analysis of tumor microenvironment composition disclosed specific differences in stromal components, indicative of immune evasion through checkpoint activation. Experiments in primary murine liver cancer cell lines confirmed oncogene-specific metabolic rearrangements and suggest elevated sensitivity towards inhibitors of lipid remodeling. Future experiments will investigate the role of altered lipid metabolism in tumor development and immune evasion in liver cancer. Citation Format: Kamal Al-Shami, Marteinn Snaebjornsson, Felix Vogel, Lisa Schlicker, Phillip Pöller, Daniel Dauch, Almut Schulze. Defining oncogene-specific metabolic vulnerabilities in a mouse model of hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3063.

Abstract 5335: Immune cell population variations in the livers of commonly used mouse strains

Abstract Previous studies have shown that the distribution of major immune cell populations differ across mouse strains in peripheral blood and hematopoietic organs at baseline. Additionally, variations in immune responses exist between mouse strains in Leishmania spp. and Melanoma models, but these studies in the context of liver diseases including Non Alcoholic Fatty Liver Disease (NAFLD) and Hepatocellular Carcinoma (HCC) have not been carried out. With the effort to state if these variations exist within the liver, we performed comprehensive spectral flow cytometry analysis on the liver and spleens of three female mouse strains commonly used in cancer research (BALB/c, C57BL/6, and FVBN). NAFLD was induced by providing mice with a methionine choline deficient diet. To promote HCC, a single genotype (myc/p53+/-) was induced by administering transposon-based vectors to overexpress Myc-Luc and CRISPR/Cas-9 vectors to knock down p53 via hydrodynamic tail-vein injection. To confirm vector integration and monitor tumor growth (luciferase activity), in vivo imaging was performed at different time points. As a result, we confirm throughout this study that differences exist within immune cell populations of the liver and spleen at baseline. Moreover, we depict differences in the shift of immune cell populations across mouse strains in the pathologic states included. In NAFLD, there is an increase of dendritic cells (DCs), macrophages, NK cells, ILC1s, T regulatory cells (Tregs), TH1, and TH2, and a decrease of CD4+ T cells, B cells, γδ-T cells, and NKT cells in the liver across all mouse strains, when compared to controls. However, the population of neutrophils in BALB/c decreases, and the population of CD8+ T cells increases in C57BL/6 mice, which differs from the patterns of change seen in the other mouse strains. Moreover, in spleens, NAFLD promotes an increase of TH1 and NK cells, and a decrease of TH2 and NKT Cells across the mouse strains included in the study, whereas the patterns of change differ between mouse strains among the remaining immune cell types. When evaluating liver immune cell population shifts on our HCC model, BALB/c mice showed a decrease in macrophages and ILC1s, C57BL/6 mice showed a decrease in γδ-T cells, prominent shifts across Neutrophils, TH1, and NKT cells, and null changes in TH2 and CD4+ T cell shifts, and FVBN mice had a less prominent decrease of B cells, which differed from the shifts observed in the mouse strains used for comparison. Immune cell populations in the spleens of our HCC mouse model also presented with differences across the mouse strains studied. In conclusion, we highlight that key differences in immune profiles exist across commonly used mouse strains for cancer research in the presence of liver pathology including HCC, suggesting that mouse strains could be possible confounders in the study of immune oncology of HCC. Citation Format: Francisco J. Rodriguez-Matos, Patrick Huang, Rajiv Trehan, Benjamin Ruf, Chi Ma, Tim F. Greten. Immune cell population variations in the livers of commonly used mouse strains [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5335.

