Neoantigens in precision cancer immunotherapy: from identification to clinical applications

Transforming tumors into 'high-risk bombs' triggers a neoantigen storm and amplifies immune responses

Although various immunotherapies have improved the treatment of several challenging malignancies in clinical applications, current research suggests that neoantigens remain fundamental to the initiation of immunotherapy, implying a dependence on high mutation loads in tumors and stable target antigens. To overcome these limitations, we propose a novel immunotherapy paradigm that interferes with splicing to induce the expression of neoantigens and neoepitopes while simultaneously blocking autophagy to prevent their degradation through endogenous pathways. This approach ensures the stable expression and accumulation of neoantigens and neoepitopes in tumor cells. To fully unleash the potential of neoantigens, we further induce tumors to undergo immunogenic cell death (ICD), triggering a "neoantigen storm" at the tumor site to recruit and activate more dendritic cells (DCs). Through a DC-dependent mechanism, communication between the tumor and the tumor-draining lymph node (TDLN) is enhanced, summoning more neoantigen-specific cytotoxic T lymphocytes to lyse tumor cells and establish immune circulation. In summary, this work presents a novel antigen-based immune sensitization strategy that stabilizes target antigens while exploring the potential of non-targeted antigens. By bypassing the cumbersome neoantigen identification process, this strategy holds promise for rapid clinical application in combination with other immunotherapies.

Tailoring nanovectors for optimal neoantigen vaccine efficacy

The primary objective of neoantigen vaccines is to elicit a robust anti-tumor immune response by generating neoantigen-specific T cells that can eradicate tumor cells. Despite substantial advancements in personalized neoantigen prediction using next-generation sequencing, machine learning, and mass spectrometry, challenges remain in efficiently expanding neoantigen-specific T cell populations in vivo. This challenge impedes the widespread clinical application of neoantigen vaccines. Nanovector-based neoantigen delivery systems have emerged as a promising solutions to this challenge. These nanovectors offer several advantages, such as enhanced stability, targeted intracellular delivery, sustained release, and improved antigen-presenting cell (APC) activation. Notably, they effectively deliver various neoantigen vaccine formulations (DC cell-based, synthetic long peptide (SLP)-based or DNA/mRNA-based) to APCs or T cells, thereby activating both CD4+ T and CD8+ T cells. This ultimately induces a specific anti-tumor immune response. This review focuses on recent innovations in neoantigen vaccine delivery vectors. We aim to identify optimal design parameters for vectors tailored to different neoantigen vaccine types, with an emphasis on enhancing the tumor microenvironment and stimulating the production of neoantigen-specific cytotoxic T cells. By maximizing the potential of these delivery systems, we aim to accelerate the clinical translation of neoantigen nanovaccines and advance cancer immunotherapy.

Innovative design concepts in tumor-targeting peptide-drug conjugates: Insights into emerging applications

ABSTRACT

Peptide-drug conjugates (PDCs) have emerged as a promising strategy in cancer therapy, offering improved therapeutic efficacy and reduced toxicity. Compared to antibody-drug conjugates (ADCs) and small molecule-drug conjugates (SMDCs), PDCs possess distinct advantages, such as lower immunogenicity, improved tumor penetration, and simpler synthesis. This review discusses the latest advancements in PDC design, including novel peptide targeting mechanisms, linker selection, and formulation improvements for increased stability. Additionally, it explores the expanding clinical applications of PDCs and examines their limitations. The aim of this review is to provide a comprehensive overview of current PDC progress and outline future directions for their role in cancer treatment.

