IL-22-mediated tumor growth reduction correlates with inhibition of ERK1/2 and AKT phosphorylation and induction of cell cycle arrest in the G2-M phase

The role of IL-22 in cancer

Interleukin-22, discovered in the year of 2000, is a pleiotropic Th17 cytokine from the IL-10 family of cytokines. IL-22 signals through the type 2 cytokine receptor complex IL-22R and predominantly activates STAT3. This pathway leads to the transcription of several different types of genes, giving IL-22 context-specific functions ranging from inducing antimicrobial peptide expression to target cell proliferation. In recent years, it has been shown that IL-22 is involved in the pathogenesis of neoplasia in some cancers through its pro-proliferative and anti-apoptotic effects. This review highlights studies with recent discoveries and conclusions drawn on IL-22 and its involvement and function in various cancers. Such a study may be helpful to better understand the role of IL-22 in cancer so that new treatment could be developed targeting IL-22.

RORγT agonists as immune modulators in anticancer therapy

RORγT is a transcription factor that directs the development of Th17 lymphocytes and other IL-17-expressing cells (e.g., Tc17 and ILC3 cells). These cells are involved in the body's defense against pathogenic bacteria and fungi, but they also participate in maintaining the proinflammatory environment in some autoimmune diseases and play a role in the immune system's response to cancer. Similar to other members of the nuclear receptor superfamily, the activity of RORγT is regulated by low-molecular-weight ligands. Therefore, extensive efforts have been dedicated to identifying inverse agonists that diminish the activity of this receptor and subsequently inhibit the development of autoimmune diseases. Unfortunately, in the pursuit of an ideal inverse agonist, the development of agonists has been overlooked. It is important to remember that these types of compounds, by stimulating lymphocytes expressing RORγT (Th17 and Tc17), can enhance the immune system's response to tumors. In this review, we present recent advancements in the biology of RORγT agonists and their potential application in anticancer therapy.

Dual Functions of T Lymphocytes in Breast Carcinoma: From Immune Protection to Orchestrating Tumor Progression and Metastasis

Breast cancer (BC) is the most common cancer type in women and the second leading cause of death. Despite recent advances, the mortality rate of BC is still high, highlighting a need to develop new treatment strategies including the modulation of the immune system and immunotherapies. In this regard, understanding the complex function of the involved immune cells and their crosstalk with tumor cells is of great importance. T-cells are recognized as the most important cells in the tumor microenvironment and are divided into several subtypes including helper, cytotoxic, and regulatory T-cells according to their transcription factors, markers, and functions. This article attempts to provide a comprehensive review of the role of T-cell subsets in the prognosis and treatment of patients with BC, and crosstalk between tumor cells and T-cells. The literature overwhelmingly contains controversial findings mainly due to the plasticity of T-cell subsets within the inflammatory conditions and the use of different panels for their phenotyping. However, investigating the role of T-cells in BC immunity depends on a variety of factors including tumor types or subtypes, the stage of the disease, the localization of the cells in the tumor tissue and the presence of different cells or cytokines.

Interleukin-22 promotes the proliferation and migration of hepatocellular carcinoma cells via the phosphoinositide 3-kinase (PI3K/AKT) signaling pathway

BACKGROUND

Interleukin-22 (IL-22) is a pro-inflammatory cytokine released during the immune response in chronic liver injury. Although IL-22 mediates tissue regeneration, its uncontrolled production may generate a carcinogenic environment resulting in hepatocellular carcinoma (HCC). This study aims to identify the effect of IL-22 on anti-apoptotic and metastatic genes and the molecular pathways responsible for IL-22-mediated hepatic carcinogenesis.

METHODS AND RESULTS

Three cancerous liver lines, HepG2, SNU-387, Huh7, and one normal liver line, THLE2, were treated with IL-22. RT-qPCR analysis was conducted to study the role of IL-22 in altering the expression levels of anti-apoptotic genes, MCL-1 and BCL-2, and metastatic genes, MMP-7 and MMP-9. A significant increase in expression levels of these genes was observed after IL-22 treatment. Furthermore, to explore the major pathways involved in IL-22-mediated upregulation of anti-apoptotic and metastatic genes, cells were treated with inhibitors of JAK/STAT and PI3K/AKT pathways along with IL-22. Resultantly, a significant decrease in expression levels of target genes was observed, indicating the involvement of JAK/STAT and PI3K/AKT signaling cascades in IL-22-mediated oncogenesis. Finally, Cell Scratch assay was performed to check the effect of IL-22 and inhibitors of JAK/STAT and PI3K/AKT on the metastatic potential of liver cells. While migration was observed in Huh7 and THLE2 cells treated with IL-22, no migration was observed in cells treated with IL-22 along with JAK/STAT and PI3K/AKT inhibitors. Results indicate that IL-22 encourages metastasis in HCC cells via the JAK/STAT and PI3K/AKT pathways.

