RUNX-3-expressing CAR T cells targeting glypican-3 in patients with heavily pretreated advanced hepatocellular carcinoma: a phase I trial

Pathogenesis and Systemic Treatment of Hepatocellular Carcinoma: Current Status and Prospects

Hepatocellular carcinoma (HCC) remains one of the major threats to human health worldwide. The emergence of systemic therapeutic options has greatly improved the prognosis of patients with HCC, particularly those with advanced stages of the disease. In this review, we discussed the pathogenesis of HCC, genetic alterations associated with the development of HCC, and alterations in the tumor immune microenvironment. Then, important indicators and emerging technologies related to the diagnosis of HCC are summarized. Also, we reviewed the major advances in treatments for HCC, offering insights into future prospects for next-generation managements.

Epigenetic landscapes drive CAR-T cell kinetics and fate decisions: Bridging persistence and resistance

Chimeric antigen receptor-T (CAR-T) cell therapy has revolutionized the treatment paradigm for B-cell malignancies and holds promise for solid tumor immunotherapy. However, CAR-T-cell therapy still faces many challenges, especially primary and secondary resistance. Some mechanisms of resistance, including CAR-T-cell dysfunction, an inhibitory tumor microenvironment, and tumor-intrinsic resistance, have been identified in previous studies. As insights into CAR-T-cell biology have increased, the role of epigenetic reprogramming in influencing the clinical effectiveness of CAR-T cells has become increasingly recognized. An increasing number of direct and indirect epigenetic targeting methods are being developed in combination with CAR-T-cell therapy. In this review, we emphasize the broad pharmacological links between epigenetic therapies and CAR-T-cell therapy, not only within CAR-T cells but also involving tumors and the tumor microenvironment. To elucidate the mechanisms through which epigenetic therapies promote CAR-T-cell therapy, we provide a comprehensive overview of the epigenetic basis of CAR-T-cell kinetics and differentiation, tumor-intrinsic factors and the microenvironment. We also describe some epigenetic strategies that have implications for CAR-T-cell therapy in the present and future. Because targeting epigenetics can have pleiotropic effects, developing more selective and less toxic targeting strategies and determining the optimal administration strategy in clinical trials are the focus of the next phase of research. In summary, we highlight the possible mechanisms and clinical potential of epigenetic regulation in CAR-T-cell therapy.

Immune microenvironment and immunotherapy in hepatocellular carcinoma: mechanisms and advances

Hepatocellular carcinoma (HCC) remains a leading cause of cancer-related mortality globally. The tumor microenvironment (TME) plays a pivotal role in HCC progression, characterized by dynamic interactions between stromal components, immune cells, and tumor cells. Key immune players, including tumor-associated macrophages (TAMs), tumor-infiltrating lymphocytes (TILs), cytotoxic T lymphocytes (CTLs), regulatory T cells (Tregs), MDSCs, dendritic cells (DCs), and natural killer (NK) cells, contribute to immune evasion and tumor progression. Recent advances in immunotherapy, such as immune checkpoint inhibitors (ICIs), cancer vaccines, adoptive cell therapy (ACT), and combination therapies, have shown promise in enhancing anti-tumor responses. Dual ICI combinations, ICIs with molecular targeted drugs, and integration with local treatments or radiotherapy have demonstrated improved outcomes in HCC patients. This review highlights the evolving understanding of the immune microenvironment and the therapeutic potential of immunotherapeutic strategies in HCC management.

Structural Features of Glypicans and their Impact on Wnt Signaling in Cancer

Glypicans (GPCs) are a family of cell surface proteoglycans involved in multiple signaling pathways that regulate cell fate and proliferation. They share a characteristic structure composed of a core protein with two or more heparan sulfate chains and a glycosyl-phosphatidylinositol anchor that attaches them to the cell membrane. Aberrant expression of certain glypicans such as GPC1, GPC2, and GPC3 has been found in multiple types of cancer and causes the dysregulation of Wnt, hedgehog, and other signaling pathways, making them emerging targets for cancer immunotherapy. The molecular mechanism by which glypicans interact with signaling factors will provide insights for the development of cancer therapeutics. However, the structural complexes of human glypicans with Wnt and other key signaling factors remain unsolved. In this brief review, we analyze the current protein structural evidence for glypicans, with an emphasis on their interaction with Wnt, in an effort to provide insights to understand the molecular mechanisms by which glypicans play positive or negative roles in Wnt signaling in cancer and to discuss their translational potentials.

