Tumors evade immune cytotoxicity by altering the surface topology of NK cells

Magnetic natural lipid nanoparticles for oral treatment of colorectal cancer through potentiated antitumor immunity and microbiota metabolite regulation

The therapeutic efficacy of oral nanotherapeutics against colorectal cancer (CRC) is restricted by inadequate drug accumulation, immunosuppressive microenvironment, and intestinal microbiota imbalance. To overcome these challenges, we elaborately constructed 6-gingerol (Gin)-loaded magnetic mesoporous silicon nanoparticles and functionalized their surface with mulberry leaf-extracted lipids (MLLs) and Pluronic F127 (P127). In vitro experiments revealed that P127 functionalization and alternating magnetic fields (AMFs) promoted internalization of the obtained P127-MLL@Gins by colorectal tumor cells and induced their apoptosis/ferroptosis through Gin/ferrous ion-induced oxidative stress and magneto-thermal effect. After oral administration, P127-MLL@Gins safely passed to the colorectal lumen, infiltrated the mucus barrier, and penetrated into the deep tumors under the influence of AMFs. Subsequently, the P127-MLL@Gin (+ AMF) treatment activated antitumor immunity and suppressed tumor growth. We also found that this therapeutic modality significantly increased the abundance of beneficial bacteria (e.g., Bacillus and unclassified-c-Bacilli), reduced the proportions of harmful bacteria (e.g., Bacteroides and Alloprevotella), and increased lipid oxidation metabolites. Strikingly, checkpoint blockers synergistically improved the therapeutic outcomes of P127-MLL@Gins (+ AMF) against orthotopic and distant colorectal tumors and significantly prolonged mouse life spans. Overall, this oral therapeutic platform is a promising modality for synergistic treatment of CRC.

Highlight of 2023: From fundamental studies to clinical trials, the importance of NK cells against cancer

In this article for the Highlights of 2023 Series, we discuss how various factors affect the ability of natural killer (NK) cells to fight tumors. For instance, tumor cells can hinder NK cell function by reducing surface protrusions or increasing HLA-E expression via platelets. Lower UTX protein levels in male NK cells also decrease their cytotoxicity compared with females. Fortunately, recent advancements in therapeutic approaches have emerged, including the development of a comprehensive atlas of NK cell heterogeneity within the tumor microenvironment, as well as a trispecific engager molecule that has shown promise in enhancing the anti-tumor functions of NK cells.

PZR suppresses innate immune response to RNA viral infection by inhibiting MAVS activation in interferon signaling mediated by RIG-I and MDA5

RNA viral infections seriously endanger human health. Src homology 2 (SH2) domain-containing protein tyrosine phosphatase 2 (SHP2) suppresses innate immunity against influenza A virus, and pharmacological inhibition of SHP2 provokes hepatic innate immunity. SHP2 binds and catalyzes tyrosyl dephosphorylation of protein zero-related (PZR), but the regulatory effect of PZR on innate immune response to viral infection is unclear. In this study, the transcription and protein level of PZR in host cells were found to be decreased with RNA viral infection, and high level of PZR was uncovered to inhibit interferon (IFN) signaling mediated by RIG-I and MDA5. Through localizing in mitochondria, PZR targeted and interacted with MAVS (also known as IPS-1/VISA/Cardif), suppressing the aggregation and activation of MAVS. Specifically, Y263 residue in ITIM is critical for PZR to exert immunosuppression under RNA viral infection. Moreover, the recruited SHP2 by PZR that modified with tyrosine phosphorylation under RNA viral infection might inhibit phosphorylation activation of MAVS. In conclusion, PZR and SHP2 suppress innate immune response to RNA viral infection through inhibiting MAVS activation. This study reveals the regulatory mechanism of PZR-SHP2-MAVS signal axis on IFN signaling mediated by RIG-I and MDA5, which may provide new sight for developing antiviral drugs.

Nanotechnology Reprogramming Metabolism for Enhanced Tumor Immunotherapy

Mutation burden, hypoxia, and immunoediting contribute to altered metabolic profiles in tumor cells, resulting in a tumor microenvironment (TME) characterized by accumulation of toxic metabolites and depletion of various nutrients, which significantly hinder the antitumor immunity via multiple mechanisms, hindering the efficacy of tumor immunotherapies. In-depth investigation of the mechanisms underlying these phenomena are vital for developing effective antitumor drugs and therapies, while the therapeutic effects of metabolism-targeting drugs are restricted by off-target toxicity toward effector immune cells and high dosage-mediated side effects. Nanotechnologies, which exhibit versatility and plasticity in targeted delivery and metabolism modulation, have been widely applied to boost tumor immunometabolic therapies via multiple strategies, including targeting of metabolic pathways. In this review, recent advances in understanding the roles of tumor cell metabolism in both immunoevasion and immunosuppression are reviewed, and nanotechnology-based metabolic reprogramming strategies for enhanced tumor immunotherapies are discussed.