CONCLUSION

Results showed that IL-22 upregulates anti-apoptotic and metastatic genes in HCC through JAK/STAT and PI3K/AKT signaling pathways.

A Critical Role of the IL-22-IL-22 Binding Protein Axis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) ranks among the five most common cancer entities worldwide and leads to hundred-thousands of deaths every year. Despite some groundbreaking therapeutical revelations during the last years, the overall prognosis remains poor. Although the immune system fights malignant transformations with a robust anti-tumor response, certain immune mediators have also been shown to promote cancer development. For example, interleukin (IL)-22 has been associated with HCC progression and worsened prognosis in multiple studies. However, the underlying mechanisms of the pathological role of IL-22-signaling as well as the role of its natural antagonist IL-22 binding protein (IL-22BP) in HCC remain elusive. Here, we corroborate the pathogenic role of IL-22 in HCC by taking advantage of two mouse models. Moreover, we observed a protective role of IL-22BP during liver carcinogenesis. While IL-22 was mainly produced by CD4⁺ T cells in HCC, IL-22BP was abundantly expressed by neutrophils during liver carcinogenesis. Hepatocytes could be identified as a major target of this pathological IL-22-signaling. Moreover, abrogation of IL-22 signaling in hepatocytes in IL22ra1^flox/flox × Alb^Cre+ mice reduced STEAP4 expression-a known oncogene-in HCC in vivo. Likewise, STEAP4 expression correlated with IL22 levels in human HCC samples, but not in healthy liver specimens. In conclusion, these data encourage the development of therapeutical approaches that target the IL-22-IL-22BP axis in HCC.

Activated T cells are the cellular source of IL-22 that enhances proliferation and survival of lymphocytes in Nile tilapia

As a pleiotropic cytokine mainly secreted by CD4⁺ T cells, interleukin (IL)-22 plays an important role in immune regulation and infection elimination. Despite IL-22 homologues have been identified in non-mammal, whether and how IL-22 participates in the adaptive immune response of early vertebrates have not been fully addressed. In this study, we identified an evolutionarily conserved IL-22 from Nile tilapia Oreochromis niloticus (defined as OnIL-22), proved by its properties regarding sequence, gene structure, functional domain, tertiary structure and phylogeny. IL-22 was broadly expressed in lymphoid-related tissues of tilapia, and with relatively higher levels in skin, gill, intestine and liver. The expression of OnIL-22 in spleen lymphocytes was markedly induced at the adaptive immune stage after Streptococcus agalactiae infection. Moreover, once lymphocytes were activated by PMA plus ionomycin or T-cell specific mitogen PHA in vitro, OnIL-22 expression was obviously up-regulated at both mRNA and protein levels. These results thus suggest that activated T cells produce IL-22 to take part in the adaptive immune response of tilapia. Furthermore, treatment of lymphocytes with recombinant OnIL-22 increased the expression of genes related to proliferation and survival, and further promoted the proliferation and reduced the apoptosis of lymphocytes during bacterial infection or T-cell activation. These cellular effects of IL-22 seem to be associated with JAK1/STAT3 axis downstream of IL-22, because IL-22 application not only elevated the mRNA expression of JAK1 and STAT3, but also enhanced their phosphorylation in lymphocytes. Altogether, we suggest that activated T cells produce IL-22 to promote lymphocyte proliferation and survival probability via JAK1/STAT3 signaling pathway, thus participating in adaptive immune response of Nile tilapia. Our study therefore provides helpful perspective for understanding the function and mechanism of adaptive immune system in teleost.

IFNγ-IL-17-IL-22+CD4+ subset and IL-22-producing cells in tumor draining lymph nodes of patients with breast cancer

BACKGROUND

A recently introduced CD4+ T subset that mainly secretes interleukin (IL-) 22 has been reported to be associated with a variety of tumors, including colon, gastric, hepatocellular, and small- and large-cell lung carcinoma. Both tumor-promoting and - suppressing roles have been suggested for these cells. In the present study, we aimed to investigate the frequency of IL-22-producing subsets in tumor-draining lymph nodes (TDLNs) of the patients with breast cancer and determine their association with the clinicopathological characterizations of the disease.