Causal effects of blood cells on breast cancer: Evidence from bidirectional Mendelian randomization combined with meta-analysis

Recent studies suggest blood cells influence breast cancer, but no Mendelian randomization (MR) studies have confirmed a causal relationship between specific blood cell phenotypes and breast cancer. MR analysis of blood cell phenotypes used breast cancer data from Finngen R11, UKB, and open genome-wide association study databases. Meta-analyzed inverse variance weighted results were adjusted for multiple comparisons. The reverse relationship was also explored. MR and meta-analysis identified significant associations between specific blood cell phenotypes and breast cancer: neutrophil perturbation response (side fluorescence standard deviation of neutrophil 4 in response to alhydrogel perturbation): odds ratio (OR) = 0.967, P = .0009; neutrophil perturbation response (forward scatter median of neutrophil 4 in response to Pam3CSK4 perturbation): OR = 0.972, P = .031; white blood cell perturbation response (side scatter coefficient of variation of WBC 2 in response to nigericin perturbation): OR = 0.972, P = .031; white blood cell perturbation response (forward scatter coefficient of variation of WBC in response to Pam3CSK4 perturbation): OR = 1.042, P = 8.15 × 10-5. And there was no reverse result. Neutrophil perturbation response (side fluorescence standard deviation of neutrophil 4 in response to alhydrogel perturbation) and white blood cell perturbation response (side scatter coefficient of variation of WBC 2 in response to nigericin perturbation) are protective factors for breast cancer. Conversely, neutrophil perturbation response (forward scatter median of neutrophil 4 in response to Pam3CSK4 perturbation) and white blood cell perturbation response (forward scatter coefficient of variation of WBC in response to Pam3CSK4 perturbation) are risk factors for breast cancer.

Reinforcing cancer immunotherapy with engineered porous hollow mycobacterium tuberculosis loaded with tumor neoantigens

BACKGROUND

Enhancing antigen cross-presentation is essential for the development of a tumor neoantigen vaccine. One approach is to stimulate antigen-presenting cells (APCs) to uptake neoantigens. Mycobacterium tuberculosis (MTb) contains pathogen-associated molecular patterns (PAMPs) recognized by APCs and adhesion molecules that facilitate MTb invasion of APCs. Therefore, we suggest using MTb as a carrier to enhance APC phagocytosis of neoantigens, thereby promoting antigen cross-presentation.

METHODS

The successful preparation of the MTb carrier (phMTb) was confirmed through electron and confocal microscopy. Fluorescence microscopy was used to detect PAMPs and adhesion molecules on phMTb as well as to observe its role in aiding dendritic cells (DCs) in antigen uptake into endosomes or lysosomes. Flow cytometry was used to assess the retention of PAMPs and adhesion molecules on phMTb, investigate antigen uptake by DCs, evaluate their activation and maturation status, examine the presentation of tumor neoantigens, and analyze immune cells in draining lymph nodes and tumor tissues. The efficacy of phMTb vaccine formulations in combination with anti-programmed cell death protein 1 (PD-1) antibody therapy was assessed using the MC38 mouse tumor models. Adverse effects were evaluated through H&E staining of major organs, assessment of reproductive capability and detection of biochemical indices.

RESULTS

The engineered porous hollow phMTb carrier successfully encapsulated model tumor neoantigens, with or without the adjuvant CpG. The phMTb retained PAMPs and adhesion molecules on its surface, similar to the parental MTb, thereby enhancing DC uptake of phMTb and its formulations containing tumor neoantigens and CpG. Vaccines formulated with phMTb facilitated DC maturation, activation, cross-presentation of tumor neoantigens, and promoted migration of phMTb-laden DCs to lymph nodes, enhancing effector and memory CD8+ T lymphocyte function. In murine tumor models, immunization with phMTb-formulated neoantigen vaccines elicited a robust tumor-specific cytotoxic T lymphocyte immune response with minimal adverse effects. Additionally, vaccination with phMTb-formulated neoantigen vaccines effectively reversed the tumor's immune-suppressive microenvironment. Concurrent administration of the PD-1 antibody with the phMTb-formulated neoantigen vaccine exhibited significant synergistic therapeutic effects.

CONCLUSIONS

The results of our study highlight the potential clinical translation of personalized tumor neoantigen vaccines using the phMTb carrier.