Effector and cytolytic function of natural killer cells in anticancer immunity

Adaptive immune cells play an important role in mounting antigen-specific antitumor immunity. The contribution of innate immune cells such as monocytes, macrophages, natural killer (NK) cells, dendritic cells, and gamma-delta T cells is well studied in cancer immunology. NK cells are innate lymphoid cells that show effector and regulatory function in a contact-dependent and contact-independent manner. The cytotoxic function of NK cells plays an important role in killing the infected and transformed host cells and controlling infection and tumor growth. However, several studies have also ascribed the role of NK cells in inducing pathophysiology in autoimmune diseases, promoting immune tolerance in the uterus, and antitumor function in the tumor microenvironment. We discuss the fundamentals of NK cell biology, its distribution in different organs, cellular and molecular interactions, and its cytotoxic and noncytotoxic functions in cancer biology. We also highlight the use of NK cell-based adoptive cellular therapy in cancer.

Enhanced CT-based radiomics model to predict natural killer cell infiltration and clinical prognosis in non-small cell lung cancer

Background

Natural killer (NK) cells are crucial for tumor prognosis; however, their role in non-small-cell lung cancer (NSCLC) remains unclear. The current detection methods for NSCLC are inefficient and costly. Therefore, radiomics represent a promising alternative.

Methods

We analyzed the radiogenomics datasets to extract clinical, radiological, and transcriptome data. The effect of NK cells on the prognosis of NSCLC was assessed. Tumors were delineated using a 3D Slicer, and features were extracted using pyradiomics. A radiomics model was developed and validated using five-fold cross-validation. A nomogram model was constructed using the selected clinical variables and a radiomic score (RS). The CIBERSORTx database and gene set enrichment analysis were used to explore the correlations of NK cell infiltration and molecular mechanisms.

Results

Higher infiltration of NK cells was correlated with better overall survival (OS) (P = 0.002). The radiomic model showed an area under the curve of 0.731, with 0.726 post-validation. The RS differed significantly between high and low infiltration of NK cells (P < 0.01). The nomogram, using RS and clinical variables, effectively predicted 3-year OS. NK cell infiltration was correlated with the ICOS and BTLA genes (P < 0.001) and macrophage M0/M2 levels. The key pathways included TNF-α signaling via NF-κB and Wnt/β-catenin signaling.

Conclusions

Our radiomic model accurately predicted NK cell infiltration in NSCLC. Combined with clinical characteristics, it can predict the prognosis of patients with NSCLC. Bioinformatic analysis revealed the gene expression and pathways underlying NK cell infiltration in NSCLC.

NK cells as powerful therapeutic tool in cancer immunotherapy

BACKGROUND

Natural killer (NK) cells have gained considerable attention and hold great potential for their application in tumor immunotherapy. This is mainly due to their MHC-unrestricted and pan-specific recognition capabilities, as well as their ability to rapidly respond to and eliminate target cells. To artificially generate therapeutic NK cells, various materials can be utilized, such as peripheral blood mononuclear cells (PBMCs), umbilical cord blood (UCB), induced pluripotent stem cells (iPSCs), and NK cell lines. Exploiting the therapeutic potential of NK cells to treat tumors through in vivo and in vitro therapeutic modalities has yielded positive therapeutic results.

CONCLUSION

This review provides a comprehensive description of NK cell therapeutic approaches for tumors and discusses the current problems associated with these therapeutic approaches and the prospects of NK cell therapy for tumors.

Microfluidics Coupled Mass Spectrometry for Single Cell Multi-Omics

Population-level analysis masks significant heterogeneity between individual cells, making it difficult to accurately reflect the true intricacies of life activities. Microfluidics is a technique that can manipulate individual cells effectively and is commonly coupled with a variety of analytical methods for single-cell analysis. Single-cell omics provides abundant molecular information at the single-cell level, fundamentally revealing differences in cell types and biological states among cell individuals, leading to a deeper understanding of cellular phenotypes and life activities. Herein, this work summarizes the microfluidic chips designed for single-cell isolation, manipulation, trapping, screening, and sorting, including droplet microfluidic chips, microwell arrays, hydrodynamic microfluidic chips, and microchips with microvalves. This work further reviews the studies on single-cell proteomics, metabolomics, lipidomics, and multi-omics based on microfluidics and mass spectrometry. Finally, the challenges and future application of single-cell multi-omics are discussed.