Abstract 5447: Microtubule-associated protein MAP2 promotes drug resistance and cancer stemness in hepatocellular carcinoma through integrin dysregulation

Abstract Integrins are adhesion molecules that mediate mechanical and chemical signal transduction pathways to support cell survival and proliferation. Dysregulated integrin signaling empowers tumor cells to drive oncogenic stemness functions, including tumor initiation, epithelial plasticity, metastatic reactivation, and resistance to therapies. However, the interplay between cancer stemness and integrin signaling in hepatocellular carcinoma (HCC) remains poorly understood. HCC cells marked by CD133 represent an important functional subset of HCC tumors, displaying a dedifferentiated status with stem cell traits. In this study, transcriptome profiling reveals specific downregulation of integrin α family genes and integrin signaling in ‘HCC’ CD133+ cells isolated from NRAS+AKT-driven HCC, but not epithelial-specific ‘normal’ CD133+ cells isolated from regenerating liver. Of note, one of the most differentially upregulated genes identified in CD133+ HCC cell profiling, microtubule-associated protein MAP2, demonstrates the ability to suppress integrin expression. MAP2 overexpression is frequently observed in HCC and correlates with aggressive clinical and stemness features, including survival, tumor stage, and stemness signatures. Epigenetic modifications by H3K27Ac contribute to MAP2 upregulation. Functionally, MAP2 promotes cancer stemness and cell invasion, and confers resistance to the targeted therapy sorafenib. Mechanistically, the inhibition of collagen-binding integrin α subunits by MAP2 subsequently ablates integrin β1-mediated cell adhesion and FAK signaling. Estramustine Phosphate (EMP), previously reported to inhibit the interaction of MAP2 with actin filaments, attains a synergistic effect in suppressing tumor initiation and growth of HCC cell lines, HCC patient-derived organoids and NRAS+AKT HCC mouse model when used in combination with sorafenib. In summary, MAP2 inhibition may represent a potential novel therapy for HCC by targeting its cancer stemness roots and altering integrin signaling. Ongoing work is focused on the study of MAP2 regulation of integrin signaling and cell behaviours in the maintenance of a more stemness state in HCC. Citation Format: Ut Kei Lou, Ka-Hei Lam, Huajian Yu, Jia Jian Loh, Ki-Fong Man, Lei Zhou, Yuan Gao, Tin-Lok Wong, Cheng-Han Yu, Stephanie Ma. Microtubule-associated protein MAP2 promotes drug resistance and cancer stemness in hepatocellular carcinoma through integrin dysregulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5447.

Abstract 5356: Wild type Kirsten rat sarcoma (Kras) activation drives evasion of interferon-mediated immunity in hepatocellular carcinoma

Abstract Background: Immune checkpoint inhibitors (ICIs) exhibit heterogeneous efficacy in patients with advanced hepatocellular carcinoma (HCC). Currently, there are no effective biomarkers to select patients who could benefit the most from ICIs or to predict response outcomes. Increasing evidence indicates that oncogenic pathway activation is associated with the generation of an unfavorable tumor microenvironment, with consequent immunotherapy resistance. Therefore, an understanding of the immune evasive mechanism of HCC is urgently needed. Methods: Utilizing the antigen-expressing c-MycOE/Tp53KO HCC mouse model, a critical oncogenic signaling pathway in immune evasion was identified by data-independent acquisition mass spectrometry (DIA-MS) proteomics. Potential downstream pathways were investigated by scRNA-seq, immune profiling, western blot, and multiplexed immunofluorescence staining. We also examined the therapeutic potential of targeting wild-type Kras using the Kras inhibitor MRTX0902 and the MEK inhibitor trametinib to enhance the efficacy of immunotherapy in HCC. Results: We identified a significant upregulation of wild-type Kras in immune-escaped tumors, with concurrent activation of its ligand-driven EGFR and its downstream MEK/ERK signaling. Likewise, endogenous Kras overexpression in this model resulted in increased tumor burden with reduced survival time in mice, implicating the regulatory role of Kras signaling in immune evasion. Clinically, wild-type Kras showed elevated expression in HCC at both the mRNA and protein levels, and was associated with tumor recurrence and poorer patient survival. Through scRNA-seq analysis, we demonstrated that Kras hindered dendritic cell recruitment, leading to compromised Cd8+ T cell activity via the suppression of interferon-mediated Cxcl9. Wild-type Kras activation further impaired HCC recognition by T cells via the downregulation of MHC-I expression. Notably, the combination therapy of MRTX0902, trametinib, and anti-PD-1 effectively enhanced intratumoral Cd8+ T cell infiltration and demonstrated a favorable response in survival outcomes. Conclusion: This study showed that wild-type Kras, via the activation of its downstream MEK/ERK signaling, acts as a crucial immune evasive mechanism in HCC and contributes to resistance to anti-PD-1 therapy. It also provided new insights into the therapeutic potential of targeting wild-type Kras to enhance the efficacy of anti-PD-1 therapy, providing a foundation for further exploration and potential clinical applications in HCC. Citation Format: Mang Leng Lei, Terence Kin Wah Lee. Wild type Kirsten rat sarcoma (Kras) activation drives evasion of interferon-mediated immunity in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5356.