Personalized Immunity: Neoantigen-Based Vaccines Revolutionizing Hepatocellular Carcinoma Treatment

Hepatocellular carcinoma (HCC), the most prevalent form of primary liver cancer, presents significant therapeutic challenges due to its molecular complexity, late-stage diagnosis, and inherent resistance to conventional treatments. The intermediate to low mutational burden in HCC and its ability to evade the immune system through multiple mechanisms complicate the development of effective therapies. Recent advancements in immunotherapy, particularly neoantigen-based vaccines, offer a promising, personalized approach to HCC treatment. Neoantigens are tumor-specific peptides derived from somatic mutations in tumor cells. Unlike normal cellular antigens, neoantigens are foreign to the immune system, making them highly specific targets for immunotherapy. Neoantigens arise from genetic alterations such as point mutations, insertions, deletions, and gene fusions, which are expressed as neoepitopes that are not present in healthy tissues, thus evading the immune tolerance mechanisms that typically protect normal cells. Preclinical and early-phase clinical studies of neoantigen-based vaccines have shown promising results, demonstrating the ability of these vaccines to elicit robust T cell responses against HCC. The aim of the current review is to provide an in-depth exploration of the therapeutic potential of neoantigen-based vaccines in HCC, focusing on neoantigen identification, vaccine platforms, and their integration with immune checkpoint inhibitors to enhance immunogenicity. It also evaluates preclinical and clinical data on efficacy and safety while addressing challenges in clinical translation. By taking advantage of the unique antigenic profile of each patient's tumor, neoantigen-based vaccines represent a promising approach in the treatment of HCC, offering the potential for improved patient outcomes, long-term remission, and a shift towards personalized, precision medicine in liver cancer therapy.

Identification of BRCA new prognostic targets and neoantigen candidates from fusion genes

Cancer-associated gene fusions serve as a potential source of highly immunogenic neoantigens. In this study, we identified fusion proteins from fusion genes and extracted fusion peptides to accurately predict Breast cancer (BRCA) neo-antigen candidates by high-throughput artificial intelligence computation. Firstly, Deepsurv was used to evaluate the prognosis of patients, providing a landscape of prognostic fusion genes in BRCA. Next, AGFusion was utilized to generate full-length fusion protein sequences and annotate functional domains. Advanced neural networks and Transformer-based analyses were implemented to predict the binding of fusion peptides to 112 types of HLA, thereby forming a new immunotherapy candidates' library of BRCA neo-antigens (n = 7791, covering 88.41% of patients). Among them, 15 neo-antigens were validated and factually translated into mass spectrometry data of BRCA patients. Finally, AlphaFold2 was applied to predict the binding sites of these neo-antigens to MHC (HLA) molecules. Notably, we identified a prognostic neoantigen from the TBC1D4-COMMD6 fusion that significantly improves patient prognosis and extensively binds to 16 types of HLA alleles. These highly immunogenic and tumor-specific neoantigens offer emerging targets for personalized cancer immunotherapies and act as prospective predictors for tumor survival prognosis and responses to immune checkpoint therapies.

NUSAP1 is Upregulated by Estrogen to Promote Lung Adenocarcinoma Growth and Serves as a Therapeutic Target

Nucleolar and spindle-associated protein 1 (NUSAP1), a microtubule-associated protein, has been recently identified to exhibit aberrant expression patterns that correlate with malignant tumorigenesis and progression across various cancer types. However, the specific regulatory mechanisms and potential targeting therapies of NUSAP1 in lung adenocarcinoma (LUAD) remain largely elusive. In this study, by conducting bioinformatics analyses as well as in vitro and in vivo experiments, we identified that NUSAP1 was significantly upregulated in LUAD, with a notable correlation with poorer overall survival, higher scores for immunogenicity and immune infiltration, as well as increased sensitivity to conventional chemotherapeutic drugs such as paclitaxel, docetaxel and vinorelbine in LUAD. Functionally, NUSAP1 overexpression significantly promoted LUAD cell proliferation, while its knockdown markedly suppressed this process. Interestingly, our results revealed that NUSAP1 upregulation was mediated by estrogen via ERβ activation. Furthermore, we identified entinostat as a novel inhibitor of NUSAP1. Pharmacological targeting ERβ/NUSAP1 axis with fulvestrant (ERβ antagonist) or entinostat (novel NUSAP1 inhibitor) significantly reduced LUAD growth both in vitro and in vivo, which may represent effective alternative therapeutic strategies for patients with LUAD.

