Antiapoptotic activity of autocrine interleukin-22 and therapeutic effects of interleukin-22-small interfering RNA on human lung cancer xenografts

IL-22: A key inflammatory mediator as a biomarker and potential therapeutic target for lung cancer

Lung cancer, one of the most prevalent cancers worldwide, stands as the primary cause of cancer-related deaths. As is well-known, the utmost crucial risk factor contributing to lung cancer is smoking. In recent years, remarkable progress has been made in treating lung cancer, particularly non-small cell lung cancer (NSCLC). Nevertheless, the absence of effective and accurate biomarkers for diagnosing and treating lung cancer remains a pressing issue. Interleukin 22 (IL-22) is a member of the IL-10 cytokine family. It exerts biological functions (including induction of proliferation and anti-apoptotic signaling pathways, enhancement of tissue regeneration and immunity defense) by binding to heterodimeric receptors containing type 1 receptor chain (R1) and type 2 receptor chain (R2). IL-22 has been identified as a pro-cancer factor since dysregulation of the IL-22-IL-22R system has been implicated in the development of different cancers, including lung, breast, gastric, pancreatic, and colon cancers. In this review, we discuss the differential expression, regulatory role, and potential clinical significance of IL-22 in lung cancer, while shedding light on innovative approaches for the future.

Electroacupuncture improves apoptosis of nucleus pulposus cells via the IL-22/JAK2-STAT3 signaling pathway in a rat model of cervical intervertebral disk degeneration

BACKGROUND

Cervical spondylosis (CS) is a prevalent disorder that can have a major negative impact on quality of life. Traditional conservative treatment has limited efficacy, and electroacupuncture (EA) is a novel treatment option. We investigated the application and molecular mechanism of EA treatment in a rat model of cervical intervertebral disk degeneration (CIDD).

METHODS

The CIDD rat model was established, following which rats in the electroacupuncture (EA) group received EA. For overexpression of IL-22 or inhibition of JAK2-STAT3 signaling, the rats were injected intraperitoneally with recombinant IL-22 protein (p-IL-22) or the JAK2-STAT3 (Janus kinase 2-signal transducer and activator of transcription protein 3) inhibitor AG490 after model establishment. Rat nucleus pulposus (NP) cells were isolated and cultured. Cell counting kit-8 and flow cytometry were used to analyze the viability and apoptosis of the NP cells. Expression of IL-22, JAK2 and STAT3 was determined using RT-qPCR. Expression of IL-22/JAK2-STAT3 pathway and apoptosis related proteins was detected by Western blotting (WB).

RESULTS

EA protected the NP tissues of CIDD rats by regulating the IL-22/JAK2-STAT3 pathway. Overexpression of IL-22 significantly promoted the expression of tumor necrosis factor (TNF)-α, IL-6, IL-1β, matrix metalloproteinase (MMP)3 and MMP13 compared with the EA group. WB demonstrated that the expression of IL-22, p-JAK2, p-STAT3, caspase-3 and Bax in NP cells of the EA group was significantly reduced and Bcl-2 elevated compared with the model group. EA regulated cytokines and MMP through activation of IL-22/JAK2-STAT3 signaling in CIDD rat NP cells.

CONCLUSION

We demonstrated that EA affected apoptosis by regulating the IL-22/JAK2-STAT3 pathway in NP cells and reducing inflammatory factors in the CIDD rat model. The results extend our knowledge of the mechanisms of action underlying the effects of EA as a potential treatment approach for CS in clinical practice.

Micro(nano)-plastics exposure induced programmed cell death and corresponding influence factors

Plastic products have played an indispensable role in our daily lives for several decades, primarily due to their cost-effectiveness and unmatched convenience. Nevertheless, recent developments in nanotechnology have propelled our attention toward a distinct category of plastic fine particulates known as micro(nano)-plastics (MPs/NPs). The investigation of the cytotoxic effects of MPs/NPs has emerged as a central and burgeoning area of research in environmental toxicology and cell biology. In the scope of this comprehensive review, we have meticulously synthesized recent scientific inquiries to delve into the intricate interplay between MPs/NPs and programmed cell death mechanisms, which encompass a range of highly regulated processes. First, the signaling pathways and molecular mechanisms of different programmed death modalities induced by MPs/NPs were elaborated, including apoptosis, autophagy, necroptosis, ferroptosis, and pyroptosis. The causes of different programmed deaths induced by MPs/NPs, such as size, surface potential, functional group modification, aging, biological crown, and co-exposure of MPs/NPs are further analyzed. In contrast, the various cellular programmed death modes induced by MPs/NPs are not alone most of the time, and lastly, the connections between different cellular programmed death modes induced by MPs/NPs, such as interconversion, mutual promotion, and mutual inhibition, are explained. Our primary objective is to unveil the multifaceted toxicological implications of MPs/NPs on the intricate web of cellular fate and biological homeostasis. This endeavor not only broadens our understanding of the potential risks associated with MPs/NPs exposure but also underscores the urgent need for comprehensive risk assessments and regulatory measures in the context of environmental health.

Immune modulation in malignant pleural effusion: from microenvironment to therapeutic implications

Immune microenvironment and immunotherapy have become the focus and frontier of tumor research, and the immune checkpoint inhibitors has provided novel strategies for tumor treatment. Malignant pleural effusion (MPE) is a common end-stage manifestation of lung cancer, malignant pleural mesothelioma and other thoracic malignancies, which is invasive and often accompanied by poor prognosis, affecting the quality of life of affected patients. Currently, clinical therapy for MPE is limited to pleural puncture, pleural fixation, catheter drainage, and other palliative therapies. Immunization is a new direction for rehabilitation and treatment of MPE. The effusion caused by cancer cells establishes its own immune microenvironment during its formation. Immune cells, cytokines, signal pathways of microenvironment affect the MPE progress and prognosis of patients. The interaction between them have been proved. The relevant studies were obtained through a systematic search of PubMed database according to keywords search method. Then through screening and sorting and reading full-text, 300 literatures were screened out. Exclude irrelevant and poor quality articles, 238 literatures were cited in the references. In this study, the mechanism of immune microenvironment affecting malignant pleural effusion was discussed from the perspectives of adaptive immune cells, innate immune cells, cytokines and molecular targets. Meanwhile, this study focused on the clinical value of microenvironmental components in the immunotherapy and prognosis of malignant pleural effusion.

IL-22 Binding Protein Controls IL-22-Driven Bleomycin-Induced Lung Injury

The high mortality rates of acute lung injury and acute respiratory distress syndrome challenge the field to identify biomarkers and factors that can be exploited for therapeutic approaches. IL-22 is a cytokine that has antibacterial and reparative properties in the lung. However, it also can exacerbate inflammation and requires tight control by the extracellular inhibitory protein known as IL-22 binding protein (IL-22BP) (Il22ra2). This study showed the necessity of IL-22BP in controlling and preventing acute lung injury using IL-22BP knockout mice (Il22ra2-/-) in the bleomycin model of acute lung injury/acute respiratory distress syndrome. Il22ra2-/- mice had greater sensitivity (weight loss and death) and pulmonary inflammation in the acute phase (first 7 days) of the injury compared with wild-type C57Bl/6 controls. The inflammation was driven by excess IL-22 production, inducing the influx of pathogenic IL-17A+ γδ T cells to the lung. Interestingly, this inflammation was initiated in part by the noncanonical IL-22 signaling to macrophages, which express the IL-22 receptor (Il22ra1) in vivo after bleomycin challenge. This study further showed that IL-22 receptor alpha-1+ macrophages can be stimulated by IL-22 to produce a number of IL-17-inducing cytokines such as IL-1β, IL-6, and transforming growth factor-β1. Together, the results suggest that IL-22BP prevents IL-22 signaling to macrophages and reduces bleomycin-mediated lung injury.

Interleukin-22 promotes proliferation and reverses LPS-induced apoptosis and steroidogenesis attenuation in human ovarian granulosa cells: implications for polycystic ovary syndrome pathogenesis

OBJECTIVE

Interleukin 22 (IL-22) plays a role in inflammatory diseases. However, whether IL-22 affects the function of ovarian granulosa cells (GCs) and its relationship with Polycystic Ovary Syndrome (PCOS)remains unclear.