Abstract 1321: In vivo immune cell programming using mRNA-LNP chimeric antigen receptors

Abstract Introduction: The tumor microenvironment (TME) is a dynamic and multifaceted system that comprises largely myeloid lineage immune cells including monocytes, neutrophils, macrophages, and dendritic cells. Reprogramming the myeloid compartment within the context of cancer therapy presents an attractive strategy to overcome current limitations in solid tumor treatment. We have developed a novel approach that harnesses the natural ability of Myeloid cells to take up mRNA loaded lipid nanoparticles, to reprogram these cells with chimeric antigen receptors (CAR’s) that arm these cells to recognize and kill tumor cells. Methods: Current LNPs technology is sufficient to deliver significant mRNA cargo to numerous cell types, including B cells, T cells and myeloid cells. Leveraging this phenomenon we have developed a new class of chimeric antigen receptors (CARs), using protein biology that imparts targeted immune cell expression and functionality, specifically in Myeloid cells. These CARs harness Immunoreceptor Tyrosine-based Activation Motif (ITAM) signaling adaptors expressed exclusively in immune cells, achieving immune cell-type specific CAR-directed tumor lysis and cytokine responses. With a FcaR I (CD89) based CAR design, we have developed a CAR that is dependent on the common Fc receptor gamma chain, primarily restricted to myeloid cells, for stable expression and function. Results: We have demonstrated specific expression of CD89-based CAR in myeloid cells in mouse and monkey following systemic mRNA/LNP delivery, and in human myeloid cells following in vitro treatment with mRNA/LNPs. Systemic mRNA/LNP delivery of CD89-based CAR has demonstrated robust anti-tumor efficacy against multiple tumor antigens in various xenograft mouse models of human breast cancer, hepatocellular carcinoma, and ovarian cancer. Furthermore, in syngeneic mouse tumor models, robust anti-tumor immune responses, characterized by tumoral infiltration of activated CD8+ T cells, diminished tumor-associated Tregs, systemic enhancement of dendritic cells and anti-tumor IgG production, were observed for treated animals. Conclusions: Taken together, we present CAR designs that achieve expression and function in targeted immune cell populations, capable of eliciting anti-tumor efficacy against multiple target antigens by leveraging innate and adaptive immune responses, and demonstrating a class of novel CAR designs to overcome limitations faced by current in vivo mRNA/LNP delivery strategy. A phase I clinical trial is currently on-going to assess the safety and preliminary efficacy of CD89-based CAR against TROP2+ epithelial malignancies. Citation Format: Shannon Argueta, Franciele K. Melber, Michael Gorgievski, Neha Divangi, Edward Cochran, Thach Chu, Yuxiao Wang, Jian Ding, Daniel Getts. In vivo immune cell programming using mRNA-LNP chimeric antigen receptors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1321.

