Natural killer cell therapy: A new frontier for obesity-associated cancer

Decrease in UCP1 by sustained high lipid promotes NK cell necroptosis to exacerbate nonalcoholic liver fibrosis

Uncoupling protein 1 (UCP1) catalyzes the leak of protons across the mitochondrial inner membrane for thermogenesis. Compromised NK cell activity is involved in the occurrence of nonalcoholic liver fibrosis. Here, decreased UCP1 in NK cells was identified in patients with advanced nonalcoholic fatty liver disease. Although no obvious changes were observed in the NK cells of physiologic UCP1-/- mice (8-10 weeks old), impaired NK cell bioactivity was shown in methionine-choline-diet (MCD)-fed UCP1-/- mice and involved in the acerbation of nonalcoholic steatohepatitis (NASH) progress to liver fibrosis. Moreover, UCP1-deficient NK cells were responsible for the aggravation of liver fibrosis, as confirmed in MCD-fed UCP1flox/flox-NCR1cre mice. Acerbation of liver fibrosis was also seen in wild-type mice when their endogenous NK cells were replaced with UCP1-/- NK cells. Transcriptions of mitophagy-associated molecules in UCP1-/- NK cells were enhanced according to RNA-seq. Electron microscopic results showed mitochondrial injuries and autophagic vesicles in MCD-fed NKWT cells, PA-treated NKWT cells, or physiologic NKKO cells. However, the co-existence of UCP1 deficiency and high lipid can synergistically induce NK cell necroptosis via DRP1S616 accompanied with reduced mitophagy. Finally, The UCP1 in NK cells was downregulated when treated by sustained high PA (600 μM) via the PPARγ/ATF2 axis. Thus, persistent high-lipid treatment not only decreases UCP1 expression but also combines with reduced UCP1 to promote NK cell necroptosis, and it is involved in NASH progression to fibrosis.

Immunotherapy of gastric cancer: Present status and future perspectives

In this editorial, we comment on the article entitled "Advances and key focus areas in gastric cancer immunotherapy: A comprehensive scientometric and clinical trial review (1999-2023)," which was published in the recent issue of the World Journal of Gastroenterology. We focused on the results of the authors' bibliometric analysis concerning gastric cancer immunotherapy, which they analyzed in depth by compiling the relevant publications of the last 20 years. Before that, we briefly describe the most recent data concerning the epidemiological parameters of gastric cancer (GC) in different countries, attempting to give an interpretation based on the etiological factors involved in the etiopathogenesis of the neoplasm. We then briefly discuss the conservative treatment (chemotherapy) of the various forms of this malignant neoplasm. We describe the treatment of resectable tumors, locally advanced neoplasms, and unresectable (advanced) cases. Special attention is given to modern therapeutic approaches with emphasis on immunotherapy, which seems to be the future of GC treatment, especially in combination with chemotherapy. There is also a thorough analysis of the results of the study under review in terms of the number of scientific publications, the countries in which the studies were conducted, the authors, and the scientific centers of origin, as well as the clinical studies in progress. Finally, an attempt is made to draw some con-clusions and to point out possible future directions.

Real-time ex vivo monitoring of NK cell migration toward obesity-associated oesophageal adenocarcinoma following modulation of CX3CR1

Oesophagogastric adenocarcinomas (OAC) are poor prognosis, obesity-associated cancers which may benefit from natural killer (NK) cell-based immunotherapies. Cellular immunotherapies encounter two key challenges to their success in OAC, namely recruitment to extratumoural tissues such as the omentum at the expense of the tumour and an immunosuppressive tumour microenvironment (TME) which can hamper NK cell function. Herein, we examined approaches to overcome the detrimental impact of obesity on NK cells and NK cell-based immunotherapies. We have demonstrated that NK cells migrate preferentially to the chemotactic signals of OAC patient-derived omentum over tumour in an ex vivo model of immune cell migration. We have identified CX3CR1 modulation and/or tumour chemokine profile remodelling as approaches to skew NK cell migration towards tumour. We also report targetable immunosuppressive facets of the obese OAC TME which dampen NK cell function, in particular cytotoxic capabilities. These data provide insights into approaches to therapeutically overcome key challenges presented by obesity and will inform superior design of NK cell-based immunotherapies for OAC.