METHODS

We investigated the level of IL-22 in human follicular fluid using ELISA. The expression and localization of the IL-22 receptor 1 (IL-22R1) in GCs were investigated by RT-PCR and immunofluorescence staining, respectively. The proliferation of KGN cells (human GCs line) was assessed by CCK-8 assay and EdU assay after treatment with recombinant human IL-22 (rhIL-22) and lipopolysaccharide (LPS). Apoptosis was assessed using flow cytometry. Apoptotic proteins and steroidogenic genes were detected by western blotting.

RESULTS

ELISA's results showed that compared with the control group, PCOS patients showed lower expression of IL-22 in follicular fluid. Immunofluorescence showed that IL-22R1 is expressed and localized in human granulosa cell membranes. IL-22 promoted cell proliferation and reversed LPS-induced inhibition of cell proliferation. IL-22 alone did not affect apoptotic or steroidogenic protein expression, however, it reversed LPS-induced apoptosis via downregulation of Bcl-2, upregulation of Bax and cleaved caspase-3, and restoration of LPS-downregulated StAR, CYP11A1, and CYP19A1 expression. Western blotting confirmed that IL-22 activated the JAK2/STAT3 signaling.

CONCLUSION

IL-22 promotes cell proliferation, inhibits apoptosis, and regulates KGN cell steroidogenesis confronted with LPS, and decreased IL-22 may be involved in the development of PCOS.

Small interference (RNAi) technique: Exploring its clinical applications, benefits and limitations

BACKGROUND

Small interference RNA (siRNA) has emerged as the most desired method for researchers and clinicians who wish to silence a specific gene of interest and has been extensively developed as a therapeutic agent. This review points to collecting all clinical trials on siRNA and understanding its benefits, pharmacokinetics and safety by reading articles published in the last 5 years.

MATERIALS AND METHODS

Searching in the PubMed database using 'siRNA' and 'in vivo' with limits to articles published in the previous 5 years, article type 'clinical trials' and language 'English' to acquire papers on in vivo studies on siRNA approaches. Features of siRNA clinical trials registered at https://clinicaltrials.gov/ were analysed.

RESULTS

So far, 55 clinical studies have been published on siRNA. Many published clinical trials on siRNA showed tolerability, safety and effectiveness in treating cancers like breast, lung, colon, and other organs and other diseases like viral infections and hereditary diseases. Many different routes of administration can silence many genes at the same time. Limitations and uncertainties associated with siRNA treatment include the effectiveness of cellular uptake, precise targeting of the intended tissue or cell and prompt elimination from the body.

CONCLUSIONS

The siRNA or RNAi method will be one of the most critical and influential techniques to fight against many different diseases. Although the RNAi approach has certain advantages, it also has limitations concerning clinical applications. Overcoming these limitations remains a daunting challenge.

Advances in Lung Cancer Treatment Using Nanomedicines

Carcinoma of the lungs is among the most menacing forms of malignancy and has a poor prognosis, with a low overall survival rate due to delayed detection and ineffectiveness of conventional therapy. Therefore, drug delivery strategies that may overcome undesired damage to healthy cells, boost therapeutic efficacy, and act as imaging tools are currently gaining much attention. Advances in material science have resulted in unique nanoscale-based theranostic agents, which provide renewed hope for patients suffering from lung cancer. Nanotechnology has vastly modified and upgraded the existing techniques, focusing primarily on increasing bioavailability and stability of anti-cancer drugs. Nanocarrier-based imaging systems as theranostic tools in the treatment of lung carcinoma have proven to possess considerable benefits, such as early detection and targeted therapeutic delivery for effectively treating lung cancer. Several variants of nano-drug delivery agents have been successfully studied for therapeutic applications, such as liposomes, dendrimers, polymeric nanoparticles, nanoemulsions, carbon nanotubes, gold nanoparticles, magnetic nanoparticles, solid lipid nanoparticles, hydrogels, and micelles. In this Review, we present a comprehensive outline on the various types of overexpressed receptors in lung cancer, as well as the various targeting approaches of nanoparticles.

T lymphocyte cell: A pivotal player in lung cancer

Lung cancer is responsible for the leading cause of cancer-related death worldwide, which lacks effective therapies. In recent years, accumulating evidence on the understanding of the antitumor activity of the immune system has demonstrated that immunotherapy is one of the powerful alternatives in lung cancer therapy. T cells are the core of cellular immunotherapy, which are critical for tumorigenesis and the treatment of lung cancer. Based on the different expressions of surface molecules and functional points, T cells can be subdivided into regulatory T cells, T helper cells, cytotoxic T lymphocytes, and other unconventional T cells, including γδ T cells, nature killer T cells and mucosal-associated invariant T cells. Advances in our understanding of T cells' functional mechanism will lead to a number of clinical trials on the discovery and development of new treatment strategies. Thus, we summarize the biological functions and regulations of T cells on tumorigenesis, progression, metastasis, and prognosis in lung cancer. Furthermore, we discuss the current advancements of technologies and potentials of T-cell-oriented therapeutic targets for lung cancer.

MicroRNAs as the critical regulators of cell migration and invasion in thyroid cancer

Thyroid cancer (TC) is one of the most frequent endocrine malignancies that is more common among females. Tumor recurrence is one of the most important clinical manifestations in differentiated TC which is associated with different factors including age, tumor size, and histological features. Various molecular processes such as genetic or epigenetic modifications and non-coding RNAs are also involved in TC progression and metastasis. The epithelial-to-mesenchymal transition (EMT) is an important biological process during tumor invasion and migration that affects the initiation and transformation of early-stage tumors into invasive malignancies. A combination of transcription factors, growth factors, signaling pathways, and epigenetic regulations affect the thyroid cell migration and EMT process. MicroRNAs (miRNAs) are important molecular factors involved in tumor metastasis by regulation of EMT-activating signaling pathways. Various miRNAs are involved in the signaling pathways associated with TC metastasis which can be used as diagnostic and therapeutic biomarkers. Since, the miRNAs are sensitive, specific, and non-invasive, they can be suggested as efficient and optimal biomarkers of tumor invasion and metastasis. In the present review, we have summarized all of the miRNAs which have been significantly involved in thyroid tumor cells migration and invasion. We also categorized all of the reported miRNAs based on their cellular processes to clarify the molecular role of miRNAs during thyroid tumor cell migration and invasion. This review paves the way of introducing a non-invasive diagnostic and prognostic panel of miRNAs in aggressive and metastatic TC patients.

Th22 Cells/IL-22 Serves as a Protumor Regulator to Drive Poor Prognosis through the JAK-STAT3/MAPK/AKT Signaling Pathway in Non-Small-Cell Lung Cancer

The interaction of immune cells and cytokines in the tumor microenvironment affects the development and prognosis of tumors with an unclear potential regulatory mechanism. Recent studies have elucidated the protumor role of Th22 cells and its lineage-specific cytokine IL-22 in different human cancers. The present study is aimed at investigating the biological effect of Th22 cells/IL-22 and its molecular mechanism in the pathogenesis process of non-small-cell lung cancer (NSCLC). It was initially found that Th22 cells were enriched in the peripheral blood of NSCLC patients. The level of Th22 cells in peripheral blood mononuclear cells (PBMCs) was positively correlated with the TNM stage, lymph node metastasis, and clinical tumor biomarkers. Furthermore, IL-22 not only antagonized the apoptosis inducing and cell cycle arresting effect by chemotherapy and molecular targeted drugs on NSCLC cell lines but also promoted tumor cell proliferation and tumor tissue growth. Moreover, IL-22 activated the JAK-STAT3/MAPK/AKT signaling pathway, both in vitro and in vivo. Conclusively, the present results confirm that Th22 cells/IL-22 may serve as a negative immune regulator in lung cancer.