Tonic signaling in CAR-T therapy: the lever long enough to move the planet

Chimeric antigen receptor (CAR) T-cell therapy has shown remarkable efficacy in treating hematological malignancies and is expanding into other indications such as autoimmune diseases, fibrosis, aging and viral infection. However, clinical challenges persist in treating solid tumors, including physical barriers, tumor heterogeneity, poor in vivo persistence, and T-cell exhaustion, all of which hinder therapeutic efficacy. This review focuses on the critical role of tonic signaling in CAR-T therapy. Tonic signaling is a low-level constitutive signaling occurring in both natural and engineered antigen receptors without antigen stimulation. It plays a pivotal role in regulating immune cell homeostasis, exhaustion, persistence, and effector functions. The "Peak Theory" suggests an optimal level of tonic signaling for CAR-T function: while weak tonic signaling may result in poor proliferation and persistence, excessively strong signaling can cause T cell exhaustion. This review also summarizes the recent progress in mechanisms underlying the tonic signaling and strategies to fine-tune the CAR tonic signaling. By understanding and precisely modulating tonic signaling, the efficacy of CAR-T therapies can be further optimized, offering new avenues for treatment across a broader spectrum of diseases. These findings have implications beyond CAR-T cells, potentially impacting other engineered immune cell therapies such as CAR-NK and CAR-M.

Recent advancements in improving the efficacy and safety of chimeric antigen receptor (CAR)-T cell therapy for hepatocellular carcinoma

The liver is one of the most frequent sites of primary malignancies in humans. Hepatocellular carcinoma (HCC) is one of the most prevalent solid tumors with poor prognosis. Current treatments showed limited efficacy in some patients, and, therefore, alternative strategies, such as immunotherapy, cancer vaccines, adoptive cell therapy (ACT), and recently chimeric antigen receptors (CAR)-T cells, are developed to offer better efficacy and safety profile in patients with HCC. Unlike other ACTs like tumor-infiltrating lymphocytes (TILs), CAR-T cells are equipped with engineered CAR receptors that effectively identify tumor antigens and eliminate cancer cells without major histocompatibility complex (MHC) restriction. This process induces intracellular signaling, leading to T lymphocyte recruitment and subsequent activation of other effector cells in the tumor microenvironment (TME). Until today, novel approaches have been used to develop more potent CAR-T cells with robust persistence, specificity, trafficking, and safety. However, the clinical application of CAR-T cells in solid tumors is still challenging. Therefore, this study aims to review the advancement, prospects, and possible avenues of CAR-T cell application in HCC following an outline of the CAR structure and function.

The molecular receptor NKBB enhances the persistence and anti-hepatocellular carcinoma activity of GPC3 CAR-T cells

Chimeric antigen receptor (CAR) T cells have encouraging results in the treatment of hematological malignancies. However, CAR-T therapy still faces numerous challenges against solid tumors, such as hepatocellular carcinoma (HCC), owing to heterogeneous antigen expression in tumor cells, limited persistence of CAR-T cells, etc. Therefore, to treat HCC more effectively, we connected the molecular receptor NKBB to a second-generation glypican-3 (GPC3) CAR to construct GC3328z-NKBB CAR-T cells, which have double specific targets of GPC3 and NKG2DLs (natural killer group 2, member D ligands), dual co-stimulation of CD28 and 41BB, and a single CD3ζ chain. Our study showed that the molecular receptor NKBB conferred GPC3 CAR-T cells with enhanced migration and infiltration abilities towards HCC, higher central memory T (TCM) cell proportion and proliferation capacity, and reduced exhaustion level. GC3328z-NKBB CAR-T cells exhibited improved cytotoxicity against HCC cells and prolonged persistence. The cathepsin L/interleukin-17 (CTSL/IL-17) axis contributed to the superior anti-HCC activity of GC3328z-NKBB CAR-T cells. Overall, the molecular receptor NKBB significantly increased the persistence of GPC3 CAR-T cells, and GC3328z-NKBB CAR-T cells possessed potent anti-HCC activity in mice, providing a new strategy for the potential improvement of adoptive T cell therapy in the treatment of HCC.

Multiplex immunohistochemistry to explore the tumor immune microenvironment in HCC patients with different GPC3 expression

OBJECTIVES

GPC3 has been recognized as a promising target for immunotherapy in hepatocellular carcinoma (HCC). However, the GPC3-targeted immunotherapies have shown limited therapeutic efficacy. The use of anti-PD-1/PD-L1 monoclonal antibodies in HCC treatment is considerably constrained. Furthermore, there is still a notable lack of understanding concerning the immune landscape in HCC, especially regarding varied GPC3 expression levels. Therefore, thorough exploration of the intricate tumor immune microenvironment at different GPC3 expression levels is essential for guiding and improving HCC treatment strategies.

METHODS

Sixty patients with HCC were enrolled in this study, receiving a first-line treatment that combined anti-angiogenesis targeted drugs and immunotherapy. Immunohistochemistry was used to assess the levels of GPC3 expression. Multiple immunohistochemical markers, such as CD8, PD-1, LAG3, TIGIT, TIM-3, CD103, Claudin18.2, PD-L1, CD4, Foxp3, CD68, CD163, GPC3, CD11C, CD14, CD66b, and HLA-DR, were used to characterize the immune microenvironment and spatial distribution of immune cells in HCC tumors with different levels of GPC3 expression. Cell expression levels and spatial distribution were determined by fluorescence staining and subsequent analysis of fluorescence intensity using the Panoramic Pathology Workstation (Pano ATLAS). This approach facilitated a detailed examination of cell characteristics and spatial information within the samples.