Noninvasive Transdermal Administration of mRNA Vaccines Encoding Multivalent Neoantigens Effectively Inhibits Melanoma Growth

It is difficult to obtain specific tumor antigens, which is one of the main obstacles in the development of tumor vaccines. The vaccines containing multivalent antigens are thought to be more effective in antitumor therapy. In this study, a mRNA encoding three neoantigens of melanoma were prepared and encapsulated into the mannosylated chitosan-modified ethosomes (EthsMC) to obtain a multivalent mRNA vaccine (MmRV) for transcutaneous immunization (TCI). MmRV can effectively induce maturation of dendritic cells, with a better performance than mRNA of a single neoantigen. TCI patches (TCIPs) loading MmRV or siRNA against PDL1 (siPDL1) were prepared and applied to the skin of melanoma-bearing mice. The results showed that TCIPs significantly increase the levels of TNF-α, IFN-γ, and IL-12 in both plasma and tumor tissues, inhibit tumor growth, as well as promote infiltration of CD4+ and CD8+ T cells in the tumor tissues. Furthermore, the combination of MmRV and siPDL1 showed much better antitumor effects than either monotherapy, suggesting a synergistic effect between the vaccine and PDL1 blocker. In addition, the treatment with the TCIPs did not cause damage to the skin, blood, and vital organs of the mice, showing good biosafety. To the best of our knowledge, this work is the first to construct a noninvasive TCI system containing MmRV and siPDL1, providing a convenient and promising approach for tumor treatment.

Targeting Neoantigens in Cancer: Possibilities and Opportunities in Breast Cancer

As one of the most prevalent forms of cancer worldwide, breast cancer has garnered significant attention within the clinical research setting. While traditional treatment employs a multidisciplinary approach including a variety of therapies such as chemotherapy, hormone therapy, and even surgery, researchers have since directed their attention to the budding role of neoantigens. Neoantigens are defined as tumor-specific antigens that result from a multitude of genetic alterations, the most prevalent of which is the single nucleotide variant. As a result of their foreign nature, neoantigens elicit immune responses upon presentation by Major Histocompatibility Complexes I and II followed by recognition by T cell receptors. Previously, researchers have been able to utilize these immunogenic properties and manufacture neoantigen-specific T-cells and neoantigen vaccines. Within the context of breast cancer, biomarkers such as tumor protein 53 (TP53), Survivin, Partner and Localizer of BRCA2 (PALB2), and protein tyrosine phosphatase receptor T (PTPRT) display exceeding potential to serve as neoantigens. However, despite their seemingly limitless potential, neoantigens must overcome various obstacles if they are to be fairly distributed to patients. For instance, a prolonged period between the identification of a neoantigen and the dispersal of treatment poses a serious risk within the context of breast cancer. Regardless of these current obstacles, it appears highly promising that future research into neoantigens will make an everlasting impact on the health outcomes within the realm of breast cancer. The purpose of this literature review is to comprehensively discuss the etiology of various forms of breast cancer and current treatment modalities followed by the significance of neoantigens in cancer therapeutics and their application to breast cancer. Further, we have discussed the limitations, future directions, and the role of transcriptomics in neoantigen identification and personalized medicine. The concepts discussed in the original and review articles were included in this review article.

Targeting Neoantigens in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and is currently the third leading cause of cancer-related death in the United States after lung and colon cancer. PDAC is estimated to be the second leading cause of cancer-related death by 2030. The diagnosis at a late stage is the underlying cause for higher mortality and poor prognosis after surgery. Treatment resistance to chemotherapy and immunotherapy results in recurrence after surgery and poor prognosis. Neoantigen burden and CD8+ T-cell infiltration are associated with clinical outcomes in PDAC and paucity of neoantigen-reactive tumor-infiltrating lymphocytes may be the underlying cause for treatment resistance for immunotherapy. This suggests a need to identify additional neoantigens and therapies targeting these neoantigens to improve clinical outcomes in PDAC. In this review, we focus on describing the pathophysiology, current treatment strategies, and treatment resistance in PDAC followed by the need to target neoantigens in PDAC.