FABP4 in macrophages facilitates obesity-associated pancreatic cancer progression via the NLRP3/IL-1β axis

Obesity is an essential risk factor for pancreatic cancer (PC). Macrophage-induced inflammation plays a pivotal role in obesity-associated carcinogenesis and disease progression; however, the underlying molecular mechanisms remain unclear. In this study, we found that fatty acid-binding protein 4 (FABP4) overexpressed in serum of obese patients and was associated with poor overall survival. In vivo and in vitro experiments have revealed that FABP4 induces macrophage-related inflammation to promote cancer cell migration, invasion and metastasis under obese conditions. Mechanistically, FABP4 participates in transferring saturated fatty acid to induce macrophages pyroptosis in a caspase-1/GSDMD-dependent manner and mediates NOD-like receptor thermal protein domain associated protein 3 (NLRP3)/IL-1β axis in macrophages, which further regulates epithelial-mesenchymal transition signals to promote the migration, invasion, and metastasis of PC cells. Our results suggest that FABP4 in macrophages is a crucial regulator of the NLRP3/IL-1β axis to promote the progression of PC under obese conditions, which could act as a promising molecular target for treating of PC patients with obesity.

Pleckstrin-2 promotes tumour immune escape from NK cells by activating the MT1-MMP-MICA signalling axis in gastric cancer

Immune escape is a major challenge in tumour immunotherapy. Pleckstrin-2(PLEK2) plays a critical role in tumour progression, but its role in immune escape in gastric cancer (GC) remains uncharacterized. RNA sequencing was used to explore the differentially expressed genes in a GC cell line that was resistant to the antitumor effect of Natural killer (NK) cells. Apoptosis and the expression of IFN-γ and TNF-α were detected by flow cytometry (FCM). PLEK2 expression was examined by Western blotting and immunohistochemistry (IHC). PLEK2 was upregulated in MGC803R cells that were resistant to the antitumor effect of NK cells. PLEK2 knockout increased the sensitivity of GC cells to NK cell killing. PLEK2 expression was negatively correlated with MICA and positively correlated with MT1-MMP expression both in vitro and in vivo. PLEK2 promoted Sp1 phosphorylation through the PI3K-AKT pathway, thereby upregulating MT1-MMP expression, which ultimately led to MICA shedding. In mouse xenograft models, PLEK2 knockout inhibited intraperitoneal metastasis of GC cells and promoted NK cell infiltration. In summary, PLEK2 suppressed NK cell immune surveillance by promoting MICA shedding, which serves as a potential therapeutic target for GC.

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.

Proximity-inducing modalities: the past, present, and future

Living systems use proximity to regulate biochemical processes. Inspired by this phenomenon, bifunctional modalities that induce proximity have been developed to redirect cellular processes. An emerging example of this class is molecules that induce ubiquitin-dependent proteasomal degradation of a protein of interest, and their initial development sparked a flurry of discovery for other bifunctional modalities. Recent advances in this area include modalities that can change protein phosphorylation, glycosylation, and acetylation states, modulate gene expression, and recruit components of the immune system. In this review, we highlight bifunctional modalities that perform functions other than degradation and have great potential to revolutionize disease treatment, while also serving as important tools in basic research to explore new aspects of biology.

Bone marrow microenvironment: roles and therapeutic implications in obesity-associated cancer

Obesity is increasing globally and has been closely linked to the initiation and progression of multiple human cancers. These relationships, to a large degree, are mediated through obesity-driven disruption of physiological homeostasis characterized by local and systemic endocrinologic, inflammatory, and metabolic changes. Bone marrow microenvironment (BMME), which evolves during obesity, has been implicated in multiple types of cancer. Growing evidence shows that physiological dysfunction of BMME with altered cellular composition, stromal and immune cell function, and energy metabolism, as well as inflammation and hypoxia, in the context of obesity contributes to cancer initiation and progression. Nonetheless, the mechanisms underlying the obesity-BMME-cancer axis remain elusive. In this review, we discuss the recent advances in understanding the evolution of BMME during obesity, its contributions to cancer initiation and progression, and the implications for cancer therapy.