Abstract 7039: Leveraging single cell RNA-seq for uncovering immune landscape of hepatocellular carcinoma

Abstract The immune cell types as well as tumor microenvironment (TME) status may influence prognosis, metastasis, tumor progression, and clinical response to immunotherapies for cancer. Hepatocellular carcinoma (HCC) is a typical highly heterogeneous solid tumor with high morbidity and mortality worldwide, especially in China, however, the immune microenvironment of HCC, especially which caused by cancerogenic substance has not been clarified so far. In this study, we employed single-cell RNA sequencing (scRNA-seq) on diethylnitrosamine (DEN)-induced mouse HCC model to dissect the immune cell dynamics during tumorigenesis. Our findings reveal distinct immune profiles in both precancerous and cancerous lesions, indicating early tumor-associated immunological alterations. Notably, specific T and B cell subpopulations are preferentially enriched in the HCC TME. Furthermore, we identified a subpopulation of naïve B cells with high CD83 expression, correlating with improved prognosis in human HCC. These signature genes were validated in The Cancer Genome Atlas (TCGA) HCC RNA-seq dataset. Moreover, cell interaction analysis revealed that subpopulations of B cells in both mouse and human samples are activated and may potentially contribute to oncogenic processes. In summary, our study provides insights into the dynamic immune microenvironment and cellular networks in HCC pathogenesis, with a specific emphasis on naïve B cells. These findings emphasize the significance of targeting TME in HCC patients to prevent HCC pathological progression, which may give a new perspective on the therapeutics for the HCC. Citation Format: Jian He. Leveraging single cell RNA-seq for uncovering immune landscape of hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7039.

Abstract 6755: NKT activation enhanced the therapeutic efficacy of neoantigen vaccine in hepatocellular carcinoma

Abstract One sentence introduction: This study indicated the potential of combinational therapy of neoantigen vaccine and iNKT activator α-GalCer in Hepatocellular carcinoma. Hepatocellular carcinoma (HCC) is a leading cause of death around the world. Current immune checkpoint blockade therapies only show effectiveness in some cancer patients, so there is an urgent need for more effective immunotherapy strategies. One alternative is the use of neoantigen-based cancer vaccines, which target tumor-specific antigens (neoantigens) on cancer cells and induce strong T-cell responses. Advances in technology now allow for precise identification of tumor neoantigens using bioinformatic analysis or mass spectrometry. While cancer vaccines have demonstrated strong anti-tumor immune responses and therapeutic effectiveness in some cancer types, their success in HCC remains limited. A contributing factor is the suppressive tumor microenvironment (TME) found in advanced HCC. Some studies suggest that combining neoantigen vaccines with anti-PD1/PD-L1 therapies can significantly enhance HCC treatment outcomes. Overcoming the suppressive immune microenvironment is crucial in cancer treatment, and reactivating intratumoral immunity is essential. In our study, we developed an HCC cancer vaccine using transcriptome sequencing and bioinformatics analysis. Our ELISpot assay results showed that this vaccine induced strong tumor-specific immune responses and significantly inhibited tumor growth in early-stage orthotopic HCC mouse models when administered five days after tumor inoculation. However, the effectiveness decreased in advanced tumors when administered ten days after tumor inoculation. We also discovered a significant relationship between the therapeutic effectiveness of the neoantigen vaccine and the activation of intratumoral NKT cells in HCC. Our study suggested that the type-I NKT cell activator, α-Galactosylceramide (α-GalCer), significantly improved the therapeutic outcomes of the cancer neoantigen vaccine in advanced orthotopic HCC mouse models. In some cases, tumors were almost completely eliminated. This indicates the potential of combining iNKT activators with neoantigen vaccines for HCC treatment. To further understand the role of NKT cells in HCC's TME, we plan to investigate intratumoral NKT cell subtypes following neoantigen vaccine therapy. Additionally, we will develop a new delivery system to deliver type I NKT cell activators and type II NKT inhibitors to tumor sites, aiming to reactivate the suppressive TME in HCC after neoantigen vaccine therapy. Citation Format: Renhao Li, Jing-Chu Hu, Li Rong, Yangfan Wu, Yige He, Jiandong Huang. NKT activation enhanced the therapeutic efficacy of neoantigen vaccine in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6755.