Th17 cells and their related cytokines: vital players in progression of malignant pleural effusion

Malignant pleural effusion (MPE) is an exudative effusion caused by primary or metastatic pleural carcinosis. Th17 cells and their cytokines are critical components in various disease including MPE. In this review, we summarize current published articles regarding the multifunctional roles of Th17 cells and their related cytokines in MPE. Th17 cells are accumulated in MPE compared with paired serum via certain manners. The upregulation of Th17 cells and the interactions between Th17 cells and other immune cells, such as Th1 cells, Th9 cells, regulatory T cells and B cells, are reported to be involved in the formation and development of MPE. In addition, cytokines, which are elaborated by Th17 cells, including IL-17A, IL-17F, IL-21, IL-22, IL-26, GM-CSF, or associated with Th17 cells differentiation, including IL-1β, IL-6, IL-23, TGF-β, are linked to the pathogenesis of MPE through exerting pro- or anti-tumorigenic functions on their own as well as regulating the generation and differentiation of Th17 cells in MPE. Based on these findings, we proposed that Th17 cells and their cytokines might be diagnostic or prognostic tools and potential therapeutic targets for MPE.

Multicellular Effects of STAT3 in Non-small Cell Lung Cancer: Mechanistic Insights and Therapeutic Opportunities

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and accounts for 85% of lung cancer cases. Aberrant activation of the Signal Transducer and Activator of Transcription 3 (STAT3) is frequently observed in NSCLC and is associated with a poor prognosis. Pre-clinical studies have revealed an unequivocal role for tumor cell-intrinsic and extrinsic STAT3 signaling in NSCLC by promoting angiogenesis, cell survival, cancer cell stemness, drug resistance, and evasion of anti-tumor immunity. Several STAT3-targeting strategies have also been investigated in pre-clinical models, and include preventing upstream receptor/ligand interactions, promoting the degradation of STAT3 mRNA, and interfering with STAT3 DNA binding. In this review, we discuss the molecular and immunological mechanisms by which persistent STAT3 activation promotes NSCLC development, and the utility of STAT3 as a prognostic and predictive biomarker in NSCLC. We also provide a comprehensive update of STAT3-targeting therapies that are currently undergoing clinical evaluation, and discuss the challenges associated with these treatment modalities in human patients.

Rationalizing heptadecaphobia: TH 17 cells and associated cytokines in cancer and metastasis

Cancer is one of the leading causes of death worldwide. When cancer patients are diagnosed with metastasis, meaning that the primary tumor has spread to at least one different site, their life expectancy decreases dramatically. In the past decade, the immune system´s role in fighting cancer and metastasis has been studied extensively. Importantly, immune cells and inflammatory reactions generate potent antitumor responses but also contribute to tumor development. However, the molecular and cellular mechanisms underlying this dichotomic interaction between the immune system and cancer are still poorly understood. Recently, a spotlight has been cast on the distinct subsets of immune cells and their derived cytokines since evidence has implicated their crucial impact on cancer development. T helper 17 cell (TH 17) cells, which express the master transcriptional factor Retinoic acid-receptor-related orphan receptor gamma t, are among these critical cell subsets and are defined by their production of type 3 cytokines, such as IL-17A, IL-17F, and IL-22. Depending on the tumor microenvironment, these cytokines can also be produced by other immune cell sources, such as T cytotoxic 17 cell, innate lymphoid cells, NKT cells, or γδ T cells. To date, a lot of data have been collected describing the divergent functions of IL-17A, IL-17F, and IL-22 in malignancies. In this comprehensive review, we discuss the role of these TH 17- and non-TH 17-derived type 3 cytokines in different tumor entities. Furthermore, we will provide a structured insight into the strict regulation and subsequent downstream mechanisms of these cytokines in cancer and metastasis.

Malignant Pleural Effusions-A Window Into Local Anti-Tumor T Cell Immunity?

The success of immunotherapy that targets inhibitory T cell receptors for the treatment of multiple cancers has seen the anti-tumor immune response re-emerge as a promising biomarker of response to therapy. Longitudinal characterization of T cells in the tumor microenvironment (TME) helps us understand how to promote effective anti-tumor immunity. However, serial analyses at the tumor site are rarely feasible in clinical practice. Malignant pleural effusions (MPE) associated with thoracic cancers are an abnormal accumulation of fluid in the pleural space that is routinely drained for patient symptom control. This fluid contains tumor cells and immune cells, including lymphocytes, macrophages and dendritic cells, providing a window into the local tumor microenvironment. Recurrent MPE is common, and provides an opportunity for longitudinal analysis of the tumor site in a clinical setting. Here, we review the phenotype of MPE-derived T cells, comparing them to tumor and blood T cells. We discuss the benefits and limitations of their use as potential dynamic biomarkers of response to therapy.

IL-22 Signaling in the Tumor Microenvironment

Interleukin (IL)-22 belongs to the IL-10 cytokine family which performs biological functions by binding to heterodimer receptors comprising a type 1 receptor chain (R1) and a type 2 receptor chain (R2). IL-22 is mainly derived from CD4+ helper T cells, CD8+ cytotoxic T cells, innate lymphocytes, and natural killer T cells. It can activate downstream signaling pathways such as signal transducer and activator of transcription (STAT)1/3/5, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT)-mammalian target of rapamycin (mTOR) through these heterodimer receptors. Although IL-22 is produced by immune cells, its specific receptor IL-22R1 is selectively expressed in nonimmune cells, such as hepatocytes, colonic epithelial cells, and pancreatic epithelial cells (Jiang et al. Hepatology 54(3):900-9, 2011; Jiang et al. BMC Cancer 13:59, 2013; Curd et al. Clin Exp Immunol 168(2):192-9, 2012). Immune cells do not respond to IL-22 stimulation directly within tumors, reports from different groups have revealed that IL-22 can indirectly regulate the tumor microenvironment (TME). In the present chapter, we discuss the roles of IL-22 in malignant cells and immunocytes within the TME, meanwhile, the potential roles of IL-22 as a target for drug discovery will be discussed.

Helper T cells in malignant pleural effusion

Malignant pleural effusion (MPE) is a frequent complication of malignancies and poses a clinical problem. CD4⁺ T lymphocytes are the most frequent cell population in MPE. Traditionally, CD4⁺ T cells are classified into two subsets based on cytokine production profiles, type 1 (Th1) and type 2 (Th2) helper T cells, which exhibit distinct functions. Recently, other T-cell subsets have been added to the Th-cell "portfolio", including regulatory T, Th17, Th9, and Th22 cells. The current review focuses on summarizing the Th-cell phenotypic characteristics, mechanism of Th-cell differentiation, and their pleural space recruitment, based on recent research. We also describe the interplay in MPE among different Th cells, as well as Th cells and lung cancer cells or mesothelial cells. Future research should expand the landscape map of human MPE immune cells, explore the immuno-regulation of B cells, and investigate the communication between macrophages and Th cells in MPE, which may facilitate meaningful advancements in the diagnoses and therapeutics of MPE.

A Double Edged Sword Role of Interleukin-22 in Wound Healing and Tissue Regeneration

Wound healing and tissue regeneration is an intricate biological process that involves repair of cellular damage and maintenance of tissue integrity. Cascades involved in wound healing and tissue regeneration highly overlap with cancer causing pathways. Usually, subsequent tissue damage events include release of a number of cytokines to accomplish post-trauma restoration. IL-22 is one of the cytokines that are immediately produced to initiate immune response against several tissue impairments. IL-22 is a fundamental mediator in inflammation, mucous production, protective role against pathogens, wound healing, and tissue regeneration. However, accumulating evidence suggests pivotal role of IL-22 in instigation of various cancers due to its pro-inflammatory and tissue repairing activity. In this review, we summarize how healing effects of IL-22, when executed in an uncontrollable fashion can lead to carcinogenesis.

Ski mediates TGF-β1-induced fibrosarcoma cell proliferation and promotes tumor growth

Background: TGF-β1 promotes cell proliferation in only some tumors and exerts bidirectional regulatory effects on the proliferation of fibroblasts. This study intends to explore whether the mechanism is related to increased expression of Ski. Methods: Cell proliferation of the fibrosarcoma cell line L929 was assessed with an ELISA BrdU kit. The mRNA and protein expression levels of the corresponding factors were measured by RT-qPCR, immunohistochemistry or Western blotting in vitro and in vivo. Additionally, c-Ski was knocked down using RNAi. The expression of Ski in human dermatofibrosarcoma protuberans (DFSP) specimens was measured by immunohistochemistry. Results: TGF-β1 promoted the continued proliferation of L929 cells in a dose-dependent manner, with increased c-Ski expression levels. Conversely, inhibition of c-Ski significantly abrogated this unidirectional effect, significantly inhibited the decrease in p21 protein levels and did not affect the increase in p-Smad2/3 levels upon TGF-β1 treatment. Similarly, inhibition of c-Ski significantly abrogated the growth-promoting effect of TGF-β1 on xenograft tumors. Furthermore, we found that high expression of Ski in DFSP was correlated with a low degree of tumor differentiation. Conclusions: Our data reveal that high c-Ski expression is a cause of TGF-β1-promoted proliferation in fibrosarcoma tumor cells and show that inhibiting Ski expression might be effective for treating tumors with high Ski levels.