Obesity contributes to hepatocellular carcinoma development via immunosuppressive microenvironment remodeling

It is generally recognized that the initiation of obesity-related hepatocellular carcinoma (HCC) is closely associated with hepatic inflammation. However, the paradoxical role of inflammation in the initiation and progression of HCC is highlighted by the fact that the inflammatory HCC is accompanied by significant immune effector cells infiltration compared to non-inflammatory HCC and HCC with enhanced immune response exhibits better survival. Importantly, the cancer progression has been primarily attributed to the immunosuppression, which can also be induced by obesity. Furthermore, the increased risk of viral infection and thus viral-HCC in obese individuals supports the view that obesity contributes to HCC via immunosuppression. Here, we have reviewed the various mechanisms responsible for obesity-induced tumor immune microenvironment and immunosuppression in obesity-related HCC. We highlight that the obesity-induced immunosuppression originates from lipid disorder as well as metabolic reprogramming and propose potential therapeutic strategy for HCC based on the current success of immunotherapy.

Investigating the Effects of Olaparib on the Susceptibility of Glioblastoma Multiforme Tumour Cells to Natural Killer Cell-Mediated Responses

Glioblastoma multiforme (GBM) is the most common adult primary brain malignancy, with dismal survival rates of ~14.6 months. The current standard-of-care consists of surgical resection and chemoradiotherapy, however the treatment response is limited by factors such as tumour heterogeneity, treatment resistance, the blood-brain barrier, and immunosuppression. Several immunotherapies have undergone clinical development for GBM but demonstrated inadequate efficacy, yet future combinatorial approaches are likely to hold more promise. Olaparib is FDA-approved for BRCA-mutated advanced ovarian and breast cancer, and clinical studies have revealed its utility as a safe and efficacious radio- and chemo-sensitiser in GBM. The ability of Olaparib to enhance natural killer (NK) cell-mediated responses has been reported in prostate, breast, and lung cancer. This study examined its potential combination with NK cell therapies in GBM by firstly investigating the susceptibility of the GBM cell line T98G to NK cells and, secondly, examining whether Olaparib can sensitise T98G cells to NK cell-mediated responses. Here, we characterise the NK receptor ligand profile of T98G cells and demonstrate that Olaparib does not dampen T98G susceptibility to NK cells or elicit immunomodulatory effects on the function of NK cells. This study provides novel insights into the potential combination of Olaparib with NK cell therapies for GBM.

Research progress of ginseng in the treatment of gastrointestinal cancers

Cancer has become one of the major causes of human death. Several anticancer drugs are available; howeve their use and efficacy are limited by the toxic side effects and drug resistance caused by their continuous application. Many natural products have antitumor effects with low toxicity and fewer adverse effects. Moreover, they play an important role in enhancing the cytotoxicity of chemotherapeutic agents, reducing toxic side effects, and reversing chemoresistance. Consequently, natural drugs are being applied as potential therapeutic options in the field of antitumor treatment. As natural medicinal plants, some components of ginseng have been shown to have excellent efficacy and a good safety profile for cancer treatment. The pharmacological activities and possible mechanisms of action of ginseng have been identified. Its broad range of pharmacological activities includes antitumor, antibacterial, anti-inflammatory, antioxidant, anti-stress, anti-fibrotic, central nervous system modulating, cardioprotective, and immune-enhancing effects. Numerous studies have also shown that throuth multiple pathways, ginseng and its active ingredients exert antitumor effects on gastrointestinal (GI) tract tumors, such as esophageal, gastric, colorectal, liver, and pancreatic cancers. Herein, we introduced the main components of ginseng, including ginsenosides, polysaccharides, and sterols, etc., and reviewed the mechanism of action and research progress of ginseng in the treatment of various GI tumors. Futhermore, the pathways of action of the main components of ginseng are discussed in depth to promote the clinical development and application of ginseng in the field of anti-GI tumors.

Revolution of CAR Engineering For Next-Generation Immunotherapy In Solid Tumors

Chimeric antigen receptor (CAR)-T cells have enormous potentials for clinical therapies. The CAR-T therapy has been approved for treating hematological malignancies. However, their application is limited in solid tumors owing to antigen loss and mutation, physical barriers, and an immunosuppressive tumor microenvironment. To overcome the challenges of CAR-T, increasing efforts are put into developing CAR-T to expand its applied ranges. Varied receptors are utilized for recognizing tumor-associated antigens and relieving immunosuppression. Emerging co-stimulatory signaling is employed for CAR-T activation. Furthermore, other immune cells such as NK cells and macrophages have manifested potential for delivering CAR. Hence, we collected and summarized the last advancements of CAR engineering from three aspects, namely, the ectodomains, endogenous domains, and immune cells, aiming to inspire the design of next-generation adoptive immunotherapy for treating solid tumors.