Signaling In Hepatocellular Carcinoma Research Articles

Tumor-Extrinsic Axl Expression Shapes an Inflammatory Microenvironment Independent of Tumor Cell Promoting Axl Signaling in Hepatocellular Carcinoma.

The activation of the receptor tyrosine kinase Axl by Gas6 is a major driver of tumorigenesis. Despite recent insights, tumor cell-intrinsic and -extrinsic Axl functions are poorly understood in hepatocellular carcinoma (HCC). Thus, we analyzed the cell-specific aspects of Axl in liver cancer cells and in the tumor microenvironment. We show that tumor-intrinsic Axl expression decreased the survival of mice and elevated the number of pulmonary metastases in a model of resection-based tumor recurrence. Axl expression increased the invasion of hepatospheres by the activation of Akt signaling and a partial epithelial-to-mesenchymal transition (EMT). However, the liver tumor burden of Axl+/+ mice induced by diethylnitrosamine plus carbon tetrachloride was reduced compared to systemic Axl-/- mice. Tumors of Axl+/+ mice were highly infiltrated with cytotoxic cells, suggesting a key immune-modulatory role of Axl. Interestingly, hepatocyte-specific Axl deficiency did not alter T cell infiltration, indicating that these changes are independent of tumor cell-intrinsic Axl. In this context, we observed an upregulation of multiple chemokines in Axl+/+ compared to Axl-/- tumors, correlating with HCC patient data. In line with this, Axl is associated with a cytotoxic immune signature in HCC patients. Together these data show that tumor-intrinsic Axl expression fosters progression, while tumor-extrinsic Axl expression shapes an inflammatory microenvironment.

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.

Glycyrrhizic acid attenuates sorafenib resistance by inducing ferroptosis via targeting mTOR signaling in hepatocellular carcinoma

Background Hepatocellular carcinoma (HCC) is the most malignant cancer worldwide. Sorafenib (SRF) is a common therapeutic drug used for patients with advanced HCC. Nevertheless, drug resistance frequently occurs in patients treated with sorafenib. Glycyrrhizic acid (GRA) is a natural compound that is identified to exhibit anti-cancer effects. In this work, we aimed to investigate the effects of GRA on SRF-resistant HCC cells and the potential regulatory mechanisms. Methods We established SRF-resistant HCC cell lines and administrated GRA treatment. We performed CCK-8 and colony formation experiments to detect cell proliferation. The accumulation of lipid reactive oxygen species (ROS) and iron levels were measured to evaluate ferroptosis. The protein levels of ferroptosis suppressor glutathione peroxidase 4 (GPX4) and SLC7A11, and the activation of AKT and mTOR were measured with western blotting assay. Results GRA treatment notably suppressed the viability and proliferation of SRF-resistant HCC cells. SRF-resistant HCC cells exhibited repressed ferroptosis level activated AKT/mTOR cascade, and GRA treatment reversed these effects. Inhibition of ferroptosis and activation of mTOR reversed the anti-proliferation effects of GRA on SRF-resistant HCC cells. Conclusion Treatment with GRA could effectively reverse the SRF resistance of HCC cells via inducing ferroptosis and inactivating the AKT/mTOR cascade.

Discovery of 6-Formylpyridyl Urea Derivatives as Potent Reversible-Covalent Fibroblast Growth Factor Receptor 4 Inhibitors with Improved Anti-Hepatocellular Carcinoma Activity.

Fibroblast growth factor receptor 4 (FGFR4) has been considered as a potential anticancer target due to FGF19/FGFR4 mediated aberrant signaling in hepatocellular carcinoma (HCC). Several FGFR4 inhibitors have been reported, but none have gained approval. Herein, a series of 5-formyl-pyrrolo[3,2-b]pyridine-3-carboxamides and a series of 6-formylpyridyl ureas were characterized as selective reversible-covalent FGFR4 inhibitors. The representative 6-formylpyridyl urea 8z exhibited excellent potency against FGFR4WT, FGFR4V550L, and FGFR4V550M with IC50 values of 16.3, 12.6, and 57.3 nM, respectively. It also potently suppressed proliferation of Ba/F3 cells driven by FGFR4WT, FGFR4V550L, and FGFR4V550M, and FGFR4-dependent Hep3B and Huh7 HCC cells, with IC50 values of 1.2, 13.5, 64.5, 15.0, and 20.4 nM, respectively. Furthermore, 8z displayed desirable microsomal stability and significant in vivo efficacy in the Huh7 HCC cancer xenograft model in nude mice. The study provides a promising new lead for anticancer drug discovery directed toward overcoming FGFR4 gatekeeper mutation mediated resistance in HCC patients.

