Extracellular Vesicle-Based Therapeutic Targeting of β-Catenin to Modulate Anticancer Immune Responses in Hepatocellular Cancer

Lipid Nanovesicle Platforms for Hepatocellular Carcinoma Precision Medicine Therapeutics: Progress and Perspectives

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality globally. HCC is highly heterogenous with diverse etiologies leading to different driver mutations potentiating unique tumor immune microenvironments. Current therapeutic options, including immune checkpoint inhibitors and combinations, have achieved limited objective response rates for the majority of patients. Thus, a precision medicine approach is needed to tailor specific treatment options for molecular subsets of HCC patients. Lipid nanovesicle platforms, either liposome- (synthetic) or extracellular vesicle (natural)-derived present are improved drug delivery vehicles which may be modified to contain specific cargos for targeting specific tumor sites, with a natural affinity for liver with limited toxicity. This mini-review provides updates on the applications of novel lipid nanovesicle-based therapeutics for HCC precision medicine and the challenges associated with translating this therapeutic subclass from preclinical models to the clinic.

Wnt/β-Catenin signaling pathway in hepatocellular carcinoma: pathogenic role and therapeutic target

Hepatocellular carcinoma (HCC) is the most common primary malignant liver tumor and one of the leading causes of cancer-related deaths worldwide. The Wnt/β-Catenin signaling pathway is a highly conserved pathway involved in several biological processes, including the improper regulation that leads to the tumorigenesis and progression of cancer. New studies have found that abnormal activation of the Wnt/β-Catenin signaling pathway is a major cause of HCC tumorigenesis, progression, and resistance to therapy. New perspectives and approaches to treating HCC will arise from understanding this pathway. This article offers a thorough analysis of the Wnt/β-Catenin signaling pathway's function and its therapeutic implications in HCC.

Membrane-Cloaked Nanoparticles for RNA Interference of β-Catenin in Triple-Negative Breast Cancer

There is an outstanding need for targeted therapies for triple-negative breast cancer (TNBC), an aggressive breast cancer subtype. Since TNBC's rapid growth and metastasis are driven by hyperactive Wnt signaling, suppressing the key-pathway mediator β-catenin through RNA interference may improve patient outcomes. However, small interfering ribonucleic acid (siRNA) molecules require a carrier to elicit targeted gene silencing. Here, we show that 4T1 cancer cell membrane wrapped poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) can deliver siRNA into TNBC cells, silence β-catenin expression, and reduce the cells' tumorigenic qualities. Compared to unwrapped and nontargeted NPs, the cancer cell membrane wrapped nanoparticles (CCNPs) exhibit dramatically improved uptake by TNBC cells versus breast epithelial cells and greater gene silencing at mRNA and protein levels. Congruently, β-catenin siRNA-loaded CCNPs significantly activate senescence in 2D cultured TNBC cells and reduce proliferation in 3D spheroids. This work advances the development of nucleic acid carriers for targeted RNA interference therapy.

Therapeutic restoration of miR-126-3p as a multi-targeted strategy to modulate the liver tumor microenvironment

BACKGROUND

Impaired natural killer (NK) cell-mediated antitumor responses contribute to the growth of liver tumors. Expression of a disintegrin and metalloprotease 9 (ADAM9) increases shedding of membrane-bound major histocompatibility complex class I chain-related protein A and results in evasion from NK cell-mediated cytolysis. ADAM9 is also involved in angiogenesis and tumor progression and is a target of miR-126-3p, a tumor suppressor that is downregulated and alters tumor cell behavior in the liver and other cancers. We evaluated the restoration of miR-126-3p and modulation of the miR-126-3p/ADAM9 axis as a therapeutic approach to simultaneously enhance NK cell-mediated cytolysis while targeting both tumor cells and their microenvironment.

METHODS

Precursor miRNAs were loaded into milk-derived nanovesicles to generate therapeutic vesicles (therapeutic milk-derived nanovesicles) for the restoration of functional miR-126-3p in recipient cancer cells.

RESULTS

Administration of therapeutic milk-derived nanovesicles increased miR-126-3p expression and reduced ADAM9 expression in target cells and was associated with an increase in membrane-bound major histocompatibility complex class I chain-related protein A. This enhanced NK cell cytolysis in adherent tumor cells and in multicellular tumor spheroids while also impairing angiogenesis and modulating macrophage chemotaxis. Moreover, IV administration of therapeutic milk-derived nanovesicles with adoptive transfer of NK cells reduced tumor burden in orthotopic hepatocellular cancer xenografts in mice.

CONCLUSION

A directed RNA therapeutic approach can mitigate NK cell immune evasion, reduce angiogenesis, and alter the tumor cell phenotype through the restoration of miR-126-3p in liver tumor cells. The pleiotropic effects elicited by this multi-targeted approach to modulate the local tumor microenvironment support its use for the treatment of liver cancer.

Understanding exosomes: Part 2-Emerging leaders in regenerative medicine

Exosomes are the smallest subset of extracellular signaling vesicles secreted by most cells with the ability to communicate with other tissues and cell types over long distances. Their use in regenerative medicine has gained tremendous momentum recently due to their ability to be utilized as therapeutic options for a wide array of diseases/conditions. Over 5000 publications are currently being published yearly on this topic, and this number is only expected to dramatically increase as novel therapeutic strategies continue to be developed. Today exosomes have been applied in numerous contexts including neurodegenerative disorders (Alzheimer's disease, central nervous system, depression, multiple sclerosis, Parkinson's disease, post-traumatic stress disorders, traumatic brain injury, peripheral nerve injury), damaged organs (heart, kidney, liver, stroke, myocardial infarctions, myocardial infarctions, ovaries), degenerative processes (atherosclerosis, diabetes, hematology disorders, musculoskeletal degeneration, osteoradionecrosis, respiratory disease), infectious diseases (COVID-19, hepatitis), regenerative procedures (antiaging, bone regeneration, cartilage/joint regeneration, osteoarthritis, cutaneous wounds, dental regeneration, dermatology/skin regeneration, erectile dysfunction, hair regrowth, intervertebral disc repair, spinal cord injury, vascular regeneration), and cancer therapy (breast, colorectal, gastric cancer and osteosarcomas), immune function (allergy, autoimmune disorders, immune regulation, inflammatory diseases, lupus, rheumatoid arthritis). This scoping review is a first of its kind aimed at summarizing the extensive regenerative potential of exosomes over a broad range of diseases and disorders.