Low Interleukin-22 Binding Protein Is Associated With High Mortality in Alcoholic Hepatitis and Modulates Interleukin-22 Receptor Expression

INTRODUCTION

In alcoholic hepatitis (AH), high interleukin (IL)-22 production is associated with disease improvement, purportedly through enhanced infection resistance and liver regeneration. IL-22 binding protein (BP) binds and antagonizes IL-22 bioactivity, but data on IL-22BP in liver disease suggest a complex interplay. Despite the scarcity of human data, IL-22 is in clinical trial as treatment of AH. We, therefore, in patients with AH, described the IL-22 system focusing on IL-22BP and associations with disease course, and mechanistically pursued the human associations in vitro.

METHODS

We prospectively studied 41 consecutive patients with AH at diagnosis, days 7 and 90, and followed them for up to 1 year. We measured IL-22 pathway proteins in liver biopsies and blood and investigated IL-22BP effects on IL-22 in hepatocyte cultures.

RESULTS

IL-22BP was produced in the gut and was identifiable in the patients with AH' livers. Plasma IL-22BP was only 50% of controls and the IL-22/IL-22BP ratio thus elevated. Consistently, IL-22-inducible genes were upregulated in AH livers at diagnosis. Low plasma IL-22BP was closely associated with high 1-year mortality. In vitro, IL-22 stimulation reduced IL-22 receptor (R) expression, but coincubation with IL-22BP sustained IL-22R expression. In the AH livers, IL-22R mRNA expression was similar to healthy livers, although IL-22R liver protein was higher at diagnosis.

DISCUSSION

Plasma IL-22BP was associated with an adverse disease course, possibly because its low level reduces IL-22R expression so that IL-22 bioactivity was reduced. This suggests the IL-BP interplay to be central in AH pathogenesis, and in future treatment trials (see Visual abstract, Supplementary Digital Content 5, http://links.lww.com/CTG/A338).

IL-17-Producing Cells in Tumor Immunity: Friends or Foes?

IL-17 is produced by RAR-related orphan receptor gamma t (RORγt)-expressing cells including Th17 cells, subsets of γδT cells and innate lymphoid cells (ILCs). The biological significance of IL-17-producing cells is well-studied in contexts of inflammation, autoimmunity and host defense against infection. While most of available studies in tumor immunity mainly focused on the role of T-bet-expressing cells, including cytotoxic CD8⁺ T cells and NK cells, and their exhaustion status, the role of IL-17-producing cells remains poorly understood. While IL-17-producing T-cells were shown to be anti-tumorigenic in adoptive T-cell therapy settings, mice deficient in type 17 genes suggest a protumorigenic potential of IL-17-producing cells. This review discusses the features of IL-17-producing cells, of both lymphocytic and myeloid origins, as well as their suggested pro- and/or anti-tumorigenic functions in an organ-dependent context. Potential therapeutic approaches targeting these cells in the tumor microenvironment will also be discussed.

Interleukin-22 Mediates the Chemotactic Migration of Breast Cancer Cells and Macrophage Infiltration of the Bone Microenvironment by Potentiating S1P/SIPR Signaling

The interleukin-22 (IL-22) signaling pathway is well known to be involved in the progression of various cancer types but its role in bone metastatic breast cancer remains unclear. We demonstrate using human GEO profiling that bone metastatic breast cancer displays elevated interleukin-22 receptor 1 (IL-22R1) and sphingosine-1-phosphate receptor 1 (S1PR1) expression. Importantly, IL-22 stimuli promoted the expression of IL-22R1 and S1PR1 in aggressive MDA-MB-231 breast cancer cells. IL-22 treatment also increased sphingosine-1-phosphate production in mesenchymal stem cells (MSCs) and induced the sphingosine-1-phosphate (S1P)-mediated chemotactic migration of MDA-MB-231 cells. This effect was inhibited by an S1P antagonist. In addition to the S1PR1 axis, IL-22 stimulated the expression of matrix metalloproteinase-9 (MMP-9), thereby promoting breast cancer cell invasion. Moreover, IL-22 induced IL22R1 and S1PR1 expression in macrophages, myeloid cell, and MCP1 expression in MSCs to facilitate macrophage infiltration. Immunohistochemistry indicated that IL-22R1 and S1PR1 are overexpressed in invasive malignant breast cancers and that this correlates with the MMP-9 levels. Collectively, our present results indicate a potential role of IL-22 in driving the metastasis of breast cancers into the bone microenvironment through the IL22R1-S1PR1 axis.

IL-22 Confers EGFR-TKI Resistance in NSCLC via the AKT and ERK Signaling Pathways

Background: The efficacy of an EGFR-targeted treatment strategy for non-small cell lung cancer (NSCLC) is reduced by drug resistance. IL-22 enhances tumor growth and induces chemotherapy resistance in human lung cancer cells. The present study elucidated the IL-22-induced mechanism underlying EGFR-tyrosine kinase inhibitor (TKI) resistance in NSCLC.

Methods: The plasma and tissues of patients who received EGFR-TKIs were utilized to determine the association between IL-22 expression and gefitinib efficacy. The IL-22 effect on the EGFR/ERK/AKT pathways in NSCLC HCC827 and PC-9 cells was determined using the CCK-8 assay, western blot, and flow cytometric analysis. A PC-9 xenograft model of IL-22 exposure was established. Gefitinib was administered to mice in combination with IL-22 or vehicle.

Results: We showed that IL-22 expression was higher in the EGFR-TKI-resistant group compared to EGFR-TKI-sensitive group. IL-22 expression was associated with EGFR-TKI efficacy in plasma. Additional treatment of IL-22 induced gefitinib resistance and reduced apoptosis in PC-9 and HCC827 cell lines. Furthermore, we showed that the effects of IL-22 attributed to p-ERK, p-EGFR, and p-AKT up-regulation. IL-22 neutralizing antibody completely abrogated the effects of IL-22 on apoptosis and AKT/EGFR/ERK signaling. Finally, we showed that IL-22 enhanced tumor growth and induced gefitinib resistance in the PC-9 xenograft model. Moreover, compared with gefitinib alone, the combination of IL-22 and gefitinib led to an increase in Ki67-positive staining and a reduction in TUNEL staining.

Conclusions: Our findings indicate that IL-22 plays a role in tumor progression and EGFR-TKI resistance in NSCLC. Thus, IL-22 might serve as a novel biomarker to overcome resistance of EGFR-TKI.

IL22 furthers malignant transformation of rat mesenchymal stem cells, possibly in association with IL22RA1/STAT3 signaling

Mesenchymal stem cells (MSCs) hold great promise as potential therapies for tumors through the delivery of various anticancer agents. However, exogenous tissue‑derived MSCs, such as those of bone marrow, have exhibited a tendency for malignant transformation in the tumor microenvironment. This issue remains controversial and is poorly understood. In the present study, the role of interleukin 22 (IL22)/IL22 receptor subunit α 1 (IL22RA1) and signal transducer and activator of transcription 3 (STAT3) signaling in the malignant transformation of MSCs was investigated. Following isolation of rat MSCs and their indirect co‑culture with C6 glioma cells, the transformed MSCs exhibited tumor cell characteristics. The Cancer Genome Atlas‑Glioblastoma Multiforme analysis revealed that primary and recurrent glioblastomas have increased IL22RA1 expression, compared with normal tissues, whereas the expression of IL22 was low in glioblastoma and normal tissues. mRNA and protein expression levels of IL22RA1 were significantly increased in the MSCs co‑cultured with C6 glioma cells. Furthermore, MSCs incubated with IL22 exhibited increased proliferation, migration and invasion. STAT3 demonstrated activation and nuclear translocation in the presence of IL22. Additionally, STAT3 small interfering RNA significantly inhibited the migration and invasion ability of MSCs, and the expression of the STAT3 downstream targets cyclin D1 and B‑cell lymphoma‑extra large under IL22 stimulation, indicating that IL22 also promoted MSC migration and invasion through STAT3 signaling. These data indicated that IL22 serves a critical role in the malignant transformation of rat MSCs, which is associated with an enhancement of the IL22RA1/STAT3 signaling pathway in the tumor microenvironment.

