Inflammatory cytokines IL-17 and TNF-α up-regulate PD-L1 expression in human prostate and colon cancer cells

Copper in cancer: From pathogenesis to therapy

One of the basic trace elements for the structure and metabolism of human tissue is copper. However, as a heavy metal, excessive intake or abnormal accumulation of copper in the body can cause inevitable damage to the organism because copper can result in direct injury to various cell components or disruption of the redox balance, eventually leading to cell death. Interestingly, a growing body of research reports that diverse cancers have raised serum and tumor copper levels. Tumor cells depend on more copper for their metabolism than normal cells, and a decrease in copper or copper overload can have a detrimental effect on tumor cells. New modalities for identifying and characterizing copper-dependent signals offer translational opportunities for tumor therapy, but their mechanisms remain unclear. Therefore, this article summarizes what we currently know about the correlation between copper and cancer and describes the characteristics of copper metabolism in tumor cells and the prospective application of copper-derived therapeutics.

HIF1α-dependent and independent pathways regulate the expression of PD-L1 in prostate cancer

PD-L1/PD-1 pathway is a major pathway exploited by human cancer types, which is a target for current immunotherapy. We investigated tumor microenvironmental factors involved in PD-L1 induction in prostate cancer (PC). We studied the expression of PD-L1 in a series of 66 PCs, in parallel with the expression of hypoxia- and acidity-related immunohistochemical markers (Hypoxia-inducible factor HIF1α, and lactate dehydrogenase LDHA) and tumor-infiltrating lymphocyte TIL density. Experiments with three PC cell lines, the 22Rv1, DU145, and PC3 were conducted focusing on the inducibility of PD-L1 by hypoxia, acidity, lymphocyte interactions, and radiation. In tissues, PD-L1 expression by cancer cells was directly related to PD-L1 expression by  TILs and macrophages (p < 0.05), and the overexpression of HIF1α and LDH5 (p < 0.05). TIL density was inversely related to ΗΙF1α (p = 0.02). Exposure of PC cell lines to hypoxia strongly induced PD-L1 and protein and mRNA levels, directly controlled by HIF1α function (p < 0.001). Irradiation with 20 Gy had no apparent effect on PD-L1 expression. Culturing PC cell lines with culture medium (CM) from PBMCs strongly induced PD-L1 at protein and mRNA levels, independently from HIF1α, which was also confirmed when cells were incubated with Interferon-γ (p < 0.001). It is concluded that the combination of anti-PD-L1/PD-1 immunotherapy with hypoxia/HIF-targeting may be important in the treatment of specific subgroups of PC patients.

Ginsenosides from Panax ginseng as Key Modulators of NF-κB Signaling Are Powerful Anti-Inflammatory and Anticancer Agents

Nuclear factor kappa B (NF-κB) signaling pathways progress inflammation and immune cell differentiation in the host immune response; however, the uncontrollable stimulation of NF-κB signaling is responsible for several inflammatory illnesses regardless of whether the conditions are acute or chronic. Innate immune cells, such as macrophages, microglia, and Kupffer cells, secrete pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1β, via the activation of NF-κB subunits, which may lead to the damage of normal cells, including neurons, cardiomyocytes, hepatocytes, and alveolar cells. This results in the occurrence of neurodegenerative disorders, cardiac infarction, or liver injury, which may eventually lead to systemic inflammation or cancer. Recently, ginsenosides from Panax ginseng, a historical herbal plant used in East Asia, have been used as possible options for curing inflammatory diseases. All of the ginsenosides tested target different steps of the NF-κB signaling pathway, ameliorating the symptoms of severe illnesses. Moreover, ginsenosides inhibit the NF-κB-mediated activation of cancer metastasis and immune resistance, significantly attenuating the expression of MMPs, Snail, Slug, TWIST1, and PD-L1. This review introduces current studies on the therapeutic efficacy of ginsenosides in alleviating NF-κB responses and emphasizes the critical role of ginsenosides in severe inflammatory diseases as well as cancers.

Role of regulation of PD-1 and PD-L1 expression in sepsis

Long term immunosuppression is problematic during sepsis. The PD-1 and PD-L1 immune checkpoint proteins have potent immunosuppressive functions. Recent studies have revealed several features of PD-1 and PD-L1 and their roles in sepsis. Here, we summarize the overall findings of PD-1 and PD-L1 by first reviewing the biological features of PD-1 and PD-L1 and then discussing the mechanisms that control the expression of PD-1 and PD-L1. We then review the functions of PD-1 and PD-L1 in physiological settings and further discuss PD-1 and PD-L1 in sepsis, including their involvement in several sepsis-related processes and their potential therapeutic relevance in sepsis. In general, PD-1 and PD-L1 have critical roles in sepsis, indicating that their regulation may be a potential therapeutic target for sepsis.

Emerging phagocytosis checkpoints in cancer immunotherapy

Cancer immunotherapy, mainly including immune checkpoints-targeted therapy and the adoptive transfer of engineered immune cells, has revolutionized the oncology landscape as it utilizes patients' own immune systems in combating the cancer cells. Cancer cells escape immune surveillance by hijacking the corresponding inhibitory pathways via overexpressing checkpoint genes. Phagocytosis checkpoints, such as CD47, CD24, MHC-I, PD-L1, STC-1 and GD2, have emerged as essential checkpoints for cancer immunotherapy by functioning as "don't eat me" signals or interacting with "eat me" signals to suppress immune responses. Phagocytosis checkpoints link innate immunity and adaptive immunity in cancer immunotherapy. Genetic ablation of these phagocytosis checkpoints, as well as blockade of their signaling pathways, robustly augments phagocytosis and reduces tumor size. Among all phagocytosis checkpoints, CD47 is the most thoroughly studied and has emerged as a rising star among targets for cancer treatment. CD47-targeting antibodies and inhibitors have been investigated in various preclinical and clinical trials. However, anemia and thrombocytopenia appear to be formidable challenges since CD47 is ubiquitously expressed on erythrocytes. Here, we review the reported phagocytosis checkpoints by discussing their mechanisms and functions in cancer immunotherapy, highlight clinical progress in targeting these checkpoints and discuss challenges and potential solutions to smooth the way for combination immunotherapeutic strategies that involve both innate and adaptive immune responses.

Blocking of programmed cell death-ligand 1 (PD-L1) expressed on endothelial cells promoted the recruitment of CD8+IFN-γ+ T cells in atherosclerosis

BACKGROUND

Programmed death ligand-1 (PD-L1) is involved in the negative regulation of immune responses in a variety of diseases. We evaluated the contribution of PD-L1 to the activation of immune cells that promote atherosclerotic lesion formation and inflammation.

METHODS AND RESULTS

Compared to ApoE^-/- mice that were provided a high-cholesterol diet in combination with anti-PD-L1 antibody developed a larger lipid burden with more abundant CD8⁺ T cells. The anti-PD-L1 antibody increased the abundance of CD3⁺PD-1⁺, CD8 + PD-1⁺,CD3⁺IFN-γ⁺ and CD8⁺IFN-γ⁺ T cell under high-cholesterol diet, as well as the serum tumor necrosis factor-α (TNF-a), IFN-γ, PF, GNLY, Gzms B and LTA. Interestingly, the anti-PD-L1 antibody increased the serum level of sPD-L1. In vitro, blocking of PD-L1 on the surface of mouse aortic endothelial cells with anti-PD-L1 antibody stimulated the activation and secretion of cytokines, including IFN-γ, PF, GNLY, Gzms B and LTA, from cytolytic CD8⁺IFN-γ⁺ T cell. However, the concentration of sPD-L1 was lower after treatment of the MAECs with anti-PD-L1 antibody.

CONCLUSIONS

Our findings highlighted that blocking of PD-L1 promoted up-regulation of CD8 + IFN-γ + T cell-mediated immune responses, leading to the secretion of inflammatory cytokine that exacerbated the atherosclerotic burden and promoted inflammation. However, further studies are needed to gain insight into whether PD-L1 activation could be a novel immunotherapy strategy for atherosclerosis.