RESULTS

Based on the result of GPC3 immunohistochemical analysis, patients with strong positive GPC3 expression were classified as high GPC3 expression, while the others were classified as low GPC3 expression. Patients in the low GPC3 expression group had longer overall survival (OS) than in the high group (P = 0.003, HR = 2.9240). Further exploration of the immune microenvironment based on different GPC3 expression levels revealed that in high GPC3 expression group, the proportions of CD8+ T cells(P = 0.0435), TIM-3+ T cells(P = 0.0447), CD103+CD8+ tissue-resident T cells(P = 0.0410), CD11C+CD14-DC cells(P = 0.0497), CD11C+HLA-DR-DC cells(P = 0.0309), CD11C+CD14-HLA-DR-DC cells(P = 0.0233), and CD11C+CD14-CD66b-DC cells(P = 0.0474) were all higher compared to low expression group. At spatial distances of 10 μm, 20 μm, and 30 μm, the levels of CD8+ T cells were higher in the high expression group compared to the low expression group (high vs. low: P = 0.0281, P = 0.0236, P = 0.0220).

CONCLUSIONS

Multiple immunohistochemistry is a powerful technique for exploring the intricate immune microenvironment of hepatocellular carcinoma, enabling the precise identification of diverse cell subsets and their spatial distribution within the tumor microenvironment. This methodology provides valuable insights into the complex interactions and spatial organization of immune cells in the context of hepatocellular carcinoma progression. Low GPC3 expression in HCC patients indicates potential benefits from combined targeted and immunotherapy. Different levels of GPC3 expression levels can predict the effectiveness of targeted combination immunotherapy in HCC patients. Additionally, different GPC3 expression patterns in HCC patients correspond to unique tumor immune microenvironments, which have implications for guiding HCC treatment approaches.

Lentivirus-based production of human chimeric antigen receptor macrophages from peripheral blood

Although chimeric antigen receptor (CAR) T cell therapy has shown remarkable efficacy against leukemic cells, it still has critical limitations. CAR macrophage has been regarded as a potential alternative to CAR T cells. However, due to the difficulties in gene transduction into macrophages, the production of primary human CAR macrophages from peripheral blood mononuclear cells (PBMC) using lentivirus is highly challenging. Here, we report on how to generate CAR macrophages from human PBMC with lentiviral particles. Using our lentiviral protocol, we produced functional CAR macrophages to lyse and phagocytose target cancer cells efficiently.

Therapeutic advantage of combinatorial chimeric antigen receptor T cell and chemotherapies

Chimeric antigen receptor (CAR) T cell therapies have transformed outcomes for many patients with hematological malignancies. However, some patients do not respond to CAR T cell treatment, and adapting CAR T cells for treatment of solid and brain tumors has been met with many challenges, including a hostile tumor microenvironment and poor CAR T cell persistence. Thus, it is unlikely that CAR T cell therapy alone will be sufficient for consistent, complete tumor clearance across patients with cancer. Combinatorial therapies of CAR T cells and chemotherapeutics are a promising approach for overcoming this because chemotherapeutics could augment CAR T cells for improved antitumor activity or work in tandem with CAR T cells to clear tumors. Herein, we review efforts toward achieving successful CAR T cell and chemical drug combination therapies. We focus on combination therapies with approved chemotherapeutics because these will be more easily translated to the clinic but also review nonapproved chemotherapeutics and drug screens designed to reveal promising new CAR T cell and chemical drug combinations. Overall, this review highlights the promise of CAR T cell and chemotherapy combinations with a specific focus on how combinatorial therapy overcomes challenges faced by either monotherapy and supports the potential of this therapeutic strategy to improve outcomes for patients with cancer. SIGNIFICANCE STATEMENT: Improving currently available CAR T cell products via combinatorial therapy with chemotherapeutics has the potential to drastically expand the types of cancers and number of patients that could benefit from these therapies when neither alone has been sufficient to achieve tumor clearance. Herein, we provide a thorough review of the current efforts toward studying CAR T and chemotherapy combinatorial therapies and offer perspectives on optimal ways to identify new and effective combinations moving forward.

Gallium-68 Labeled Positron Emission Computed Tomography Tracer Targeting Glypican-3 with High Contrast for Hepatocellular Carcinoma Imaging

Hepatocellular carcinoma (HCC) represents the predominant form of primary liver cancer, yet early, precise, and noninvasive detection continues to pose a considerable clinical challenge. Glypican-3 (GPC3), a membrane-bound proteoglycan, is markedly overexpressed in most HCC cases, while exhibiting low expression in normal and hepatitis-affected liver tissues. Given its crucial role in malignant transformation and tumor progression, GPC3 emerges as a compelling target for imaging. In this study, we developed and evaluated 2 68Ga-labeled GPC3-targeted positron emission tomography (PET) probes, each incorporating either polyethylene glycol (PEG) or 4-(p-methylphenyl)butanoic acid (an albumin-binding moiety). Comparative analyses revealed that 68Ga-ALB-GBP, which includes the albumin-binding moiety, exhibited superior in vivo stability, enhanced tumor uptake, and an improved tumor-to-liver ratio relative to 68Ga-PEG2-GBP in subcutaneous HCC mouse models. Micro-PET/computed tomography imaging of orthotopic liver cancer with 68Ga-ALB-GBP demonstrated a tumor-to-liver ratio of 2.29 ± 0.13 and a tumor-to-muscle ratio of 13.03 ± 1.63 at 3 h postinjection, outperforming the performance of the clinically used 18F-fluorodeoxyglucose PET imaging. These findings suggest that 68Ga-ALB-GBP is a promising diagnostic tool for HCC and a strong candidate for clinical translation with potential utility in both diagnostic and therapeutic settings. Moreover, the incorporation of an albumin-binding moiety into PET tracers significantly extends blood circulation time, thereby enhancing bioavailability and facilitating high-contrast PET imaging.