Interleukin-22 Promotes Osteosarcoma Cell Proliferation and Invasion via STAT3 Activation

BACKGROUND Interleukin-22 (IL-22) is one of the cytokines secreted by T-helper 17 (Th17) cells. It belongs to the IL-10 cytokine family and influences a variety of immune reactions. Studies have indicated that IL-22 can promote cancer progression and metastases. However, the function of IL-22 in osteosarcoma (OS) remains unclear. MATERIAL AND METHODS In this study, the expression of IL-22 in the OS cell line was detected by qRT-PCR. The role of IL-22 in proliferation and invasion in OS cells was tested by MTT and Transwell assays. The protein expression of STAT3, phospho-STAT3, AKT, and phospho-AKT was detected by Western blot analysis. RESULTS The results showed that IL-22 was upregulated in OS cells. IL-22 dose-independently promoted OS cells proliferation and invasion, which could be reversed by IL-22 antibody or STAT3 siRNA. Furthermore, IL-22 exposure of OS cells resulted in dose-independently increased levels of phosphorylated STAT3 protein kinases. Interestingly, IL-22 did not influence the expression of phosphorylated AKT. CONCLUSIONS These results suggest that IL-22 promotes OS cells proliferation and invasion and its effect is mediated by activation of the STAT3 pathway. These findings demonstrate that IL-22 may serve as a promising molecular biomarker for diagnosis and therapy for OS patients.

Recruitment and significance of Th22 cells and Th17 cells in malignant ascites

T helper (Th)22 and Th17 cells are implicated in the pathogenesis of a number of types of cancer. However, the function of Th22 and Th17 cells in malignant ascites (MA) remains unknown. The present study aimed at examining the distribution, phenotypes, recruitment, and prognostic value of Th22 and Th17 cells in MA from patients with hepatocellular carcinoma (HCC). A total of 26 patients with HCC with MA and 15 healthy controls were included in the present study. The proportion of Th22 cells, Th17 cells, C-C motif chemokine receptor (CCR)4, CCR6 and CCR10 were examined using flow cytometry. Interleukin (IL-)22, IL-17, C-C motif chemokine ligand (CCL)20, CCL22 and CCL27 were investigated using ELISA. In addition, the chemoattractant activity of chemokines for Th22 and Th17 cells in vitro were examined via a chemotaxis assay. The results of the present study demonstrated that Th22 cells, Th17 cells, IL-22 and IL-17 were significantly increased in MA compared with the corresponding blood and peripheral blood from healthy controls. Additionally, Th22 cells expressed increased concentrations of CCR6, CCR4 and CCR10, and Th17 cells expressed increased concentrations of CCR4 and CCR6 in MA compared with the corresponding blood. The chemotaxis assay revealed that CCL20/CCR6, CCL22/CCR4 and CCL27/CCR10 were responsible for the recruitment of Th22 cells into MA, whereas CCL22/CCR4 was responsible for the recruitment of Th17 cells. Furthermore, the patients with an increased number of Th17 cells exhibited an increased survival time compared with patients with a limited number of Th17 cells. Th22 and Th17 cells serve an important function in the development of MA, and the accumulation of Th22 and Th17 cells in MA may be due to a local increase in proinflammatory cytokines and chemokines. Increased Th17 cell numbers in MA may indicate the improvement of patient survival.

IL22 Promotes Kras-Mutant Lung Cancer by Induction of a Protumor Immune Response and Protection of Stemness Properties

Somatic KRAS mutations are the most common oncogenic variants in lung cancer and are associated with poor prognosis. Using a Kras-induced lung cancer mouse model, CC-LR, we previously showed a role for inflammation in lung tumorigenesis through activation of the NF-κB pathway, along with induction of interleukin 6 (IL6) and an IL17-producing CD4+ T-helper cell response. IL22 is an effector molecule secreted by CD4+ and γδ T cells that we previously found to be expressed in CC-LR mice. IL22 mostly signals through the STAT3 pathway and is thought to act exclusively on nonhematopoietic cells with basal IL22 receptor (IL22R) expression on epithelial cells. Here, we found that higher expression of IL22R1 in patients with KRAS-mutant lung adenocarcinoma was an independent indicator of poor recurrence-free survival. We then showed that genetic ablation of Il22 in CC-LR mice (CC-LR/IL22KO mice) caused a significant reduction in tumor number and size. This was accompanied by significantly lower tumor cell proliferation, angiogenesis, and STAT3 activation. Il22 ablation was also associated with significant reduction in lung-infiltrating inflammatory cells and expression of protumor inflammatory cytokines. Conversely, this was accompanied with increased antitumor Th1 and cytotoxic CD8+ T-cell responses, while suppressing the protumor immunosuppressive T regulatory cell response. In CC-LR/IL22KO mice, we found significantly reduced expression of core stemness genes and the number of prototypical SPC+CCSP+ stem cells. Thus, we conclude that IL22 promotes Kras-mutant lung tumorigenesis by driving a protumor inflammatory microenvironment with proliferative, angiogenic, and stemness contextual cues in epithelial/tumor cells. Cancer Immunol Res; 6(7); 788-97. ©2018 AACR.

Interleukin-22 (IL-22) Regulates Apoptosis of Paclitaxel-Resistant Non-Small Cell Lung Cancer Cells Through C-Jun N-Terminal Kinase Signaling Pathway

BACKGROUND Reducing drug resistance in tumor cells has become an important issue for cancer treatment. The purpose of this study was to investigate whether IL-22 was involved in lung cancer cell resistance to paclitaxel (PTX), and to explore the underlying molecular mechanism. MATERIAL AND METHODS Non-small cell lung cancer (NSCLC) cell line A549 and the drug resistant cell line A549/PTX were used in the present study. The inhibitory rate of PTX on A549 and A549/PTX cell proliferation was determined by MTT assay and the half-maximal inhibitory concentration (IC50) value was calculated. The expression level of IL-22 was detected using Western blot and qRT-PCR. To elucidate the mechanism by which IL-22 is involved in PTX resistance, a stable IL-22-silenced A549/PTX cell line was generated by using IL-22-siRNA. Cell apoptosis was analyzed by flow cytometry, and the c-Jun N-terminal kinase (JNK) signal pathway was determined using Western blot analysis. RESULTS We found that IL-22 expression level was markedly higher in A549/PTX cells than in A549 cells, and IL-22 gene knockdown significantly enhanced the cell proliferation inhibition rate of PTX to A549/PTX cells and decreased the IC50 value of PTX to A549/PTX cells, indicating IL-22 was involved in cell PTX resistance. Our findings also suggest that IL-22 knockdown notably increased PTX induced apoptosis in A549/PTX cells. Moreover, the results showed that p-JNK and Caspase 3 expression were significantly increased in IL-22 knockdown A549/PTX cells, while Bcl-2 expression was significantly decreased. CONCLUSIONS IL-22 is involved in A549 cell resistance to PTX through regulating cell apoptosis via the JNK signaling pathway.

A catch-22: Interleukin-22 and cancer

Barrier surfaces of multicellular organisms are in constant contact with the environment and infractions to the integrity of epithelial surfaces is likely a frequent event. Interestingly, components of the immune system, that can be activated by environmental compounds such as the microbiota or nutrients, are interspersed among epithelial cells or directly underlie the epithelium. It is now appreciated that immune cells continuously receive and integrate signals from the environment. Curiously, such continuous reception of stimulation does not normally trigger an inflammatory response but mediators produced by immune cells in response to such signals seem to rather promote barrier integrity and repair. The molecular mediators involved in this process are poorly understood. In recent years, the cytokine interleukin-22, produced mainly by group 3 innate lymphoid cells (ILCs), has been studied as a paradigm for how immune cells can control various aspects of epithelial cell function because expression of its receptor is restricted to non-hematopoietic cells. We will summarize here the diverse roles of IL-22 for the malignant transformation of epithelial cells, for tumor growth, wound healing and tissue repair. Furthermore, we will discuss IL-22 as a potential therapeutic target.