Activation of the IL-17/TRAF6/NF-κB pathway is implicated in Aβ-induced neurotoxicity

BACKGROUND

Neuroinflammation plays a critical role in Amyloid-β (Aβ) pathophysiology. The cytokine, interleukin-17A (IL-17) is involved in the learning and memory process in the central nervous system and its level was reported to be increased in Alzheimer's disease (AD) brain, while the effect of IL-17 on the course of Aβ has not been well defined.

METHODS

Here, we used APP/PS1 mice to detect the IL-17 expression level. Primary hippocampal neurons were treated with IL-17, and immunofluorescence was used to investigate whether IL-17 induced neuron damage. At the same time, male C57BL/6 mice were injected with Aβ42 to mimic the Aβ model. Then IL-17 neutralizing antibody (IL-17Ab) was used to inject into the lateral ventricle, and the Open field test, Novel Objective Recognition test, Fear condition test were used to detect cognitive function. LTP was used to assess synaptic plasticity, molecular biology technology was used to assess the IL-17/TRAF6/NF-κB pathway, and ELISA was used to detect inflammatory factors.

RESULTS

Altogether, we here found that IL-17 was increased in APP/PS1 mice, and it induced neural damage by the administration to primary hippocampal neurons. Interestingly, Using Aβ42 mice, the results showed that the level of IL-17 was increased in Aβ42 model mice, and IL-17Ab could ameliorate Aβ-induced neurotoxicity and cognitive decline in C57BL/6 mice by downregulation the TRAF6/NF-κB pathway.

CONCLUSION

These findings highlight the pathogenic role of IL-17 in Aβ induced-synaptic dysfunction and cognitive deficits. Inhibition of IL-17 could ameliorate Aβ-induced neurotoxicity and cognitive decline in C57BL/6 mice by downregulation of the TRAF6/NF-κB pathway, which provides new clues for the mechanism of Aβ-induced cognitive impairments, and a basis for therapeutic intervention.

Regulation of programmed death ligand 1 expression by interferon-γ and tumour necrosis factor-α in canine tumour cell lines

Expression of programmed death ligand 1 (PD-L1) on tumour cells provides an immune evasion mechanism by inducing suppression of cytotoxic T cells. Various regulatory mechanisms of PD-L1 expression have been described in human tumours, however, little is known in canine tumours. To investigate whether inflammatory signalling is involved in PD-L1 regulation in canine tumours, the effects of interferon (IFN)-γ and tumour necrosis factor (TNF)-α treatment were examined in canine malignant melanoma cell lines (CMeC and LMeC) and an osteosarcoma cell line (HMPOS). The protein level of PD-L1 expression was upregulated by IFN-γ and TNF-α stimulation. Upon IFN-γ stimulation, all cell lines showed an increase in expression of PD-L1, signal transducer and activator of transcription (STAT)1, STAT3 and genes regulated by STAT activation. Upregulated expression of these genes was suppressed by the addition of a JAK inhibitor, oclacitinib. Contrastingly, upon TNF-α stimulation, all cell lines exhibited higher gene expression of the nuclear factor kappa B (NF-κB) gene RELA and genes regulated by NF-κB activation, whereas expression of PD-L1 was upregulated in LMeC only. Upregulated expression of these genes was suppressed by the addition of an NF-κB inhibitor, BAY 11-7082. The expression level of cell surface PD-L1 induced by IFN-γ and TNF-α treatment was reduced by oclacitinib and BAY 11-7082, respectively, indicating that upregulation of PD-L1 expression by IFN-γ and TNF-α stimulation is regulated via the JAK-STAT and NF-κB signalling pathways, respectively. These results provide insights into the role of inflammatory signalling in PD-L1 regulation in canine tumours.

Targeted inhibition of RBPJ transcription complex alleviates the exhaustion of CD8+ T cells in hepatocellular carcinoma

Impaired function of CD8+ T cells in hepatocellular carcinoma (HCC) is an important reason for acquired resistance. Compared with single-target inhibitors, small-molecule compounds that could both inhibit tumor cells and alleviate T cell exhaustion are more promising to reduce resistance. In this study, we screened immunosuppressive targets in HCC by combining cancer-immunity cycle score with weighted gene co-expression network and system analysis. Through in vitro and in vivo validation experiments, we found that one of the screened molecules, recombination signal binding protein for immunoglobulin kappa J region (RBPJ), was negatively correlated with CD8+ T cell mediated killing function. More importantly, its transcription complex inhibitor RIN1 not only inhibited the malignant biological behaviors of HCC cells by inhibiting mTOR pathway, but also reduced the expression of PD-L1 and L-kynurenine synthesis in HCC cells, thus alleviating T cell exhaustion. Meanwhile, the combination of RIN1 and anti-PD-1/PD-L1 antibodies could further activate CD8+ T cells. In short, RBPJ is an important factor regulating the function of T cells. Target inhibition of RBPJ transcription complex by small molecule compound may be a new strategy for immunotherapy of HCC.

Diesel exhaust particle exposure accelerates oxidative DNA damage and cytotoxicity in normal human bronchial epithelial cells through PD-L1

Diesel exhaust particles (DEPs) are a major cause of cancer progression as well as a variety of acute and chronic diseases. It is well-known that programmed death-ligand 1 (PD-L1) is an immune checkpoint molecule that can induce immune escape in tumor cells. However, the function of PD-L1 in bronchial epithelial cells or how PD-L1 relates to cellular oxidation under DEPs-mediated oxidative stress is not well known. In this study, we investigated how PD-L1 affected DEPs-induced oxidative stress and cytotoxicity in human bronchial epithelial (HBE) cells, Beas-2B. DEPs not only induced intracellular reactive oxygen species (ROS) production, but also increased PD-L1 expression in HBE cells. Beas-2B cells overexpressing PD-L1 showed higher levels of ROS production, DNA damage, and apoptosis after DEPs treatment compared to control cells. In particular, the expression of an antioxidant enzyme heme-oxygenase-1 (HO-1) and nuclear translocation and transcriptional activity of Nrf2, a major regulator of HO-1, were lower in Beas-2B overexpressing PD-L1 cells than in control cells. DEPs-induced ROS generation, DNA damage and apoptosis in Beas-2B cells overexpressing PD-L1 were significantly restored by overexpressing HO-1. Collectively, our results suggest that DEPs can increase the expression of PD-L1 in HBE cells and that overexpressing PD-L1 might eventually promote DEPs-induced oxidative DNA damage and apoptosis.

Research progress of abnormal lactate metabolism and lactate modification in immunotherapy of hepatocellular carcinoma

Tumors meet their energy, biosynthesis, and redox demands through metabolic reprogramming. This metabolic abnormality results in elevated levels of metabolites, particularly lactate, in the tumor microenvironment. Immune cell reprogramming and cellular plasticity mediated by lactate and lactylation increase immunosuppression in the tumor microenvironment and are emerging as key factors in regulating tumor development, metastasis, and the effectiveness of immunotherapies such as immune checkpoint inhibitors. Reprogramming of glucose metabolism and the "Warburg effect" in hepatocellular carcinoma (HCC) lead to the massive production and accumulation of lactate, so lactate modification in tumor tissue is likely to be abnormal as well. This article reviews the immune regulation of abnormal lactate metabolism and lactate modification in hepatocellular carcinoma and the therapeutic strategy of targeting lactate-immunotherapy, which will help to better guide the medication and treatment of patients with hepatocellular carcinoma.

WNT signaling in the tumor microenvironment promotes immunosuppression in murine pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is associated with activation of WNT signaling. Whether this signaling pathway regulates the tumor microenvironment has remained unexplored. Through single-cell RNA sequencing of human pancreatic cancer, we discovered that tumor-infiltrating CD4+ T cells express TCF7, encoding for the transcription factor TCF1. We conditionally inactivated Tcf7 in CD4 expressing T cells in a mouse model of pancreatic cancer and observed changes in the tumor immune microenvironment, including more CD8+ T cells and fewer regulatory T cells, but also compensatory upregulation of PD-L1. We then used a clinically available inhibitor of Porcupine, a key component of WNT signaling, and observed similar reprogramming of the immune response. WNT signaling inhibition has limited therapeutic window due to toxicity, and PD-L1 blockade has been ineffective in PDA. Here, we show that combination targeting reduces pancreatic cancer growth in an experimental model and might benefit the treatment of pancreatic cancer.