The war between the immune system and the tumor - using immune biomarkers as tracers

Nowadays, immunotherapy is one of the most promising anti-tumor therapeutic strategy. Specifically, immune-related targets can be used to predict the efficacy and side effects of immunotherapy and monitor the tumor immune response. In the past few decades, increasing numbers of novel immune biomarkers have been found to participate in certain links of the tumor immunity to contribute to the formation of immunosuppression and have entered clinical trials. Here, we systematically reviewed the oncogenesis and progression of cancer in the view of anti-tumor immunity, particularly in terms of tumor antigen expression (related to tumor immunogenicity) and tumor innate immunity to complement the cancer-immune cycle. From the perspective of integrated management of chronic cancer, we also appraised emerging factors affecting tumor immunity (including metabolic, microbial, and exercise-related markers). We finally summarized the clinical studies and applications based on immune biomarkers. Overall, immune biomarkers participate in promoting the development of more precise and individualized immunotherapy by predicting, monitoring, and regulating tumor immune response. Therefore, targeting immune biomarkers may lead to the development of innovative clinical applications.

Unraveling neoantigen-associated genes in bladder cancer: An in-depth analysis employing 101 machine learning algorithms

The therapeutic outcomes for bladder cancer (BLCA) remain suboptimal. Concurrently, there is a growing appreciation for the role of neoantigens in tumors. In this study, we explored the mechanisms underlying the involvement of neoantigen-associated genes in BLCA and their impact on prognosis. Our analysis incorporated both single-cell sequencing and bulk sequencing data sourced from publicly available databases. By employing a comprehensive set of 10 machine learning algorithms, we generated 101 algorithm combinations. The optimal combination, determined based on consistency indices, was utilized to construct a prognostic model comprising nine genes (CAPG, ACTA2, PDIA6, AKNA, PTMS, SNAP23, ID2, CD3G, SP140). Subsequently, we validated this model in an independent cohort, demonstrating its robust testing efficacy. Moreover, we explored the correlations between various clinical traits, model scores, and genes. Leveraging extensive public data resources, we conducted a drug sensitivity analysis to provide insights for targeted drug screening. Additionally, consensus clustering analysis and immune infiltration analysis were performed on bulk sequencing datasets and immunotherapy cohorts. These analyses yield valuable insights into the role of neoantigens in BLCA, guiding future research endeavors.

Current Landscape of Cancer Immunotherapy: Harnessing the Immune Arsenal to Overcome Immune Evasion

Cancer immune evasion represents a leading hallmark of cancer, posing a significant obstacle to the development of successful anticancer therapies. However, the landscape of cancer treatment has significantly evolved, transitioning into the era of immunotherapy from conventional methods such as surgical resection, radiotherapy, chemotherapy, and targeted drug therapy. Immunotherapy has emerged as a pivotal component in cancer treatment, harnessing the body's immune system to combat cancer and offering improved prognostic outcomes for numerous patients. The remarkable success of immunotherapy has spurred significant efforts to enhance the clinical efficacy of existing agents and strategies. Several immunotherapeutic approaches have received approval for targeted cancer treatments, while others are currently in preclinical and clinical trials. This review explores recent progress in unraveling the mechanisms of cancer immune evasion and evaluates the clinical effectiveness of diverse immunotherapy strategies, including cancer vaccines, adoptive cell therapy, and antibody-based treatments. It encompasses both established treatments and those currently under investigation, providing a comprehensive overview of efforts to combat cancer through immunological approaches. Additionally, the article emphasizes the current developments, limitations, and challenges in cancer immunotherapy. Furthermore, by integrating analyses of cancer immunotherapy resistance mechanisms and exploring combination strategies and personalized approaches, it offers valuable insights crucial for the development of novel anticancer immunotherapeutic strategies.