Unraveling the Complexities of Immune Checkpoint Inhibitors in Hepatocellular Carcinoma

Immune checkpoint inhibitors (ICIs) have emerged as effective therapeutics for multiple cancers. Nevertheless, as immunotherapeutic approaches are being extensively utilized, substantial hurdles have arisen for clinicians. These include countering ICIs resistance and ensuring precise efficacy assessments of these drugs, especially in the context of hepatocellular carcinoma (HCC). This review attempts to offer a holistic overview of the latest insights into the ICIs resistance mechanisms in HCC, the molecular underpinnings, and immune response. The intent is to inspire the development of efficacious combination strategies. This review also examines the unconventional response patterns, namely pseudoprogression (PsP) and hyperprogression (HPD). The prompt and rigorous evaluation of these treatment efficacies has emerged as a crucial imperative. Multiple clinical, radiological, and biomarker tests have been advanced to meticulously assess tumor response. Despite progress, precise mechanisms of action and predictive biomarkers remain elusive. This necessitates further investigation through prospective cohort studies in the impending future.

Emerging Roles of Using Small Extracellular Vesicles as an Anti-Cancer Drug

Small extracellular vesicles (sEVs) are emerging as a novel therapeutic strategy for cancer therapy. Tumor-cell-derived sEVs contain biomolecules that can be utilized for cancer diagnosis. sEVs can directly exert tumor-killing effects or modulate the tumor microenvironment, leading to anti-cancer effects. In this review, the application of sEVs as a diagnostic tool, drug delivery system, and active pharmaceutical ingredient for cancer therapy will be highlighted. The therapeutic efficacies of sEVs will be compared to conventional immune checkpoint inhibitors. Additionally, this review will provide strategies for sEV engineering to enhance the therapeutic efficacies of sEVs. As a bench-to-bedside application, we will discuss approaches to encourage good-manufacturing-practice-compliant industrial-scale manufacturing and purification of sEVs.

Extracellular vesicle RNA signaling in the liver tumor microenvironment

The tumor microenvironment (TME) in liver cancers such as hepatocellular cancer (HCC) consists of a complex milieu of liver tissue-resident cells, infiltrated immune cells, and secreted factors that collectively serve to promote tumor growth and progression. Intercellular crosstalk contributes to tissue homeostasis, and perturbations during injury, inflammation and tumorigenesis that are important for tumor progression. Extracellular vesicle (EV)-mediated transfer of a payload of RNA molecules that serve as an intercellular signaling is an important contributor to tissue homeostasis within the TME. Several types of RNA have been implicated in EV-mediated signaling. Biological processes that can be modulated by EV RNA signaling within the liver include tumor growth, invasion, metastasis, angiogenesis, and modulation of the immune cell activities. This mini-review describes the liver TME, and the biological effects of EV RNA-mediated signaling within the liver to highlight the role of EV RNA in intercellular communication.

Extracellular Vesicles Act as Carriers for Cargo Delivery and Regulate Wnt Signaling in the Hepatocellular Carcinoma Tumor Microenvironment

As the primary type of liver cancer, hepatocellular carcinoma (HCC) causes a large number of deaths every year. Despite extensive research conducted on this disease, the prognosis of HCC remains unclear. Recently, research has largely focused on extracellular vesicles (EVs), and they have been found to participate in various ways in the development of various diseases, including HCC, such as by regulating cell signaling pathways. However, recent studies have reported the mechanisms underlying the regulation of Wnt signaling by EVs in HCC, primarily focusing on the regulation of the canonical pathways. This review summarizes the current literature on the regulation of Wnt signaling by EVs in HCC and their underlying mechanisms. In addition, we also present future research directions in this field. This will deepen the understanding of HCC and provide new ideas for its treatment.

Advances of multi-omics applications in hepatic precancerous lesions and hepatocellular carcinoma: The role of extracellular vesicles

Due to the lack of distinct early symptoms and specific biomarkers, most patients with hepatocellular carcinoma (HCC) are usually diagnosed at advanced stages, rendering the treatment ineffective and useless. Therefore, recognition of the malady at precancerous lesions and early stages is particularly important for improving patient outcomes. The interest in extracellular vesicles (EVs) has been growing in recent years with the accumulating knowledge of their multiple cargoes and related multipotent roles in the modulation of immune response and tumor progression. By virtue of the rapid advancement of high-throughput techniques, multiple omics, including genomics/transcriptomics, proteomics, and metabolomics/lipidomics, have been widely integrated to analyze the role of EVs. Comprehensive analysis of multi-omics data will provide useful insights for discovery of new biomarkers and identification of therapeutic targets. Here, we review the attainment of multi-omics analysis to the finding of the potential role of EVs in early diagnosis and the immunotherapy in HCC.

The application of nanoparticles in immunotherapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer-related deaths worldwide, however, current clinical diagnostic and treatment approaches remain relatively limited, creating an urgent need for the development of effective technologies. Immunotherapy has emerged as a powerful treatment strategy for advanced cancer. The number of clinically approved drugs for HCC immunotherapy has been increasing. However, it remains challenging to improve their transport and therapeutic efficiency, control their targeting and release, and mitigate their adverse effects. Nanotechnology has recently gained attention for improving the effectiveness of precision therapy for HCC. We summarize the key features of HCC associated with nanoparticle (NPs) targeting, release, and uptake, the roles and limitations of several major immunotherapies in HCC, the use of NPs in immunotherapy, the properties of NPs that influence their design and application, and current clinical trials of NPs in HCC, with the aim of informing the design of delivery platforms that have the potential to improve the safety and efficacy of HCC immunotherapy，and thus, ultimately improve the prognosis of HCC patients.