Next-generation immunotherapy: igniting new hope for lung cancer

Adoption of immunotherapy has completely transformed the treatment landscape of cancer. Patients with advanced cancer treated with immunotherapy may benefit from durable tumor response and long-term survival. The most widely used immunotherapy in solid tumors is anti-programmed-death (ligand) protein (PD-(L)1), which is now an integral part of non-small cell lung cancer (NSCLC) treatment irrespective of histological cell types and tumor stage. However, the vast majority of patients with advanced NSCLC treated with anti-PD-(L)1 still develop therapeutic resistance, and the prognosis after anti-PD-(L)1 resistance is poor. Resistance mechanisms to PD-1 blockade are often complex and encompass a combination of defects within the cancer-immunity cycle. These defects include failure in antigen presentation and T-cell priming, presence of co-inhibitory immune checkpoints, inability of immune cells to infiltrate the tumor, and presence of immunosuppressive tumor microenvironment. Recently, advances in drug design, genomic sequencing, and gene editing technologies have led to development of next-generation immunotherapies that may potentially overcome these resistance mechanisms. In this review, we will discuss the anti-PD-(L)1 resistance mechanism landscape in NSCLC and four novel modalities of immunotherapy in detail, namely novel immune checkpoint inhibitor and targeted therapy combinations, bispecific antibodies, cancer vaccine, and cell therapy. These novel therapeutics have all demonstrated early clinical data in NSCLC treatment and may work synergistically with each other to restore anticancer immunity. In addition, we share our perspectives on the future promises and challenges in the transformation of these novel immunotherapies to standard clinical care.

Chimeric Antigen Receptor (CAR)-T Cells: A New Era for Hepatocellular Carcinoma Treatment

Hepatocellular carcinoma (HCC) is one of the most common cancers and a worldwide health concern that requires novel treatment approaches. Tyrosine kinase inhibitors (TKIs) and immune checkpoint blockades (ICBs) are the current standard of care; however, their clinical benefits are limited in some advanced and metastatic patients. With the help of gene engineering techniques, a novel adoptive cellular therapy (ACT) called chimeric antigen receptor (CAR)-T cells was recently introduced for treating HCC. A plethora of current clinical and preclinical studies are attempting to improve the efficacy of CAR-T cells by dominating the immunosuppressive environment of HCC and finding the best tumor-specific antigens (TSAs). The future of care for HCC patients might be drastically improved due to the convergence of novel therapeutic methods and the continuous progress in ACT research. However, the clinical application of CAR-T cells in solid tumors is still facing several challenges. In this study, we provide an overview of the advancement and prospects of CAR-T cell immunotherapy in HCC, as well as an investigation of how cutting-edge engineering could improve CAR-T cell efficacy and safety profile.

CAR T-cells for pediatric solid tumors: where to go from here?

Despite the great success that chimeric antigen receptor (CAR) T-cells have had in patients with B-cell malignancies and multiple myeloma, they continue to have limited efficacy against most solid tumors. Especially in the pediatric population, pre- and post-treatment biopsies are rarely performed due to ethical reasons, and thus, our understanding is still very limited regarding the mechanisms in the tumor microenvironment by which tumor cells exclude effectors and attract immune-suppressive cells. Nevertheless, based on the principles that are known, current T-cell engineering has leveraged some of these processes and created more potent CAR T-cells. The recent discovery of new oncofetal antigens and progress made in CAR design have expanded the potential pool of candidate antigens for therapeutic development. The most promising approaches to enhance CAR T-cells are novel CAR gating strategies, creative ways of cytokine delivery to the TME without enhancing systemic toxicity, and hijacking the chemokine axis of tumors for migratory purposes. With these new modifications, the next step in the era of CAR T-cell development will be the clinical validation of these promising preclinical findings.

Progress and challenges in glypican-3 targeting for hepatocellular carcinoma therapy

INTRODUCTION

Glypican-3 (GPC3) is a cell membrane-anchored heparan sulfate proteoglycan that has recently garnered attention as a cancer antigen owing to its high expression in numerous cancers, particularly hepatocellular carcinoma (HCC), and to limited expression in adult normal tissue.