Cancer cells induce interleukin-22 production from memory CD4+ T cells via interleukin-1 to promote tumor growth

IL-22 has been identified as a cancer-promoting cytokine that is secreted by infiltrating immune cells in several cancer models. We hypothesized that IL-22 regulation would occur at the interface between cancer cells and immune cells. Breast and lung cancer cells of murine and human origin induced IL-22 production from memory CD4+ T cells. In the present study, we found that IL-22 production in humans is dependent on activation of the NLRP3 inflammasome with the subsequent release of IL-1β from both myeloid and T cells. IL-1 receptor signaling via the transcription factors AhR and RORγt in T cells was necessary and sufficient for IL-22 production. In these settings, IL-1 induced IL-22 production from a mixed T helper cell population comprised of Th1, Th17, and Th22 cells, which was abrogated by the addition of anakinra. We confirmed these findings in vitro and in vivo in two murine tumor models, in primary human breast and lung cancer cells, and in deposited expression data. Relevant to ongoing clinical trials in breast cancer, we demonstrate here that the IL-1 receptor antagonist anakinra abrogates IL-22 production and reduces tumor growth in a murine breast cancer model. Thus, we describe here a previously unrecognized mechanism by which cancer cells induce IL-22 production from memory CD4+ T cells via activation of the NLRP3 inflammasome and the release of IL-1β to promote tumor growth. These findings may provide the basis for therapeutic interventions that affect IL-22 production by targeting IL-1 activity.

Tethering Interleukin-22 to Apolipoprotein A-I Ameliorates Mice from Acetaminophen-induced Liver Injury

Increasing evidence indicates that interleukin-22 (IL-22) holds tremendous potential as a protective agent in preventing liver injury, but its pleiotropic effects and pathogenic role in carcinogenesis, rheumatoid arthritis and psoriasis restrict its systemic application. Here, we first developed a nanoparticle (liposIA) as a liver-targeted agent through IL-22 tethered to apolipoprotein A-I (ApoA-I) in a gene therapy vector. LiposIA was prepared using thin film dispersion method and the complexes exhibited desirable nanoparticle size, fine polydisperse index, highly efficient transfection, and excellent serum and storage stability. Biodistribution and hepatic STAT3 phosphorylation studies revealed that IL-22 tethered to ApoA-I led to highly efficient liver targeting. More importantly, our studies showed that a single-dose of liposIA was able to protect mice against acetaminophen-induced liver injury and did not initiate inflammatory response or systemic toxicity in vivo. During this process, activated STAT3/Erk and Akt/mTOR signaling transductions were observed, as well as inhibition of reactive oxygen species (ROS) generation, which prevented mitochondrial dysfunction. These studies demonstrated that IL-22 tethered to apolipoprotein A-I could target and ameliorate acetaminophen-induced acute liver injury, which highlighted that a targeted strategy for IL-22 delivery might have broad utility for the protection of hepatocellular damage.

Anti-apoptotic effect of interleukin-22 on fibroblast-like synoviocytes in patients with rheumatoid arthritis is mediated via the signal transducer and activator of transcription 3 signaling pathway

AIM

Inadequate apoptosis of fibroblast-like synoviocytes (FLS) plays a crucial role in the immunopathogenesis of rheumatoid arthritis (RA). Interleukin-22 (IL-22) is a novel member of the cytokine network that has been found to be involved in the immunological process underlying RA. In this study, we investigated the effect of IL-22 on the survival of RA-FLS from RA patients and examined the possible mechanism to determine new therapeutic strategies for RA.

METHODS

FLS obtained from patients with RA were cultured in vitro and treated with sodium nitroprussiate (SNP) to induce apoptosis in the presence or absence of IL-22. RA-FLS viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RA-FLS apoptosis was analyzed by annexin V/propidium iodide staining (AV/PI). The levels of IL-22R1, pSTAT3-Y705, pSTAT3-S727, total STAT3, Bcl-xL and Bcl-2 were detected by Western blot analysis.

RESULTS

IL-22R1 was expressed on RA-FLS. IL-22 pretreatment at concentrations ranging from 10 to 100 ng/mL increased RA-FLS viability and prevented SNP-induced apoptosis. Treatment with the STAT3 inhibitors, HO3867 or STA21, reversed the protective effect of IL-22 on SNP-induced apoptosis of RA-FLS. IL-22-induced phosphorylation of STAT3 (pSTAT3-Y705 and pSTAT3-S727) was increased in RA-FLS. Also IL-22 increased Bcl-2 expression in SNP-treated RA-FLS, and the effect was reversed by treatment with HO3867 or STA21.

CONCLUSION

IL-22 protects against SNP-induced apoptosis in RA-FLS by activating the STAT3 pathway and the downstream target gene, Bcl-2. Therefore, therapeutic strategies that target the IL-22/STAT3 pathway are implicated as candidates for RA treatment.

The inflammatory cytokine IL-22 promotes murine gliomas via proliferation

Interleukin (IL)-22 is newly identified proinflammatory cytokine involved in the T helper (Th)17 and Th22 response. However, the possible role of IL-22 in glioma remains uncertain. The results of the present study demonstrated higher expression levels of IL-22 and the receptor IL-22BP in the brain of GL261 glioma-inoculation mice, suggesting the regulatory role of IL-22 in glioma. Injection of IL-22 increased the severity of glioma in vivo and higher expression levels of IL-6, IL-1β and tumor necrosis factor (TNF)-α were detected in the brain using ELISA following IL-22 injection. To elucidate the mechanism underlying the effects of IL-22, the present study aimed firstly to determine the expression levels of IL-22 receptor in a glioma cell line via reverse transcription quantitative polymerase chain reaction. IL-22 treatment significantly increased the expression levels of signal transducer and activator of transcription (STAT)3 and the mRNA expression levels of STAT6 compared with the vehicle control. These results suggested that IL-22 may activate the Janus kinase (JAK)/STAT signaling pathway in glioma. Furthermore, IL-22 positively regulated the proliferation of glioma, consistent with its role in vivo. Conversely, IL-22-deficient mice exhibited prolonged survival compared with wild-type (WT) mice, and the expression levels of inflammatory cytokines were decreased in the brain of IL-22 knock-out (KO) mice compared with WT mice. Concordant with these results, it was observed that IL-22-neutralising antibody was able to increase the survival of mice with glioma and attenuate the disease by significantly reducing the cytokine levels in the brain. In conclusion, the results of the present study demonstrated that expression levels of IL-22 in the brain of mice with glioma may enhance symptoms due to the increased cytokine production of IL-6, IL-1β and TNF-α; this is consistent with IL-6/JAK/STAT signalling activation in vitro. Decreasing the expression levels of IL-22, achieved either with IL-22-KO mice or IL-22-neutralising antibody demonstrated protective effects on glioma development. Therefore, IL-22 may serve as a potential therapeutic target for glioma.

Interleukin-22 and Cyclosporine in Aggressive Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinomas (SCCs) account for up to 10,000 deaths annually in the United States. Most of the more than 700,000 SCCs diagnosed are cured by excision with clear margins; however, metastasis can occur despite seemingly adequate treatment in some cases. Immune-suppressed organ transplant recipients are 60 to 100 times more likely to develop SCC than immune-competent individuals. Transplant-associated SCCs occur more frequently and behave more aggressively, showing higher risk of recurrence and metastasis. This article identifies a potential role for interleukin-22 in driving SCC proliferation, particularly in solid organ transplant recipients taking cyclosporine.

