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Liver cancer is a significant global health concern, prompting the search for innovative therapeutic solutions. Yadanziolide A (Y-A), a natural derivative of Brucea javanica, has emerged as a promising candidate for cancer treatment; however, its efficacy and underlying mechanisms in liver cancer remain incompletely understood. In this study, we conducted a comprehensive evaluation of Y-A’s effects on liver cancer cells using a range of in vitro assays and an orthotopic liver cancer mouse model. Our findings reveal that Y-A exerts dose-dependent cytotoxic effects on liver cancer cells, significantly inhibiting proliferation, migration, and invasion at concentrations ≥ 0.1 μM. Furthermore, Y-A induces apoptosis, as evidenced by increased apoptotic cell populations and apoptosome formation. In vivo studies confirm that Y-A inhibits tumor growth and reduces liver damage in mouse models. Mechanistically, Y-A targets the TNF-α/STAT3 pathway, inhibiting STAT3 and JAK2 phosphorylation, thereby activating apoptotic pathways and suppressing tumor cell growth. These results suggest that Y-A has promising anticancer activity and potential utility in liver cancer therapy.

Type I interferons (IFN-Is) have key roles in immune defense and treatments for various diseases, including chronic hepatitis B virus (HBV) infection. All IFN-Is signal through a shared IFN-I heterodimeric receptor complex comprising IFN-α receptor 1 (IFNAR1) and IFNAR2 subunits, but differences in antiviral and immunomodulatory responses among IFN-I subtypes remain largely unknown. Because the IFN-IFNAR interactions are species-specific, mice exhibit weak responses to human IFN-I. To more fully characterize the actions of human IFN-α and its subtypes , a gene targeting strategy was employed to generate gene knock-in mice with extracellular-humanized IFNAR1/2 (IFNAR-hEC) in the C57BL/6N strain. IFNAR-hEC mice actively responded to human IFN-I, and endogenous mouse IFN-I signalling remained active in heterozygous mice ( ). Analyses of IFNAR-hEC mice and isolated cells showed that human IFN-α2 and α14 subtypes exerted differential effect on the activation of JAK-STAT signalling and immune responses. Compared with IFN-α2, IFN-α14 induced greater activation of STAT1/2 and IFN-stimulated genes, synergistically elicited IFN-α and -γ signalling, and induced higher numbers of antigen-specific CD8 T cells. Moreover, IFNAR-hEC mice with HBV replication displayed long-term viral suppression upon treatment with the clinically-used PEGylated hIFN-α2. These results indicate that IFNAR-hEC mice may be useful for elucidating antiviral and immunomodulatory functions of human IFN-Is and for conducting preclinical studies. A better understanding of the distinct activities of IFN-α subtypes can provide insights concerning the development of improved IFN-based therapy.

In recent years, it has become clear that members of the signal transducer and activator of transcription (STAT) family of genes play an important role in cancer. The STAT family consists of seven genes, STAT1‐4, STAT5A, STAT5B and STAT6, that are involved in regulating cellular proliferation, apoptosis, angiogenesis and the immune system response. Constitutive activation of STAT3, via mutational changes, is important in oncogenesis in both solid and hematopoietic cancers. In the case of hematopoietic neoplasms, STAT3 driver mutations have been described in T‐cell large granular lymphocytic (T‐LGL) leukemia and chronic natural killer lymphoproliferative disorders (CLPD‐NK) and are seen in 30%‐40% of T‐LGL leukemia patients. STAT5B is also mutated in T‐LGL leukemia and CLPD‐NK, but in a much smaller proportion. Here we review past and current research on STAT genes in hematopoietic and solid cancers with emphasis on STAT3 and STAT5B and their roles in the pathogenesis of hematopoietic malignancies, particularly T‐LGL leukemia and CLPD‐NK. Mutations in the STAT family of genes are seen in solid tumors and hematopoietic neoplasms. Here we review the STAT genes and their roles in the pathogenesis of these cancers with emphasis on hematopoietic entities.

Natural killer (NK) cells were so named for their uniqueness in killing certain tumor and virus-infected cells without prior sensitization. Their functions are modulated in vivo by several soluble immune mediators; interleukin-15 (IL-15) being the most potent among them in enabling NK cell homeostasis, maturation, and activation. During microbial infections, NK cells stimulated with IL-15 display enhanced cytokine responses. This priming effect has previously been shown with respect to increased IFN-γ production in NK cells upon IL-12 and IL-15/IL-2 co-stimulation. In this study, we explored if this effect of IL-15 priming can be extended to various other cytokines and observed enhanced NK cell responses to stimulation with IL-4, IL-21, IFN-α, and IL-2 in addition to IL-12. Notably, we also observed elevated IFN-γ production in primed NK cells upon stimulation through the Ly49H activation receptor. Currently, the fundamental processes required for priming and whether these signaling pathways work collaboratively or independently for NK cell functions are poorly understood. To identify the key signaling events for NK cell priming, we examined IL-15 effects on NK cells in which the pathways emanating from IL-15 receptor activation were blocked with specific inhibitors. Our results demonstrate that the PI3K-AKT-mTOR pathway is critical for cytokine responses in IL-15 primed NK cells. Furthermore, this pathway is also implicated in a broad range of IL-15-induced NK cell effector functions such as proliferation and cytotoxicity. Likewise, NK cells from mice treated with rapamycin to block the mTOR pathway displayed defects in proliferation, and IFN-γ and granzyme B productions resulting in elevated viral burdens upon murine cytomegalovirus infection. Taken together, our data demonstrate the requirement of PI3K-mTOR pathway for enhanced NK cell functions by IL-15, thereby coupling the metabolic sensor mTOR to NK cell anti-viral responses.