MiRNome targeting NF-κB signaling orchestrates macrophage-triggered cancer metastasis and recurrence

Whether and how tumor intrinsic signature determines macrophage-elicited metastasis remain elusive. Here, we show, in detailed studies of data regarding 7,477 patients of 20 types of human cancers, that only 13.8%± 2.6%/27.9%± 3.03% of patients with high macrophage infiltration index exhibit early recurrence/vascular invasion. In parallel, although macrophages enhance the motility of various hepatoma cells, their enhancement intensity is significantly heterogeneous. We identify that the expression of malignant Dicer, a ribonuclease that cleaves miRNA precursors into mature miRNAs, determines macrophage-elicited metastasis. Mechanistically, the downregulation of Dicer in cancer cells leads to defects in miRNome targeting NF-κB signaling, which in turn enhances the ability of cancer cells to respond to macrophage-related inflammatory signals and ultimately promotes metastasis. Importantly, transporting miR-26b-5p, the most potential miRNA targeting NF-κB signaling in hepatocellular carcinoma, can effectively reverse macrophage-elicited metastasis of hepatoma invivo. Our results provide insights into the crosstalk between Dicer-elicited miRNome and cancer immune microenvironments and suggest that strategies to remodel malignant cell miRNome may overcome pro-tumorigenic activities of inflammatory cells.

Role of Ubiquitin-specific Proteases in Hepatocellular Carcinoma Pathogenesis.

Signaling pathways in hepatocellular carcinoma are primarily mediated by the phosphorylation and ubiquitination of post-translational proteins. In mammalian cells, ubiquitin-specific proteases (USPs) account for the majority of protein deubiquitination activities. In addition to transcriptional and post-translational regulation, ubiquitination plays an important role in the regulation of key proteins. There is a possibility that altered biological processes may lead to serious human diseases, including cancer. Recent studies have revealed the role of USPs in hepatocellular carcinoma tumorigenesis. The purpose of this review is to summarize the involvement of this class of enzymes in the regulation of cell signaling in hepatocellular carcinoma and the therapeutic development of inhibitors that target USPs, which may lead to novel therapies to treat hepatocellular carcinoma.

The Role of TGF-β/SMAD Signaling in Hepatocellular Carcinoma: from Mechanism to Therapy and Prognosis.

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, with high incidence and mortality, accounting for approximately 90% of liver cancer. The development of HCC is a complex process involving the abnormal activation or inactivation of multiple signaling pathways. Transforming growth factor-β (TGF-β)/Small mothers against decapentaplegic (SMAD) signaling pathway regulates the development of HCC. TGF-β activates intracellular SMADs protein through membrane receptors, resulting in a series of biological cascades. Accumulating studies have demonstrated that TGF-β/SMAD signaling plays multiple regulatory functions in HCC. However, there is still controversy about the role of TGF-β/SMAD in HCC. Because it involves different pathogenic factors, disease stages, and cell microenvironment, as well as upstream and downstream relationships with other signaling pathways. This review will summary the regulatory mechanism of the TGF-β/SMAD signaling pathway in HCC, involving the regulation of different pathogenic factors, different disease stages, different cell populations, microenvironments, and the interaction with microRNAs. In addition, we also introduced small molecule inhibitors, therapeutic vaccines, and traditional Chinese medicine extracts based on targeting the TGF-β/SMAD signaling pathway, which will provide future research direction for HCC therapy targeting the TGF-β/SMAD signaling pathway.

Inhibition of SIRT7 promotes STAT1 activation and STAT1-dependent signaling in hepatocellular carcinoma

The signal transducer and activator of transcription 1 (STAT1) plays a crucial role in regulating tumor progression. However, the mechanisms governing its phosphorylation and biological functions remain incompletely understood. Here, we present compelling evidence indicating that knockdown of SIRT7 inhibits Smurf1-induced ubiquitination of STAT1, consequently impeding the proteasome pathway degradation of STAT1. This inhibition leads to increased stability of STAT1 and enhanced binding to JAK1. Importantly, SIRT7 exerts a negative regulatory effect on STAT1 activation and IFN-γ/STAT1 signaling in hepatocellular carcinoma (HCC). Etoposide treatment not only facilitates STAT1 activation but also downregulates SIRT7 expression. Notably, knockdown of STAT1 in SIRT7-deficient cells attenuates the increase in cell apoptosis induced by Etoposide treatment. In conclusion, our data shed light on the intricate interplay between ubiquitination, STAT1, SIRT7, and Smurf1, elucidating their impact on STAT1-related signaling. These insights contribute to a more comprehensive understanding of the molecular mechanisms involved in STAT1 regulation and suggest potential avenues for the development of targeted therapies against cancer.

