Preclinical Models Of Hepatocellular Carcinoma Research Articles

IFRD1 promotes tumor cells “low-cost” survival under glutamine starvation via inhibiting histone H1.0 nucleophagy

Glutamine addiction represents a metabolic vulnerability of cancer cells; however, effective therapeutic targeting of the pathways involved remains to be realized. Here, we disclose the critical role of interferon-related developmental regulator 1 (IFRD1) in the adaptive survival of hepatocellular carcinoma (HCC) cells during glutamine starvation. IFRD1 is induced under glutamine starvation to inhibit autophagy by promoting the proteasomal degradation of the key autophagy regulator ATG14 in a TRIM21-dependent manner. Conversely, targeting IFRD1 in the glutamine-deprived state increases autophagy flux, triggering cancer cell exhaustive death. This effect largely results from the nucleophilic degradation of histone H1.0 and the ensuing unchecked increases in ribosome and protein biosynthesis associated with globally enhanced chromatin accessibility. Intriguingly, IFRD1 depletion in preclinical HCC models synergizes with the treatment of the glutaminase-1 selective inhibitor CB-839 to potentiate the effect of limiting glutamine. Together, our findings reveal how IFRD1 supports the adaptive survival of cancer cells under glutamine starvation, further highlighting the potential of IFRD1 as a therapeutic target in anti-cancer applications.

Abstract 4547: A novel drug combination with improved therapeutic efficacy over sorafenib in multiple preclinical models of hepatocellular carcinoma

Abstract Introduction: Due to the heterogeneity of hepatocellular carcinoma (HCC), the incidence of resistance and toxicity to first-line therapy sorafenib is high. Combinations of drugs can be used to exploit synergistic effects to reduce adverse events, while improving efficacy and survival. In-vitro studies performed by our team identified irinotecan and sonidegib to have potential for synergistic therapeutic effects in combination with sorafenib. Follow up in-vivo dose optimization studies in a murine NASH induced HCC found this 3-drug combination to be more effective than sorafenib-alone at arresting tumor development and progression. In this study, we tested the in-vivo efficacy of the combination in two separate preclinical cell-line derived xenograft (CDX) models. Experimental Procedure: HCC CDX models were generated by injecting two distinct HCC cell lines, Huh7 and HepG2, subcutaneously in the flank of male NOD.Cg-PrkdcscidIL2rgtm1Wjl/SzJ (NSG) mice. Mice were administered either vehicle, sorafenib, or a 3-drug combination, and mouse tumor volumes and weights were tracked for duration of study. Mice were all euthanized at study endpoint and tissues collected for analysis, including the assessment of tumor weights, differentiation, grade, necrosis, and proliferation status. Serum collected from endpoint blood was measured for human alpha fetoprotein (AFP) and alanine transaminase (ALT) levels. Changes in protein expression of tumors were assessed by western blot analysis. Results: Huh7 and HepG2 tumors were both sensitive to sorafenib-alone treatment. However, Huh7 tumors treated with the 3-drug combination had a significant decrease in tumor volume and weight at endpoint compared to the vehicle and sorafenib-alone. HepG2 tumors treated with the combination also had a significant decrease in tumor volume and weight at endpoint compared to the vehicle. Though the difference in tumor volume and weight was not statistically significant for the combination compared to sorafenib, a trend towards decrease was observed. This was further confirmed by significantly reduced AFP levels in the combination compared to the vehicle and sorafenib in HepG2 and Huh7. Drug toxicities, measured by mouse weights and ALT levels, were not significantly different. Histological and immunohistochemical assessment of tumors showed necrosis and Ki67 staining to be significantly elevated in vehicle and sorafenib-alone compared to the 3-drug group. The targets for all three drugs present in the combination were downregulated in the combination compared to the vehicle and sorafenib-alone. Conclusion: This study provides strong evidence that a novel 3-drug combination of irinotecan, sonidegib, and low dose sorafenib can significantly reduce tumor proliferation and burden in multiple independent pre-clinical in-vivo HCC models compared to high dose sorafenib monotherapy. Citation Format: Anastasia Chambers, Sunaina Shrestha, Alexandra Ladd, Sergio Duarte, Ali Zarrinpar. A novel drug combination with improved therapeutic efficacy over sorafenib in multiple preclinical models 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 4547.

Abstract 1228: Selective FGFR4 inhibitor Irpagratinib (ABSK011) exhibits broad synergistic and combinatory anti-tumor effects with other therapeutic agents in preclinical HCC models