METHODS

Thirty untreated women diagnosed with breast cancer were enrolled and their axillary lymph nodes were dissected during surgery. Mononuclear cells were isolated using Ficoll density gradient, activated, permeabilized, and stained by fluorochrome-conjugated antibodies against CD4, IL-22, IL-17, and IFNγ. The cells were then acquired on the FACSCalibur flow cytometer, and raw data was analyzed by the FlowJo software package (V10).

RESULTS

Our results demonstrated that 2.39% ± 0.39 of CD4+ lymphocytes in TDLNs of patients with breast cancer produced IL-22. Among them, 0.64% ± 0.8 just produced IL-22 but were negative for IFNγ and IL-17. Statistical analysis indicated that the frequency of CD4+IL-22+ cells was significantly higher in the patients with stage III and the ones with 3-9 tumor involved lymph nodes (N2) compared to those with stage II and those having 1-3 tumor involved lymph nodes (N1) (P = 0.008 and P = 0.004, respectively).

CONCLUSION

The higher frequency of IL-22-producing cells in draining lymph nodes of patients with more advanced tumors (higher stage (stage III) and more involved lymph nodes) suggests a role for IL-22-producing cells in the tumor progression and invasion. However, further studies with larger sample size and more functional studies are needed to clarify the role of IL-22-producing cells in breast cancer pathogenesis.

Multifaceted Roles of Chemokines and Chemokine Receptors in Tumor Immunity

Simple Summary

Various immune cells are involved in host immune responses to cancer. T-helper (Th) 1 cells, cytotoxic CD8⁺ T cells, and natural killer cells are the major effector cells in anti-tumor immunity, whereas cells such as regulatory T cells and myeloid-derived suppressor cells are negatively involved in anti-tumor immunity. Th2 cells and Th17 cells have been shown to have both pro-tumor and anti-tumor activities. The migratory properties of various immune cells are essential for their function and critically regulated by the chemokine superfamily. In this review, we summarize the roles of various immune cells in tumor immunity and their migratory regulation by the chemokine superfamily. We also assess the therapeutic possibilities of targeting chemokines and chemokine receptors in cancer immunotherapy.

Abstract

Various immune cells are involved in host tumor immune responses. In particular, there are many T cell subsets with different roles in tumor immunity. T-helper (Th) 1 cells are involved in cellular immunity and thus play the major role in host anti-tumor immunity by inducing and activating cytotoxic T lymphocytes (CTLs). On the other hand, Th2 cells are involved in humoral immunity and suppressive to Th1 responses. Regulatory T (Treg) cells negatively regulate immune responses and contribute to immune evasion of tumor cells. Th17 cells are involved in inflammatory responses and may play a role in tumor progression. However, recent studies have also shown that Th17 cells are capable of directly inducting CTLs and thus may promote anti-tumor immunity. Besides these T cell subsets, there are many other innate immune cells such as dendritic cells (DCs), natural killer (NK) cells, and myeloid-derived suppressor cells (MDSCs) that are involved in host immune responses to cancer. The migratory properties of various immune cells are critical for their functions and largely regulated by the chemokine superfamily. Thus, chemokines and chemokine receptors play vital roles in the orchestration of host immune responses to cancer. In this review, we overview the various immune cells involved in host responses to cancer and their migratory properties regulated by the chemokine superfamily. Understanding the roles of chemokines and chemokine receptors in host immune responses to cancer may provide new therapeutic opportunities for cancer immunotherapy.

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.

Interleukin 22 Expression During the Implantation Window in the Endometrium of Women with Unexplained Recurrent Pregnancy Loss and Unexplained Infertility Compared to Healthy Parturient Individuals

We evaluated the expression of interleukin-22 (IL-22) in the endometrium of women with unexplained recurrent pregnancy loss (uRPL) and unexplained infertility (UI) compared to the women with normal pregnancies. Endometrial tissues were collected from 20 women with UI, 20 women with uRPL, and 24 healthy women as a control group. Immunohistochemical expression and gene expression of IL-22 were analyzed by immunohistochemistry (IHC) and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) methods. The controls showed lower IL-22 expression than the uRPL group (P > 0.05) using PCR. It was also found that patients with UI had lower levels of IL-22 expression compared to the uRPL group (P > 0.05). Although IL-22 expression in the endometrium of patients with UI was higher than the control group, this difference was not statistically significant (P < 0.05). IL-22 immunoreactivity was observed in the endometrial glands and stromal tissues using IHC. We found the lowest IL-22 expression in the control group and the highest in uRPL samples (P < 0.05). Our findings suggest that a significant increase in IL-22 expression in uRPL patients may affect fertility and pregnancy outcomes or even have a considerable impact on immune function deficits. Further studies on the critical function of IL-22 during pregnancy are suggested.