Abstract 5927: ACBP/DBI inhibition suppresses NASH-induced hepatocarcinogenesis

Abstract Background: Non-alcoholic fatty liver disease (NAFLD) or its severe form non-alcoholic steatohepatitis (NASH) is becoming an ever more prevalent risk factor of hepatocellular carcinoma (HCC). Currently, there are no approved drugs for the treatment of NASH. Extracellular ACBP/DBI (Acyl coenzyme A binding protein, also called diazepam-binding inhibitor) acts as an autophagy checkpoint and neutralization of ACBP/DBI prevents NASH. Therefore, we investigated the functional roles, mechanisms, and clinical relevance of ACBP/DBI in HCC. Methods: ACBP/DBI was blocked by four strategies: an inducible Acbp/Dbi knockout (Acbp-/-, control: Acbp+/+), a constitutive Gabrg2F77I mutation that prevents binding of ACBP/DBI to the receptor (control: WT), induction of ACBP/DBI-specific autoantibodies (induced by KLH-DBI, control: KLH), and monoclonal anti-DBI antibody (control: isotype). Three different types of HCC mouse models, including toxins/diet-based NASH-induced models (western diet plus CCl4), hydrodynamic transfection of oncogenes (Myc+Ctnnb1), and orthotopic transplantation (Hep55.1C) were used in combination with the aforementioned ACBP/DBI inhibition strategies to determine the association of ACBP/DBI and HCC. Results: ACBP/DBI inhibition attenuates tumorigenesis in mice with NASH, blunts oncogene induced HCC, and reduces the growth of orthotopically transplanted cancers. Mechanistically, ACBP/DBI inhibition retards cell cycle, suppresses cell proliferation, and favors ferroptosis, as determined by RNA-seq data and mass spectrometric metabolomics. CCK-8 proliferation, colony formation, and cell cycle assays performed on Huh-7, HepG2 and Hep55.1C cells demonstrated that ACBP/DBI knockdown reduced cell proliferation and induced G0/G1 arrest. IHC detection of Ki67 and PCNA in liver sections revealed antiproliferative effects of ACBP/DBI inhibition. qRT-PCR demonstrated the ACBP/DBI inhibition-induced upregulation of cell cycle inhibitor genes and downregulation of genes invoded in G0/G1 phase in liver tissues. qRT-PCR and immunoblot confirmed the upregulation of pro-ferroptotic and the downregulation of anti-ferroptotic genes and proteins in liver tissues upon ACBP/DBI inhibition. Primary HCC cell lines from Acbp+/+ and Acbp-/- mice further confirmed the pro-ferroptotic effects of ACBP/DBI inhibition obtained in liver tissues. Acbp-/- cell lines were more sensitivity to RSL3-induced ferroptosis. Conclusion: ACBP/DBI inhibition constitutes a potential strategy for treating NASH and NASH-induced HCC. Citation Format: Sijing Li, Omar Motiño, Flavia Lambertucci, Maria Chiara Maiuri, Isabelle Martins, Guido Kroemer. ACBP/DBI inhibition suppresses NASH-induced hepatocarcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5927.

Cancer cell genetics shaping of the tumor microenvironment reveals myeloid cell-centric exploitable vulnerabilities in hepatocellular carcinoma

Myeloid cells are abundant and plastic immune cell subsets in the liver, to which pro-tumorigenic, inflammatory and immunosuppressive roles have been assigned in the course of tumorigenesis. Yet several aspects underlying their dynamic alterations in hepatocellular carcinoma (HCC) progression remain elusive, including the impact of distinct genetic mutations in shaping a cancer-permissive tumor microenvironment (TME). Here, in newly generated, clinically-relevant somatic female HCC mouse models, we identify cancer genetics’ specific and stage-dependent alterations of the liver TME associated with distinct histopathological and malignant HCC features. Mitogen-activated protein kinase (MAPK)-activated, NrasG12D-driven tumors exhibit a mixed phenotype of prominent inflammation and immunosuppression in a T cell-excluded TME. Mechanistically, we report a NrasG12D cancer cell-driven, MEK-ERK1/2-SP1-dependent GM-CSF secretion enabling the accumulation of immunosuppressive and proinflammatory monocyte-derived Ly6Clow cells. GM-CSF blockade curbs the accumulation of these cells, reduces inflammation, induces cancer cell death and prolongs animal survival. Furthermore, GM-CSF neutralization synergizes with a vascular endothelial growth factor (VEGF) inhibitor to restrain HCC outgrowth. These findings underscore the profound alterations of the myeloid TME consequential to MAPK pathway activation intensity and the potential of GM-CSF inhibition as a myeloid-centric therapy tailored to subsets of HCC patients.