Abstract Background: Hepatocellular carcinoma (HCC) is the most common primary liver cancer, ranking as the sixth most prevalent cancer and the third leading cause of death worldwide. Approved therapeutic drugs, including chemotherapy, anti-angiogenesis agents and immunotherapy-based combination regimen (atezolizumab plus bevacizumab), have shown suboptimal clinical benefits for patients with HCC. There are critical unmet medical needs for additional therapeutic options to address this challenge. Deregulation of FGF19-FGFR4 signaling accounts for roughly 30% of HCC and plays a pivotal role in driving HCC tumorigenesis. To date, several FGFR4 inhibitors have advanced to the clinical stage for the treatment of HCC patients. Among them, a recently discovered novel and highly selective inhibitor, Irpagratinib (ABSK011), has demonstrated the potential to become a first-in-class or best-in-class FGFR4 inhibitor. It showed promising anti-tumor activity in an ongoing phase Ib clinical study, with an ORR of 40.7% observed in FGF19 overexpressed late line HCC patients in cohorts treated with BID regimens. To further expand the therapeutic potential of irpagratinib, we carried out an array of combination treatments and revealed its broad synergistic effects with various immune and targeted agents in treating HCC. Methods: We evaluated the combination effects of Irpagratinib with a variety of therapeutic agents, covering both targeted and immune-oncology agents, in preclinical HCC in vivo models. The tested agents, including lenvatinib, atezolizumab plus bevacizumab, anti-PD-(L)1, SHP2 inhibitors and EGFR antagonists, were assessed across a range of preclinical models, such as cell-derived or patient-derived xenografts, engineered syngeneic models and humanized models. Results: Synergistic anti-tumor effects of irpagratinib were observed in combination with the indicated agents, demonstrating more profound effects than either single agent alone in the selected preclinical in vivo models. This resulted in significant effects on inducing tumor regression or inhibiting tumor progression. Conclusions: In summary, these findings collectively illustrate very broad synergistic anti-tumor effects of irpagratinib when combined with various other therapeutic agents. These results may pave the road for potential novel combinatory therapeutic strategies that could expand the utility of irpagratinib and provide innovative and more effective therapies to HCC patients. Citation Format: Nannan Zhang, Bin Shen, Zhidong He, Cheng Dai, Jie Wang, Jie Zhang, Manqi Liu, Yongxian Zhang, Zhui Chen. Selective FGFR4 inhibitor Irpagratinib (ABSK011) exhibits broad synergistic and combinatory anti-tumor effects with other therapeutic agents in preclinical HCC models [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 1228.

Abstract 5924: RNAi mediated inhibition of beta-catenin demonstrates anti-tumor efficacy and immune microenvironment modulation in preclinical hepatocellular carcinoma models

Abstract Hepatocellular carcinoma (HCC) is the fifth most common solid tumor worldwide, and the third most common cause of cancer-related deaths. For the 40% to 50% of HCC patients who are candidates for systemic therapies, the landscape has evolved significantly in the last 10 years, with most recently, immunotherapies such as combination of atezolizumab and bevacizumab emerging as the current first-line systemic therapy for patients with intermediate or advanced disease. However, there are no predictive biomarkers for patients with HCC to enable selection of those most likely to benefit from these therapies and this remains a disease with high unmet medical need. Activation of the WNT pathway via mutational events or indirect pathway activation is implicated in many cancers including up to 50% of HCC patient tumors. High expression of beta-catenin, encoded by the CTNNB1 gene, has been shown to correlate with decreased survival and more rapid disease progression in HCC patients. In addition, WNT/beta-catenin pathway activation has been shown to result in immune exclusion and resistance to immunotherapy in HCC. ALN-BCAT comprises a chemically modified siRNA encapsulated in a lipid nanoparticle formulation which generates robust and highly specific reductions of CTNNB1 mRNA, downstream biomarkers and tumor cell proliferation in in vitro model systems. Anti-tumor activity has been demonstrated in multiple in vivo orthotopic HCC mouse models, in both early and late treatment settings as measured by liver to body weight ratio. Reductions in tumor burden were orthogonally confirmed by histology analysis and shown to be associated with changes in CTNNB1-related biomarkers. Finally, ALN-BCAT treatment results in changes in the tumor microenvironment in a mouse syngeneic HCC model, with increases in CD4+ and CD8+ T cells and reductions in M2 macrophages, consistent with a shift to a more immune stimulatory anti-tumor microenvironment. Here, we demonstrate that ALN-BCAT provides a novel approach to the inhibition of the WNT pathway as a therapeutic approach for treatment of HCC patients and WNT pathway activated tumors. Citation Format: Tulin Dadali, Spencer Miller, Gaurav Saawant, Stephen Abbott, Mikyung Yu, Svetlana Morskaya, Brandon Lehrich, Satdarshan Monga, Gloria Lau, Martin Maier, Wendy Broom. RNAi mediated inhibition of beta-catenin demonstrates anti-tumor efficacy and immune microenvironment modulation in preclinical hepatocellular carcinoma models [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 5924.

Abstract 5547: Non-invasive monitoring of tumor biomechanics and implications for immunotherapy in HCC