The role of Th22 cells, from tissue repair to cancer progression

CD4⁺ T helper (Th) cells play a significant role in modulating host defense. In the presence of lineage specific cytokine cocktail, Naive CD4⁺ T cells can differentiate into several categories with distinct cytokines profile and effector functions. Th22 cells are a recently identified subset of CD4⁺ T cell, which differentiate from Naive CD4⁺ T in the presence of IL-6 and TNF-α. Th22 characterized by the production of interleukin-22 (IL-22) and expression of aryl hydrocarbon receptor (AHR). The main function of Th22 cells is to participate in mucosal defense, tissue repair, and wound healing. However, controversial data have shown that overexpression of IL-22 can lead to pathological changes under inflammatory conditions and tumor progression. This review summarizes our knowledge about the role of Th22 and IL-22 cells in tumor progression through induction of inflammation.

Multifunctional Thio-Stabilized Gold Nanoparticles for Near-Infrared Fluorescence Detection and Imaging of Activated Caspase-3

Background

Gold nanoparticles (AuNPs) are commonly used in nanomedicine because of their unique spectral properties, chemical and biological stability, and ability to quench the fluorescence of organic dyes attached to their surfaces. However, the utility of spherical AuNPs for activatable fluorescence sensing of molecular processes have been confined to resonance-matched fluorophores in the 500 nm to 600 nm spectral range to maximize dye fluorescence quenching efficiency. Expanding the repertoire of fluorophore systems into the NIR fluorescence regimen with emission >800 nm will facilitate the analysis of multiple biological events with high detection sensitivity.

Objective

The primary goal of this study is to determine if spherical AuNP-induced radiative rate suppression of non-resonant near-infrared (NIR) fluorescent probes can serve as a versatile nanoconstruct for highly sensitive detection and imaging of activated caspase-3 in aqueous media and cancer cells. This required the development of activatable NIR fluorescence sensors of caspase-3 designed to overcome the nonspecific degradation and release of the surface coatings in aqueous media.

Method

We harnessed the fluorescence-quenching properties and multivalency of spherical AuNPs to develop AuNP-templated activatable NIR fluorescent probes to detect activated caspase-3, an intracellular reporter of early cell death. Freshly AuNPs were coated with a multifunctional NIR fluorescent dye-labeled peptide (LS422) consisting of an RGD peptide sequence that targets α_vβ₃-integrin protein (α_vβ₃) on the surface of cancer cells to mediate the uptake and internalization of the sensors in tumor cells; a DEVD peptide sequence for reporting the induction of cell death through caspase-3 mediated NIR fluorescence enhancement; and a multidentate hexacysteine sequence for enhancing self-assembly and stabilizing the multifunctional construct on AuNPs. The integrin binding affinity of LS422 and caspase-3 kinetics were determined by a radioligand competitive binding and fluorogenic peptide assays, respectively. Detection of intracellular caspase-3, cell viability, and the internalization of LS422 in cancer cells were determined by confocal NIR fluorescence spectroscopy and microscopy.

Results

Narrow size AuNPs (13 nm) were prepared and characterized by transmission electron microscopy and dynamic light scattering. When assembled on the AuNPs, the binding constant of LS422 for α_vβ₃ improved 11-fold from 13.2 nM to 1.2 nM. Whereas the catalytic turnover of caspase-3 by LS422-AuNPs was similar to the reference fluorogenic peptide, the binding affinity for the enzyme increased by a factor of 2. Unlike the α_vβ₃ positive, but caspase-3 negative breast cancer MCF-7 cells, treatment of the α_vβ₃ and caspase-3 positive lung cancer A549 cells with Paclitaxel showed significant fluorescence enhancement within 30 minutes, which correlated with caspase-3 specific activation of LS422-AuNPs fluorescence. Incorporation of a 3.5 mW NIR laser source into our spectrofluorometer increased the detection sensitivity by an order of magnitude (limit of detection ~0.1 nM of cypate) and significantly decreased the signal noise relative to a xenon lamp. This gain in sensitivity enabled the detection of substrate hydrolysis at a broad range of inhibitor concentrations without photobleaching the cypate dye.

Conclusion

The multifunctional AuNPs demonstrate the use of a non-resonant quenching strategy to design activatable NIR fluorescence molecular probes. The nanoconstruct offers a selective reporting method for detecting activated caspase-3, imaging of cell viability, identifying dying cells, and visualizing the functional status of intracellular enzymes. Performing these tasks with NIR fluorescent probes creates an opportunity to translate the in vitro and cellular analysis of enzymes into in vivo interrogation of their functional status using deep tissue penetrating NIR fluorescence analytical methods.