Extracellular vesicle‑mediated miR‑126‑3p transfer contributes to inter‑cellular communication in the liver tumor microenvironment

Extracellular vesicles (EVs) and their contents are gaining recognition as important mediators of intercellular communication through the transfer of bioactive molecules, such as non‑coding RNA. The present study comprehensively assessed the microRNA (miRNA/miR) content within EVs released from HepG2 liver cancer (LC) cells and LX2 hepatic stellate cells (HSCs) and determined the contribution of EV miRNA to intercellular communication. Using both transwell and spheroid co‑cultures of LC cells and HSCs, miR‑126‑3p within EV was established as a mediator of HSC to LC cell communication that influenced tumor cell migration and invasion, as well as the growth of multicellular LC/HSC spheroids. Manipulation of miR‑126‑3p either by enforced expression using pre‑miR‑126‑3p or by inhibition using antimiR‑126‑3p did not alter tumor cell viability, proliferation or sensitivity to either sorafenib or regorafenib. By contrast, enforced expression of miR‑126‑3p decreased tumor‑cell migration. Knockdown of miR‑126‑3p in tumor cells increased disintegrin and metalloproteinase domain‑containing protein 9 (ADAM9) expression and in HSCs increased collagen‑1A1 accumulation with an increase in compactness of multicellular spheroids. Within LC/HSC spheroids, ADAM9 and vascular endothelial growth factor expression was increased by silencing of miR‑126‑3p but diminished with the restoration of miR‑126‑3p. These studies implicate miR‑126‑3p in functional effects on migration, invasion and spheroid growth of tumor cells in the presence of HSCs, and thereby demonstrate functional EV‑RNA‑based intercellular signaling between HSCs and LC cells that is directly relevant to tumor‑cell behavior.

New advances in pharmaceutical strategies for sensitizing anti-PD-1 immunotherapy and clinical research

Attempts have been made continuously to use nano-drug delivery system (NDDS) to improve the effect of antitumor therapy. In recent years, especially in the application of immunotherapy represented by antiprogrammed death receptor 1 (anti-PD-1), it has been vigorously developed. Nanodelivery systems are significantly superior in a number of aspects including increasing the solubility of insoluble drugs, enhancing their targeting ability, prolonging their half-life, and reducing side effects. It can not only directly improve the efficacy of anti-PD-1 immunotherapy, but also indirectly enhance the antineoplastic efficacy of immunotherapy by boosting the effectiveness of therapeutic modalities such as chemotherapy, radiotherapy, photothermal, and photodynamic therapy (PTT/PDT). Here, we summarize the studies published in recent years on the use of nanotechnology in pharmaceutics to improve the efficacy of anti-PD-1 antibodies, analyze their characteristics and shortcomings, and combine with the current clinical research on anti-PD-1 antibodies to provide a reference for the design of future nanocarriers, so as to further expand the clinical application prospects of NDDSs. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

The emerging roles of extracellular vesicles as intercellular messengers in liver physiology and pathology

Extracellular vesicles (EVs) are membrane-enclosed particles released from almost all cell types. EVs mediate intercellular communication by delivering their surface and luminal cargoes, including nucleic acids, proteins, and lipids, which reflect the pathophysiological conditions of their cellular origins. Hepatocytes and hepatic non-parenchymal cells utilize EVs to regulate a wide spectrum of biological events inside the liver and transfer them to distant organs through systemic circulation. The liver also receives EVs from multiple organs and integrates these extrahepatic signals that participate in pathophysiological processes. EVs have recently attracted growing attention for their crucial roles in maintaining and regulating hepatic homeostasis. This review summarizes the roles of EVs in intrahepatic and interorgan communications under different pathophysiological conditions of the liver, with a focus on chronic liver diseases including nonalcoholic steatohepatitis, alcoholic hepatitis, viral hepatitis, liver fibrosis, and hepatocellular carcinoma. This review also discusses recent progress for potential therapeutic applications of EVs by targeting or enhancing EV-mediated cellular communication for the treatment of liver diseases.

Overcoming resistance to immune checkpoint inhibitors in hepatocellular carcinoma: Challenges and opportunities

Hepatocellular carcinoma is one of the leading causes of cancer mortality globally, and its incidence is increasing. Immune checkpoint therapy has revolutionized the treatment of hepatocellular carcinoma over the past few years. However, only a limited proportion of patients with hepatocellular carcinoma respond to immunotherapy. Despite the significant breakthroughs, the molecular mechanisms that drive immune responses and evasion are largely unresolved. Predicting tumor response and resistance to immune checkpoint inhibitors is a significant challenge. In this review, we focus on the current research progress of immune checkpoint inhibitors in hepatocellular carcinoma. Importantly, this review highlights the underlying mechanisms of resistance to immune checkpoint inhibitors and summarizes potential strategies to overcome the resistance to immune checkpoint inhibitors in hepatocellular carcinoma.

Role of Exosomes in Immunotherapy of Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma is one of the most lethal malignancies, having a significantly poor prognosis. Immunotherapy, as an emerging tumor treatment option, provides new hope for many cancer patients. However, a large proportion of patients do not benefit from immunotherapy. As a critical cell-to-cell communication mediator in the tumor immune microenvironment, exosomes may play a unique role in hepatocellular carcinoma immune response and thus affect the efficiency of immunotherapy. In this review, we discuss related research on the roles of exosomes in the current immunotherapy resistance mechanism of hepatocellular carcinoma. Furthermore, we also clarify the excellent predictive value of exosomes and the roles they play in improving immunotherapy efficacy for hepatocellular carcinoma patients. We hope that our review can help readers to gain a more comprehensive understanding of exosomes’ roles in hepatocellular carcinoma immunotherapy.

Abstract

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies, having a significantly poor prognosis and no sufficiently efficient treatments. Immunotherapy, especially immune checkpoint inhibitors (ICIs), has provided new therapeutic approaches for HCC patients. Nevertheless, most patients with HCC do not benefit from immunotherapy. Exosomes are biologically active lipid bilayer nano-sized vesicles ranging in size from 30 to 150 nm and can be secreted by almost any cell. In the HCC tumor microenvironment (TME), numerous cells are involved in tumor progression, and exosomes—derived from tumor cells and immune cells—exhibit unique composition profiles and act as intercellular communicators by transporting various substances. Showing the dual characteristics of tumor promotion and suppression, exosomes exert multiple functions in shaping tumor immune responses in the crosstalk between tumor cells and surrounding immune cells, mediating immunotherapy resistance by affecting the PD-1/PD-L1 axis or the anti-tumor function of immune cells in the TME. Targeting exosomes or the application of exosomes as therapies is involved in many aspects of HCC immunotherapies (e.g., ICIs, tumor vaccines, and adoptive cell therapy) and may substantially enhance their efficacy. In this review, we discuss the impact of exosomes on the HCC TME and comprehensively summarize the role of exosomes in immunotherapy resistance and therapeutic application. We also discuss the potential of exosomes as biomarkers for predicting the efficacy of immunotherapy to help clinicians in identifying HCC patients who are amenable to immunotherapies.