Abstract Shear-wave elastography (SWE) is a novel non-invasive technique used to quantify tissue stiffness. This approach can be used to longitudinally monitor tumor biomechanics and holds promise for guiding informed clinical decision-making. This study aims to explore the impact of tumor stiffness, as evaluated by SWE, on the proliferative potential of endothelial, tumor, and immune cells in a preclinical model of hepatocellular carcinoma. Tumor tissue sections from a Buffalo-McA-RH7777 rat HCC tumor model, utilizing a rat hepatoma cell line stably expressing green fluorescent protein genes (fluc/GFP) were selected based on the degree of tumor stiffness assessed by SWE. Nodules were separated based on mean shear wave values (3.05 versus 2.26 m/s) and categorized as stiff or soft, respectively. A 6-color panel was used to assess the percentages of different tumor, immune, and endothelial phenotypes in different areas of the tumor including immune cells (CD45+), endothelial cells (CD34+), green fluorescent protein (GFP), Ki67 (cell proliferation), and class-III intermediate filaments - vimentin. Our findings demonstrated increased expression of vimentin on immune cells (CD45+) within the tumor margin interphase. Stiffer tumors exhibited a higher percentage of CD45 cells co-expressing vimentin compared to softer tumors (P=0.01), whereas softer tumors showed an increased prevalence of CD34+ cells concurrently expressing Ki67 (P=0.01). Same pattern persisted in the tumor margin interphase regarding the proliferation of tumor cells identified by the expression of GFP co-expressing Ki67 (P<0.01). These findings highlight a significant association between tumor mechanical properties and the proliferative activity of endothelial and tumor cells, suggesting a link between tissue stiffness and the regulatory mechanisms associated with cellular proliferation and aggressiveness in HCC. Additionally, the presence of vimentin in immune cells may suggest that stiffer tumors may require enhanced migratory and invasive properties to compensate for changes in tumor mechanics thus potentially influencing immune function. Citation Format: Andrea C. Cortes, Kiyoyuki Minamiguchi, Hannah Kostan, Maria S. Stenkamp, Simone Anfossi, Natalie Wall Fowlkes, Rony Avritcsher. Non-invasive monitoring of tumor biomechanics and implications for immunotherapy in HCC [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 5547.

SUMOylation inhibitors activate anti-tumor immunity by reshaping the immune microenvironment in a preclinical model of hepatocellular carcinoma.

High levels of heterogeneity and immunosuppression characterize the HCC immune microenvironment (TME). Unfortunately, the majority of hepatocellular carcinoma (HCC) patients do not benefit from immune checkpoint inhibitors (ICIs) therapy. New small molecule therapies for the treatment of HCC are the goal of our research. SUMOylation inhibitors (TAK-981 and ML-792) were evaluated for the treatment of preclinical mouse HCC models (including subcutaneous and orthotopic HCC models). We profile immune cell subsets from tumor samples after SUMOylation inhibitors treatment using single-cell RNA sequencing (scRNA-seq), mass cytometry (CyTOF), flow cytometry, and multiple immunofluorescences (mIF). We discover that SUMOylation is higher in HCC patient samples compared to normal liver tissue. TAK-981 and ML-792 decrease SUMOylation at nanomolar levels in HCC cells and also successfully reduced the tumor burden. Analysis combining scRNA-seq and CyTOF demonstrate that treatment with SUMOylation inhibitors reduces the exhausted CD8+T (Tex) cells while enhancing the cytotoxic NK cells, M1 macrophages and cytotoxic T lymphocytes (CTL) in preclinical mouse HCC model. Furthermore, SUMOylation inhibitors have the potential to activate innate immune signals from CD8+T, NK and macrophages while promoting TNFα and IL-17 secretion. Most notably, SUMOylation inhibitors can directly alter the TME by adjusting the abundance of intestinal microbiota, thereby restoring anti-tumor immunity in HCC models. This preclinical study suggests that SUMO signaling inhibitors may be beneficial for the treatment of HCC.

RNA helicase DDX5 modulates sorafenib sensitivity in hepatocellular carcinoma via the Wnt/β-catenin–ferroptosis axis

Reduced expression of the RNA helicase DDX5 associated with increased hepatocellular carcinoma (HCC) tumor grade and poor patient survival following treatment with sorafenib. While immunotherapy is the first-line treatment for HCC, sorafenib and other multi-tyrosine kinase inhibitors (mTKIs) are widely used when immunotherapy is contra-indicated or fails. Herein, we elucidate the role of DDX5 in sensitizing HCC to sorafenib, offering new therapeutic strategies. Treatment of various human HCC cell lines with sorafenib/mTKIs downregulated DDX5 in vitro and in preclinical HCC models. Conversely, DDX5 overexpression reduced the viability of sorafenib-treated cells via ferroptosis, suggesting a role for DDX5 in sorafenib sensitivity. RNAseq of wild-type vs. DDX5-knockdown cells treated with or without sorafenib identified a set of common genes repressed by DDX5 and upregulated by sorafenib. This set significantly overlaps with Wnt signaling genes, including Disheveled-1 (DVL1), an indispensable Wnt activator and prognostic indicator of poor survival for sorafenib-treated patients. DDX5-knockout (DDX5KO) HCC cells exhibited DVL1 induction, Wnt/β-catenin pathway activation, and ferroptosis upon inhibition of canonical Wnt signaling. Consistently, xenograft HCC tumors exhibited reduced growth by inhibition of Wnt/β-catenin signaling via induction of ferroptosis. Significantly, overexpression of DDX5 in HCC xenografts repressed DVL1 expression and increased ferroptosis, resulting in reduced tumor growth by sorafenib. We conclude that DDX5 downregulation by sorafenib mediates adaptive resistance by activating Wnt/β-catenin signaling, leading to ferroptosis escape. Conversely, overexpression of DDX5 in vivo enhances the anti-tumor efficacy of sorafenib by suppressing Wnt/β-catenin activation and induction of ferroptosis. Thus, DDX5 overexpression in combination with mTKIs is a promising therapeutic strategy for HCC.