Forks in the road for CAR T and CAR NK cell cancer therapies

The advent of chimeric antigen receptor (CAR) T cell therapy has resulted in unprecedented long-term clearance of relapse/refractory hematological malignancies in both pediatric and adult patients. However, severe toxicities, such as cytokine release syndrome and neurotoxicity, associated with CAR T cells affect therapeutic utility; and treatment efficacies for solid tumors are still not impressive. As a result, engineering strategies that modify other immune cell types, especially natural killer (NK) cells have arisen. Owing to both CAR-dependent and CAR-independent (innate immune-mediated) antitumor killing capacity, major histocompatibility complex-independent cytotoxicity, reduced risk of alloreactivity and lack of major CAR T cell toxicities, CAR NK cells constitute one of the promising next-generation CAR immune cells that are also amenable as 'off-the-shelf' therapeutics. In this Review, we compare CAR T and CAR NK cell therapies, with particular focus on immunological synapses, engineering strategies and challenges.

Killer instincts: natural killer cells as multifactorial cancer immunotherapy

Natural killer (NK) cells integrate heterogeneous signals for activation and inhibition using germline-encoded receptors. These receptors are stochastically co-expressed, and their concurrent engagement and signaling can adjust the sensitivity of individual cells to putative targets. Against cancers, which mutate and evolve under therapeutic and immunologic pressure, the diversity for recognition provided by NK cells may be key to comprehensive cancer control. NK cells are already being trialled as adoptive cell therapy and targets for immunotherapeutic agents. However, strategies to leverage their naturally occurring diversity and agility have not yet been developed. In this review, we discuss the receptors and signaling pathways through which signals for activation or inhibition are generated in NK cells, focusing on their roles in cancer and potential as targets for immunotherapies. Finally, we consider the impacts of receptor co-expression and the potential to engage multiple pathways of NK cell reactivity to maximize the scope and strength of antitumor activities.

N6-Methyladenosine-Modified LEAWBIH Drives Hepatocellular Carcinoma Progression through Epigenetically Activating Wnt/β-Catenin Signaling

Purpose

N6-methyladenosine (m6A) modification plays an important role in regulating RNA maturation, stability, and translation. Thus, m6A modification is involved in various pathophysiological processes including hepatocellular carcinoma (HCC). However, the direct contribution of m6A modifications to RNA function in HCC remains unclear. Here, we identified LEAWBIH (long non-coding RNA epigenetically activating Wnt/β-catenin signalling in HCC) as an m6A-modified long non-coding RNA (lncRNA) and investigated the effects of m6A on the function of LEAWBIH in HCC.

Methods

Quantitative polymerase chain reaction was performed to measure the gene expression in tissues and cells. The level of m6A modification was detected using a methylated RNA immunoprecipitation assay and single-base elongation- and ligation-based qPCR amplification method. Cell proliferation was evaluated using the Glo cell viability and CCK-8 assays. Cell migration and invasion were evaluated using Transwell migration and invasion assays. The mechanisms of m6A modified LEAWBIH were investigated using chromatin isolation by RNA purification, chromatin immunoprecipitation, and dual-luciferase reporter assays.

Results

LEAWBIH was highly expressed and correlated with poor survival in HCC patients. LEAWBIH was identified as a m6A-modified transcript. m6A modification increased LEAWBIH transcript stability. The m6A modification level of LEAWBIH was increased in HCC, and a high m6A modification level of LEAWBIH predicted poor survival. LEAWBIH promotes HCC cell proliferation, migration, and invasion in an m6A modification-dependent manner. Mechanistic investigations revealed that m6A-modified LEAWBIH activated Wnt/β-catenin signaling. m6A-modified LEAWBIH binds to the m6A reader YTHDC1, which further interacts with and recruits H3K9me2 demethylase KDM3B to CTNNB1 promoter, leading to H3K9me2 demethylation and CTNNB1 transcription activation. Functional rescue assays showed that blocking Wnt/β-catenin signaling abolished the role of LEAWBIH in HCC.