Emerging roles of T helper 17 and regulatory T cells in lung cancer progression and metastasis

Lung cancer is a leading cause of cancer-related deaths worldwide. Lung cancer risk factors, including smoking and exposure to environmental carcinogens, have been linked to chronic inflammation. An integral feature of inflammation is the activation, expansion and infiltration of diverse immune cell types, including CD4⁺ T cells. Within this T cell subset are immunosuppressive regulatory T (Treg) cells and pro-inflammatory T helper 17 (Th17) cells that act in a fine balance to regulate appropriate adaptive immune responses.In the context of lung cancer, evidence suggests that Tregs promote metastasis and metastatic tumor foci development. Additionally, Th17 cells have been shown to be an integral component of the inflammatory milieu in the tumor microenvironment, and potentially involved in promoting distinct lung tumor phenotypes. Studies have shown that the composition of Tregs and Th17 cells are altered in the tumor microenvironment, and that these two CD4⁺ T cell subsets play active roles in promoting lung cancer progression and metastasis.We review current knowledge on the influence of Treg and Th17 cells on lung cancer tumorigenesis, progression, metastasis and prognosis. Furthermore, we discuss the potential biological and clinical implications of the balance among Treg/Th17 cells in the context of the lung tumor microenvironment and highlight the potential prognostic function and relationship to metastasis in lung cancer.

Interleukin-22 promotes papillary thyroid cancer cell migration and invasion through microRNA-595/Sox17 axis

Interleukin-22 (IL-22) is an inflammatory cytokine mainly produced by activated Th17 and Th22 cells. The data presented here demonstrate that IL-22 induced the migration and invasion of papillary thyroid cancer (PTC) cells. MicroRNA expression analysis and functional studies indicated that IL-22-mediated migration and invasion is positively regulated by miR-595. Further mechanistic studies revealed that sex-determining region Y-box 17 (Sox17) is directly targeted by miR-595. We then demonstrated that IL-22 regulated migration and invasion of PTC cells via inhibiting Sox17 expression. Interestingly, in PTC cell lines and PTC tissues, expression of IL-22 and miR-595 was upregulated and Sox17 downregulated compared with normal thyroid, and their expression levels were closely correlated. Taken together, this present study suggests that IL-22 stimulation enhances the migration and invasion of PTC cells by regulating miR-595 and its target Sox17.

The IL-17-Th1/Th17 pathway: an attractive target for lung cancer therapy?

INTRODUCTION

There is strong pharmaceutical development of agents targeting the IL-17-TH17 pathway for the treatment of psoriasis (Ps) and psoriatic arthritis (PsA). Lung cancer accounts for 28% of all cancer-related deaths worldwide, and roughly 80% of patients with newly-diagnosed non-small cell lung cancer (NSCLC) present with metastatic disease, with a poor prognosis of around 12 months. Therefore, there is a high unmet medical need for the development of new and potent systemic treatments in this deadly disease. The emergence of immunotherapies such as anti-PD-1 or anti-PDL1 as candidate therapies in non-small cell lung cancer (NSCLC) indicates that targeting critical immuno-modulatory cytokines including those within the IL-17-Th1/Th17 axis may have proven benefit in the treatment of lung cancer. Areas covered: In this review we describe the current evidence for aberrant IL-17-Th1/Th17 settings in cancer, particularly with regard to targeting this axis in NSCLC. We further discuss the current agents under pharmaceutical development which could potentially target this axis, and discuss the current limitations and areas of concern regarding the use of these in lung cancer. Expert opinion: Current evidence suggests that moving forward agents targeting the IL-17-Th1/Th17 pathway may have novel new oncoimmunology indications in the treatment paradigm for NSCLC.

Interleukin-22 is elevated in lavage from patients with lung cancer and other pulmonary diseases

BACKGROUND

Interleukin-22 (IL-22) is involved in lung diseases such as pneumonia, asthma and lung cancer. Lavage mirrors the local environment, and may provide insights into the presence and role of IL-22 in patients.

METHODS

Bronchoscopic lavage (BL) samples (n = 195, including bronchoalveolar lavage and bronchial washings) were analysed for IL-22 using an enzyme-linked immunosorbent assay. Clinical characteristics and parameters from lavage and serum were correlated with lavage IL-22 concentrations.

RESULTS

IL-22 was higher in lavage from patients with lung disease than in controls (38.0 vs 15.3 pg/ml, p < 0.001). Patients with pneumonia and lung cancer had the highest concentrations (48.9 and 33.0 pg/ml, p = 0.009 and p < 0.001, respectively). IL-22 concentration did not correlate with systemic inflammation. IL-22 concentrations did not relate to any of the analysed cell types in BL indicating a potential mixed contribution of different cell populations to IL-22 production.

CONCLUSIONS

Lavage IL-22 concentrations are high in patients with lung cancer but do not correlate with systemic inflammation, thus suggesting that lavage IL-22 may be related to the underlying malignancy. Our results suggest that lavage may represent a distinct compartment where the role of IL-22 in thoracic malignancies can be studied.

The interplay between the microbiome and the adaptive immune response in cancer development

The data from different studies suggest a bacterial role in cancer genesis/progression, often modulating the local immune response. This is particularly so at the mucosal level where the bacterial presence is strong and the immune system is highly reactive. The epithelial surfaces of the body, such as the skin and mucosa, are colonized by a vast number of microorganisms, which represent the so-called normal microbiome. Normally the microbiome does not cause a proinflammatory response because the immune system has developed different strategies for the tolerance of commensal bacteria, but when these mechanisms are impaired or new pathogenic bacteria are introduced into this balanced system, the immune system reacts to the microbiome and can trigger tumor growth in the intestine. In this review, we discuss the potential role of the bacterial microbiome in carcinogenesis, focusing on the direct and indirect immune adaptive mechanisms, that the bacteria can modulate in different ways.

Proteomic-Based Approaches for the Study of Cytokines in Lung Cancer

Proteomic techniques are currently used to understand the biology of different human diseases, including studies of the cell signaling pathways implicated in cancer progression, which is important in knowing the roles of different proteins in tumor development. Due to its poor prognosis, proteomic approaches are focused on the identification of new biomarkers for the early diagnosis, prognosis, and targeted treatment of lung cancer. Cytokines are proteins involved in inflammatory processes and have been proposed as lung cancer biomarkers and therapeutic targets because it has been reported that some cytokines play important roles in tumor development, invasion, and metastasis. In this review, we aim to summarize the different proteomic techniques used to discover new lung cancer biomarkers and therapeutic targets. Several cytokines have been identified as important players in lung cancer using these techniques. We underline the most important cytokines that are useful as biomarkers and therapeutic targets. We also summarize some of the therapeutic strategies targeted for these cytokines in lung cancer.

Cyclosporine A immunosuppression drives catastrophic squamous cell carcinoma through IL-22

Immune-suppressed organ transplant recipients (OTRs) can develop catastrophic squamous cell carcinoma (SCC), characterized by multiple primary tumors, extensive body surface area involvement, or metastases. There are currently no curative systemic therapies available. We previously showed that IL-22 enhances SCC proliferation. Herein, we examined links between cyclosporine (CSA), IL-22, and SCC in patients, cell lines, and mice with UV light-induced SCC. Eighteen of 114 OTRs developed catastrophic SCC, which was strongly associated with CSA treatment. We found that CSA drives T cell polarization toward IL-22-producing T22 cells, and CSA treatment increased IL-22 receptor in SCC cells. SCC tissue from OTRs showed increased expression of IL-22RA1. CSA potentiated rescue by IL-22 of serum-starved SCC cells; treatment of SCC cells with IL-22 and CSA increased both their migratory and invasive capacity. In a UV-induced model of SCC in SKH-1 immunocompetent mice, treatment with anti-IL-22 antibody reduced tumor number and tumor burden. We found that catastrophic SCC in OTRs is associated with CSA use, which may be acting by favoring T22 polarization. Since anti-IL-22 antibody administration decreased tumor number and tumor burden in vivo, blockade of the IL-22 axis may be developed as a viable therapeutic option for catastrophic SCC.

The Role of IL-22 in Viral Infections: Paradigms and Paradoxes

Interleukin-22 (IL-22) is a member of the IL-10 family of cytokines. Hematopoietic cells express IL-22, and this cytokine signals through the heterodimeric IL-22 receptor expressed by non-hematopoietic cells. A growing body of evidence points toward a role for IL-22 in a diverse array of biological functions ranging from cellular proliferation, tissue protection and regeneration, and inflammation. In recent years, the role that IL-22 plays in antiviral immune responses has been examined in a number of infection models. Herein, we assess our current understanding of how IL-22 determines the outcome of viral infections and define common mechanisms that are evident from, sometimes paradoxical, findings derived from these studies. Finally, we discuss the potential therapeutic utility of IL-22 manipulation in the treatment and prevention of viral infections and associated pathologies.