Research progress of therapeutic effects and drug resistance of immunotherapy based on PD-1/PD-L1 blockade

The binding of programmed death-1 (PD-1) on the surface of T cells and PD-1 ligand 1 (PD-L1) on tumor cells can prevent the immune-killing effect of T cells on tumor cells and promote the immune escape of tumor cells. Therefore, immune checkpoint blockade targeting PD-1/PD-L1 is a reliable tumor therapy with remarkable efficacy. However, the main challenges of this therapy are low response rate and acquired resistance, so that the outcomes of this therapy are usually unsatisfactory. This review begins with the description of biological structure of the PD-1/PD-L1 immune checkpoint and its role in a variety of cells. Subsequently, the therapeutic effects of immune checkpoint blockers (PD-1 / PD-L1 inhibitors) in various tumors were introduced and analyzed, and the reasons affecting the function of PD-1/PD-L1 were systematically analyzed. Then, we focused on analyzing, sorting out and introducing the possible underlying mechanisms of primary and acquired resistance to PD-1/PD-L1 blockade including abnormal expression of PD-1/PD-L1 and some factors, immune-related pathways, tumor immune microenvironment, and T cell dysfunction and others. Finally, promising therapeutic strategies to sensitize the resistant patients with PD-1/PD-L1 blockade treatment were described. This review is aimed at providing guidance for the treatment of various tumors, and highlighting the drug resistance mechanisms to offer directions for future tumor treatment and improvement of patient prognosis.

Network pharmacology, molecular docking and bioinformatics reveal the mechanism of Tripterygii Wilfordii against Osteosarcoma

Osteosarcoma (OS) is a malignant bone tumor of mesenchymal origin. Tripterygii Wilfordii (TW) is a traditional Chinese medicine widely used for its anti-inflammatory and immunomodulatory effects. Various components of TW have been shown to have antitumor effects, however, no systematic study has been conducted to prove the anti-OS effects of TW. This study aimed to investigate the effects of TW on OS and its mechanism based on network pharmacology and molecular docking. The web pharmacology section includes the gathering of the active components of TW, the collection of predicted targets of TW and OS-related targets, the analysis of therapeutic targets of TW, the enrichment of gene ontology (GO), and the enrichment of Kyoto Encyclopedia of Genes and Genomes (KEGG). The Veen diagram showed 451 targets for OS treatment in TW. The therapeutic target enrichment analysis results showed that TW treated OS via multiple targets and pathways. TW can affect OS proliferation, apoptosis, migration, infiltration, and angiogenesis through a signaling network formed by hub genes that cascade through numerous signaling pathways. In addition, molecular docking results showed that triptolide, kaempferol, and 5,8-Dihydroxy-7-(4-hydroxy-5-methyl-coumarin-3)-coumarin have relatively high potential to become drugs for patients with OS and improve the 5-year survival rate of patients with OS. Network pharmacology and molecular docking suggest that TW affects the biological behavior of OS through multiple pathways involving multiple targets, such as proliferation, apoptosis, migration, and infiltration. Upregulation of the cellular tumor antigen p53 (TP53) gene and downregulation of peroxisome proliferator-activated receptor gamma (PPARG) and signal transducer and activator of transcription 1-alpha/beta (STAT1) genes can prolong the survival time of patients with OS. Triptolide, kaempferol, and 5,8-Dihydroxy-7-(4-hydroxy-5 methyl-coumarin-3)-coumarin have a relatively high potential to become a treatment for patients with OS and improve 5-year survival of OS patients.

Combination of IL-17A/F and TNF-α uniquely alters the bronchial epithelial cell proteome to enhance proteins that augment neutrophil migration

Background

The heterodimer interleukin (IL)-17A/F is elevated in the lungs in chronic respiratory disease such as severe asthma, along with the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α). Although IL-17A/F and TNF-α are known to functionally cooperate to exacerbate airway inflammation, proteins altered by their interaction in the lungs are not fully elucidated.

Results

We used Slow Off-rate Modified Aptamer-based proteomic array to identify proteins that are uniquely and/or synergistically enhanced by concurrent stimulation with IL-17A/F and TNF-α in human bronchial epithelial cells (HBEC). The abundance of 38 proteins was significantly enhanced by the combination of IL-17A/F and TNF-α, compared to either cytokine alone. Four out of seven proteins that were increased > 2-fold were those that promote neutrophil migration; host defence peptides (HDP; Lipocalin-2 (LCN-2) and Elafin) and chemokines (IL-8, GROα). We independently confirmed the synergistic increase of these four proteins by western blots and ELISA. We also functionally confirmed that factors secreted by HBEC stimulated with the combination of IL-17A/F and TNF-α uniquely enhances neutrophil migration. We further showed that PI3K and PKC pathways selectively control IL-17A/F + TNF-α-mediated synergistic production of HDPs LCN-2 and Elafin, but not chemokines IL-8 and GROα. Using a murine model of airway inflammation, we demonstrated enhancement of IL-17A/F, TNF-α, LCN-2 and neutrophil chemokine KC in the lungs, thus corroborating our findings in-vivo.

Conclusion

This study identifies proteins and signaling mediated by concurrent IL-17A/F and TNF-α exposure in the lungs, relevant to respiratory diseases characterized by chronic inflammation, especially neutrophilic airway inflammation such as severe asthma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12950-022-00323-w.

Programmed Cell Death-Ligand 1 in Head and Neck Squamous Cell Carcinoma: Molecular Insights, Preclinical and Clinical Data, and Therapies

Aberrant expression of the programmed cell death protein ligand 1 (PD-L1) constitutes one of the main immune evasion mechanisms of cancer cells. The approval of drugs against the PD-1-PD-L1 axis has given new impetus to the chemo-therapy of many malignancies. We performed a literature review from 1992 to August 2022, summarizing evidence regarding molecular structures, physiological and pathological roles, mechanisms of PD-L1 overexpression, and immunotherapy evasion. Furthermore, we summarized the studies concerning head and neck squamous cell carcinomas (HNSCC) immunotherapy and the prospects for improving the associated outcomes, such as identifying treatment response biomarkers, new pharmacological combinations, and new molecules. PD-L1 overexpression can occur via four mechanisms: genetic modifications; inflammatory signaling; oncogenic pathways; microRNA or protein-level regulation. Four molecular mechanisms of resistance to immunotherapy have been identified: tumor cell adaptation; changes in T-cell function or proliferation; alterations of the tumor microenvironment; alternative immunological checkpoints. Immunotherapy was indeed shown to be superior to traditional chemotherapy in locally advanced/recurrent/metastatic HNSCC treatments.

Role of non-coding RNA in immune microenvironment and anticancer therapy of gastric cancer

Gastric cancer remains one of the cancers with the highest mortality in the world; therefore, it is very important to investigate its pathogenesis to improve the prognosis of gastric cancer patients. Recently, noncoding RNAs have become a research hotspot in the field of oncology. These RNA molecules play complex roles in the regulation of tumor cells, immune cells, and the tumor microenvironment. Therefore, studying their ability to regulate the gastric cancer immune microenvironment will provide us with a better perspective to understand their potential role in anticancer therapy. In this review, we discuss the regulatory effects of several common noncoding RNAs on the immune microenvironment of gastric cancer and their prospects in anticancer therapy to provide some novel insight into the identification of valuable diagnostic markers and improving the prognosis of gastric cancer patients.

EphA2 Promotes the Development of Cervical Cancer through the CXCL11/PD-L1 Pathway

Erythropoietin-producing hepatoma receptor A2 (EphA2), receptor tyrosine kinase, the most widespread member of the largest receptor tyrosine kinase family, plays a critical role in physiological and pathological conditions. In recent years, the role of EphA2 in the occurrence and development of cancer has become a research hotspot and is considered a promising potential target. Our previous studies have shown that EphA2 has an indisputable cancer-promoting role in cervical cancer, but its related mechanism requires further research. In this study, high-throughput sequencing was performed on EphA2 knockdown cervical cancer cells and the control group. An analysis of differentially expressed genes revealed that EphA2 may exert its cancer-promoting effect through C-X-C motif chemokine ligand 11 (CXCL11). In addition, we found that EphA2 could further regulate programmed cell death ligand 1 (PD-L1) through CXCL11. This has also been further demonstrated in in vivo experiments. Our study demonstrated that EphA2 plays a tumor-promoting role in cervical carcinoma through the CXCL11/PD-L1 pathway, providing new guidance for the targeted therapy and combination therapy of cervical carcinoma.