Olaparib enhances radiation-induced systemic anti-tumor effects via activating STING-chemokine signaling in hepatocellular carcinoma

Although Poly (ADP-ribose) polymerase (PARP) inhibitors have been clinically approved for cancers with BRCA mutations and are known to augment radiotherapy responses, their roles in promoting the abscopal effect and mediating immunotherapy in BRCA-proficient hepatocellular carcinoma (HCC) remain underexplored. Our study elucidates that olaparib enhances the radio-sensitivity of HCC cells. Coadministration of olaparib and irradiation induces significant DNA damage by generating double-strand breaks (DSBs), as revealed both in vitro and in immune-deficient mice. These DSBs activate the cGAS-STING pathway, initiating immunogenic cell death in abscopal tumors. STING activation reprograms the immune microenvironment in the abscopal tumors, triggering the release of type I interferon and chemokines, including CXCL9, CXCL10, CXCL11, and CCL5. This in turn amplifies T cell priming against tumor neoantigens, leading to an influx of activated, neoantigen-specific CD8+ T-cells within the abscopal tumors. Furthermore, olaparib attenuated the immune exhaustion induced by radiation and enhances the responsiveness of HCC to immune checkpoint inhibitors. Collectively, our data advocate that a synergistic regimen of PARP inhibitors and radiotherapy can strategically reinforce both local (primary) and systemic (abscopal) tumor control, bolstering HCC susceptibility to immunotherapy.

New insights into fibrotic signaling in hepatocellular carcinoma

New insights into fibrotic signaling in hepatocellular carcinoma

Complex roles of Hippo-YAP/TAZ signaling in hepatocellular carcinoma.

The Hippo signaling pathway is an evolutionarily conserved signaling module that controls organ sizein different species, and the disorder of the Hippo pathway can induce liver cancer in organisms, especiallyhepatocellular carcinoma (HCC). The exact mechanism that causes cancer is still unknown. Recent studies haveshown that it is a classical kinase cascade that phosphorylates the Mst1/2-sav1 complex and activates thephosphorylation of the Lats1/2-mob1A/B complex for inactivating Yap and Taz. These kinases and scaffolds areregarded as primary regulators of the Hippo pathway, and help in activating a variety of carcinogenic processes.Among them, Yap/Taz is seen to be the main effector molecule, which is downstream of the Hippo pathway, and itsabnormal activation is related to a variety of human cancers including liver cancer. Currently, since Yap/Taz plays avariety of roles in cancer promotion and tumor regeneration, the Hippo pathway has emerged as an attractive targetin recent drug development research. We collect and review relevant literature in web of Science and Pubmed. This review highlights the important roles of Yap/Taz in activating Hippo pathway in liver cancer. Therecent findings on the crosstalks between the Hippo and other cancer associated pathways and moleculars arealso discussed. In this review, we summarized and discussed recent breakthroughs in our understanding of how key components of the Hippo-YAP/TAZ pathway influence the hepatocellular carcinoma, including their effects on tumor occurrence and development, their roles in regulating metastasis, and their function in chemotherapy resistance. Further, the molecular mechanism and roles in regulating cross talk between Hippo-YAP/TAZ pathway and other cancer-associated pathways or oncogenes/cancer suppressor genes were summarized and discussed. More, many other inducers and inhibitors of this signaling cascade and available experimental therapies against the YAP/TAZ/TEAD axis were discussed. Targeting this pathway for cancer therapy may have great significance in the treatment of hepatocellular carcinoma. Graphical summary of the complex role of Hippo-YAP/TAZ signaling in hepatocellular carcinoma.