Low-dose radiotherapy combined with dual PD-L1 and VEGFA blockade elicits antitumor response in hepatocellular carcinoma mediated by activated intratumoral CD8+ exhausted-like T cells

Atezolizumab (anti-PD-L1) combined with bevacizumab (anti-VEGFA) is the first-line immunotherapy for advanced hepatocellular carcinoma (HCC), but the number of patients who benefit from this regimen remains limited. Here, we combine dual PD-L1 and VEGFA blockade (DPVB) with low-dose radiotherapy (LDRT), which rapidly inflames tumors, rendering them vulnerable to immunotherapy. The combinatorial therapy exhibits superior antitumor efficacy mediated by CD8+ T cells in various preclinical HCC models. Treatment efficacy relies upon mobilizing exhausted-like CD8+ T cells (CD8+ Tex) with effector function and cytolytic capacity. Mechanistically, LDRT sensitizes tumors to DPVB by recruiting stem-like CD8+ Tpex, the progenitor exhausted CD8+ T cells, from draining lymph nodes (dLNs) into the tumor via the CXCL10/CXCR3 axis. Together, these results further support the rationale for combining LDRT with atezolizumab and bevacizumab, and its clinical translation.

Personalized treatment for hepatocellular carcinoma in the era of targeted medicine and bioengineering.

Hepatocellular carcinoma (HCC) is a major global health burden, causing approximately 8.3 million deaths each year, and it is the third leading cause of cancer-related death worldwide, with a relative 5-year survival rate of around 18%. Due to the advanced stage of diagnosis in most patients, systemic treatment based on targeted therapy has become the only feasible option. Genomic studies have established a profile of molecular alterations in hepatocellular carcinoma with potentially actionable mutations, but these mutations have yet to be translated into clinical practice. The first targeted drug approved for systemic treatment of patients with advanced hepatocellular carcinoma was Sorafenib, which was a milestone. Subsequent clinical trials have identified multiple tyrosine kinase inhibitors, such as Lenvatinib, Cabozantinib, and Regorafenib, for the treatment of hepatocellular carcinoma, with survival benefits for the patient. Ongoing systemic therapy studies and trials include various immune-based combination therapies, with some early results showing promise and potential for new therapy plans. Systemic therapy for hepatocellular carcinoma is complicated by the significant heterogeneity of the disease and its propensity for developing drug resistance. Therefore, it is essential to choose a better, individualized treatment plan to benefit patients. Preclinical models capable of preserving in vivo tumor characteristics are urgently needed to circumvent heterogeneity and overcome drug resistance. In this review, we summarize current approaches to targeted therapy for HCC patients and the establishment of several patient-derived preclinical models of hepatocellular carcinoma. We also discuss the challenges and opportunities of targeted therapy for hepatocellular carcinoma and how to achieve personalized treatment with the continuous development of targeted therapies and bioengineering technologies.

Abstract 497: HX301, a first-in-class ARK5i, demonstrates antitumor activity in preclinical HCC models with high ARK5/Myc expression

Abstract Introduction: Hepatocellular carcinoma (HCC) is an aggressive malignance of high mortality (6th most common worldwide) with few treatment options. Current drug treatments, including chemo-/target therapies (e.g., sorafenib), are usually ineffective among advanced HCC and with high toxicity. ARK5, or NUAK1, a novel AMP-activated protein kinase (AMPK) family member 5, is found overexpressed in many malignancies including HCC and usually associated with poor prognosis, as well as drug resistance. For example, doxorubicin, first-line chemotherapy for TACE, and transarterial chemoembolization for advanced HCC. In addition, ARK5 is found to be vitally involved in oncoprotein Myc-driven oncogenesis (metabolic homeostasis/cell survival), particularly in tumors under nutrition/oxygen-deprivations, including HCC. HX301 is a clinical stage first-in-class (FIC) ARK5 inhibitor (ARK5i) and other kinase activities (e.g., CDK4/6, CSF1R, etc.). In this study we evaluate HX301 antitumor activity in HCC over-expressing both ARK5 and c-Myc. Methods: A panel of subcutaneous HCC patient-derived xenografts (PDXs) were genomically profiled by whole transcriptome sequencing by RNAseq, and several selected models with different expression of ARK5 and c-myc expression were assessed pharmacologically using daily dosing of 100mg/kg HX301. Subcutaneous tumor responses to HX301 were calculated by tumor growth inhibition (TGI). Results: HCC PDX models LI1035, LI6610 both had high expression of ARK5 and Myc genes, whereas LI6650 had lower expression level of Myc than LI1035 and LI6610. LI6652 had lower expression level of ARK5 than LI1035 and LI6610. The log2 FPKM values of ARK5 and Myc in model of LI1035 was 3.9284 and 4.8177, 3.6629 and 5.3658 for LI6610, 3.1228 and -0.0556 for LI6650, -0.3538 and 6.5785 for LI6652. The TGI for LI1035 and LI6610 was 64% (P = 0.0293) and 62% (P = 0.0257) respectively whereas in comparison a smaller TGI of 44% (P = 0.034) was observed in LI6650. In the model of LI6652, TGI for HX301 was 58%, but a statistically significant difference was not observed when comparing the treatment group with the vehicle group (P = 0.138). Conclusions: Our preliminary results demonstrate that HX301 had strong antitumor activity in HCC PDX models expressing both ARK5 and c-Myc. HX301 has the potential to be a first-in-class ARK5i candidate for the treatment of advanced HCC with high expression of c-Myc, warranting further clinical investigation. Citation Format: Zhihua Jiao, Jingjing Wang, Hang Ke, Faming Zhang, Henry Li. HX301, a first-in-class ARK5i, demonstrates antitumor activity in preclinical HCC models with high ARK5/Myc expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 497.