Biological and pathological activities of interleukin-22

Interleukin (IL)-22, a member of the IL-10 family, is a cytokine secreted by several types of immune cells including IL-22(+)CD4(+) T cells (Th22) and IL-22 expressing innate leukocytes (ILC22). Recent studies have demonstrated that IL-22 is a key component in mucosal barrier defense, tissue repair, epithelial cell survival, and proliferation. Furthermore, accumulating evidence has defined both protective and pathogenic properties of IL-22 in a number of conditions including autoimmune disease, infection, and malignancy. In this review, we summarize the expression and signaling pathway and functional characteristics of the IL-22 and IL-22 receptor axis in physiological and pathological scenarios and discuss the potential to target IL-22 signaling to treat human diseases.

Interleukin-22 promotes lung cancer cell proliferation and migration via the IL-22R1/STAT3 and IL-22R1/AKT signaling pathways

Lung cancer continues to be an enormous burden on current health care systems throughout the world, with more than a million deaths every year. Previous studies have shown that interleukin-22 (IL-22) promotes survival and resistance to chemotherapy in human lung cancer cells. However, the association of IL-22 expression with recurrence of lung cancer is still unclear. In this study, we found that expression of IL-22 was upregulated in tumor tissues and serum from patients with recurrent non-small cell lung cancer (NSCLC) as compared to primary NSCLC samples. Treatment with IL-22 promoted cell proliferation and enhanced migration and invasion in A549 and H125 cell lines. Furthermore, we revealed that phosphorylation of STAT3 and AKT was highly induced by treatment with IL-22 via IL-22R1. IL-22R1 was also consistently overexpressed in recurrent NSCLC tissues. Finally, we found that siRNA-mediated depletion of IL-22R1 completely abrogated the effects of IL-22 treatment on cell proliferation and migration activity in NSCLC cell lines. Our findings indicate that IL-22 and IL-22R1 may be novel therapeutic targets for treatment of advanced NSCLC.

Intra-tumoral IFN-γ-producing Th22 cells correlate with TNM staging and the worst outcomes in pancreatic cancer

PDAC (pancreatic ductal adenocarcinoma) is the fifth leading cause of cancer-related death. The causes of this cancer remain unknown, but increasing evidence indicates a key role of the host immune response and cytokines in human carcinogenesis. Intra-tumoral IL (interleukin)-22 levels have been shown to be elevated in PDAC patients. However, little is known regarding the expression and clinical relevance of Th22 cells in human PDAC and, furthermore, which TILs (tumour-infiltrating lymphocytes) are the main producers of IL-22 is unknown. In the present study, we characterized the functional proprieties of the different subsets of IL-22-producing TILs and analysed their relationship with the TNM staging system and patient survival. We have demonstrated for the first time that, in PDAC patients, the T-cells co-producing IFN-γ (interferon γ) and exerting perforin-mediated cytotoxicity are the major intra-tumoral source of IL-22. In addition, isolated Th22 cells were able to induce apoptosis, which was antagonized by IL-22. Finally, we observed that the IL-22-producing T-cells were significantly increased in tumour tissue and that this increase was positively correlated with TNM staging of PDAC and poorer patient survival. These novel findings support the dual role of the anti-tumour immune system and that IL-22-producing cells may participate in PDAC pathogenesis. Therefore monitoring Th22 levels could be a good diagnostic parameter, and blocking IL-22 signalling may represent a viable method for anti-PDAC therapies.

Innate lymphoid cells involve in tumorigenesis

Innate lymphoid cells (ILCs) promptly initiate cytokine responses to pathogen exposure in the mucosa and mucosal-associated lymphoid tissues. ILCs were recently categorized as being of the lymphoid lineage and have been classified into three groups. ILCs play important roles in immunity against pathogens, and an anti-tumor immune-related function was recently demonstrated. In this review we discuss whether and how ILCs involve in the tumorigenesis, providing new insights into the mechanisms underlying the particular functions of ILCs as well as the potential targets for tumor intervention.

Clinical Implications of Hepatocyte Growth Factor, Interleukin-20, and Interleukin-22 in Serum and Bronchoalveolar Fluid of Patients with Non-Small Cell Lung Cancer

Hepatocyte growth factor (HGF) is involved in tumorigenesis, interleukin-20 (IL-20) is an inhibitor of angiogenesis, and interleukin-22 (IL-22) stimulates tumor growth. The aim of this study was to determine the level of HGF, IL-20, and IL-22 in both serum and bronchoalveolar lavage fluid (BALF) of non-small cell lung cancer (NSCLC) patients before onset of chemotherapy, the nature of the interrelationships between these markers, and their prognostic significance regarding post-chemotherapy survival time. We studied 46 NSCLC patients and 15 healthy subjects as a control group. We found significantly higher serum levels of HGF and IL-22 in the NSCLC patients than those in controls [pg/ml: HGF - 1911 (693-6510) vs. 1333 (838-3667), p = 0.0004; IL-22 - 10.66 (1.44-70.34) vs. 4.69 (0.35-12.29), p = 0.0007]. In contrast, concentrations of HGF and IL-22 in BALF were lower in NSCLC patients than those in controls [pg/ml: HGF - 72 (6-561) vs. 488 (14-2003), p = 0.0002; IL-22 - 2.28 (0.70-6.52) vs. 3.72 (2.76-5.64), p = 0.002]. In the NSCLC patients, there was a negative correlation between the serum level of IL-20 and time to tumor progression (r = -0.405, p = 0.04) and between the serum level of HGF and survival time (r = -0.41, p = 0.005). In addition, a higher serum level of HGF and a higher BALF level of IL-22 in patients were linked with a shorter overall survival. We conclude that HGF, IL-20, and IL-22 in the serum and BALF of NSCLC patients before chemotherapy may be a prognostic of cancer progression.

Th22 cells control colon tumorigenesis through STAT3 and Polycomb Repression complex 2 signaling

Th22 cells traffic to and retain in the colon cancer microenvironment, and target core stem cell genes and promote colon cancer stemness via STAT3 and H3K79me2 signaling pathway and contribute to colon carcinogenesis. However, whether Th22 cells affect colon cancer cell proliferation and apoptosis remains unknown. We studied the interaction between Th22 cells and colon cancer cells in the colon cancer microenvironment. Colon cancer proliferation was examined by flow cytometry analysis and H(3) thymidine incorporation. Cell cycle related genes were quantified by real-time PCR and Western blotting. We transfected colon cancer cells with lentiviral vector encoding specific gene shRNAs and used chromatin immunoprecipitation (ChIP) assay to determine the genetic signaling involved in interleukin (IL)-22-mediated colon cancer cell proliferation. We showed that Th22 cells released IL-22 and stimulated colon cancer proliferation. Mechanistically, IL-22 activated STAT3, and subsequently STAT3 bound to the promoter areas of the Polycomb Repression complex 2 (PRC2) components SUZ12 and EED, and stimulated the expression of PRC2. Consequently, the activated PRC2 catalyzed the promoters of the cell cycle check-point genes p16 and p21, and inhibited their expression through H3K27me3-mediated histone methylation, and ultimately caused colon cancer cell proliferation. Bioinformatics analysis revealed that the levels of IL-22 expression positively correlated with the levels of genes controlling cancer proliferation and cell cycling in colon cancer. In addition to controlling colon cancer stemness, Th22 cells support colon carcinogenesis via affecting colon cancer cell proliferation through a distinct histone modification.

Immunity, inflammation, and cancer: an eternal fight between good and evil

Cancer development and its response to therapy are strongly influenced by innate and adaptive immunity, which either promote or attenuate tumorigenesis and can have opposing effects on therapeutic outcome. Chronic inflammation promotes tumor development, progression, and metastatic dissemination, as well as treatment resistance. However, cancer development and malignant progression are also associated with accumulation of genetic alterations and loss of normal regulatory processes, which cause expression of tumor-specific antigens and tumor-associated antigens (TAAs) that can activate antitumor immune responses. Although signals that trigger acute inflammatory reactions often stimulate dendritic cell maturation and antigen presentation, chronic inflammation can be immunosuppressive. This antagonism between inflammation and immunity also affects the outcome of cancer treatment and needs to be considered when designing new therapeutic approaches.