Dissecting the role of the NADPH oxidase NOX4 in TGF-beta signaling in hepatocellular carcinoma

The NADPH oxidase NOX4 has been proposed as necessary for the apoptosis induced by the Transforming Growth Factor-beta (TGF-β) in hepatocytes and hepatocellular carcinoma (HCC) cells. However, whether NOX4 is required for TGF-β-induced canonical (SMADs) or non-canonical signals is not fully understood yet, neither its potential involvement in other parallel actions induced by TGF-β. In this work we have used CRISPR Cas9 technology to stable attenuate NOX4 expression in HCC cells. Results have indicated that NOX4 is required for an efficient SMAD2/3 phosphorylation in response to TGF-β, whereas non-canonical signals, such as the phosphorylation of the Epidermal Growth Receptor or AKT, are higher in NOX4 silenced cells. TGF-β-mediated inhibition of cell proliferation and viability is attenuated in NOX4 silenced cells, correlating with decreased response in terms of apoptosis, and maintenance of high expression of MYC and CYCLIN D1. These results would indicate that NOX4 is required for all the tumor suppressor actions of TGF-β in HCC. However, analysis in human HCC tumors has revealed a worse prognosis for patients showing high expression of TGF-β1-related genes concomitant with high expression of NOX4. Deepening into other tumorigenic actions of TGF-β that may contribute to tumor progression, we found that NOX4 is also required for TGF-β-induced migratory effects. The Epithelial-Mesenchymal transition (EMT) program does not appear to be affected by attenuation of NOX4 levels. However, TGF-β-mediated regulation of cytoskeleton dynamics and focal adhesions require NOX4, which is necessary for TGF-β-induced increase in the chaperone Hsp27 and correct subcellular localization of Hic-5 within focal adhesions, as well for upregulation of the metalloprotease MMP9. All these results together point to NOX4 as a key element in the whole TGF-β signaling in HCC cells, revealing an unknown role for NOX4 as tumor promoter in HCC patients presenting activation of the TGF-β pathway.

FRI-387 - Dickkopf-1 inhibitor enhances the anti-tumor effects of sorafenib through inhibition of PI3K/Akt/Wnt signaling in hepatocellular carcinoma

FRI-387 - Dickkopf-1 inhibitor enhances the anti-tumor effects of sorafenib through inhibition of PI3K/Akt/Wnt signaling in hepatocellular carcinoma

SAT-282 - Immunological impact of Axl/TGF-beta signaling in hepatocellular carcinoma

SAT-282 - Immunological impact of Axl/TGF-beta signaling in hepatocellular carcinoma

Prognostic Value of Erythroblastic Leukemia Viral Oncogene Homolog 2 and Neuregulin 4 in Hepatocellular Carcinoma.

Although the roles of erythroblastic leukemia viral oncogene homolog 2 (ERBB2), neuregulin 4 (NRG4), and mitogen-inducible gene 6 (MIG6) in epidermal growth factor receptor signaling in hepatocellular carcinoma (HCC) and other malignancies have been previously investigated, the prognostic value of their serum levels in HCC remains undetermined. In the present study, correlations between serum levels and tumor characteristics, overall survival, and tumor recurrence were analyzed. Furthermore, the prognostic potential of the serum levels of these biomarkers was evaluated relative to that of alpha-fetoprotein. Both ERBB2 and NRG4 correlated with the Barcelona Clinic Liver Cancer stage, ERBB2 correlated with the tumor-maximal diameter, and NRG4 correlated with a tumor number. Cox proportional hazards regression analysis revealed that ERBB2 (hazard ratio [HR], 2.719; p = 0.007) was an independent prognostic factor for overall survival. Furthermore, ERBB2 (HR, 2.338; p = 0.002) and NRG4 (HR, 431.763; p = 0.001) were independent prognostic factors for tumor recurrence. The products of ERBB2 and NRG4 had a better area under the curve than alpha-fetoprotein for predicting 6-month, 1-year, 3-year, and 5-year mortality. Therefore, these factors could be used to evaluate prognosis and monitor treatment response in patients with HCC.