Abstract 2679: Combination of CDK 4/6 inhibitor palbociclib with rapamycin synergistically inhibits growth of hepatocellular carcinoma in preclinical models

Abstract Introduction: The cell cycle inhibitor palbociclib has been shown to have a cytostatic effect on hepatocellular carcinoma (HCC) cells via the induction of quiescence and senescence, though it has limited cytocidal effect. We hypothesized that arrested HCC cells upregulate mTOR signaling to stay metabolically active and investigated the effect of combining palbociclib with the mTOR inhibitor rapamycin on preclinical models of HCC. Methods: We identified commonly altered molecular markers in HCC, including cell cycle related genes, using single sample gene set enrichment analysis (ssGSEA) of 13 paired (tumor and adjacent non-tumor) RNA-seq and 15 paired proteomic data sets as well as 50 paired RNA-seq data sets from TCGA. Subsequently, we studied the in-vitro effects of palbociclib and rapamycin by evaluating induction of senescence, inhibition of cell growth with fixed ratio combination treatment as well as Western Blotting to establish mechanistic effects. We tested the in-vivo anti-tumor efficacy of palbociclib plus rapamycin in athymic nude mice with growing xenograft tumors. We then generated immunocompetent murine HCC models using hydrodynamic transfection of oncogenes ΔN90-β-catenin and c-Met, and measured plasma AFP levels as a marker of HCC to assess the efficacy of treatment with palbociclib and/or rapamycin. Results: ssGSEA revealed significant positive enrichment of several cell cycle related gene sets in all our HCC cases. Palbociclib treatment in vitro showed an increase in senescence associated β-galactosidase staining as well as increased levels of intrinsic CDK inhibitors p16, p15, p21 and p27, indicating senescence. Fixed ratio treatment with palbociclib and rapamycin established a synergistic interaction between the drugs, as indicated by a combination index of less than 1. We also observed an increase in levels of proteins of the mTOR pathway (p-mTOR, p-4eBP1, p-p70 and p-s6) after palbociclib treatment, followed by suppression of the levels on addition of rapamycin. In the xenograft HCC model, combination treatment with palbociclib and rapamycin resulted in slower tumor growth and significantly increased time to critical tumor volume (2000 mm3) (log rank, p <0.001). In the hydrodynamic transfection HCC model, we observed a significantly lower mean AFP level in the combination treatment group, along with lower liver weights which were closer to the liver weights of normal mice. Conclusion: HCC cells overexpress genes and proteins that drive cell cycle progression. Palbociclib induces senescence in HCC cells along with an associated upregulation in mTOR signaling, and combination with rapamycin has a synergistic effect on inhibition of tumor growth in vitro as well as in vivo, possibly by abrogating both actively growing and quiescent/senescent HCC cells. The combination of the two drugs may have potential as a novel therapy for HCC. Citation Format: Ankur Tiwari, Araceli Huerta, Hakim Bouamar, Debodipta Das, Francisco Cigarroa, LuZhe Sun. Combination of CDK 4/6 inhibitor palbociclib with rapamycin synergistically inhibits growth of hepatocellular carcinoma in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2679.

Abstract 6167: Targeting TBL1 with tegavivint promotes anti-tumor and immunomodulatory responses in preclinical models of hepatocellular carcinoma

Abstract Background: Hepatocellular cancer (HCC) is the 3rd leading cause of death worldwide with approximately 30% of patients possessing a beta-catenin activating mutation. Despite recent progress in combination with VEGF inhibition, resistance to immune checkpoint inhibitors (ICI) still occurs in a majority of HCC patients. Recent studies suggest that activated beta-catenin regulates both tumor metabolism and immune microenvironment in CTNNB1-mutated HCCs. Transducin beta-like protein 1 (TBL1) is necessary for canonical Wnt -regulated gene transcription by binding nuclear beta-catenin, which prevents its nuclear degradation and promotes recruitment to Wnt-target gene promoters. The TBL1 inhibitor, tegavivint, disrupts the TBL1-beta-catenin complex and inhibits beta catenin signaling. This study measures TBL1 levels and determines tegavivint response within preclinical models of HCC. Methods: Tegavivint cytotoxicity (GI50) was determined in an HCC cell line panel. Tegavivint activity was measured in a syngeneic mouse model of HCC. Tumors were collected for FACS analysis of cell subpopulations of interest from the vehicle and tegavivint group at study termination. Efficacy and tolerability were measured and evaluated by tumor growth curve and body weight change in treatment groups. Liver and tumor tissue were collected at study termination. TBL1 levels were measured in HCC cells and mouse tumors via western blot and immunohistochemical (IHC) staining. Results: Tegavivint sensitivity was measured in a of HCC cell line panel resulting in GI50 values ranging from 0.03 μM - 0.20 μM. Correlation between cell sensitivity and activating beta-catenin mutational status was identified and further characterized by measurement of active beta-catenin and TBL1 expression in cell lysates. In an HCC syngeneic mouse model with reported elevated levels of beta-catenin, tegavivint significantly inhibited tumor growth in comparison to vehicle control and demonstrated a significant change in PD-1+ CD3+ and PD-1+ CD4+ subpopulations. TBL1 and active beta-catenin levels were also characterized in tumor mouse tissue relative to tegavivint response. Conclusion: Tegavivint monotherapy demonstrated antitumor activity in a range of HCC preclinical models. In vitro studies show correlation between tegavivint potency and beta-catenin mutation. In a syngeneic HCC mouse model with elevated beta-catenin, tegavivint reduces tumor growth and induces an activated T-cell subpopulation. We are currently characterizing potential biomarkers of TBL1/beta-catenin activity to identify HCC patient populations that will be most responsive to tegavivint in a clinical setting. Citation Format: Kimberly R. Holloway, Thomas Drake, Thomas Bird, Stephen Horrigan. Targeting TBL1 with tegavivint promotes anti-tumor and immunomodulatory responses in preclinical models of hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6167.