Tracing New Landscapes in the Arena of Nanoparticle-Based Cancer Immunotherapy

Over the past two decades, unique and comprehensive cancer treatment has ushered new hope in the holistic management of the disease. Cancer immunotherapy, which harnesses the immune system of the patient to attack the cancer cells in a targeted manner, scores over others by being less debilitating compared to the existing treatment strategies. Significant advancements in the knowledge of immune surveillance in the last few decades have led to the development of several types of immune therapy like monoclonal antibodies, cancer vaccines, immune checkpoint inhibitors, T-cell transfer therapy or adoptive cell therapy (ACT) and immune system modulators. Intensive research has established cancer immunotherapy to be a safe and effective method for improving survival and the quality of a patient’s life. However, numerous issues with respect to site-specific delivery, resistance to immunotherapy, and escape of cancer cells from immune responses, need to be addressed for expanding and utilizing this therapy as a regular mode in the clinical treatment. Development in the field of nanotechnology has augmented the therapeutic efficiency of treatment modalities of immunotherapy. Nanocarriers could be used as vehicles because of their advantages such as increased surface areas, targeted delivery, controlled surface and release chemistry, enhanced permeation and retention effect, etc. They could enhance the function of immune cells by incorporating immunomodulatory agents that influence the tumor microenvironment, thus enabling antitumor immunity. Robust validation of the combined effect of nanotechnology and immunotherapy techniques in the clinics has paved the way for a better treatment option for cancer than the already existing procedures such as chemotherapy and radiotherapy. In this review, we discuss the current applications of nanoparticles in the development of ‘smart’ cancer immunotherapeutic agents like ACT, cancer vaccines, monoclonal antibodies, their site-specific delivery, and modulation of other endogenous immune cells. We also highlight the immense possibilities of using nanotechnology to accomplish leveraging the coordinated and adaptive immune system of a patient to tackle the complexity of treating unique disease conditions and provide future prospects in the field of cancer immunotherapy.

RNA-mediated immunotherapy regulating tumor immune microenvironment: next wave of cancer therapeutics

Accumulating research suggests that the tumor immune microenvironment (TIME) plays an essential role in regulation of tumor growth and metastasis. The cellular and molecular nature of the TIME influences cancer progression and metastasis by altering the ratio of immune- suppressive versus cytotoxic responses in the vicinity of the tumor. Targeting or activating the TIME components show a promising therapeutic avenue to combat cancer. The success of immunotherapy is both astounding and unsatisfactory in the clinic. Advancements in RNA-based technology have improved understanding of the complexity and diversity of the TIME and its effects on therapy. TIME-related RNA or RNA regulators could be promising targets for anticancer immunotherapy. In this review, we discuss the available RNA-based cancer immunotherapies targeting the TIME. More importantly, we summarize the potential of various RNA-based therapeutics clinically available for cancer treatment. RNA-dependent targeting of the TIME, as monotherapy or combined with other evolving therapeutics, might be beneficial for cancer patients’ treatment in the near future.

Extracellular vesicles as a new hope for diagnosis and therapeutic intervention for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common cancer with a high mortality rate. Early diagnosis and treatment before tumor progression into an advanced stage is ideal. The current diagnosis of HCC is mainly based on imaging modalities such as ultrasound, computed tomography, and magnetic resonance imaging. These methods have some limitations including diagnosis in the case of very small tumors with atypical imaging patterns. Extracellular vesicles (EVs) are nanosized vesicles which have been shown to act as an important vector for cell-to-cell communication. In the past decade, EVs have been investigated with regard to their roles in HCC formation. Since these EVs contain biomolecular cargo such as nucleic acid, lipids, and proteins, it has been proposed that they could be a potential source of tumor biomarkers and a vector for therapeutic cargo. In this review, reports on the roles of HCC-derived EVs in tumorigenesis, and clinical investigations using circulating EVs as a biomarker for HCC and their potential diagnostic roles have been comprehensively summarized and discussed. In addition, findings from in vitro and in vivo reports investigating the potential roles of EVs as therapeutic interventions are also presented. These findings regarding the potential benefits of EVs will encourage further investigations and may allow us to devise novel strategies using EVs in the early diagnosis as well as for treatment of HCC in the future.

Biological Nanotherapeutics for Liver Disease

Extracellular vesicles (EVs) are a heterogeneous group of biological nano-sized vesicles that are released from cells and contribute to intercellular communication. Emerging knowledge about their biogenesis, composition, release, and uptake has resulted in broad interest in elucidating their potential roles in disease pathophysiology. The distinct biological properties of these biological nanoparticles emphasize several appealing advantages for potential therapeutic applications compared with the use of synthetic nanoparticles. When administered systemically, EVs are taken up and sequestered within the liver, further emphasizing opportunities for therapeutic use. Consequently, there is growing interest in their use for liver diseases. EVs can be used directly as therapeutics, and several studies have highlighted the intrinsic therapeutic properties of mesenchymal stem cell-derived EVs for chronic and acute liver diseases. Alternatively, EVs can be modified to facilitate their use for the delivery of therapeutic cargo. In this review, we discuss the cellular sources of EV, provide a concise overview of their potential use in diverse processes, and outline several promising applications for the use of EV-based therapeutics for liver diseases. The use of EV-based therapeutics provides a viable approach to target hepatic pathophysiology.