Prognostic and predictive value of YTHDF1 and YTHDF2 and their correlation with tumor-infiltrating immune cells in non-small cell carcinoma

BACKGROUND

YTH domain-containing family protein 1 (YTHDF1) or YTHDF2 play crucial roles in cancer immunotherapy. We examine the expression of YTHDF1, YTHDF2, CD8, CD4, and FOXP3 to identify their prognostic or predictive role for PD-1/PD-L1 inhibitor in non-small cell lung cancer (NSCLC).

METHODS

Immunohistochemical expression of YTHDF1, YTHDF2, CD8, CD4, and FOXP3 was investigated in 266 patients not receiving PD-1/PD-L1 inhibitors and in 59 patients receiving PD-1/PD-L1 inhibitors. Immunohistochemical results were verified using mRNA dataset obtained from The Cancer Genome Atlas (TCGA) database.

RESULTS

Immunohistochemical expression of YTHDF1 or YTHDF2 was negatively associated with CD8- and CD4-positive T cells; however, the same expression was positively associated with FOXP3-positive T cells. YTHDF1 or YTHDF2 mRNA expression was also negatively associated with CD8- and CD4-positive T cells. Gene set enrichment analysis revealed that low YTHDF1 was related to immune hot tumor gene sets. Expression of YTHDF1 or YTHDF2 was negatively associated with expression of most immune checkpoints. YTHDF1 and YTHDF2 were predictive markers of response to PD-1/PD-L1 inhibitors. YTHDF1 or YTHDF2 expression was associated with better prognosis. YTHDF1 has an immune hot profile in both cell types, whereas YTHDF2 is only seen in adenocarcinoma.

CONCLUSION

Low YTHDF1 or YTHDF2 reflects an immune hot tumor signature and may serve as a predictor or prognostic marker.

Bone Marrow Immune Microenvironment in Myelodysplastic Syndromes

The BM, the major hematopoietic organ in humans, consists of a pleiomorphic environment of cellular, extracellular, and bioactive compounds with continuous and complex interactions between them, leading to the formation of mature blood cells found in the peripheral circulation. Systemic and local inflammation in the BM elicit stress hematopoiesis and drive hematopoietic stem cells (HSCs) out of their quiescent state, as part of a protective pathophysiologic process. However, sustained chronic inflammation impairs HSC function, favors mutagenesis, and predisposes the development of hematologic malignancies, such as myelodysplastic syndromes (MDS). Apart from intrinsic cellular mechanisms, various extrinsic factors of the BM immune microenvironment (IME) emerge as potential determinants of disease initiation and evolution. In MDS, the IME is reprogrammed, initially to prevent the development, but ultimately to support and provide a survival advantage to the dysplastic clone. Specific cellular elements, such as myeloid-derived suppressor cells (MDSCs) are recruited to support and enhance clonal expansion. The immune-mediated inhibition of normal hematopoiesis contributes to peripheral cytopenias of MDS patients, while immunosuppression in late-stage MDS enables immune evasion and disease progression towards acute myeloid leukemia (AML). In this review, we aim to elucidate the role of the mediators of immune response in the initial pathogenesis of MDS and the evolution of the disease.

Chemokines and cytokines: Axis and allies in prostate cancer pathogenesis

Chemokines are recognized as the major contributor to various tumorigenesis, tumor heterogeneity, and failures of current cancer therapies. The tumor microenvironment (TME) is enriched with chemokines and cytokines and plays a pivotal role in cancer progression. Chronic inflammation is also considered an instructive process of cancer progression, where chemokines are spatiotemporally secreted by malignant cells and leukocyte subtypes that initiate cell trafficking into the TME. In various cancers, prostate cancer (PCa) is reported as one of the leading cancers in the worldwide male population. The chemokines-mediated signaling pathways are intensively involved in PCa progression and metastasis. Emerging evidence suggests that chemokines and cytokines are responsible for the pleiotropic actions in cancer, including the growth, angiogenesis, endothelial mesenchymal transition, leukocyte infiltration, and hormone escape for advanced PCa and therapy resistance. Chemokine's system and immune cells represent a promising target to suppress tumorigenic environments and serve as potential therapy/immunotherapy for the PCa. In this review, an attempt has been made to shed light on the alteration of chemokine and cytokine profiles during PCa progression and metastasis. We also discussed the recent findings of the diverse molecular signaling of these circulating chemokines and their corresponding receptors that could become future targets for therapeutic management of PCa.

TNF-α-dependent lung inflammation upregulates PD-L1 in monocyte-derived macrophages to contribute to lung tumorigenesis

Chronic inflammation, which is dominated by macrophage-involved inflammatory responses, is an instigator of cancer initiation. Macrophages are the most abundant immune cells in healthy lungs, and associated with lung tumor development and promotion. PD-L1 is a negative molecule in macrophages and correlated with an immunosuppressive function in tumor environment. Macrophages expressing PD-L1, rather than tumor cells, exhibits a critical role in tumor growth and progression. However, whether and how PD-L1 in macrophages contributes to inflammation-induced lung tumorigenesis requires further elucidation. Here, we found that higher expression of PD-L1 in CD11b⁺ CD206⁺ macrophages was positively correlated with tumor progression and PD-1⁺ CD8⁺ T cells population in human adenocarcinoma patients. In the urethane-induced inflammation-driven lung adenocarcinoma (IDLA) mouse model, the infiltration of circulating CD11b^high F4/80⁺ monocyte-derived macrophages (MoMs) was increased in pro-tumor inflamed lung tissues and lung adenocarcinoma. PD-L1 was mainly upregulated in MoMs associated with enhanced T cells exhaustion in lung tissues. Anti-PD-L1 treatment can reduce T cells exhaustion at pro-tumor inflammatory stage, and then inhibit tumorigenesis in IDLA. The pro-tumor lung inflammation depended on TNF-α to upregulate PD-L1 and CSN6 expression in MoMs, and induced cytokines production by alveolar type-II cells (AT-II). Furthermore, inflammatory AT-II cells could secret TNF-α to upregulate PD-L1 expression in bone-marrow driven macrophages (BM-M0). Inhibition of CSN6 decreased PD-L1 expression in TNF-α-activated macrophage in vitro, suggesting a critical role of CSN6 in PD-L1 upregulation. Thus, pro-tumor inflammation can depend on TNF-α to upregulate PD-L1 in recruited MoMs, which may be essential for lung tumorigenesis.

Immune marker expression of irradiated mesothelioma cell lines

Background

Though immune checkpoint inhibition has recently shown encouraging clinical efficacy in mesothelioma, most patients do not respond. Combining immune checkpoint inhibition with radiotherapy presents an attractive option for improving treatment responses owing to the various immunomodulatory effects of radiation on tumors. However, the ideal dosing and scheduling of combined treatment remains elusive, as it is poorly studied in mesothelioma. The present study characterizes the dose- and time-dependent changes to expression of various immune markers and cytokines important to antitumor responses following irradiation of mesothelioma cell lines.

Methods

Two murine (AB1, AE17) and two human (BYE, JU77) mesothelioma cell lines were treated with titrated gamma-radiation doses (1-8 Gy) and the expression of MHC class-I, MHC class-II and PD-L1 was measured over a series of post-irradiation timepoints (1-72 hours) by flow cytometry. Levels of cytokines IL-1α, IL-1β, IL-6, IL-10, IL-12p70, IL-17A, IL-23, IL-27, MCP-1, IFN-β, IFN-γ, TNF-α, and GM-CSF were measured by multiplex immunoassay in murine cell lines following 8 Gy radiation.

Results

Following irradiation, a dose-dependent upregulation of MHC-I and PD-L1 was observed on three of the four cell lines studied to varying extents. For all cell lines, the increase in marker expression was most pronounced 72 hours after radiation. At this timepoint, increases in levels of cytokines IFN-β, MCP-1 and IL-6 were observed following irradiation with 8 Gy in AB1 but not AE17, reflecting patterns in marker expression.