Features and roles of T helper 22 cells in immunological diseases and malignancies

T helper 22 (Th22) cell populations are a newly identified subset of CD4+  T cells that primarily mediate biological effects on the epithelial barrier through interleukin (IL)-22. Although, new studies showed that both Th22 and IL-22 are closely associated with the pathogenesis of inflammatory, autoimmune and allergic disease as well as malignancies. In this review, we aim to describe the development and characteristics of Th22 cells as well as their roles in the immunopathogenesis of immune-related disorders and cancer.

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.

Role of the Cyclooxygenase Pathway in the Association of Obstructive Sleep Apnea and Cancer

The objective of this review is to examine the findings that link obstructive sleep apnea (OSA) with cancer and the role played by the cyclooxygenase (COX) pathway in this association. Epidemiological studies in humans suggest a link between OSA and increased cancer incidence and mortality. Studies carried out in animal models have shown that intermittent hypoxia (IH) induces changes in several signaling pathways involved in the regulation of host immunological surveillance that results in tumor establishment and invasion. IH induces the expression of cyclooxygenase 2 (COX-2) that results in an increased synthesis of prostaglandin E2 (PGE2). PGE2 modulates the function of multiple cells involved in immune responses including T lymphocytes, NK cells, dendritic cells, macrophages, and myeloid-derived suppressor cells. In a mouse model blockage of COX-2/PGE2 abrogated the pro-oncogenic effects of IH. Despite the fact that aspirin inhibits PGE2 production and prevents the development of cancer, none of the epidemiological studies that investigated the association of OSA and cancer included aspirin use in the analysis. Studies are needed to investigate the regulation of the COX-2/PGE2 pathway and PGE2 production in patients with OSA, to better define the role of this axis in the physiopathology of OSA and the potential role of aspirin in preventing the development of cancer.

Evaluation of the effects of IL‑22 on the proliferation and differentiation of keratinocytes in vitro

Psoriasis is one of the most common chronic inflammatory skin diseases, it is characterized by hyperproliferation of keratinocytes and infiltration of inflammatory cells. Several in vitro studies have reported that interleukin (IL)‑22 is involved in excessive proliferation and abnormal differentiation of human keratinocytes. However, the association between IL‑22 and CCAAT enhancer binding protein α (C/EBPα) in the pathogenesis of psoriasis remains unclear. Therefore, the present study aimed to investigate the association between IL‑22 and C/EBPα, and the effects of IL‑22 on the proliferation and differentiation of keratinocytes. Keratinocytes were treated with different concentrations of IL‑22 (30, 60 and 90 ng/ml) and subsequently cells were collected at different time intervals. The expression levels of the key molecules of the mitogen‑activated protein kinase (MAPK) signaling pathway were detected using western blot analysis. In addition, the effect of IL‑22 on the proliferation rate of keratinocytes and the mRNA expression levels of C/EBPα were determined using a Cell Counting Kit‑8 assay and reverse transcription‑quantitative PCR, respectively. Furthermore, keratinocytes were transfected with C/EBPα small interfering (si)RNA or control using Lipofectamine® 2000. The results revealed that IL‑22 significantly induced the proliferation of keratinocytes and the expression of phosphorylated (p)‑JNK, p‑ERK and p‑p38 (P<0.05). Additionally, IL‑22 significantly inhibited the differentiation of keratinocytes, and the mRNA and protein expression of C/EBPα (P<0.05). Furthermore, downregulation of C/EBPα increased the proliferation rate of keratinocytes and reduced the expression levels of cytokeratin 10 and involucrin. Therefore, these results suggested that the effect of IL‑22 on the proliferation and differentiation of keratinocytes may be mediated via the regulation of the MAPK signaling pathway and the expression of C/EBPα.

Differential gene expression of tumor-infiltrating CD4+ T cells in advanced versus early stage colorectal cancer and identification of a gene signature of poor prognosis