Cerebral hypoxia or ischemia results in cell death and cerebral edema, as well as other cellular reactions such as angiogenesis and the reestablishment of functional microvasculature to promote recovery from brain injury. Vascular endothelial growth factor is expressed in the central nervous system after hypoxic/ischemic brain injury, and is involved in the process of brain repair via the regulation of angiogenesis, neurogenesis, neurite outgrowth, and cerebral edema, which all require vascular endothelial growth factor signaling. In this review, we focus on the role of the vascular endothelial growth factor signaling pathway in the response to hypoxic/ischemic brain injury, and discuss potential therapeutic interventions.

Background Immune checkpoint inhibitors targeting the programmed cell death‐1 (PD‐1)/PD‐1 ligand 1 (PD‐L1) axis have shown promising results in patients with nonsmall cell lung cancer (NSCLC). One major PD‐L1 inducer is IFNγ, which is secreted by T cells and NK cells. Importantly, IFNγ‐induced PD‐L1 is one of the major mechanisms by which cancer cells escape host immunity. Methods Here, we found that the NSCLC cell line, LC‐2/ad, has a unique character; the PD‐L1 expression in these cells is up‐regulated by both IFNγ and epidermal growth factor (EGF). Results Comparative analysis of the cell signaling pathway showed that IFNγ activates STAT1 signaling, while EGF activates AKT, MAPK, and ribosomal protein S6 kinase in LC‐2/ad cells. IFNγ‐induced PD‐L1, but not EGF‐induced PD‐L1, was clearly blocked by the JAK‐STAT inhibitor tofacitinib. Interestingly, IFNγ decreased the expression of NK cell‐activating ligands while increasing the expression of MHC class I molecules, resulting in a phenotype that can easily escape from NK cells, theoretically. Finally, we showed that IFNγ stimuli attenuated NK cell‐mediated cytotoxicity in LC‐2/ad cells, which was, however, blocked by tofacitinib. Conclusions Taken together, our study shows that tofacitinib blocks the IFNγ‐induced transformation from an NK cell‐sensitive phenotype to an NK cell‐resistant one in IFNγ‐reacted LC‐2/ad cells, thereby implicating that tofacitinib may be a promising agent to overcome IFNγ‐induced tumor immune escape, although it may be adapted to the limited number of NSCLC patients. The JAK‐STAT inhibitor tofacitinib blocks the IFNγ‐induced transformation from an NK cell‐sensitive phenotype to an NK cell‐resistant one in IFNγ‐reacted LC‐2/ad cells, thereby implicating that tofacitinib may be a promising agent to overcome IFNγ‐induced tumor immune escape, although it could be adapted to the limited number of NSCLC patients.

The long non‐coding RNA GAS5 has been reported as a tumor suppressor in many cancers. However, its functions and mechanisms remain largely unknown in esophageal squamous cell carcinoma (ESCC). In this study, we found that GAS5 was over‐expressed in ESCC tissue compared with that in normal esophageal tissue in a public database. Functional studies showed that GAS5 could inhibit ESCC cell proliferation, migration and invasion in vitro. Further analysis revealed that GAS5 was regulated by interferon (IFN) responses via the JAK‐STAT pathway. Moreover, as an IFN‐stimulated gene (ISG), GAS5 was a positive regulator of IFN responses. The feedback loop between GAS5 and the IFN signaling pathway plays an important antitumor role in ESCC, thus providing novel potential therapeutic targets. In this study, we found that long non‐coding RNA GAS5 was transcription activated by interferons via JAK‐STAT pathway, and could inhibit cancer cell proliferation, migration, and invasion in esophageal squamous cell carcinoma (ESCC). What's more, GAS5 was a positive regulator of interferon responses. The feedback loop between GAS5 and the IFN signaling pathway plays an important antitumor role in ESCC, thus providing novel potential therapeutic targets.