Conclusions

Overall, this study establishes the dose- and time-dependent changes in immune marker expression of commonly studied mesothelioma cell lines following radiation and will inform future study into optimal dosing and scheduling of combined radiotherapy and immune checkpoint inhibition for mesothelioma.

NF-κB Signaling in Tumor Pathways Focusing on Breast and Ovarian Cancer

Immune disorders and cancer share a common pathway involving NF-κb signaling. Through involvement with GM-CSF, NF-κB can contribute to proliferation and activation of T- and B- cells as well as immune cell migration to sites of inflammation. In breast cancer, this signaling pathway has been linked to resistance with endocrine and chemotherapies. Similarly, in ovarian cancer, NF-κB influences angiogenesis and inflammation pathways. Further, BRCA1 signaling common to both breast and ovarian cancer also has the capability to induce NF-κB activity. Immunotherapy involving NF-κB can also be implemented to combat chemoresistance. The complex signaling pathways of NF-κB can be harnessed for developing cancer therapeutics to promote immunotherapy for improving patient outcomes.

Transcriptomic Correlates of Tumor Cell PD-L1 Expression and Response to Nivolumab Monotherapy in Metastatic Clear Cell Renal Cell Carcinoma

PURPOSE

PD-L1 expression on tumor cells (TC) is associated with response to anti-PD-1-based therapies in some tumor types, but its significance in clear cell renal cell carcinoma (ccRCC) is uncertain. We leveraged tumor heterogeneity to identify molecular correlates of TC PD-L1 expression in ccRCC and assessed their role in predicting response to anti-PD-1 monotherapy.

EXPERIMENTAL DESIGN

RNA sequencing was performed on paired TC PD-L1 positive and negative areas isolated from eight ccRCC tumors and transcriptomic features associated with PD-L1 status were identified. A cohort of 232 patients with metastatic ccRCC from the randomized CheckMate-025 (CM-025) trial was used to confirm the findings and correlate transcriptomic profiles with clinical outcomes.

RESULTS

In both the paired samples and the CM-025 cohort, TC PD-L1 expression was associated with combined overexpression of immune- and cell proliferation-related pathways, upregulation of T-cell activation signatures, and increased tumor-infiltrating immune cells. In the CM-025 cohort, TC PD-L1 expression was not associated with clinical outcomes. A molecular RCC subtype characterized by combined overexpression of immune- and cell proliferation-related pathways (previously defined by unsupervised clustering of transcriptomic data) was enriched in TC PD-L1 positive tumors and displayed longer progression-free survival (HR, 0.32; 95% confidence interval, 0.13-0.83) and higher objective response rate (30% vs. 0%, P = 0.04) on nivolumab compared with everolimus.

CONCLUSIONS

Both TC-extrinsic (immune-related) and TC-intrinsic (cell proliferation-related) mechanisms are likely intertwined in the regulation of TC PD-L1 expression in ccRCC. The quantitation of these transcriptional programs may better predict benefit from anti-PD-1-based therapy compared with TC PD-L1 expression alone in ccRCC.

Non-apoptotic activity of the mitochondrial protein SMAC/Diablo in lung cancer: Novel target to disrupt survival, inflammation, and immunosuppression

Mitochondrial SMAC/Diablo induces apoptosis by binding the inhibitor of apoptosis proteins (IAPs), thereby activating caspases and, subsequently, apoptosis. Previously, we found that despite its pro-apoptotic activity, SMAC/Diablo is overexpressed in cancer, and demonstrated that in cancer it possesses new essential and non-apoptotic functions that are associated with regulating phospholipid synthesis including modulating mitochondrial phosphatidylserine decarboxylase activity. Here, we demonstrate additional functions for SMAC/Diablo associated with inflammation and immunity. CRISPR/Cas9 SMAC/Diablo-depleted A549 lung cancer cells displayed inhibited cell proliferation and migration. Proteomics analysis of these cells revealed altered expression of proteins associated with lipids synthesis and signaling, vesicular transport and trafficking, metabolism, epigenetics, the extracellular matrix, cell signaling, and neutrophil-mediated immunity. SMAC-KO A549 cell-showed inhibited tumor growth and proliferation and activated apoptosis. The small SMAC-depleted “tumor” showed a morphology of alveoli-like structures, reversed epithelial-mesenchymal transition, and altered tumor microenvironment. The SMAC-lacking tumor showed reduced expression of inflammation-related proteins such as NF-kB and TNF-α, and of the PD-L1, associated with immune system suppression. These results suggest that SMAC is involved in multiple processes that are essential for tumor growth and progression. Thus, targeting SMAC’s non-canonical function is a potential strategy to treat cancer.

Tumor accomplice: T cell exhaustion induced by chronic inflammation

The development and response to treatment of tumor are modulated by inflammation, and chronic inflammation promotes tumor progression and therapy resistance. This article summarizes the dynamic evolution of inflammation from acute to chronic in the process of tumor development, and its effect on T cells from activation to the promotion of exhaustion. We review the mechanisms by which inflammatory cells and inflammatory cytokines regulate T cell exhaustion and methods for targeting chronic inflammation to improve the efficacy of immunotherapy. It is great significance to refer to the specific state of inflammation and T cells at different stages of tumor development for accurate clinical decision-making of immunotherapy and improving the efficiency of tumor immunotherapy.

Understanding the functional inflammatory factors involved in therapeutic response to immune checkpoint inhibitors for pan-cancer

Immune checkpoint inhibitors (ICIs) fight tumor progression by activating immune conditions. The inflammatory factors are playing a functional role in programmed death-1 (PD-1) or other immune checkpoints. They are involved in regulating the expression of programmed death ligand-1 (PD-L1), the only predictor recognized by the guidelines in response to ICIs. In addition, abundant components of the tumor microenvironment (TME) all interact with various immune factors contributing to the response to ICIs, including infiltration of various immune cells, extracellular matrix, and fibroblasts. Notably, the occurrence of immune-related adverse events (irAEs) in patients receiving ICIs is increasingly observed in sundry organs. IrAEs are often regarded as an inflammatory factor-mediated positive feedback loop associated with better response to ICIs. It deserves attention because inflammatory factors were observed to be different when targeting different immune checkpoints or in the presence of different irAEs. In the present review, we address the research progresses on regulating inflammatory factors for an intentional controlling anti-cancer response with immune checkpoint inhibitors.

The gamble between oncolytic virus therapy and IFN

Various studies are being conducted on oncolytic virotherapy which one of the mechanisms is mediating interferon (IFN) production by it exerts antitumor effects. The antiviral effect of IFN itself has a negative impact on the inhibition of oncolytic virus or tumor eradication. Therefore, it is very critical to understand the mechanism of IFN regulation by oncolytic viruses, and to define its mechanism is of great significance for improving the antitumor effect of oncolytic viruses. This review focuses on the regulatory mechanisms of IFNs by various oncolytic viruses and their combination therapies. In addition, the exerting and the producing pathways of IFNs are briefly summarized, and some current issues are put forward.

Network pharmacology and molecular docking to elucidate the mechanism of pulsatilla decoction in the treatment of colon cancer

Objective: Colon cancer is a malignant neoplastic disease that seriously endangers the health of patients. Pulsatilla decoction (PD) has some therapeutic effects on colon cancer. This study is based on the analytical methods of network pharmacology and molecular docking to study the mechanism of PD in the treatment of colon cancer.

Methods: Based on the Traditional Chinese Medicine Systems Pharmacology Database, the main targets and active ingredients in PD were filtered, and then, the colon cancer-related targets were screened using Genecards, OMIM, PharmGKB, and Drugbank databases. Then, the screened drug and disease targets were Venn analyzed to obtain the intersection targets. Cytoscape software was used to construct the “Components–Targets–Pathway” map, and the String database was used to analyze the protein interaction network of the intersecting targets and screen the core targets, and then, the core targets were analyzed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Molecular docking was implemented using AutoDockTools to predict the binding capacity for the core targets and the active components in PD.