Emerging role of tumor-derived extracellular vesicles in T cell suppression and dysfunction in the tumor microenvironment

Immunotherapeutic drugs including immune checkpoint blockade antibodies have been approved to treat patients in many types of cancers. However, some patients have little or no reaction to the immunotherapy drugs. The mechanisms underlying resistance to tumor immunotherapy are complicated and involve multiple aspects, including tumor-intrinsic factors, formation of immunosuppressive microenvironment, and alteration of tumor and stromal cell metabolism in the tumor microenvironment. T cell is critical and participates in every aspect of antitumor response, and T cell dysfunction is a severe barrier for effective immunotherapy for cancer. Emerging evidence indicates that extracellular vesicles (EVs) secreted by tumor is one of the major factors that can induce T cell dysfunction. Tumor-derived EVs are widely distributed in serum, tissues, and the tumor microenvironment of patients with cancer, which serve as important communication vehicles for cancer cells. In addition, tumor-derived EVs can carry a variety of immune suppressive signals driving T cell dysfunction for tumor immunity. In this review, we explore the potential mechanisms employed by tumor-derived EVs to control T cell development and effector function within the tumor microenvironment. Especially, we focus on current understanding of how tumor-derived EVs molecularly and metabolically reprogram T cell fates and functions for tumor immunity. In addition, we discuss potential translations of targeting tumor-derived EVs to reconstitute suppressive tumor microenvironment or to develop antigen-based vaccines and drug delivery systems for cancer immunotherapy.

Combination Immunotherapies to Overcome Intrinsic Resistance to Checkpoint Blockade in Microsatellite Stable Colorectal Cancer

Although immune checkpoint inhibitors (ICIs) have shown promising results in the treatment of treating various malignancies, progress has been severely limited in metastatic colorectal cancer (mCRC). ICIs are effective in a fraction of patients with microsatellite instability-high mCRC but have little clinical efficacy in patients with microsatellite stable (MSS) mCRC, which accounts for 95% of mCRC cases. MSS mCRCs are considered to have intrinsic resistance to ICI monotherapy through multiple mechanisms. (1) They are poorly immunogenic because of their low tumor mutation burden; (2) frequent activation of the WNT/β-catenin signaling pathway excludes intratumoral CD8+ T cell immunity; (3) the tumor microenvironment is immunosuppressive because of the presence of various immunosuppressive cells, including tumor-associated macrophages and regulatory T cells; and (4) frequent liver metastasis in MSS mCRC may reduce the efficacy of ICIs. To overcome these resistance mechanisms, combination approaches using various agents, including STING agonists, MEK inhibitors, VEGF/R inhibitors, WNT/β-catenin inhibitors, oncolytic viruses, and chemo/radiotherapy, are actively ongoing. Preliminary evidence of the efficacy of some has been shown in early clinical trials. This review summarizes novel combination immunotherapy strategies described in recent preclinical and clinical studies to overcome the limitations of ICI monotherapy in MSS mCRC.

Evaluation of In Vivo Toxicity of Biological Nanoparticles

Biologically derived nanoparticles such as extracellular vesicles are promising candidates for therapeutic applications. In vivo toxicity of biological nanoparticles can result in tissue or organ damage, immunological perturbations, or developmental effects but cannot be readily predicted from in vitro studies. Therefore, an essential component of the preclinical assessment of these particles for their use as therapeutics requires screening for adverse effects and detailed characterization of their toxicity in vivo. However, there are no standardized, comprehensive methods to evaluate the toxicity profile of nanoparticle treatment in a preclinical model. Here, we first describe a method to prepare bovine milk-derived nanovesicles (MNVs). These MNVs are inexpensive to isolate, have a scalable production platform, and can be modified to achieve a desired biological effect. We also describe two vertebrate animal models, mice and zebrafish, that can be employed to evaluate the toxicity profile of biologically derived nanoparticles, using MNVs as an example. Treatment-induced organ toxicity and immunological effects can be assessed in mice receiving systemic injections of MNVs, and developmental toxicity can be assessed in zebrafish embryos exposed to MNVs in embryo water. Utilizing these animal models provides opportunities to analyze the toxicity profiles of therapeutic extracellular vesicles in vivo. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Preparation of milk-derived nanovesicles Basic Protocol 2: In vivo screening for organ toxicity and immune cell profiling using mice Basic Protocol 3: In vivo developmental toxicity screening using zebrafish.

Fabrication and Characterization of a Biomaterial Based on Extracellular-Vesicle Functionalized Graphene Oxide

Mesenchymal stem cell (MSC) derived extracellular vesicles (EV) are emerging as acellular therapeutics for solid organ injury and as carriers for drug delivery. Graphene-based materials are novel two-dimensional crystal structure-based materials with unique characteristics of stiffness, strength and elasticity that are being explored for various structural and biological applications. We fabricated a biomaterial that would capture desirable properties of both graphene and stem cell derived EV. Metabolically engineered EV that express azide groups were cross-linked with alkyne-functionalized graphene oxide (GO) via a copper catalyzed alkyne-azide cycloaddition (CuAAC) reaction. The crosslinking between EV and GO was accomplished without the need for ligand expression on the metal. Scanning electron and fluorescence microscopy demonstrated excellent cross-linking between EV and GO. Biological effects were assessed by phagocytosis studies and cell viability studies. The uptake of GO or sonicated GO (sGO) resulted in a durable pro-inflammatory immune response. Cell studies further showed that crosslinked GO-EV scaffolds exhibited cell-type dependent cytotoxicity on liver cancer cells whereas there was minimal impact on healthy hepatocyte proliferation. In vitro, neither GO-EV nor sGO-EV induced DNA strand breaks. In vivo studies in zebrafish revealed gross developmental malformations but treatment-induced mortality was only seen with the highest doses of GO-EV and sGO-EV. With these advantages, this engineered biomaterial combining the versatility of graphene with the therapeutic effects of MSC-EV has potential for applications in tissue engineering and regenerative medicine.