Tumor-infiltrating lymphocytes (TILs) play indispensable roles in the progression and response to treatment of solid tumors. However, the prognostic significance of CD4⁺ TILs is not fully disclosed in cancers generally and in CRC in particular, mainly due to the existence of different functional subsets of CD4⁺ T cells. We performed transcriptomic profiling of CD4⁺ TILs isolated from CRC patients in order to identify differentially expressed genes and their functional pathways in early versus advanced disease stages. We found that in advanced stages, genes related to immune and inflammatory responses, in particular Th1-mediated immune response and cytotoxicity-mediated genes, were downregulated; while epigenetic-mediated silencing genes were upregulated. Interestingly, we identified genes, which were steadily upregulated or downregulated in CD4⁺ TILs with CRC progression from stage I to IV. Additionally, of the top 200 deregulated genes, 43 upregulated and 64 downregulated genes showed similar deregulation trends in the cancer genome atlas CRC dataset. From these 97 deregulated genes, we identified a “poor prognosis CD4 gene signature (ppCD4sig)”. Patients with high ppCD4sig score showed shorter disease-specific survival (DSS) and progression-free interval (PFI). The ppCD4sig was an independent prognostic indicator for DSS (HR = 1.73, 95% CI 1.32–2.27, P = 0.0001) and PFI (HR = 1.75, 95% CI 1.3–2.35, P = 0.0016). Additionally, patients at advanced stages and at a younger age (<55 years) were more likely to have a high ppCD4sig score. Altogether, our data provide novel insights and a unique prognostic gene signature of CD4⁺ TILs in the CRC microenvironment.

IL6 Induces an IL22+ CD8+ T-cell Subset with Potent Antitumor Function

CD8+ T cells can be polarized into several different subsets as defined by the cytokines they produce and the transcription factors that govern their differentiation. Here, we identified the polarizing conditions to induce an IL22-producing CD8+ Tc22 subset, which is dependent on IL6 and the aryl hydrocarbon receptor transcription factor. Further characterization showed that this subset was highly cytolytic and expressed a distinct cytokine profile and transcriptome relative to other subsets. In addition, polarized Tc22 were able to control tumor growth as well as, if not better than, the traditional IFNγ-producing Tc1 subset. Tc22s were also found to infiltrate the tumors of human patients with ovarian cancer, comprising up to approximately 30% of expanded CD8+ tumor-infiltrating lymphocytes (TIL). Importantly, IL22 production in these CD8+ TILs correlated with improved recurrence-free survival. Given the antitumor properties of Tc22 cells, it may be prudent to polarize T cells to the Tc22 lineage when using chimeric antigen receptor (CAR)-T or T-cell receptor (TCR) transduction-based immunotherapies.

Immunity, Hypoxia, and Metabolism-the Ménage à Trois of Cancer: Implications for Immunotherapy

It is generally accepted that metabolism is able to shape the immune response. Only recently we are gaining awareness that the metabolic crosstalk between different tumor compartments strongly contributes to the harsh tumor microenvironment (TME) and ultimately impairs immune cell fitness and effector functions. The major aims of this review are to provide an overview on the immune system in cancer; to position oxygen shortage and metabolic competition as the ground of a restrictive TME and as important players in the anti-tumor immune response; to define how immunotherapies affect hypoxia/oxygen delivery and the metabolic landscape of the tumor; and vice versa, how oxygen and metabolites within the TME impinge on the success of immunotherapies. By analyzing preclinical and clinical endeavors, we will discuss how a metabolic characterization of the TME can identify novel targets and signatures that could be exploited in combination with standard immunotherapies and can help to predict the benefit of new and traditional immunotherapeutic drugs.

Regulation of Immunity in Breast Cancer

Breast cancer affects millions of women worldwide, leading to many deaths and significant economic burden. Although there are numerous treatment options available, the huge potentials of immunotherapy in the management of localized and metastatic breast cancer is currently being explored. However, there are significant gaps in understanding the complex interactions between the immune system and breast cancer. The immune system can be pro-tumorigenic and anti-tumorigenic depending on the cells involved and the conditions of the tumor microenvironment. In this review, we discuss current knowledge of breast cancer, including treatment options. We also give a brief overview of the immune system and comprehensively highlight the roles of different cells of the immune system in breast tumorigenesis, including recent research discoveries. Lastly, we discuss some immunotherapeutic strategies for the management of breast cancer.

Interleukin-22 promotes triple negative breast cancer cells migration and paclitaxel resistance through JAK-STAT3/MAPKs/AKT signaling pathways

PURPOSE

Owing to the absence of any targeted therapies, triple negative breast cancer (TNBC), which accounts for approximately 15% of all breast cancers, typically have a poorer outcome. In an attempt to find out the TNBCs' microenvironment, we ran into the endogenous expression of a newly discovered cytokine known as Interleukin (IL)-22.

METHODS

Thirty TNBC patients were recruited and the levels of IL-22 producing (Th22) cells in tumor, paratumor and normal breast tissues were measured. Then we studied the role and mechanism of IL-22 in migration and paclitaxel resistance in TNBC cells MDA-MB 468 and MDA-MB 231.

RESULTS

The prevalence of Th22 cells were gradually increased in normal, paratumor and tumor tissues. In vitro, IL-22 promotes TNBC cells migration and induces paclitaxel resistance. Importantly, IL-22 exposure of TNBC cells resulted in JAK-STAT3/MAPKs/AKT signaling pathways activated.