Tumor neoantigens and tumor immunotherapies

As a high-risk group of patients with cancer, the elderly exhibit limited efficacy with traditional treatments. Immunotherapy emerges as a promising adjunctive therapeutic approach that holds potential in addressing the needs of geriatric patients with cancer. Neoantigens, a unique class of tumor-specific antigens generated by non-synonymous mutations, are garnering increasing attention as targets for immunotherapy in clinical applications. Newly developed technologies, such as second-generation gene sequencing and mass spectrometry, have provided powerful technical support for the identification and prediction of neoantigens. At present, neoantigen-based immunotherapy has been extensively applied in clinical trials and has demonstrated both safety and efficacy, marking the beginning of a new era for cancer immunotherapy. This article reviews the conception, classification, inducers, and screening process of tumor neoantigens, as well as the application prospects and combination therapy strategies of neoantigen-based cancer immunotherapy.

Personalised neoantigen-based therapy in colorectal cancer

Colorectal cancer (CRC) has become one of the most common tumours with high morbidity, mortality and distinctive evolution mechanism. The neoantigens arising from the somatic mutations have become considerable treatment targets in the management of CRC. As cancer-specific aberrant peptides, neoantigens can trigger the robust host immune response and exert anti-tumour effects while minimising the emergence of adverse events commonly associated with alternative therapeutic regimens. In this review, we summarised the mechanism, generation, identification and prognostic significance of neoantigens, as well as therapeutic strategies challenges of neoantigen-based therapy in CRC. The evidence suggests that the establishment of personalised neoantigen-based therapy holds great promise as an effective treatment approach for patients with CRC.

Cancer/Testis Antigens as Targets for RNA-Based Anticancer Therapy

In the last few decades, RNA-based drugs have emerged as a promising candidate in the treatment of various diseases. The introduction of messenger RNA (mRNA) as a vaccine or therapeutic agent enables the production of almost any functional protein/peptide. The key to applying RNA therapy in clinical trials is developing safe and effective delivery systems. Exosomes and lipid nanoparticles (LNPs) have been exploited as promising vehicles for drug delivery. This review discusses the feasibility of exosomes and LNPs as vehicles for mRNA delivery. Cancer/testis antigens (CTAs) show restricted expression in normal tissues and widespread expression in cancer tissues. Many of these CTAs show expression in the sera of patients with cancers. These characteristics of CTAs make them excellent targets for cancer immunotherapy. This review summarizes the roles of CTAs in various life processes and current studies on mRNAs encoding CTAs. Clinical studies present the beneficial effects of mRNAs encoding CTAs in patients with cancers. This review highlight clinical studies employing mRNA-LNPs encoding CTAs.

The potential use and experimental validation of genomic instability-related lncRNA in pancreatic carcinoma

This study explored the potential role of long noncoding RNA (lncRNAs) associated with genomic instability in the diagnosis and treatment of pancreatic adenocarcinoma (PAAD). Transcriptome and single-nucleotide variation data of PAAD samples were downloaded from the cancer genome atlas database to explore genomic instability-associated lncRNAs. We constructed a genomic instability-associated lncRNA prognostic signature. Then gene ontology and Kyoto encyclopedia of genes and genomes enrichment analyses were used to explore the physiological role of lncRNAs involved in genomic instability. Tumor microenvironments, immunotherapy response, immune cell infiltration, immune checkpoint, and drug sensitivity were compared between high-risk and low-risk groups. In vitro experiments were performed for external validation. Six lncRNAs associated with genomic instability were identified, capable of predicting the prognosis of PAAD. Patients were assigned to low-risk or high-risk groups using these biomarkers, with better or worse prognosis, respectively. The tumor immune score, immune cell infiltration, and efficacy of immunotherapy were worse in the high-risk group. A drug sensitivity analysis revealed the high- and low-risk groups had different half-maximal inhibitory concentrations. The expression of cancer susceptibility candidate 8 was significantly higher in tumor tissues than in normal tissues, while the expression of LYPLAL1-AS1 exhibited an opposite pattern. They may be potential diagnostic or prognostic biomarkers for patients with pancreatic cancer. Genomic instability-associated lncRNAs were explored in this study and predicted the prognosis of PAAD and stratified patients risk in PAAD. These lncRNAs also predicted the efficacy of immunotherapy and potential therapeutic targets in PAAD.