Nucleic acid delivery with extracellular vesicles

Extracellular vesicles (EVs) are membrane-enclosed particles, heterogeneous in size, shape, contents, biogenesis and structure. They are released by eukaryotic and prokaryotic cells and exert (patho-)physiological roles as mediators for transmitting molecular information from the producer (donor) to a recipient cell. This review focuses on the potential of EVs for delivering nucleic acids, as particularly problematic cargoes with regard to stability/protection and uptake efficacy. It highlights important properties of EVs for nucleic acid delivery and discusses their physiological and pathophysiological roles with regard to various cellular RNA species. It then describes the application of EVs for delivering a broad selection of nucleic acids/oligonucleotides, in particular giving a comprehensive overview of preclinical in vivo studies and the various strategies explored. In this context, different techniques for EV loading are discussed, as well as other important technical aspects related to EV preparation, characterization and in particular, the various approaches of artificial EV modification.

Extracellular Vesicles and Their Current Role in Cancer Immunotherapy

Simple Summary

In recent years, immunotherapy has shown great advancement, becoming a powerful tool to combat cancer. In this context, the use of biologically derived vesicles has also acquired importance for cancer immunotherapy. Extracellular vesicles are thus proposed to transport molecules able to trigger an immune response and thus fight cancer cells. As a particular immunotherapeutic approach, a new technique also consists in the exploitation of extracellular vesicles as new cancer vaccines. The present review provides basic notions on cancer immunotherapy and describes several clinical trials in which therapeutic anticancer vaccines are tested. In particular, the potential of extracellular vesicles-based therapeutic vaccines in the treatment of cancer patients is highlighted, even with advanced stage-cancer. A focus on the clinical studies, already completed or still in progress, is offered and a systematic collection and reorganization of the present literature on this topic is proposed to the reader.

Abstract

Extracellular vesicles (EVs) are natural particles formed by the lipid bilayer and released from almost all cell types to the extracellular environment both under physiological conditions and in presence of a disease. EVs are involved in many biological processes including intercellular communication, acting as natural carriers in the transfer of various biomolecules such as DNA, various RNA types, proteins and different phospholipids. Thanks to their transfer and targeting abilities, they can be employed in drug and gene delivery and have been proposed for the treatment of different diseases, including cancer. Recently, the use of EVs as biological carriers has also been extended to cancer immunotherapy. This new technique of cancer treatment involves the use of EVs to transport molecules capable of triggering an immune response to damage cancer cells. Several studies have analyzed the possibility of using EVs in new cancer vaccines, which represent a particular form of immunotherapy. In the literature there are only few publications that systematically group and collectively discuss these studies. Therefore, the purpose of this review is to illustrate and give a partial reorganization to what has been produced in the literature so far. We provide basic notions on cancer immunotherapy and describe some clinical trials in which therapeutic cancer vaccines are tested. We thus focus attention on the potential of EV-based therapeutic vaccines in the treatment of cancer patients, overviewing the clinically relevant trials, completed or still in progress, which open up new perspectives in the fight against cancer.

Advances in siRNA delivery strategies for the treatment of MDR cancer

RNA interference (RNAi) represents a promising therapeutic method that uses siRNA for cancer treatment. Although the RNAi technique has been increasingly used for clinical trials, systemic siRNA delivery into targeted cells is still challenging. The barriers impeding siRNA therapeutics delivery and impacting the treatment outcome must overcome with negligible systemic toxicity for a desirable and successful delivery of siRNA to MDR cancer cells. Nano delivery strategies have been investigated for nanocarrier functionalization, cancer immunotherapy and cancer targeting. Lipid nanoparticles (LNPs), dynamic polyconjugates (DPC™), GalNAc-siRNA conjugates, exosome and RBC systems have shown potential for efficient delivery of siRNA to cancer cells. Delivery of siRNA to tumor cells, immune cells to regulate T cell functions for immunotherapy are promising approaches.

The Current View of Nonalcoholic Fatty Liver Disease-Related Hepatocellular Carcinoma

Simple Summary

The incidence of nonalcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC) is increasing. However, an effective screening or surveillance method is not established. Recently, the NAFLD/nonalcoholic steatohepatitis (NASH) guidelines of Japan were revised to incorporate new strategies and evidence for the management and surveillance of NAFLD/NASH. Advanced fibrosis and lifestyle-related and metabolic comorbidities, especially obesity and diabetes mellitus, are associated with HCC development. At the first screening, serum markers of hepatic fibrosis (hyaluronic acid, type IV collagen 7S, and mac-2 binding protein), or the fibrosis (FIB)-4 index or the nonalcoholic fatty liver disease fibrosis score (NFS), or a platelet count should be evaluated. When liver fibrosis is indicated, consultation with a gastroenterology specialist should be considered for the second screening. The risk of HCC should be stratified using the FIB-4 index or the NFS. Liver stiffness should be measured using vibration-controlled transient elastography in those at intermediate or high risk. Blood tests and imaging should be performed every 6–12 months in patients with advanced fibrosis for HCC surveillance. We review here what is known about NAFLD-HCC and provide perspectives for future research.

Abstract

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and can develop into hepatocellular carcinoma (HCC). The incidence of NAFLD-related HCC, which is accompanied by life-threatening complications, is increasing. Advanced fibrosis and lifestyle-related and metabolic comorbidities, especially obesity and diabetes mellitus, are associated with HCC development. However, HCC is also observed in the non-cirrhotic liver. Often, diagnosis is delayed until the tumor is relatively large and the disease is advanced; an effective screening or surveillance method is urgently required. Recently, the NAFLD/nonalcoholic steatohepatitis (NASH) guidelines of Japan were revised to incorporate new strategies and evidence for the management and surveillance of NAFLD/NASH. Fibrosis must be tested for noninvasively, and the risk of carcinogenesis must be stratified. The treatment of lifestyle-related diseases is expected to reduce the incidence of NAFLD and prevent liver carcinogenesis.

Extracellular vesicles and oncogenic signaling

In recent years, extracellular vesicles (EVs) emerged as potential diagnostic and prognostic markers for cancer therapy. While the field of EV research is rapidly developing and their application as vehicles for therapeutic cargo is being tested, little is still known about the exact mechanisms of signaling specificity and cargo transfer by EVs, especially in vivo. Several signaling cascades have been found to use EVs for signaling in the tumor-stroma interaction. These include potentially oncogenic, verbatim transforming, signaling cascades such as Wnt and TGF-β signaling, and other signaling cascades that have been tightly associated with tumor progression and metastasis, such as PD-L1 and VEGF signaling. Multiple mechanisms of how these signaling cascades and EVs interplay to mediate these complex processes have been described, such as direct signal activation through pathway components on or in EVs or indirectly by influencing vesicle biogenesis, cargo sorting, or uptake dynamics. In this review, we summarize the current knowledge of EVs, their biogenesis, and our understanding of EV interactions with recipient cells with a focus on selected oncogenic and cancer-associated signaling pathways. After an in-depth look at how EVs mediate and influence signaling, we discuss potentially translatable EV functions and existing knowledge gaps.