CONCLUSION

IL-22 may play an accelerating role in the development of TNBC and may open a new therapeutic approach for TNBC.

Nobiletin (NOB) suppresses autophagic degradation via over-expressing AKT pathway and enhances apoptosis in multidrug-resistant SKOV3/TAX ovarian cancer cells

Chemotherapy could be used as an effective therapeutic treatment for ovarian cancer and subsequent peritoneal metastasis. However, the occurrence of drug resistance reduced the treatment effect originated from cancer chemotherapy. Accumulating evidences indicated the significant role of autophagy in tumor cell resistance to chemotherapy. Thus, inhibition of autophagy using natural compounds could be a promising candidate to overcome multidrug resistance in human ovarian cancer cells. Nobiletin (NOB), a polymethoxyflavonoid found in citrus fruits such as Citrus depressa and Citrus reticulate, exhibits a number of bioactivities. In the present study, NOB selectively suppressed the growth and proliferation of human SKOV3/TAX cells, inducing G0/G1 phase arrest and reducing G2/M phase, along with the increase of p53 and p21. In addition, NOB induced significant apoptosis in SKOV3/TAX cells through the intrinsic apoptosis pathway, as evidenced by the up-regulation of cleaved Caspase-9/-3 and PARP. Further, NOB impaired the autophagic degradation in SKOV3/TAX cells, resulting in autophagic flux inhibition. Moreover, the impaired autophagic flux enhanced NOB-induced apoptosis in SKOV3/TAX cells. Importantly, AKT signaling was activated by NOB, which was involved in autophagic degradation and apoptotic cell death. In conclusion, the findings here supplied the illustration that NOB could overcome multidrug resistance in human ovarian cancer cells through AKT-regulated suppression of autophagic degradation.

Anti‑cancer effects of a novel Pan‑RAF inhibitor in a hepatocellular carcinoma cell line

The RAF/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK (RAF/MEK/ERK) signaling cascade serves a prominent role in hepatocellular carcinoma (HCC) proliferation. Sorafenib (BAY 43‑9006) is a potent multikinase inhibitor of RAF kinases and a few receptor tyrosine kinases. Additionally, sorafenib causes apoptosis in a number of human tumor cell lines such as leukemia cell lines. Sorafenib is the first targeted drug to prolong the overall survival of patients with advanced HCC. However, sorafenib activity is less favorable in certain cancers, including sarcomas and melanomas, due to patient insensitivity and drug resistance. In the present study, a novel bi‑aryl urea, N‑(3‑trifluoromethylphenyl)‑N'-(2-methyl-4-(6‑cyclopropanecarboxamido-pyrimidin-4-yl) oxyphenyl) urea (CBI‑5725), is shown to be a potential candidate for the treatment of liver cancer. In the present study, the in vitro activities of CBI‑5725 and sorafenib in PLC/PRF/5 HCC cells were examined and the corresponding in vivo antitumor activities in PLC/PRF/5 human tumor xenografts. An alamar blue assay confirmed that CBI‑5725 was more cytotoxic than sorafenib to PLC/PRF/5 cells, suggesting that CBI‑5725 inhibited tumor cell proliferation more potently than sorafenib. CBI‑5725 inhibited the RAF/MEK/ERK signaling pathway to the same extent as sorafenib. In addition, CBI‑5725 elicited cell cycle arrest in the G2/M phase, while sorafenib did not markedly alter the cell cycle. Furthermore, CBI‑5725 induced apoptosis more strongly than sorafenib in a dose‑dependent manner, which may be attributed to greater caspase‑3 and poly(adenosine 5'‑diphosphate‑ribose) polymerase activation by CBI‑5725. In the PLC/PRF/5 xenograft model, 2 mg/kg CBI‑5725 inhibited tumor growth by 73%. At doses ranging from 6 to 18 mg/kg, CBI‑5725 nearly completely prevented tumor growth. These results imply that the antitumor efficacy of CBI‑5725 in HCC models may result from the suppression of the RAF/MEK/ERK signaling pathway, the induction of cell cycle arrest in the G2/M phase, and the initiation of caspase‑3‑dependent apoptosis. These observations suggested that CBI‑5725 may be a potent novel compound for the treatment of HCC.

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.

Association of interleukin-22 polymorphisms with the colon cancer: A case-control study

INTRODUCTION

Interleukin-22 (IL-22), an IL-10 family cytokine produced by T cells and innate lymphoid cells, is implicated in inflammation and tumorigenesis. In this study, we aimed to investigate the association of IL-22 polymorphisms with the colon cancer in a Chinese population.