Results: Sixty-five ingredients containing 188 nonrepetitive targets were screened and 180 potential targets of PD anticolon cancer were identified, including 10 core targets, namely, MAPK1, JUN, AKT1, TP53, TNF, RELA, MAPK14, CXCL8, ESR1, and FOS. The results of GO analysis showed that PD anticolon cancer may be related to cell proliferation, apoptosis, energy metabolism, immune regulation, signal transduction, and other biological processes. The results of KEGG analysis indicated that the PI3K-Akt signaling pathway, MAPK signaling pathway, proteoglycans in cancer, IL-17 signaling pathway, cellular senescence, and TNF signaling pathway were mainly involved in the regulation of tumor cells. We further selected core targets with high degree values as receptor proteins for molecular docking with the main active ingredients of the drug, including MAPK1, JUN, and AKT1. The docking results showed good affinity, especially quercetin.

Conclusion: This study preliminarily verified that PD may exert its effect on the treatment of colon cancer through multi-ingredients, multitargets, and multipathways. This will deepen our understanding of the potential mechanisms of PD anticolon cancer and establish a foundation for further basic experimental research.

Tumor-specific T cell-mediated upregulation of PD-L1 in myelodysplastic syndrome cells does not affect T-cell killing

The PD-1:PD-L1 axis is a binary interaction that delivers inhibitory signals to T cells, impeding both immune surveillance and response to immunotherapy. Here we analyzed a phenomenon whereby tumor-specific T cells induce PD-L1 upregulation in autologous MDS cells in short-term culture, through a mechanism that is cell-contact-independent and partially IFNγ-dependent. After investigating a panel of small-molecule inhibitors, we determined that PD-L1 upregulation was attributed to the PKR-like ER kinase (PERK) branch of the unfolded protein response. Interestingly, we found that the cytotoxic capacity of tumor-specific T cells was not impaired by the expression of PD-L1 on MDS target cells. These results highlight a little appreciated aspect of PD-1:PD-L1 regulation in hematologic cancers and indicate that this phenomenon, while likely to hinder autochthonous immune surveillance, may not be an obstacle to immunotherapies such as personalized adoptive T-cell therapy.

Cyclic adenosine monophosphate/phosphodiesterase 4 pathway associated with immune infiltration and PD-L1 expression in lung adenocarcinoma cells

Background

The cyclic adenosine monophosphate/phosphodiesterase 4 (cAMP/PDE4) pathway is involved in inflammation and immune regulation; however, the effect of cAMP/PDE4 on immune infiltration and immune evasion in lung adenocarcinoma (LUAD) remains unclear.

Methods

CBioPortal, which is the The Cancer Genome Atlas (TCGA) online database, and the Kaplan Meier plotter were used to analyze the association between genes and the prognosis of TCGA-LUAD. Tumor Immune Estimation Resource (TIMER) was used to analyze the association between gene expression and immune infiltration. The Genecards database was used to identify the transcription factors of related genes. The lung adenocarcinoma cell line H1299 and A549 were treated with cAMP pathway drugs. Flow cytometry and qRT-PCR were used to detect the PD-L1 protein and gene expression, respectively. A one-way analysis of variance with Tukey’s post-hoc test or a Student’s t-test were used.

Results

It was found that PDE4B and CREB1, which are downstream genes of the cAMP/PDE4 axis, were differentially expressed in LUAD and adjacent tissues and are correlated with the prognosis and immune infiltration of LUAD. In the CBioPortal database, cAMP pathway genes are closely related to programmed cell death-ligand 1 (PD-L1) expression in TCGA-LUAD. The protein-protein interaction revealed that there was a direct interaction between CREB1/CREBBP, which are the downstream molecules of the cAMP/PDE4 axis, and MYC; additionally, MYC was predicted to bind to the PD-L1 transcription site and regulate PD-L1 expression. CREB1 was also predicted to transcriptionally bind to both MYC and PD-L1. These results predicted the interaction network of cAMP/PDE4/CREB1/CREBP/MYC/PD-L1, and the core factor may be related to MYC. In the cell experiment, forskolin (an adenylate cyclase activator) and zardaverine (a PDE4 inhibitor) enhance the cAMP pathway and decrease PD-L1 expression, while SQ2253 (an adenylate cyclase inhibitor) inhibits the cAMP pathway and increases PD-L1 expression of the LUAD cell lines H1299 and A549, and MYC regulation by these drugs was positively correlated with PD-L1 regulation, which verified the regulation of the cAMP/PDE4 pathway on MYC and PD-L1.

Conclusions

This study showed that the cAMP/PDE4 pathway may play an important role in PD-L1 regulation and immune infiltration in LUAD.

Autophagy blockade potentiates cancer-associated immunosuppression through programmed death ligand-1 upregulation in bladder cancer

A high basal level of autophagic flux in bladder cancer (BC) cells prevents cell death and weakens chemotherapy efficacy. However, how autophagy influences cancer-associated immunosuppression in BC remains undetermined. In this study, we observed a negative correlation between the autophagy-related markers LC3-II and programmed death ligand-1 (PD-L1) in BC cells. The autophagy inhibitors chloroquine (CQ) and bafilomycin A1 (Baf-A1) increased PD-L1 expression in BC cells through the ERK-JNK-c-Jun signal-transduction pathway. Moreover, the treatment of BC cells with CQ and Baf-A1 inhibited hsa-microRNA-34a (miR-34a) expression and miR-34a overexpression in BC cells prevented the autophagy blockade-induced PD-L1 expression; a negative correlation between miR-34a and PD-L1 expression was observed during treatment with autophagy inhibitors. Furthermore, miR-34a overexpression induced the cytotoxic activity of natural killer cells against BC cells. Our results provide evidence that autophagy blockade and its regulatory pathway affect cancer-associated immunosuppression through PD-L1 elevation. Thus, the coadministration of autophagy inhibitors and a PD-L1 immune checkpoint blockade provides a potential therapeutic approach for treating BC.

Prognostic biomarker IL17A correlated with immune infiltrates in head and neck cancer

Background

The underlying functions and mechanisms of the Th17 pathway in Head and neck squamous cell carcinoma (HNSCC) progression and tumor immunology are still unclear. We investigated the correlation between IL17A expression and certain clinical parameters, tumor-infiltrating immune cells (TIICs) in TCGA HNSCC samples.

Methods

HNSCC files from the TCGA database were analyzed to obtain data on immune system infiltrates, gene expression, and related clinical information. R (Version 3.6.3) software, GEPIA, and TIMER online analysis tools were used to profile the relationship between the expression of IL17A and the prognosis, clinical stages, survival status and immune cell tumor-infiltrating levels of HNSCC patients. GEPIA and TIMER online analysis tools were used to verify the data.

Results

The expression of IL17A was significantly decreased in tumor tissues from HNSCC. IL17A expression was associated with M, N stage, lymphovascular invasion, and patients OS event. GSEA revealed that IL17A was closely related to humoral immune response, T cells response, and cytokine signal. TCGA database and TIMER online analysis indicated that the B cells and T cells levels were correlated with IL17A. The correlation between IL17A expression and correlated genes was analyzed.

Conclusions

IL-17A plays a key role in HNSCC. The levels of IL17A are important values for the determination of the occurrence and development of the HNSCC. The IL17A and correlated genes may be potential immunotherapeutic targets for HNSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02703-1.

Tumor microenvironment involvement in colorectal cancer progression via Wnt/β-catenin pathway: Providing understanding of the complex mechanisms of chemoresistance

Colorectal cancer (CRC) continues to be one of the main causes of death from cancer because patients progress unfavorably due to resistance to current therapies. Dysregulation of the Wnt/β-catenin pathway plays a fundamental role in the genesis and progression of several types of cancer, including CRC. In many subtypes of CRC, hyperactivation of the β-catenin pathway is associated with mutations of the adenomatous polyposis coli gene. However, it can also be associated with other causes. In recent years, studies of the tumor microenvironment (TME) have demonstrated its importance in the development and progression of CRC. In this tumor nest, several cell types, structures, and biomolecules interact with neoplastic cells to pave the way for the spread of the disease. Cross-communications between tumor cells and the TME are then established primarily through paracrine factors, which trigger the activation of numerous signaling pathways. Crucial advances in the field of oncology have been made in the last decade. This Minireview aims to actualize what is known about the central role of the Wnt/β-catenin pathway in CRC chemoresistance and aggressiveness, focusing on cross-communication between CRC cells and the TME. Through this analysis, our main objective was to increase the understanding of this complex disease considering a more global context. Since many treatments for advanced CRC fail due to mechanisms involving chemoresistance, the data here exposed and analyzed are of great interest for the development of novel and effective therapies.