Background Guillain‒Barré syndrome (GBS) is an immune‐mediated peripheral neuropathy in which inflammatory cells and cytokines participate. The JAK‐STAT signaling pathway is a major pathway involved in cytokine signal transduction, but the role of this pathway in GBS is not clear. AG490 is a tyrosine kinase inhibitor that specifically inhibits JAK2 activity and downregulates STAT3 phosphorylation. The aim of this study was to investigate the function of the JAK2/STAT3 pathway in a rat model of experimental autoimmune neuritis (EAN). Methods Lewis rats were divided into three groups: the control, the EAN, and the AG490 groups. The EAN and AG490 groups were immunized with P2 peptide to create the EAN models, while the control group received an equal volume of vehicle solution without P2 peptide. Starting from Day 5 post‐immunization (PI), the AG490 group was administered AG490 (10 mg/kg) every other day, while the control and EAN groups received an equal volume of vehicle solution without AG490. All rats were weighed and evaluated according to the EAN function score (1–10) by two investigators. Rats were sacrificed on Day 16 PI, and the sciatic nerves were examined by light microscopy, indirect immunohistochemistry, and western blotting. Results AG490‐treated rats had improved clinical scores compared with those of EAN rats. Hematoxylin and eosin (H&E) and CD45 staining showed significant inflammatory infiltration of the sciatic nerve in the EAN group compared with the control group, and demonstrated reduced inflammatory infiltration in the AG490 group. Luxol fast blue (LFB) staining showed a reduction of myelin loss in the AG490 group compared with the EAN group. The levels of TGF‐β1, IFN‐γ, and IL‐6 increased in the EAN group and showed a significant decrease in rats treated with AG490. The JAK2‐STAT3 signaling pathway was activated in EAN rats, and the AG490 group showed decreased expression levels of JAK2, p‐JAK2, and p‐STAT3 compared with those of the EAN group. Immunofluorescence also showed a decrease in the levels of p‐JAK2 and p‐STAT3 in the sciatic nerve of EAN rats. Conclusions The JAK2/STAT3 signaling pathway is involved in the pathogenesis of EAN, and inhibition of this pathway can reduce the inflammatory response in EAN rats. Despite the limitations in extrapolating EAN findings to human GBS, this study provided new insights into the pathogenesis and potential therapeutic targets of human GBS. We developed the EAN model in Lewis rat, and investigated the effect of the JAK2/STAT3 pathway inhibitor AG490 on EAN. AG490 reduced the inflammatory infiltration and mitigated demyelination damage in EAN rats through the inhibition of JAK2/STAT3 signaling pathway.

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm classified according to the 2016 revision of World Health Organization Classification of Tumors and Haematopoietic and Lymphoid Tissue. Ruxolitinib is an oral inhibitor of Janus kinase approved in the USA for the treatment of intermediate or high-risk PMF and approved in Europe for the treatment of splenomegaly and constitutional symptoms of the disease. More recently, case reports described serious opportunistic infections in this neoplasm treated with ruxolitinib. Research studies demonstrated the immunological derangement of this compound mainly based on T, dendritic, and natural killer cell defects. The purpose of this review of the literature was to analyze the relationship among ruxolitinib, immune system and bacterial, viral, fungal, and protozoan infections. A literature search was conducted using PubMed articles published between January 2010 and November 2016. The efficacy of drug in patients with PMF was demonstrated in two phase III studies, Controlled MyeloFibrosis Study with ORal Jak inhibitor Treatment (COMFORT-I and COMFORT-II). Grade 3 and 4 neutropenia were recognized in 7.1% and 2% of patients in the ruxolitinib and placebo arm of COMFORT-I. Grade 3 or 4 neutropenia or leukopenia were observed in 8.9% and 6.3% of ruxolitinib treated patients of 5-year follow-up of COMFORT-II. In addition, leukocyte subpopulations, lymphocyte functions, or antibody deficiency were not documented in either of the studies. The complex interactions between ruxolitinib, bone marrow, immune system, and infections in PMF need further investigation, robust data from a randomized clinical trial, registry, or large case-series.

Accumulating data on cellular and molecular pathways help to develop novel therapeutic strategies in skin inflammation and autoimmunity. Examples are psoriasis and atopic dermatitis, two clinically and immunologically well-defined disorders. Here, the elucidation of key pathogenic factors such as IL-17A/IL-23 on the one hand and IL-4/IL-13 on the other hand profoundly changed our therapeutic practice. The knowledge on intracellular pathways and governing factors is shifting our attention to new druggable molecules. Multiple cytokine receptors signal through Janus kinases (JAKs) and associated signal transducer and activators of transcription (STATs). Inhibition of JAKs can simultaneously block the function of multiple cytokines. Therefore, JAK inhibitors (JAKi) are emerging as a new class of drugs, which in dermatology can either be used systemically as oral drugs or locally in topical formulations. Inhibition of JAKs has been shown to be effective in various skin disorders. The first oral JAKi have been recently approved for the treatment of rheumatoid arthritis and psoriatic arthritis. Currently, multiple inhibitors of the JAK/STAT pathway are being investigated for skin diseases like alopecia areata, atopic dermatitis, dermatomyositis, graft-versus-host-disease, hidradenitis suppurativa, lichen planus, lupus erythematosus, psoriasis, and vitiligo. Here, we aim to discuss the immunological basis and current stage of development of JAKi in dermatology.