Dynamic network biomarker C1QTNF1 regulates tumor formation at the tipping point of hepatocellular carcinoma.

Identifying the precise moment before the onset of hepatocellular carcinoma (HCC) remains a significant challenge in the medical field. The existing biomarkers fall short of pinpointing the critical point preceding HCC formation. This study aimed to determine the exact tipping point for the transition from cirrhosis to HCC, identify the core Dynamic Network Biomarker (DNB), and elucidate its regulatory effects on HCC. A spontaneous HCC mouse model was established to mimic HCC formation in patients with chronic hepatitis. Using the DNB method, C1q and tumor necrosis factor (TNF) related 1 (C1QTNF1) protein was identified as the key DNB at the crucial tipping time of spontaneous HCC development. Both in vitro and in vivo studies showed that C1QTNF1 could inhibit tumor growth. Overexpression of C1QTNF1 before the tipping point effectively prevented HCC occurrence. Patients with elevated C1QTNF1 expression demonstrated improved overall survival (OS) (P = 0.03) and disease-free survival (DFS) (P = 0.03). The diagnostic value of C1QTNF1 was comparable to that of alpha-fetoprotein (AFP) (area under the curve [AUC] = 0.84; sensitivity 85%; specificity 80%). Furthermore, our research indicated that platelet-expressed C1QTNF1 is involved in cancer-associated signaling pathways. Our findings introduce a novel perspective by highlighting C1QTNF1 as the pivotal biomarker at the tipping point of primary HCC formation using DNB. We propose C1QTNF1 as a prognostic biomarker for HCC, potentially influencing tumor development through a platelet-related cancer signaling pathway.

Repolarization of immunosuppressive macrophages by targeting SLAMF7-regulated CCL2 signaling sensitizes hepatocellular carcinoma to immunotherapy.

Immune checkpoint inhibitors have limited efficacy in hepatocellular carcinoma (HCC). Macrophages are the most abundant immune cells in HCC, suggesting that a better understanding of the intrinsic processes by which tumor cells regulate macrophages could help identify strategies to improve response to immunotherapy. As signaling lymphocytic activation molecule (SLAM) family members regulate various immune functions, we investigated the role of specific SLAM receptors in the immunobiology of HCC. Comparison of the transcriptomic landscapes of immunotherapy-responsive and non-responsive advanced HCC patients identified SLAMF7 upregulation in immunotherapy-responsive HCC, and HCC patients who responded to immunotherapy also displayed higher serum levels of SLAMF7. Loss of Slamf7 in liver-specific knockout mice led to increased hepatocarcinogenesis and metastasis, elevated immunosuppressive macrophage infiltration, and upregulated PD-1 expression in CD8+ T cells. HCC cell-intrinsic SLAMF7 suppressed MAPK/ATF2-mediated CCL2 expression to regulate macrophage migration and polarization in vitro. Mechanistically, SLAMF7 associated with SH2 domain-containing adaptor protein B (SHB) through its cytoplasmic 304 tyrosine site to facilitate the recruitment of SHIP1 to SLAMF7 and inhibit the ubiquitination of TRAF6, thereby attenuating MAPK pathway activation and CCL2 transcription. Pharmacological antagonism of the CCL2/CCR2 axis potentiated the therapeutic effect of anti-PD-1 antibody in orthotopic HCC mouse models with low SLAMF7 expression. In conclusion, this study highlights SLAMF7 as a regulator of macrophage function and a potential predictive biomarker of immunotherapy response in HCC. Strategies targeting CCL2 signaling to induce macrophage repolarization in HCC with low SLAMF7 might enhance the efficacy of immunotherapy.