Generation, secretion and degradation of cancer immunotherapy target PD-L1

Cancer immunotherapy is a rapidly developing and effective method for the treatment of a variety of malignancies in recent years. As a significant immune checkpoint, programmed cell death 1 ligand 1 (PD-L1) and its receptor programmed cell death protein 1 (PD-1) play the most significant role in cancer immune escape and cancer immunotherapy. Though PD-L1 have become an important target for drug development and there have been various approved drugs and clinic trials targeting it, and various clinical response rate and adverse reactions prevent many patients from benefiting from it. In recent years, combination trials have become the main direction of PD-1/PD-L1 antibodies development. Here, we summarized PD-L1 biofunctions and key roles in various cancers along with the development of PD-L1 inhibitors. The regulators that are involved in controlling PD-L1 expression including post-translational modification, mRNA level regulation as well as degradation and exosome secretory pathway of PD-L1 were focused. This systematic summary may provide comprehensive understanding of different regulations on PD-L1 as well as a broad prospect for the search of the important regulator of PD-L1. The regulatory factors of PD-L1 can be potential targets for immunotherapy and increase strategies of immunotherapy in combination.

Long noncoding RNA NNT-AS1 inhibits IL-17-induced proliferation, migration, and invasion of gastric cancer cells by regulating miR-518a-3p

BACKGROUND

Interleukin 17 (IL-17) is a cytokine secreted in many cell types, which is related to the development of tumor cells. The expression of the long noncoding RNA (lncRNA) nicotinamide nucleotide transhydrogenase antisense RNA1 (NNT-AS1) is up-regulated in gastric cancer tissues. NNT-AS1 may inhibit the proliferation and invasion of gastric cancer cells and arrest cell cycle progression by reducing the expression of miR-363. The regulatory mechanism of NNT-AS1 and IL-17 on gastric cancer cells is still not completely clear.

AIM

To explore the molecular mechanism by which NNT-AS1 inhibits IL-17-induced proliferation, migration, and invasion of gastric cancer cells.

METHODS

IL-17 was used to treat gastric cancer AGS cells, and the cells were divided into Con group, IL-17 group, IL-17 + si-NC group, IL-17 + si-lncRNA NNT-AS1 group, IL-17 + si-lncRNA NNT-AS1 + anti-miR-NC group, and IL-17 + si-lncRNA NNT-AS1 + anti-miR-518a-3p group. Real-time fluorescence quantitative PCR (RT-qPCR) was used to detect miR-518a-3p and NNT-AS1 expression. Colony forming assay and Transwell assay were performed to detect AGS cell proliferation, migration, and invasion. Western blot was used to detect relevant protein expression. Dual luciferase assay was used to detect the relationship of miR-518a-3p and NNT-AS1.

RESULTS

Compared with the Con group, the number of cell colonies, the number of migrating cells, and the number of invasive cells in the IL-17 group increased, the expression of Ki-67, N-cadherin, and MMP2 proteins increased, the expression of E-cadherin protein decreased, the expression of NNT-AS1 increased, and the expression of miR-518a-3p decreased. Down-regulation of NNT-AS1 decreased the number of cell colonies formed, the number of migrating cells, and the number of invasive cells in gastric cancer cells treated with IL-17, decreased the expression of Ki-67, matrix metalloproteinase 2 (MMP2), and N-cadherin proteins, and increased the expression of E-cadherin protein. NNT-AS1 targets and regulates the expression of miR-518a-3p. Inhibition of miR-518a-3p can reverse the effect of down-regulation of NNT-AS1 on IL-17-induced proliferation, migration, and invasion of gastric cancer cells.

CONCLUSION

NNT-AS1 inhibits IL-17-induced gastric cancer cell proliferation, migration, and invasion possibly by regulating the expression of miR-518a-3p.

Targeting interleukin-17 enhances tumor response to immune checkpoint inhibitors in colorectal cancer

Although immune checkpoint inhibitors (ICIs) have gained much attention in managing cancer, only a minority of patients, especially those with tumors that have been classified as immunologically "cold" such as microsatellite stable (MSS) colorectal cancers (CRC), experience clinical benefit from ICIs. Surprisingly, interleukin-17 (IL-17) and its primary source Th17 are enriched in CRC and inversely associated with patient outcome. Our previous study revealed that IL-17A could upregulate programmed death-ligand 1 (PD-L1) expression and impede the efficacy of immunotherapy. IL-17, therefore, can be a possible target to sensitize tumor cells to ICIs. The detailed clinical results from our trial, which is the first to show the benefits of the combination of anti-PD-1 with anti-IL-17 therapy for MSS CRC, have also been presented. In this review, we highlight the role of IL-17 in ICIs resistance and summarize the current clinical evidence for the use of combination therapy. Directions for future strategies to warm up immunologically "cold" MSS CRCs have also been proposed.

A Metabolic Gene Signature to Predict Breast Cancer Prognosis

Background: The existing metabolic gene signatures for predicting breast cancer outcomes only focus on gene expression data without considering clinical characteristics. Therefore, this study aimed to establish a predictive risk model combining metabolic enzyme genes and clinicopathological characteristics to predict the overall survival in patients with breast cancer.

Methods: Transcriptomics and corresponding clinical data for patients with breast cancer were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Differentially expressed metabolic genes between tumors and normal tissues were identified in the TCGA dataset (training dataset). A prognostic model was then built using univariate and multifactorial Cox proportional hazards regression analyses in the training dataset. The capability of the predictive model was then assessed using the receiver operating characteristic in both datasets. Pathway enrichment analysis and immune cell infiltration were performed using Kyoto Encyclopedia of Genes and Genomes (KEGG)/Gene Ontology (GO) enrichment and CIBERSORT algorithm, respectively.

Results: In breast cancer and normal tissues, 212 metabolic enzyme genes were differentially expressed. The predictive model included four factors: age, stage, and expression of SLC35A2 and PLA2G10. Patients with breast cancer were classified into high- and low-risk groups based on the model; the high-risk group had a significantly poorer overall survival rate than the low-risk group. Furthermore, the two risk groups showed different activation of pathways and alterations in the properties of tumor microenvironment-infiltrating immune cells.

Conclusion: We developed a powerful model to predict prognosis in patients with breast cancer by combining the gene expression of metabolic enzymes with clinicopathological characteristics.

Natural Products and their Derivatives as Immune Check Point Inhibitors: Targeting Cytokine/Chemokine Signalling in Cancer

Cancer immunotherapy is the new generation and widely accepted form of tumour treatment. It is, however, associated with exclusive challenges which include organ-specific inflammation, and single-target strategies. Therefore, approaches that can enhance the efficiency of existing immunotherapies and expand their indications are required for the further development of immunotherapy. Natural products and medicines are stated to have this desired effect on cancer immunotherapy (adoptive immune-cells therapy, cancer vaccines, and immune-check point inhibitors). They refurbish the immunosuppressed tumour microenvironment, which is the primary location of interaction of tumour cells with the host immune system. Various immune cell subsets, via interaction with cytokine/chemokine receptors, are recruited into this microenvironment, and these subsets have roles in tumour progression and treatment responsiveness. This review summarises cytokine/chemokine signalling, types of cancer immunotherapy and the herbal medicine-derived natural products targeting cytokine/chemokines and immune checkpoints. These natural compounds possess immunomodulatory activities and exert their anti-tumour effect by either blocking the interaction or modulating the expression of the proteins linked with immune checkpoint signaling pathways. Some compounds also show a synergistic effect in combination with existing monoclonal antibody drugs to reverse the tumour microenvironment. Additionally, we have also reported some studies about the derivatives and formulations used to overcome the limitations of natural forms. This review can provide important insights for directing future research.