Neuropilins as potential biomarkers in hepatocellular carcinoma: a systematic review of basic and clinical implications.

Hepatocellular carcinoma (HCC) is one of the most common and deadly cancers worldwide and is characterized by complex molecular carcinogenesis. Neuropilins (NRPs) NRP1 and NRP2 are the receptors of multiple proteins involved in key signaling pathways associated with tumor progression. We aimed to systematically review all the available findings on their role in HCC. We searched the Scopus, Web of Science (WOS), PubMed, Cochrane and Embase databases for articles evaluating NRPs in preclinical or clinical HCC models. This study was registered in PROSPERO (CRD42022349774) and include 49 studies. Multiple cellular and molecular processes have been associated with one or both NRPs, indicating that they are potential diagnostic and prognostic biomarkers in HCC patients. Mainly NRP1 has been shown to promote tumor cell survival and progression by modulating several signaling pathways. NRPs mainly regulate angiogenesis, invasion and migration and have shown to induce invasion and metastasis. They also regulate the immune response and tumor microenvironment, showing a crucial interplay with the hypoxia response and microRNAs in HCC. Altogether, NRP1 and NRP2 are potential biomarkers and therapeutic targets, providing novel insight into the clinical landscape of HCC patients.

312 (PB092) - Mechanisms of resistance toward FGFR4 inhibition in hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC), which accounts for up to 90% of all primary liver cancers, is a leading cause of cancer mortality worldwide. FGF19 is a gut secreted endocrine hormone that acts in liver through its unique receptor FGFR4 and co-receptor KLB, to regulate bile acid synthesis and hepatocyte proliferation. FGF19 is reported to be overexpressed and/or amplified in ∼30% of HCC. Genomic and functional studies have identified FGF19 as a potential driver oncogene in HCC. Several FGFR4 inhibitors have entered clinical trials for treating HCC patients. BLU-554 is a potent, selective, and irreversible FGFR4 inhibitor that has demonstrated preliminary efficacy as a second-line treatment in HCC patients harboring FGF19 overexpression. The observed responses, however, on average only last few months before patient relapse, suggesting likely occurrence of acquired resistance. Here, we investigated the changes that occur with long-term FGFR4 inhibition and the development of resistance in preclinical HCC models, in order to identify resistance mechanisms and possible combination strategies. Materials and methods: We established resistant cell lines following long-term exposure of Huh7 with BLU-554. Proteomic, genomic and transcriptomic characterizations were performed to identify potential resistance mechanisms. Results: Huh7 cells resistant to BLU-554 were generated and confirmed with insensitivity to BLU-554. In addition, the cells were also resistant to other FGFR4 inhibitors including FGF-401, H3B-6527 and erdafitinib. Genomic analysis found no mutations on the FGFR4 gene itself. Proteomic analysis revealed activation of a RTK in the BLU-554 resistant cells compared with the parental cells. Transcriptomic analysis revealed changes in gene expression and GSEA analysis revealed multiple relevant gene sets were significantly enriched in the resistant cells. We tested several inhibitors against the identified RTK pathway and found complete inhibition this pathway could restore BLU-554 sensitivity. Conclusions: These data suggest the bypass activation of other RTK may contribute to acquired resistance of FGFR4 inhibition and potential combination strategy to overcome resistance. No conflict of interest.

Dual-tracer positron emission tomography/computed tomography as an imaging probe of de novo lipogenesis in preclinical models of hepatocellular carcinoma.