The screening, identification, design and clinical application of tumor-specific neoantigens for TCR-T cells

Recent advances in neoantigen research have accelerated the development of tumor immunotherapies, including adoptive cell therapies (ACTs), cancer vaccines and antibody-based therapies, particularly for solid tumors. With the development of next-generation sequencing and bioinformatics technology, the rapid identification and prediction of tumor-specific antigens (TSAs) has become possible. Compared with tumor-associated antigens (TAAs), highly immunogenic TSAs provide new targets for personalized tumor immunotherapy and can be used as prospective indicators for predicting tumor patient survival, prognosis, and immune checkpoint blockade response. Here, the identification and characterization of neoantigens and the clinical application of neoantigen-based TCR-T immunotherapy strategies are summarized, and the current status, inherent challenges, and clinical translational potential of these strategies are discussed.

Immune checkpoint inhibitors promising role in cancer therapy: clinical evidence and immune-related adverse events

The advent of immune checkpoint inhibitors (ICIs) has led to noteworthy progressions in the management of diverse cancer types, as evidenced by the pioneering "ipilimumab" medication authorized by US FDA in 2011. Importantly, ICIs agents have demonstrated encouraging potential in bringing about transformation across diverse forms of cancer by selectively targeting the immune checkpoint pathways that are exploited by cancerous cells for dodging the immune system, culminating in progressive and favorable health outcomes for patients. The primary mechanism of action (MOA) of ICIs involves blocking inhibitory immune checkpoints. There are three approved categories including Programmed Death (PD-1) inhibitors (cemiplimab, nivolumab, and pembrolizumab), Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) (Ipilimumab), and Programmed Death-Ligand 1 (PDL-1) (Avelumab). Although ICIs promisingly increase therapeutic response and cancer survival rates, using ICIs has demonstrated some limitations including autoimmune reactions and toxicities, requiring close monitoring. The present review endeavors to explicate the underlying principles of the MOA and pharmacokinetics of the approved ICIs in the realm of cancer induction, including an appraisal of their level of practice-based evidence.

CAR T Cell Therapy: Remedies of Current Challenges in Design, Injection, Infiltration and Working

Chimeric antigen receptor (CAR) T cell therapy, as an innovative immunotherapy, plays a huge role in current cancer therapy. Although CAR T cell therapy has demonstrated therapeutic effects in some subtypes of B cell leukemia or lymphoma, there are many challenges that limit the therapeutic efficacy of CAR T cells in solid tumors. And how to efficiently transport CAR T cells to tumor tissues is a continuing concern for us. In this review, experiments have been extensively studied and compared. We finally compared the influence of different injection methods on therapeutic efficacy. We also carefully explored the difficulties of designing, homing, and working of CAR T cells, and ultimately came up with better solutions for each process to help CAR T cells reach tumor tissue more efficiently and quickly. These results will have significant implications for guiding CAR T cell therapy in cancer treatment.

Tumor microenvironment-mediated immune evasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is the third leading cause of tumor-related mortality worldwide. In recent years, the emergency of immune checkpoint inhibitor (ICI) has revolutionized the management of HCC. Especially, the combination of atezolizumab (anti-PD1) and bevacizumab (anti-VEGF) has been approved by the FDA as the first-line treatment for advanced HCC. Despite great breakthrough in systemic therapy, HCC continues to portend a poor prognosis owing to drug resistance and frequent recurrence. The tumor microenvironment (TME) of HCC is a complex and structured mixture characterized by abnormal angiogenesis, chronic inflammation, and dysregulated extracellular matrix (ECM) remodeling, collectively contributing to the immunosuppressive milieu that in turn prompts HCC proliferation, invasion, and metastasis. The tumor microenvironment coexists and interacts with various immune cells to maintain the development of HCC. It is widely accepted that a dysfunctional tumor-immune ecosystem can lead to the failure of immune surveillance. The immunosuppressive TME is an external cause for immune evasion in HCC consisting of 1) immunosuppressive cells; 2) co-inhibitory signals; 3) soluble cytokines and signaling cascades; 4) metabolically hostile tumor microenvironment; 5) the gut microbiota that affects the immune microenvironment. Importantly, the effectiveness of immunotherapy largely depends on the tumor immune microenvironment (TIME). Also, the gut microbiota and metabolism profoundly affect the immune microenvironment. Understanding how TME affects HCC development and progression will contribute to better preventing HCC-specific immune evasion and overcoming resistance to already developed therapies. In this review, we mainly introduce immune evasion of HCC underlying the role of immune microenvironment, describe the dynamic interaction of immune microenvironment with dysfunctional metabolism and the gut microbiome, and propose therapeutic strategies to manipulate the TME in favor of more effective immunotherapy.