AREAS COVERED

Here, we propose the potential of GPC3 as a cancer antigen based on our experience with the GPC3 peptide vaccine against HCC, having developed a vaccine that progressed from preclinical studies to first-in-human clinical trials. In this review, we present a summary of the current status and future prospects of immunotherapies targeting GPC3 by focusing on clinical trials; peptide vaccines, mRNA vaccines, antibody therapy, and chimeric antigen receptor/T-cell receptor - T-cell therapy and discuss additional strategies for effectively eliminating HCC through immunotherapy.

EXPERT OPINION

GPC3 is an ideal cancer antigen for HCC immunotherapy. In resectable HCC, immunotherapies that leverage physiological immune surveillance, immune checkpoint inhibitors, and GPC3-target cancer vaccines appear promising in preventing recurrence and could be considered as a prophylactic adjuvant therapy. However, in advanced HCC, clinical trials have not demonstrated sufficient anti-tumor efficacy, in contrast with preclinical studies. Reverse translation, bedside-to-bench research, is crucial to identify the factors that have hindered GPC3 target immunotherapies.

Global research trends in the tumor microenvironment of hepatocellular carcinoma: insights based on bibliometric analysis

Objective

This study aimed to use visual mapping and bibliometric analysis to summarize valuable information on the tumor microenvironment (TME)-related research on hepatocellular carcinoma (HCC) in the past 20 years and to identify the research hotspots and trends in this field.

Methods

We screened all of the relevant literature on the TME of HCC in the Web of Science database from 2003 to 2023 and analysed the research hotspots and trends in this field via VOSviewer and CiteSpace.

Results

A total of 2,157 English studies were collected. According to the prediction, the number of papers that were published in the past three years will be approximately 1,394, accounting for 64.63%. China published the most papers (n=1,525) and had the highest total number of citations (n=32,253). Frontiers In Immunology published the most articles on the TME of HCC (n=75), whereas, Hepatology was the journal with the highest total number of citations (n=4,104) and average number of citations (n=91). The four clusters containing keywords such as "cancer-associated fibroblasts", "hepatic stellate cells", "immune cells", "immunotherapy", "combination therapy", "landscape", "immune infiltration", and "heterogeneity" are currently hot research topics in this field. The keywords "cell death", "ferroptosis", "biomarkers", and "prognostic features" have emerged relatively recently, and these research directions are becoming increasingly popular.

Conclusions

We identified four key areas of focus in the study of the TME in HCC: the main components and roles in the TME, immunotherapy, combination therapy, and the microenvironmental landscape. Moreover, the result of our study indicate that effect of ferroptosis on the TME in HCC may become a future research trend.

Lymphodepletion in Chimeric Antigen Receptor T-Cell Therapy for Solid Tumors: A Focus on Brain Tumors

Chimeric antigen receptor (CAR)-T cell therapy, which has demonstrated remarkable efficacy in hematologic malignancies, is being extended to the treatment of refractory solid tumors, including brain tumors. Lymphodepletion (LD) is an essential preconditioning process that enhances CAR-T efficacy by promoting CAR-T cell expansion and persistence in the body, and has become a standard regimen for hematologic cancers. Recent clinical results of CAR-T therapy for solid tumors, including brain tumors, have shown that cyclophosphamide/fludarabine-based preconditioning has potential benefits and is gradually becoming adopted in solid tumor CAR-T trials. Furthermore, some CAR-T trials for solid tumors are attempting to develop LD regimens optimized specifically for solid tumors, distinct from the standard LD regimens used in hematologic cancers. In contrast, CAR-T therapy targeting brain tumors frequently employs locoregionally repeated administration in tumors or cerebrospinal fluid, resulting in less frequent use of LD compared to other solid tumors. Nevertheless, several clinical studies suggest that LD may still provide potential benefits for CAR-T expansion and improvement in clinical responses in systemic CAR-T administration. The studies presented in this review suggest that while LD can be beneficial for enhancing CAR-T efficacy, considerations must be made regarding its compatibility with the CAR-T administration route, potential excessive activation based on CAR-T structural characteristics, and target expression in normal organs. Additionally, given the unique characteristics of brain tumors, optimized selection of LD agents, as well as dosing and regimens, may be required, highlighting the need for further research.

Prognostic significance of HS2ST1 expression in patients with hepatocellular carcinoma

BACKGROUND

Heparan sulfate 2-O-sulfotransferase 1 (HS2ST1) catalyzes the sulfation of glucuronic acid residues in heparan sulfate proteoglycans, enabling these proteoglycans to interact with numerous ligands within tumor microenvironments. However, the prognostic role of HS2ST1 expression in cancer remains unclear.

OBJECTIVE

This investigated HS2ST1 expression levels and their prognostic significance in various cancer types, demonstrated the prognostic value of HS2ST1 expression in hepatocellular carcinoma (HCC) patients, and identified molecular signatures associated with HS2ST1 expression.

METHODS

HS2ST1 expression and patient survival data from The Cancer Genome Atlas (TCGA) datasets were analyzed using the Gene Expression Profiling Interactive Analysis (GEPIA) portal. We obtained gene expression and clinicopathological information on HCC patients from the TCGA and the Japan and France International Cancer Genome Consortium (ICGC) databases and performed survival analyses. We also examined relevant protein networks, differentially expressed genes, gene set enrichments, and tumor immune microenvironment features associated with HS2ST1 expression.