BackgroundDe novo lipogenesis is upregulated in many cancers, and targeting it represents a metabolic approach to cancer treatment. However, the treatment response is unpredictable because lipogenic activity varies greatly among individual tumors, thereby necessitating the assessment of lipogenic activity before treatment. Here, we proposed an imaging probe, positron emission tomography/computed tomography (PET/CT) with dual tracers combining 11C-acetate and 18F-fluorodeoxyglucose (18F-FDG), to assess the lipogenic activity of hepatocellular carcinoma (HCC) and predict the response to lipogenesis-targeted therapy.MethodsWe investigated the association between 11C-acetate/18F-FDG uptake and de novo lipogenesis in three HCC cell lines (from well-differentiated to poorly differentiated: HepG2, Hep3B, and SkHep1) by examining the expression of lipogenic enzymes: acetyl-CoA synthetase 2 (ACSS2), fatty acid synthase (FASN), and ATP citrate lyase (ACLY). The glycolysis level was determined through glycolytic enzymes: pyruvate dehydrogenase expression (PDH). On the basis of the findings of dual-tracer PET/CT, we evaluated the treatment response to a lipase inhibitor (orlistat) in cell culture experiments and xenograft mice.ResultsDual-tracer PET/CT revealed the lipogenic activity of various HCC cells, which was positively associated with 11C-acetate uptake and negatively associated with 18F-FDG uptake. This finding represents the negative association between 11C-acetate and 18F-FDG uptake. Because these two tracers revealed the lipogenic and glycolytic activity, respectively, which implies an antagonism between lipogenic metabolism and glucose metabolism in HCC. In addition, dual-tracer PET/CT not only revealed the lipogenic activity but also predicted the treatment response to lipogenesis-targeted therapy. For example, HepG2 xenografts with high 11C-acetate but low 18F-FDG uptake exhibited high lipogenic activity and responded well to orlistat treatment, whereas SkHep1 xenografts with low 11C-acetate but high 18F-FDG uptake exhibited lower lipogenic activity and poor response to orlistat.ConclusionThe proposed non-invasive dual-tracer PET/CT imaging can reveal the lipogenesis and glycolysis status of HCC, thus providing an ideal imaging probe for predicting the therapeutic response of HCC to lipogenesis-targeted therapy.

Abstract PO001: Preclinical activity of glypican-3 (GPC3) and NKp46 directed FLEX-NK™ engager antibody (CYT-303) in combination with iPSC derived natural killer cells (iNKs) or peripheral blood (PB) NK cells in hepatocellular carcinoma (HCC)

Abstract BACKGROUND: GPC3 is highly expressed in HCC while it is hardly expressed in adult normal tissues except placenta. Given the presence of dysfunctional NK cells in the HCC tumor microenvironment that contribute to poor anti-tumor immune responses, we sought to develop an iNK cell therapy in combination with GPC3 targeted NK cell engagers (NKE). FLEX-NK™ is a proprietary tetravalent IgG1-like multifunctional antibody NKE platform with a novel FLEX-linker to allow for simultaneous binding to different antigens on different cells. CYT-303 was constructed to engage NK cells via the activation receptor NKp46 and to target cancer cells via GPC3. We hypothesized that CYT-303 may be active in the tumor microenvironment where there are sufficient number and function of endogenous NK cells, but that this activity may be augmented by fresh functional NK cells. iNK cells derived from iPSC, a uniform starting material with unlimited self-renewal capabilities, can be expanded to produce a universal off-the-shelf allogeneic therapy. We investigated the combination of CYT-303 to enhance tumor specificity and potency of iNKs. METHODS: CYT-303 was expressed in CHOZEN cells and purified by step column chromatography. iNK’s were differentiated from iPSC’s and expanded using irradiated feeder cells. PB-NK cells were purified from healthy donor blood. iNK and PB-NK cytotoxicity against Hep3B tumors was evaluated in the presence of CYT-303 or isotype control antibodies at a fixed E/T ratio. CYT-303 pharmacokinetics in mice was evaluated following a single intravenous injection. Anti-tumor efficacy of the iNK combination with CYT-303 was evaluated in NSG-IL15 mice bearing subcutaneous Hep3B tumors following intra-tumoral injection of iNKs and intravenous dosing with CYT-303. Blood alpha-fetoprotein (AFP) levels were assessed by immunoassay. Cytokine release assessments for CYT-303 was evaluated in an in-vitro PBMC activation assay. RESULTS: iNK cells express high levels of multiple activation receptors including NKp46, but low levels of CD16. Despite low expression of CD16, natural cytotoxicity of iNK’s against Hep3B tumors was higher than with fresh PB-NK and CYT-303 redirected killing of Hep3B tumors was comparable to PB-NK’s. The CYT-303 pharmacokinetics study in mice showed a terminal half-life of 17 hrs. In a Hep3B tumor model in NSG-hIL-15 mice, the combination of CYT-303 and iNK’s showed significantly greater tumor growth inhibition compared to iNK’s alone plus an IgG1 isotype control. Blood AFP levels decreased in the CYT-303 plus iNK combination compared to iNK’s alone. Cytokine release assessment of CYT-303 in the human PBMC assay showed no evidence of cytokine release while high levels of cytokine release was observed with anti-CD28 (TGN1412) and CD3 antibody controls. CONCLUSIONS: The combination of NK cell engager CYT-303 and iNK cells is active in preclinical models of HCC with low levels of cytokine release. These data support further development of CYT-303 and iNKs to engage and empower NK cells as an off the shelf therapeutic approach in HCC. Citation Format: Antonio Arulanandam, Liang Lin, Hao-Ming Chang, Harish Potu, Vishal Khairnar, David Zou, Melissa Triggiano, Nejmi Dilmac, Yinan Yang, Shira Kahlon, Stanley Frankel, Jean Kadouche, Daniel Teper, Ofer Mandelboim, Yoav Hershkovitz, Yaron Ilan, Wei Li. Preclinical activity of glypican-3 (GPC3) and NKp46 directed FLEX-NK™ engager antibody (CYT-303) in combination with iPSC derived natural killer cells (iNKs) or peripheral blood (PB) NK cells in hepatocellular carcinoma (HCC) [abstract]. In: Proceedings of the AACR Special Conference: Advances in the Pathogenesis and Molecular Therapies of Liver Cancer; 2022 May 5-8; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(17_Suppl):Abstract nr PO001.