Current advances and challenges in CAR T-Cell therapy for solid tumors: tumor-associated antigens and the tumor microenvironment

The past decade has witnessed ongoing progress in immune therapy to ameliorate human health. As an emerging technique, chimeric antigen receptor (CAR) T-cell therapy has the advantages of specific killing of cancer cells, a high remission rate of cancer-induced symptoms, rapid tumor eradication, and long-lasting tumor immunity, opening a new window for tumor treatment. However, challenges remain in CAR T-cell therapy for solid tumors due to target diversity, tumor heterogeneity, and the complex microenvironment. In this review, we have outlined the development of the CAR T-cell technique, summarized the current advances in tumor-associated antigens (TAAs), and highlighted the importance of tumor-specific antigens (TSAs) or neoantigens for solid tumors. We also addressed the challenge of the TAA binding domain in CARs to overcome off-tumor toxicity. Moreover, we illustrated the dominant tumor microenvironment (TME)-induced challenges and new strategies based on TME-associated antigens (TMAs) for solid tumor CAR T-cell therapy.

Neoantigens: promising targets for cancer therapy

Recent advances in neoantigen research have accelerated the development and regulatory approval of tumor immunotherapies, including cancer vaccines, adoptive cell therapy and antibody-based therapies, especially for solid tumors. Neoantigens are newly formed antigens generated by tumor cells as a result of various tumor-specific alterations, such as genomic mutation, dysregulated RNA splicing, disordered post-translational modification, and integrated viral open reading frames. Neoantigens are recognized as non-self and trigger an immune response that is not subject to central and peripheral tolerance. The quick identification and prediction of tumor-specific neoantigens have been made possible by the advanced development of next-generation sequencing and bioinformatic technologies. Compared to tumor-associated antigens, the highly immunogenic and tumor-specific neoantigens provide emerging targets for personalized cancer immunotherapies, and serve as prospective predictors for tumor survival prognosis and immune checkpoint blockade responses. The development of cancer therapies will be aided by understanding the mechanism underlying neoantigen-induced anti-tumor immune response and by streamlining the process of neoantigen-based immunotherapies. This review provides an overview on the identification and characterization of neoantigens and outlines the clinical applications of prospective immunotherapeutic strategies based on neoantigens. We also explore their current status, inherent challenges, and clinical translation potential.

Mechanisms of Primary and Acquired Resistance to Immune Checkpoint Inhibitors in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common liver cancer and a relevant global health problem. Immune checkpoint inhibitors (ICIs) represent the most effective systemic treatment for HCC. However, due to primary resistance, approximately 40% of HCC patients do not achieve a disease control with ICIs. Moreover, a similar proportion will experience disease progression after an initial response caused by secondary resistance. This review describes the mechanisms of primary and secondary resistance and reports the ongoing therapeutic strategies to overcome these obstacles.

The Identification and Clinical Applications of Mutated Antigens in the Era of Immunotherapy

The era of personalized cancer therapy is here. Advances in the field of immunotherapy have paved the way for the development of individualized neoantigen-based therapies that can translate into favorable treatment outcomes and fewer side effects for patients. Addressing challenges related to the identification, access, and clinical application of neoantigens is critical to accelerating the development of individualized immunotherapy for cancer patients.