Conclusion

m6A-modified LEAWBIH exerts oncogenic effects in HCC by epigenetically activating Wnt/β-catenin signaling, highlighting m6A-modified LEAWBIH as a promising therapeutic target for HCC.

m6A modification of AC026356.1 facilitates hepatocellular carcinoma progression by regulating the IGF2BP1-IL11 axis

N6-methyladenosine (m6A) is the most common RNA modification in eukaryotic RNAs. Although the important roles of m6A in RNA fate have been revealed, the potential contribution of m6A to RNA function in various diseases, including hepatocellular carcinoma (HCC), is still unclear. In this study, we identified a novel m6A-modified RNA AC026356.1. We found that AC026356.1 was increased in HCC tissues and cell lines. High expression of AC026356.1 was correlated with poor survival of HCC patients. m6A modification level of AC026356.1 was also increased in HCC and more significantly correlated with poor survival of HCC patients. Functional assays showed that m6A-modified AC026356.1 promoted HCC cellular proliferation, migration, and liver metastasis. Gene set enrichment analysis showed that AC026356.1 activated IL11/STAT3 signaling. Mechanistic investigation showed that m6A-modified AC026356.1 bound to IGF2BP1. The interaction between m6A-modified AC026356.1 and IGF2BP1 promoted the binding of IL11 mRNA to IGF2BP1, leading to increased IL11 mRNA stability and IL11 secretion. Functional rescue assays showed that depletion of IL11 reversed the oncogenic roles of AC026356.1. These findings revealed the potential influences of m6A modification on RNA biological functions and suggested that targeting m6A modification may be a novel strategy for HCC treatment.

NK cell exhaustion in the tumor microenvironment

Natural killer (NK) cells kill mutant cells through death receptors and cytotoxic granules, playing an essential role in controlling cancer progression. However, in the tumor microenvironment (TME), NK cells frequently exhibit an exhausted status, which impairs their immunosurveillance function and contributes to tumor immune evasion. Emerging studies are ongoing to reveal the properties and mechanisms of NK cell exhaustion in the TME. In this review, we will briefly introduce the maturation, localization, homeostasis, and cytotoxicity of NK cells. We will then summarize the current understanding of the main mechanisms underlying NK cell exhaustion in the TME in four aspects: dysregulation of inhibitory and activating signaling, tumor cell-derived factors, immunosuppressive cells, and metabolism and exhaustion. We will also discuss the therapeutic approaches currently being developed to reverse NK cell exhaustion and enhance NK cell cytotoxicity in the TME.

Identification and validation of a novel NK cells-related signature to predict prognosis and immune microenvironment in LUAD

BACKGROUND

The prevalence and fatality rates of lung cancer are experiencing a rapid escalation. Natural Killer (NK) cells have been established to have a crucial role in both tumor initiation and progression. Nevertheless, uncertainties persist regarding their precise implications in the prognosis of LUAD.

METHODS

The data were obtained from reputable sources, such as the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) database, and our internally generated sequencing data. Utilizing the TCGA data as a background, we selected intersecting genes, validated by cluster analysis, to establish a Cox model and validated it using the GEO datasets. Furthermore, we conducted extensive analyses to investigate the significance of potential biomarkers in relation to immune cell infiltration, single-cell data, differential gene expression, and drug sensitivity.

RESULTS

67 immune-related genes associated with NK cells (NK-IRGs) were identified in the TCGA datasets, whose research potential was demonstrated by cluster analysis. A prognostic signature was identified utilizing the univariate and multivariate Cox model, resulting in the identification of five genes, which was validated using GEO datasets. Additionally, the nomogram's calibration curve demonstrated exceptional concordance between the projected and actual survival rates. Subsequent investigations uncovered that this prognostic signature demonstrated its independence as a risk factor. Notably, in the low-risk group, NK cells exhibited elevated levels of immune checkpoint molecules, indicating heightened sensitivity to immune therapy. These findings highlight the potential of utilizing this signature as a valuable tool in the selection of patients who could benefit from targeted immune interventions.

Social Determinants modulate NK cell activity via obesity, LDL, and DUSP1 signaling

Adverse social determinants of health (aSDoH) are associated with obesity and related comorbidities like diabetes, cardiovascular disease, and cancer. Obesity is also associated with natural killer cell (NK) dysregulation, suggesting a potential mechanistic link. Therefore, we measured NK phenotypes and function in a cohort of African-American (AA) women from resource-limited neighborhoods. Obesity was associated with reduced NK cytotoxicity and a shift towards a regulatory phenotype. In vitro, LDL promoted NK dysfunction, implicating hyperlipidemia as a mediator of obesity-related immune dysregulation. Dual specific phosphatase 1 (DUSP1) was induced by LDL and was upregulated in NK cells from subjects with obesity, implicating DUSP1 in obesity-mediated NK dysfunction. In vitro, DUSP1 repressed LAMP1/CD107a, depleting NK cells of functional lysosomes to prevent degranulation and cytokine secretion. Together, these data provide novel mechanistic links between aSDoH, obesity, and immune dysregulation that could be leveraged to improve outcomes in marginalized populations.