RESULTS

HS2ST1 exhibited higher expression in eight tumor types compared with normal tissues and was associated with poor prognoses in five tumors, including HCC. HS2ST1 status correlated with poor prognosis in two ICGC HCC cohorts. Elevated HS2ST1 expression in HCC tumors was associated with signaling pathways involved in cell cycle progression, protein secretion, and mTORC1 signaling. Moreover, HS2ST1 expression levels were inversely correlated with immune cell infiltration in the tumor microenvironment.

CONCLUSION

Our study elucidates the prognostic significance of HS2ST1 expression in HCC patients and provides insights into the potential roles of HS2ST1 in signaling pathways and the tumor microenvironment.

Transcriptional rewiring in CD8+ T cells: implications for CAR-T cell therapy against solid tumours

T cells engineered to express chimeric-antigen receptors (CAR-T cells) can effectively control relapsed and refractory haematological malignancies in the clinic. However, the successes of CAR-T cell therapy have not been recapitulated in solid tumours due to a range of barriers such as immunosuppression, poor infiltration, and tumour heterogeneity. Numerous strategies are being developed to overcome these barriers, which include improving culture conditions and manufacturing protocols, implementing novel CAR designs, and novel approaches to engineering the T cell phenotype. In this review, we describe the various emerging strategies to improve CAR T cell therapy for solid tumours. We specifically focus on new strategies to modulate cell function and fate that have precipitated from the growing knowledge of transcriptional circuits driving T cell differentiation, with the ultimate goal of driving more productive anti-tumour T cell immunity. Evidence shows that enrichment of particular phenotypic subsets of T cells in the initial cell product correlates to improved therapeutic responses and clinical outcomes. Furthermore, T cell exhaustion and poor persistence are major factors limiting therapeutic efficacy. The latest preclinical work shows that targeting specific master regulators and transcription factors can overcome these key barriers, resulting in superior T cell therapeutic products. This can be achieved by targeting key transcriptional circuits promoting memory-like phenotypes or sustaining key effector functions within the hostile tumour microenvironment. Additional discussion points include emerging considerations for the field such as (i) targeting permutations of transcription factors, (ii) transient expression systems, (iii) tissue specificity, and (iv) expanding this strategy beyond CAR-T cell therapy and cancer.

Immunotherapy in liver cancer: overcoming the tolerogenic liver microenvironment

Liver cancer is a major global health concern, ranking among the top causes of cancer-related deaths worldwide. Despite advances in medical research, the prognosis for liver cancer remains poor, largely due to the inherent limitations of current therapies. Traditional treatments like surgery, radiation, and chemotherapy often fail to provide long-term remission and are associated with significant side effects. Immunotherapy has emerged as a promising avenue for cancer treatment, leveraging the body's immune system to target and destroy cancer cells. However, its application in liver cancer has been limited. One of the primary challenges is the liver's unique immune microenvironment, which can inhibit the effectiveness of immunotherapeutic agents. This immune microenvironment creates a barrier, leading to drug resistance and reducing the overall efficacy of treatment. Recent studies have focused on understanding the immunological landscape of liver cancer to develop strategies that can overcome these obstacles. By identifying the specific factors within the liver that contribute to immune suppression and drug resistance, researchers aim to enhance the effectiveness of immunotherapy. Prospective strategies include combining immunotherapy with other treatments, using targeted therapies to modulate the immune microenvironment, and developing new agents that can bypass or counteract the inhibitory mechanisms in the liver. These advancements hold promise for improving outcomes in liver cancer treatment.

Reshaping the tumor immune microenvironment to improve CAR-T cell-based cancer immunotherapy

In many hematologic malignancies, the adoptive transfer of chimeric antigen receptor (CAR) T cells has demonstrated notable success; nevertheless, further improvements are necessary to optimize treatment efficacy. Current CAR-T therapies are particularly discouraging for solid tumor treatment. The immunosuppressive microenvironment of tumors affects CAR-T cells, limiting the treatment's effectiveness and safety. Therefore, enhancing CAR-T cell infiltration capacity and resolving the immunosuppressive responses within the tumor microenvironment could boost the anti-tumor effect. Specific strategies include structurally altering CAR-T cells combined with targeted therapy, radiotherapy, or chemotherapy. Overall, monitoring the tumor microenvironment and the status of CAR-T cells is beneficial in further investigating the viability of such strategies and advancing CAR-T cell therapy.