Dissecting the role of the NADPH Oxidase NOX4 in TGF-beta signaling in hepatocellular carcinoma

Dissecting the role of the NADPH Oxidase NOX4 in TGF-beta signaling in hepatocellular carcinoma

LncRNA RPPH1 acts as a molecular sponge for miR-122 to regulate Wnt1/β-catenin signaling in hepatocellular carcinoma

This study aimed to explore the role of lncRNA RPPH1 in hepatocellular carcinoma. The expression of RPPH1 and miR-122 was determined by Real-time PCR. Cell proliferation and colony formation assays were employed to monitor cell growth in vitro. Wound healing and Transwell assays were applied to detect cell migration and invasion. A dual-luciferase reporter assay was used to verify the interaction between RPPH1 and miR-122. The in vivo function of RPPH1 was illustrated by xenograft tumor models. The results showed that the expression of RPPH1 was markedly upregulated in human HCC specimens and cell lines compared to normal controls. However, the trend of miR-122 was the opposite. RPPH1 facilitates the proliferation, migration, and invasion of HCC cells and synchronously suppresses cell apoptosis. The dual-luciferase assay confirmed the relationship between RPPH1 and miR-122. Rescue experiments showed that RPPH1 acted as a competing endogenous RNA (ceRNA) by sponging miR-122 in HCC cells. Moreover, RPPH1 positively regulated the expression of Wnt1 and its downstream targets through miR-122. Our study demonstrates for the first time that RPPH1 promotes HCC progression via the miR-122/Wnt1/β-catenin axis, which may represent a valuable therapeutic target for patients with HCC.

Interplay Between Fatty Acids, Stearoyl-Co-A Desaturase, Mechanistic Target of Rapamycin, and Yes-Associated Protein/Transcriptional Coactivator With PDZ-Binding Motif in Promoting Hepatocellular Carcinoma

Interplay Between Fatty Acids, Stearoyl-Co-A Desaturase, Mechanistic Target of Rapamycin, and Yes-Associated Protein/Transcriptional Coactivator With PDZ-Binding Motif in Promoting Hepatocellular Carcinoma

Hypoxia signaling in hepatocellular carcinoma: Challenges and therapeutic opportunities.

Hepatocellular carcinoma (HCC) is one of the most common cancers with a relatively high cancer-related mortality. The uncontrolled proliferation of HCC consumes a significant amount of oxygen, causing the development of a hypoxic tumor microenvironment (TME). Hypoxia-inducible factors (HIFs), crucial regulators in the TME, activate several cancer hallmarks leading to the hepatocarcinogenesis of HCC and resistance to current therapeutics. As such, HIFs and their signaling pathways have been explored as potential therapeutic targets for the future management of HCC. This review discusses the current understanding of the structure and function of HIFs and their complex relationship with the various cancer hallmarks. To address tumor hypoxia, this review provides an insight into the various potential novel therapeutic agents for managing HCC, such as hypoxia-activated prodrugs, HIF inhibitors, nanomaterials, antisense oligonucleotides, and natural compounds, that target HIFs/hypoxic signaling pathways in HCC. Because of HCC's relatively high incidence and mortality rates in the past decades, greater efforts should be put in place to explore novel therapeutic approaches to improve the outcome for HCC patients.

Biological impact and therapeutic perspective of targeting PI3K/Akt signaling in hepatocellular carcinoma: Promises and Challenges

Cancer progression results from activation of various signaling networks. Among these, PI3K/Akt signaling contributes to proliferation, invasion, and inhibition of apoptosis. Hepatocellular carcinoma (HCC) is a primary liver cancer with high incidence rate, especially in regions with high prevalence of viral hepatitis infection. Autoimmune disorders, diabetes mellitus, obesity, alcohol consumption, and inflammation can also lead to initiation and development of HCC. The treatment of HCC depends on the identification of oncogenic factors that lead tumor cells to develop resistance to therapy. The present review article focuses on the role of PI3K/Akt signaling in HCC progression. Activation of PI3K/Akt signaling promotes glucose uptake, favors glycolysis and increases tumor cell proliferation. It inhibits both apoptosis and autophagy while promoting HCC cell survival. PI3K/Akt stimulates epithelial-to-mesenchymal transition (EMT) and increases matrix-metalloproteinase (MMP) expression during HCC metastasis. In addition to increasing colony formation capacity and facilitating the spread of tumor cells, PI3K/Akt signaling stimulates angiogenesis. Therefore, silencing PI3K/Akt signaling prevents aggressive HCC cell behavior. Activation of PI3K/Akt signaling can confer drug resistance, particularly to sorafenib, and decreases the radio-sensitivity of HCC cells. Anti-cancer agents, like phytochemicals and small molecules can suppress PI3K/Akt signaling by limiting HCC progression. Being upregulated in tumor tissues and clinical samples, PI3K/Akt can also be used as a biomarker to predict patients’ response to therapy.