Extracellular vesicles and oncogenic signaling

In recent years, extracellular vesicles (EVs) emerged as potential diagnostic and prognostic markers for cancer therapy. While the field of EV research is rapidly developing and their application as vehicles for therapeutic cargo is being tested, little is still known about the exact mechanisms of signaling specificity and cargo transfer by EVs, especially in vivo. Several signaling cascades have been found to use EVs for signaling in the tumor-stroma interaction. These include potentially oncogenic, verbatim transforming, signaling cascades such as Wnt and TGF-β signaling, and other signaling cascades that have been tightly associated with tumor progression and metastasis, such as PD-L1 and VEGF signaling. Multiple mechanisms of how these signaling cascades and EVs interplay to mediate these complex processes have been described, such as direct signal activation through pathway components on or in EVs or indirectly by influencing vesicle biogenesis, cargo sorting, or uptake dynamics. In this review, we summarize the current knowledge of EVs, their biogenesis, and our understanding of EV interactions with recipient cells with a focus on selected oncogenic and cancer-associated signaling pathways. After an in-depth look at how EVs mediate and influence signaling, we discuss potentially translatable EV functions and existing knowledge gaps.

Wnt/β-Catenin Signaling as a Driver of Hepatocellular Carcinoma Progression: An Emphasis on Molecular Pathways

Liver cancers cause a high rate of death worldwide and hepatocellular carcinoma (HCC) is considered as the most common primary liver cancer. HCC remains a challenging disease to treat. Wnt/β-catenin signaling pathway is considered a tumor-promoting factor in various cancers; hence, the present review focused on the role of Wnt signaling in HCC, and its association with progression and therapy response based on pre-clinical and clinical evidence. The nuclear translocation of β-catenin enhances expression level of genes such as c-Myc and MMPs in increasing cancer progression. The mutation of CTNNB1 gene encoding β-catenin and its overexpression can lead to HCC progression. β-catenin signaling enhances cancer stem cell features of HCC and promotes their growth rate. Furthermore, β-catenin prevents apoptosis in HCC cells and increases their migration via triggering EMT and upregulating MMP levels. It is suggested that β-catenin signaling participates in mediating drug resistance and immuno-resistance in HCC. Upstream mediators including ncRNAs can regulate β-catenin signaling in HCC. Anti-cancer agents inhibit β-catenin signaling and mediate its proteasomal degradation in HCC therapy. Furthermore, clinical studies have revealed the role of β-catenin and its gene mutation (CTNBB1) in HCC progression. Based on these subjects, future experiments can focus on developing novel therapeutics targeting Wnt/β-catenin signaling in HCC therapy.

The Wnt Signalling Pathway: A Tailored Target in Cancer

Cancer is one of the greatest public health challenges. According to the World Health Organization (WHO), 9.6 million cancer deaths have been reported in 2018. The most common cancers include lung, breast, colorectal, prostate, skin (non-melanoma) and stomach cancer. The unbalance of physiological signalling pathways due to the acquisition of mutations in tumour cells is considered the most common cancer driver. The Wingless-related integration site (Wnt)/β-catenin pathway is crucial for tissue development and homeostasis in all animal species and its dysregulation is one of the most relevant events linked to cancer development and dissemination. The canonical and the non-canonical Wnt/β-catenin pathways are known to control both physiological and pathological processes, including cancer. Herein, the impact of the Wnt/β-catenin cascade in driving cancers from different origin has been examined. Finally, based on the impact of Extracellular Vesicles (EVs) on tumour growth, invasion and chemoresistance, and their role as tumour diagnostic and prognostic tools, an overview of the current knowledge linking EVs to the Wnt/β-catenin pathway is also discussed.

Nature-derived compounds modulating Wnt/ -catenin pathway: a preventive and therapeutic opportunity in neoplastic diseases

The Wnt/β-catenin signaling is a conserved pathway that has a crucial role in embryonic and adult life. Dysregulation of the Wnt/β-catenin pathway has been associated with diseases including cancer, and components of the signaling have been proposed as innovative therapeutic targets, mainly for cancer therapy. The attention of the worldwide researchers paid to this issue is increasing, also in view of the therapeutic potential of these agents in diseases, such as Parkinson's disease (PD), for which no cure is existing today. Much evidence indicates that abnormal Wnt/β-catenin signaling is involved in tumor immunology and the targeting of Wnt/β-catenin pathway has been also proposed as an attractive strategy to potentiate cancer immunotherapy. During the last decade, several products, including naturally occurring dietary agents as well as a wide variety of products from plant sources, including curcumin, quercetin, berberin, and ginsenosides, have been identified as potent modulators of the Wnt/β-catenin signaling and have gained interest as promising candidates for the development of chemopreventive or therapeutic drugs for cancer. In this review we make an overview of the nature-derived compounds reported to have antitumor activity by modulating the Wnt/β-catenin signaling, also focusing on extraction methods, chemical features, and bio-activity assays used for the screening of these compounds.