Immune landscape of hepatocellular carcinoma: From dysregulation of the immune responses to the potential immunotherapies

Hepatocellular carcinoma (HCC) presents a considerable global health burden due to its late diagnosis and high morbidity. The liver's specific anatomical and physiological features expose it to various antigens, requiring precise immune regulation. To the best of our knowledge, this is the first time that a comprehensive overview of the interactions between the immune system and gut microbiota in the development of HCC, as well as the relevant therapeutic approaches are discussed. Dysregulation of immune compartments within the liver microenvironment drives HCC pathogenesis, characterized by elevated regulatory cells such as regulatory T cells (Tregs), myeloid-derived suppressor cells, and M2 macrophages as well as suppressive molecules, alongside reduced number of effector cells like T cells, natural killer cells, and M1 macrophages. Dysbiosis of gut microbiota also contributes to HCC by disrupting intestinal barrier integrity and triggering overactivated immune responses. Immunotherapy approaches, particularly immune checkpoint inhibitors, have exhibited promise in HCC management, yet adoptive cell therapy and cancer vaccination research are in the early steps with relatively less favorable outcomes. Further understanding of immune dysregulation, gut microbiota involvement, and therapeutic combination strategies are essential for advancing precision immunotherapy in HCC.

The Role of CD4+T Cells in Nonalcoholic Steatohepatitis and Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) has become the fourth leading cause of cancer-related deaths worldwide; annually, approximately 830,000 deaths related to liver cancer are diagnosed globally. Since early-stage HCC is clinically asymptomatic, traditional treatment modalities, including surgical ablation, are usually not applicable or result in recurrence. Immunotherapy, particularly immune checkpoint blockade (ICB), provides new hope for cancer therapy; however, immune evasion mechanisms counteract its efficiency. In addition to viral exposure and alcohol addiction, nonalcoholic steatohepatitis (NASH) has become a major cause of HCC. Owing to NASH-related aberrant T cell activation causing tissue damage that leads to impaired immune surveillance, NASH-associated HCC patients respond much less efficiently to ICB treatment than do patients with other etiologies. In addition, abnormal inflammation contributes to NASH progression and NASH-HCC transition, as well as to HCC immune evasion. Therefore, uncovering the detailed mechanism governing how NASH-associated immune cells contribute to NASH progression would benefit HCC prevention and improve HCC immunotherapy efficiency. In the following review, we focused our attention on summarizing the current knowledge of the role of CD4+T cells in NASH and HCC progression, and discuss potential therapeutic strategies involving the targeting of CD4+T cells for the treatment of NASH and HCC.

The dilemmas and possible solutions for CAR-T cell therapy application in solid tumors

Chimeric antigen receptor T (CAR-T) cell therapy, as an adoptive immunotherapy, is playing an increasingly important role in the treatment of malignant tumors. CAR-T cells are referred to as "living drugs" as they not only target tumor cells directly, but also induce long-term immune memory that has the potential to provide long-lasting protection. CD19.CAR-T cells have achieved complete response rates of over 90 % for acute lymphoblastic leukemia and over 60 % for non-Hodgkin's lymphoma. However, the response rate of CAR-T cells in the treatment of solid tumors remains extremely low and the side effects potentially severe. In this review, we discuss the limitations that the solid tumor microenvironment poses for CAR-T application and the solutions that are being developed to address these limitations, in the hope that in the near future, CAR-T cell therapy for solid tumors can attain the same success rates as are now being seen clinically for hematological malignancies.

Hepatocellular Carcinoma and the Multifaceted Relationship with Its Microenvironment: Attacking the Hepatocellular Carcinoma Defensive Fortress

Hepatocellular carcinoma is a malignant tumor that originates from hepatocytes in an inflammatory substrate due to different degrees of liver fibrosis up to cirrhosis. In recent years, there has been growing interest in the role played by the complex interrelationship between hepatocellular carcinoma and its microenvironment, capable of influencing tumourigenesis, neoplastic growth, and its progression or even inhibition. The microenvironment is made up of an intricate network of mesenchymal cells, immune system cells, extracellular matrix, and growth factors, as well as proinflammatory cytokines and translocated bacterial products coming from the intestinal microenvironment via the enterohepatic circulation. The aim of this paper is to review the role of the HCC microenvironment and describe the possible implications in the choice of the most appropriate therapeutic scheme in the prediction of tumor response or resistance to currently applied treatments and in the possible development of future therapeutic perspectives, in order to circumvent resistance and break down the tumor's defensive fort.

Immunosuppressive tumor microenvironment and immunotherapy of hepatocellular carcinoma: current status and prospectives

Hepatocellular carcinoma (HCC) is a major health concern worldwide, with limited therapeutic options and poor prognosis. In recent years, immunotherapies such as immune checkpoint inhibitors (ICIs) have made great progress in the systemic treatment of HCC. The combination treatments based on ICIs have been the major trend in this area. Recently, dual immune checkpoint blockade with durvalumab plus tremelimumab has also emerged as an effective treatment for advanced HCC. However, the majority of HCC patients obtain limited benefits. Understanding the immunological rationale and exploring novel ways to improve the efficacy of immunotherapy has drawn much attention. In this review, we summarize the latest progress in this area, the ongoing clinical trials of immune-based combination therapies, as well as novel immunotherapy strategies such as chimeric antigen receptor T cells, personalized neoantigen vaccines, oncolytic viruses, and bispecific antibodies.