IFNAR blockade synergizes with oncolytic VSV to prevent virus-mediated PD-L1 expression and promote antitumor T cell activity

Oncolytic virotherapies have shown excellent promise in a variety of cancers by promoting antitumor immunity. However, the effects of oncolytic virus-mediated type I interferon (IFN-I) production on antitumor immunity remain unclear. Recent reports have highlighted immunosuppressive functions of IFN-I in the context of checkpoint inhibitor and cell-based therapies. In this study, we demonstrate that oncolytic virus-induced IFN-I promotes the expression of PD-L1 in tumor cells and leukocytes in a IFN receptor (IFNAR)-dependent manner. Inhibition of IFN-I signaling using a monoclonal IFNAR antibody decreased IFN-I-induced PD-L1 expression and promoted tumor-specific T cell effector responses when combined with oncolytic virotherapy. Furthermore, IFNAR blockade improved therapeutic response to oncolytic virotherapy in a manner comparable with PD-L1 blockade. Our study highlights a critical immunosuppressive role of IFN-I on antitumor immunity and uses a combination strategy that improves the response to oncolytic virotherapy.

Puerarin: A Potential Therapeutic for Colon Adenocarcinoma (COAD) Patients Suffering From SARS-CoV-2 Infection

Patients with colonic adenocarcinoma (COAD) are at relatively high risk of SARS-CoV-2 infection. However, there is a lack of medical strategies to treat COVID-19/COAD comorbidity. Puerarin, a natural product, is a known antiviral, antitumor, and immunomodulatory effect. Therefore, we hypothesised that puerarin could be used to treat COVID-19/COAD patients. Based on network pharmacology and bioinformatics analysis, the potential targets and pharmacological mechanisms of puerarin in COVID-19/COAD were identified. By intersecting therapeutic target genes for puerarin, COVID-19-related genes and COAD-related genes, 42 target genes of puerarin that could potentially treat COVID-19/COAD comorbidity were obtained. By using the 42 potential target genes to construct the protein-protein interaction (PPI) network, we obtained five core target genes, namely RELA, BCL2, JUN, FOS, and MAPK1. The results of bioinformatics analysis revealed that puerarin could be able to treat COVID-19/COAD comorbidity through apoptosis, antiviral, antioxidant, NF-κB signaling pathway, MAPK signaling pathway, IL-17 signaling pathway, TNF signaling pathway, and HIF-1 signaling pathway etc. This study found that puerarin has the potential to treat COVID-19/COAD patients and that the therapeutic target genes obtained in the study may provide clues for the treatment of COVID19/COAD comorbidity.

Extrafollicular Plasmablasts Present in the Acute Phase of Infections Express High Levels of PD-L1 and Are Able to Limit T Cell Response

During infections with protozoan parasites or some viruses, T cell immunosuppression is generated simultaneously with a high B cell activation. It has been described that, as well as producing antibodies, plasmablasts, the differentiation product of activated B cells, can condition the development of protective immunity in infections. Here, we show that, in T. cruzi infection, all the plasmablasts detected during the acute phase of the infection had higher surface expression of PD-L1 than other mononuclear cells. PD-L1^hi plasmablasts were induced in vivo in a BCR-specific manner and required help from Bcl-6⁺CD4⁺T cells. PD-L1^hi expression was not a characteristic of all antibody-secreting cells since plasma cells found during the chronic phase of infection expressed PD-L1 but at lower levels. PD-L1^hi plasmablasts were also present in mice infected with Plasmodium or with lymphocytic choriomeningitis virus, but not in mice with autoimmune disorders or immunized with T cell-dependent antigens. In vitro experiments showed that PD-L1^hi plasmablasts suppressed the T cell response, partially via PD-L1. Thus, this study reveals that extrafollicular PD-L1^hi plasmablasts, whose peaks of response precede the peak of germinal center response, may have a modulatory function in infections, thus influencing T cell response.

Burgeoning Exploration of the Role of Natural Killer Cells in Anti-PD-1/PD-L1 Therapy

Antibodies targeting programmed death receptor-1 (PD-1)/programmed death ligand-1 (PD-L1) have been considered breakthrough therapies for a variety of solid and hematological malignancies. Although cytotoxic T cells play an important antitumor role during checkpoint blockade, they still show a potential killing effect on tumor types showing loss of/low major histocompatibility complex (MHC) expression and/or low neoantigen load; this knowledge has shifted the focus of researchers toward mechanisms of action other than T cell-driven immune responses. Evidence suggests that the blockade of the PD-1/PD-L1 axis may also improve natural killer (NK)-cell function and activity through direct or indirect mechanisms, which enhances antitumor cytotoxic effects; although important, this topic has been neglected in previous studies. Recently, some studies have reported evidence of PD-1 and PD-L1 expression in human NK cells, performed exploration of the intrinsic mechanism by which PD-1/PD-L1 blockade enhances NK-cell responses, and made some progress. This article summarizes the recent advances regarding the expression of PD-1 and PD-L1 molecules on the surface of NK cells as well as the interaction between anti-PD-1/PD-L1 drugs and NK cells and associated molecular mechanisms in the tumor microenvironment.

Candida albicans induces upregulation of programmed death ligand 1 in oral squamous cell carcinoma

BACKGROUND

The potential association between Candida albicans (C. albicans) infection and oral squamous cell carcinoma (OSCC) has been noticed for a long time. Programmed death ligand-1 (PD-L1) is a key molecule of tumor immune escape and tumor progression. This study aimed to explore whether C. albicans could influence PD-L1 expression in OSCC in vitro and in mouse model.

METHODS

OSCC cell lines (Cal27 and HN6) were infected with C. albicans for 2 and 24 h, then PD-L1 expression was detected by quantitative real-time polymerase chain reaction (RT-qPCR), western blot (WB), and flow cytometry (FCM). To identify the underlying mechanisms, PD-L1 expression in OSCC cells treated with heat-inactivated C. albicans or with biofilm metabolites derived from C. albicans were explored respectively. Meanwhile, signaling pathways involved in PD-L1 regulation were explored by RT-qPCR, and the candidate genes were verified by WB. Moreover, an OSCC mouse model induced by 4-nitroquinoline-1 oxide was used to further explore the role of C. albicans infection in PD-L1 expression in vivo.

RESULTS

C. albicans and heat-inactivated C. albicans upregulated the PD-L1 expression in Cal27 and HN6 cells. Various signaling pathways involved in PD-L1 regulation were influenced by C. albicans infection. Among them, TLR2/MyD88 and TLR2/NF-κB pathways might participate in this process. Furthermore, PD-L1 expression in oral mucosa epithelium was upregulated by C. albicans infection in both normal and OSCC mice.

CONCLUSIONS

This study suggests that C. albicans could induce upregulation of PD-L1 in OSCC in vitro and in mouse model, which might due to the activation of TLR2/MyD88 and TLR2/NF-κB pathways.

Over-expression of Programmed Death Ligand 1 (PD-L1) in Refractory Inflammatory Bowel Disease (IBD)

Programmed death ligand 1 (PD-L1) dysregulation has been implicated in chronic inflammatory diseases, but its role in regulating intestinal mucosa inflammation is still unclear. The aim of this study was to assess PD-L1 expression in the intestinal mucosa of patients with refractory inflammatory bowel disease (IBD) compared to controls. We evaluated PD-L1 expression by immunohistochemistry in colectomy specimens of patients with ulcerative colitis (UC) and Crohn disease (CD) compared to controls. PD-L1 expression was assessed in colonic epithelium and inflammatory cells, along with the location of the inflammatory cells expressing PD-L1. All cases were stained with CD3, CD4, CD8, FOXP3, CD20, CD68, and CD90 immunostains to determine the types of cells expressing PD-L1. The UC group showed significantly higher PD-L1 expression in the colonic epithelium compared to both CD and control groups (both P<0.001), and CD was also significantly higher than the control group (P=0.004). Both UC and CD groups showed similar PD-L1 expression in the inflammatory infiltrate, but significantly higher than the control group (both P<0.001). Among both IBD groups, higher IBD activity was associated with higher levels of PD-L1 expression in the colonic epithelium (P<0.05) and inflammatory infiltrate (P<0.001). When comparing PD-L1 expression to lineage specific markers, CD3+, CD4+ T cells, CD68+ macrophages, and CD90+ colonic stromal cells appeared to be expressing PD-L1. These findings implicate a role for PD-L1 in the dysregulation of the immune response in refractory IBD. Further studies are warranted to better understand the role of the immune regulatory pathways in intestinal mucosa.