Study and analysis of antitumor resistance mechanism of PD1/PD-L1 immune checkpoint blocker

Immunocheckpoint proteins of tumor infiltrating lymphocytes play an important role in tumor prognosis in the course of tumor clinicopathology. PD‐1 (Programmed cell death protein 1) is an important immunosuppressive molecule. By binding to PD‐L1 (programmed cell death‐ligand 1), it blocks TCR and its costimulus signal transduction, inhibits the activation and proliferation of T cells, depletes the function of effector T cells, and enables tumor cells to achieve immune escape. In recent years, immunocheckpoint blocking therapy targeting the PD‐1/PD‐L1 axis has achieved good results in a variety of malignant tumors, pushing tumor immunotherapy to a new milestone, such as anti‐PD‐1 monoclonal antibody Nivolumab, Pembrolizumab, and anti‐PD‐L1 monoclonal antibody Atezolizumab, which are considered as potential antitumor drugs. It was found in clinical use that some patients obtained long‐term efficacy, but most of them developed drug resistance recurrence in the later stage. The high incidence of drug resistance (including primary and acquired drug resistance) still cannot be ignored, which limited its clinical application and became a new problem in this field. Due to tumor heterogeneity, current limited research shows that PD‐1 or PD‐L1 monoclonal antibody drug resistance may be related to the following factors: mutation of tumor antigen and antigen presentation process, multiple immune checkpoint interactions, immune microenvironment changes dynamically, activation of oncogenic pathways, gene mutation and epigenetic changes of key proteins in tumors, tumor competitive metabolism, and accumulation of metabolites, etc, mechanisms of resistance are complex. Therefore, it is the most urgent task to further elucidate the mechanism of immune checkpoint inhibitor resistance, discover multitumor universal biomarkers, and develop new target agents to improve the response rate of immunotherapy in patients. In this study, the mechanism of anti‐PD‐1/PD‐L1 drug resistance in tumors, the potential biomarkers for predicting PD‐1 acquired resistance, and the recent development of combination therapy were reviewed one by one. It is believed that, based on the complex mechanism of drug resistance, it is of no clinical significance to simply search for and regulate drug resistance targets, and it may even produce drug resistance again soon. It is speculated that according to the possible tumor characteristics, three types of treatment methods should be combined to change the tumor microenvironment ecology and eliminate various heterogeneous tumor subsets, so as to reduce tumor drug resistance and improve long‐term clinical efficacy.

Heterogeneous responses in hepatocellular carcinoma: the achilles heel of immune checkpoint inhibitors

Treatment of patients with hepatocellular carcinoma (HCC) remains a serious challenge due to high heterogeneity and limited treatment options. In the past few decades, immune therapy, especially immune checkpoint therapy, has become an alternative option for the treatment of malignancies including HCC. Immune checkpoint inhibitors (ICIs) have raised attention because of their significant antitumor effect and low toxicity. However, such immunotherapy fails to be responsive in a major proportion of patients with HCC. Recent studies suggest that failures in antigen presentation, an impaired immune microenvironment, alterations in immune checkpoint molecules and immune-suppressive cells are responsible for the heterogeneous responses and resistance. Based on the specific characteristics above, we proposed a model stratifying patients with HCC into two subtypes that could predict response or resistance to ICI. Furthermore, supplementing ICIs with agents targeting the microenvironment could achieve an increased response rate, which is a step forward in precision treatment for HCC. In addition, emerging studies have revealed that liver transplantation, epigenetic drugs and other novel strategies also provide synergistic effects with ICIs in the treatment of HCC.

The Extracellular RNA Communication Consortium: Establishing Foundational Knowledge and Technologies for Extracellular RNA Research

The Extracellular RNA Communication Consortium (ERCC) was launched to accelerate progress in the new field of extracellular RNA (exRNA) biology and to establish whether exRNAs and their carriers, including extracellular vesicles (EVs), can mediate intercellular communication and be utilized for clinical applications. Phase 1 of the ERCC focused on exRNA/EV biogenesis and function, discovery of exRNA biomarkers, development of exRNA/EV-based therapeutics, and construction of a robust set of reference exRNA profiles for a variety of biofluids. Here, we present progress by ERCC investigators in these areas, and we discuss collaborative projects directed at development of robust methods for EV/exRNA isolation and analysis and tools for sharing and computational analysis of exRNA profiling data.

RNA Nanotechnology-Mediated Cancer Immunotherapy

RNA molecules (e.g., siRNA, microRNA, and mRNA) have shown tremendous potential for immunomodulation and cancer immunotherapy. They can activate both innate and adaptive immune system responses by silencing or upregulating immune-relevant genes. In addition, mRNA-based vaccines have recently been actively pursued and tested in cancer patients, as a form of treatment. Meanwhile, various nanomaterials have been developed to enhance RNA delivery to the tumor and immune cells. In this review article, we summarize recent advances in the development of RNA-based therapeutics and their applications in cancer immunotherapy. We also highlight the variety of nanoparticle platforms that have been used for RNA delivery to elicit anti-tumor immune responses. Finally, we provide our perspectives of potential challenges and opportunities of RNA-based nanotherapeutics in clinical translation towards cancer immunotherapy.

Emerging role of extracellular vesicles in liver diseases

Extracellular vesicles (EVs) are membrane-defined nanoparticles released by most cell types. The EVs released by cells may differ quantitatively and qualitatively from physiological states to disease states. There are several unique properties of EVs, including their proteins, lipids and nucleic acid cargoes, stability in circulation, and presence in biofluids, which make them a critical vector for cell-to-cell communication and impart utility as a biomarker. EVs may also serve as a vehicle for selective cargo secretion. Similarly, EV cargo may be selectively manipulated for targeted therapeutic delivery. In this review an overview is provided on the EV classification, biogenesis, and secretion pathways, which are conserved across cell types. Next, cargo characterization and effector cell responses are discussed in the context of nonalcoholic steatohepatitis, alcoholic hepatitis, and acetaminophen-induced liver injury. The review also discusses the potential biomarker and therapeutic uses of circulating EVs.

Optimizing Advances in Nanoparticle Delivery for Cancer Immunotherapy

Cancer immunotherapy is one of the fastest growing and most promising fields in clinical oncology. T-cell checkpoint inhibitors are revolutionizing the management of advanced cancers including non-small cell lung cancer and melanoma. Unfortunately, many common cancers are not responsive to these drugs and resistance remains problematic. A growing number of novel cancer immunotherapies have been discovered but their clinical translation has been limited by shortcomings of conventional drug delivery. Immune signaling is tightly-regulated and often requires simultaneous or near-simultaneous activation of multiple signals in specific subpopulations of immune cells. Nucleic acid therapies, which require intact intracellular delivery, are among the most promising approaches to modulate the tumor microenvironment to a pro-immunogenic phenotype. Advanced nanomedicines can be precisely engineered to overcome many of these limitations and appear well-poised to enable the clinical translation of promising cancer immunotherapies.