Personalized neoantigen vaccine combined with PD-1 blockade increases CD8+ tissue-resident memory T-cell infiltration in preclinical hepatocellular carcinoma models

BackgroundPersonalized neoantigen vaccine could induce a robust antitumor immune response in multiple cancers, whose efficacy could be further enhanced by combining with programmed cell death 1 blockade (α-PD-1). However, the...

FRI596 - Inhibition of Wee1 induces antitumoral effects in preclinical models of hepatocellular carcinoma independently of p53 mutational status

FRI596 - Inhibition of Wee1 induces antitumoral effects in preclinical models of hepatocellular carcinoma independently of p53 mutational status

Glypican-3-specific CAR-NKT cells overexpressing BATF3 mediate potent antitumor activity against hepatocellular carcinoma.

e14521 Background: Hepatocellular carcinoma (HCC), the fourth leading cause of cancer-related deaths worldwide, is amenable to immunotherapies that target glypican-3 (GPC3), a protein expressed by over 75% of HCCs but not by healthy tissues. The invariant natural killer T cells (NKTs) prevent HCC tumorogenesis through interactions with the gut microbiome in mice, and the presence of tumor-infiltrating NKTs is associated with improved clinical outcomes. We previously tested GPC3-specific chimeric antigen receptors (CARs) and selected a receptor with both CD28 and 41BB costimulatory endodomains based on its ability to mediate superior antitumor activity of transduced NKTs in vivo. Co-expression of interleukin-15 (IL15), a cytokine that supports NKT expansion and persistence, with the chosen GPC3-CAR further enhanced this activity. GPC3-CAR NKTs co-expressing IL15 (15.GPC3-CAR) overexpressed the Basic Leucine Zipper ATF-Like Transcription Factor 3 (BATF3), a member of the AP-1 family. Since AP-1 family proteins are master regulators of cell survival and proliferation, we hypothesized that overexpressing BATF3 in GPC3-CAR NKTs (BATF3.GPC3-CAR) will lead to superior expansion, persistence, and antitumor activity compared to 15.GPC3-CAR NKTs. Methods: We used RNAseq and flow cytometry to define the transcriptomic and phenotypic characteristics, respectively, of BATF3-overexpressing NKTs at baseline and after tumor cell killing in co-culture. We also used co-culture assays to evaluate the ability of BATF3- or IL15-expressing NKTs to proliferate, produce effector cytokines, and kill tumor cells after multiple rounds of exposure. Finally, we evaluated the ability of BATF3.GPC3-CAR and IL15.GPC3-CAR NKTs to expand, persist, and target tumors in an HCC xenograft murine model. Results: BATF3 overexpression in NKTs induced significant differences in gene expression profiles compared to a GFP control at baseline (DEGs up: 20; down: 26, p < 0.01) and after tumor cell killing (DEGs up: 19; down: 32; p < 0.01; fold change > 2 or < 0.5, respectively) corresponding to enrichment of gene sets related to metabolic fitness. Importantly, CD62L+ NKTs, which have enhanced antitumor properties, were enriched in BATF3-expressing NKTs (27.6% vs 8.2%, p < 0.05, versus GFP control). Further, BATF3 significantly enhanced NKT proliferation (area under the curve of absolute NKT cell counts: 5x1011 vs 1.1x1011, p = 0.001; fold expansion: 6.12x104 vs 1.2x104, p = 0.001, versus IL15 NKTs). Finally, BATF3.GPC3-CAR NKTs induced long-term tumor control and significantly improved survival of HCC xenograft-bearing mice compared to 15.GPC3-CAR NKTs (p = 0.0002, Mantel-Cox analysis). Conclusions: BATF3.GPC3-CAR NKTs induce robust antitumor activity in pre-clinical models of HCC. These results provide a foundation for evaluating BATF3.GPC3-CAR NKTs in patients with relapsed/refractory HCC.

An acid trip activates protumoral macrophages to promote hepatocellular carcinoma malignancy.

Tumor-associated macrophages (TAMs) promote metastasis and tumor cell extravasation, survival, and growth. In hepatocellular carcinoma (HCC), the presence of TAM subpopulations correlates with poor outcome. In this issue of the JCI, Ning et al. report on their use of cell culture, mouse models, and human data sets to investigate the interactions between aerobic glycolysis and carbonic anhydrase XII (CA12) expression in HCC. Aerobic glycolysis promoted CA12 upregulation in TAMs, which induced a protumoral phenotype to promote tumor growth and metastasis. Tumor cell factors derived from HCC samples induced CA12 upregulation in tumor-infiltrating TAMs via the HIF1α pathway. In preclinical models of HCC, CA12 inhibition reduced tumor growth and lung metastasis and reduced TAM infiltrate. Notably, dual treatment with anti-PD1 and CA12 inhibitors synergistically attenuated tumor growth and metastasis and enhanced survival compared with either treatment alone. These findings suggest that targeting CA12 in combination with immune-checkpoint blockade may provide treatment options for HCC.