CRISPR-Cas9 applications in T cells and adoptive T cell therapies

T cell immunity is central to contemporary cancer and autoimmune therapies, encompassing immune checkpoint blockade and adoptive T cell therapies. Their diverse characteristics can be reprogrammed by different immune challenges dependent on antigen stimulation levels, metabolic conditions, and the degree of inflammation. T cell-based therapeutic strategies are gaining widespread adoption in oncology and treating inflammatory conditions. Emerging researches reveal that clustered regularly interspaced palindromic repeats-associated protein 9 (CRISPR-Cas9) genome editing has enabled T cells to be more adaptable to specific microenvironments, opening the door to advanced T cell therapies in preclinical and clinical trials. CRISPR-Cas9 can edit both primary T cells and engineered T cells, including CAR-T and TCR-T, in vivo and in vitro to regulate T cell differentiation and activation states. This review first provides a comprehensive summary of the role of CRISPR-Cas9 in T cells and its applications in preclinical and clinical studies for T cell-based therapies. We also explore the application of CRISPR screen high-throughput technology in editing T cells and anticipate the current limitations of CRISPR-Cas9, including off-target effects and delivery challenges, and envisioned improvements in related technologies for disease screening, diagnosis, and treatment.

Chimeric Antigen Receptor T Cell Therapy for Hepatocellular Carcinoma: Where Do We Stand?

Hepatocellular carcinoma (HCC) remains a global health challenge that urgently calls for innovative therapeutic strategies. Chimeric antigen receptor T cell (CAR T) therapy has emerged as a promising avenue for HCC treatment. However, the therapeutic efficacy of CAR T immunotherapy in HCC patients is significantly compromised by some major issues including the immunosuppressive environment within the tumor, antigen heterogeneity, CAR T cell exhaustion, and the advanced risk for on-target/off-tumor toxicity. To overcome these challenges, many ongoing preclinical and clinical trials are underway focusing on the identification of optimal target antigens and the decryption of the immunosuppressive milieu of HCC. Moreover, limited tumor infiltration constitutes a significant obstacle of CAR T cell therapy that should be addressed. The continuous effort to design molecular targets for CAR cells highlights the importance for a more practical approach for CAR-modified cell manufacturing. This review critically examines the current landscape of CAR T cell therapy for HCC, shedding light on the changes in innate and adaptive immune responses in the context of HCC, identifying potential CAR T cell targets, and exploring approaches to overcome inherent challenges. Ongoing advancements in scientific research and convergence of diverse treatment modalities offer the potential to greatly enhance HCC patients' care in the future.

Recruiting In Vitro Transcribed mRNA against Cancer Immunotherapy: A Contemporary Appraisal of the Current Landscape

Over 100 innovative in vitro transcribed (IVT)-mRNAs are presently undergoing clinical trials, with a projected substantial impact on the pharmaceutical market in the near future. Τhe idea behind this is that after the successful cellular internalization of IVT-mRNAs, they are subsequently translated into proteins with therapeutic or prophylactic relevance. Simultaneously, cancer immunotherapy employs diverse strategies to mobilize the immune system in the battle against cancer. Therefore, in this review, the fundamental principles of IVT-mRNA to its recruitment in cancer immunotherapy, are discussed and analyzed. More specifically, this review paper focuses on the development of mRNA vaccines, the exploitation of neoantigens, as well as Chimeric Antigen Receptor (CAR) T-Cells, showcasing their clinical applications and the ongoing trials for the development of next-generation immunotherapeutics. Furthermore, this study investigates the synergistic potential of combining the CAR immunotherapy and the IVT-mRNAs by introducing our research group novel, patented delivery method that utilizes the Protein Transduction Domain (PTD) technology to transduce the IVT-mRNAs encoding the CAR of interest into the Natural Killer (NK)-92 cells, highlighting the potential for enhancing the CAR NK cell potency, efficiency, and bioenergetics. While IVT-mRNA technology brings exciting progress to cancer immunotherapy, several challenges and limitations must be acknowledged, such as safety, toxicity, and delivery issues. This comprehensive exploration of IVT-mRNA technology, in line with its applications in cancer therapeutics, offers valuable insights into the opportunities and challenges in the evolving landscape of cancer immunotherapy, setting the stage for future advancements in the field.

Advances in Immunotherapy for Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related deaths in the world. More than half of patients with HCC present with advanced stage, and highly active systemic therapies are crucial for improving outcomes. Immune checkpoint inhibitor (ICI)-based therapies have emerged as novel therapy options for advanced HCC. Only one third of patients achieve an objective response with ICI-based therapies due to primary resistance or acquired resistance. The liver tumor microenvironment is naturally immunosuppressive, and specific mutations in cell signaling pathways allow the tumor to evade the immune response. Next, gene sequencing of the tumor tissue or circulating tumor DNA may delineate resistance mechanisms to ICI-based therapy and provide a rationale for novel combination therapies. In this review, we discuss the results of key clinical trials that have led to approval of ICI-based therapy options in advanced HCC and summarize the ongoing clinical trials. We review resistance mechanisms to ICIs and discuss how immunotherapies may be optimized based on the emerging research of tumor biomarkers and genomic alterations.