MATERIALS AND METHODS

Five hundred forty colon cancer cases and 540 healthy controls were recruited in the case-control study. The fluorogenic 5' exonuclease assays were used for genotype analysis of three common polymorphisms (-429C/T, +1046T/A and +1995A/C) of the IL-22 gene.

RESULTS

Colon cancer cases had a significantly higher frequency of IL-22-429 TT genotype [odds ratio (OR)=1.69, 95% confidence interval (CI)=1.24, 2.30; P=0.001] and -429T allele (OR=1.35, 95% CI=1.14, 1.60; P=0.001) than healthy controls. The findings are still emphatic by the Bonferroni correction (P<0.017). When stratifying by the differentiation of colon cancer, we found that colon cancer cases with poor differentiation had a significantly higher frequency of IL-22-429 TT genotype (OR=1.45, 95% CI=1.02, 2.07; P=0.04). When stratifying by the tumor location, tumor size, growth pattern and TNM stage of colon cancer, we found no statistical association. The IL-22 +1046T/A and IL-22 +1995A/C gene polymorphisms were not associated with colon cancer.

CONCLUSION

Our findings suggested that the IL-22 -429C/T gene polymorphisms might be associated with colon cancer.

Increased frequency of circulating Th22 cells in patients with B-cell non-Hodgkin's lymphoma

T helper (Th) 22 cells play important roles in the pathogenesis of autoimmune and inflammatory diseases, and their function in tumors remains uncertain. In the current study, we investigated the alternations and clinical significance of circulating Th22 cells in patients with B-cell non-Hodgkin's lymphoma (B-NHL). We found that the frequency of Th22 cells was significantly elevated in peripheral blood of newly-diagnosed B-NHL patients, and returned to normal level after chemotherapy. In consistent with increased Th22 frequency, plasma IL-22 and IL-6 levels in B-NHL patients were remarkably increased. Moreover, the increased Th22 frequency was associated with the older age (> 60 yr) and a poorer response to therapy in B-NHL patients. In addition, there existed a statistically positive correlation between circulating Th22 and Th17 frequencies in B-NHL patients. Our data demonstrated that circulating Th22 frequency was associated with the clinical outcome and prognosis of B-NHL patients, indicating that Th22 immune response might play an important role in the development and progression of B-NHL.

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.

Innate Lymphoid Cells in Tumor Immunity

Innate lymphoid cells (ILCs) are a group of immune cells of the lymphoid lineage that do not possess antigen specificity. The group includes natural killer (NK) cells, lymphoid tissue inducer (LTi) cells and the recently identified ILC1s, ILC2s and ILC3s. Although the role of NK cells in the context of cancer has been well established, the involvement of other ILC subsets in cancer progression and resistance is just emerging. Here, we review the literature on the role of the different ILC subsets in tumor immunity and discuss its implications for cancer treatment and monitoring.

T Helper Lymphocyte Subsets and Plasticity in Autoimmunity and Cancer: An Overview

In response to cytokine signalling and other factors, CD4-positive T lymphocytes differentiate into distinct populations that are characterized by the production of certain cytokines and are controlled by different master transcription factors. The spectrum of such populations, which was initially limited to Th1 and Th2 subsets, is currently broadened to include Th17 and Treg subsets, as well as a number of less studied subtypes, such as Tfh, Th9, and Th22. Although these subsets appear to be relatively stable, certain plasticity exists that allows for transition between the subsets and formation of hybrid transition forms. This provides the immune system flexibility needed for adequate response to pathogens but, at the same time, can play a role in the pathogenic processes in cases of deregulation. In this review, we will discuss the properties of T lymphocyte subsets and their plasticity, as well as its implications for cancer and autoimmune diseases.

Association between interleukin-22 genetic polymorphisms and bladder cancer risk

OBJECTIVE

The cytokine interleukin-22 (IL-22), which is produced by T cells and natural killer cells, is associated with tumorigenesis and tumor progression in cancers. However, the role of IL-22 in bladder cancer has not been investigated.

MATERIALS AND METHODS

A prospective hospital-based case-control study comprising 210 patients with pathologically proven bladder cancer and 210 age- and gender-matched healthy controls was conducted. The genotypes of 3 common polymorphisms (-429 C/T, +1046 T/A and +1995 A/C) of the IL-22 gene were determined with fluorogenic 5' exonuclease assays.

RESULTS

Patients with bladder cancer had a significantly higher frequency of the IL-22 -429 TT genotype [odds ratio (OR)=2.04, 95% confidence interval (CI)=1.19, 3.49; p=0.009] and -429 T allele (OR=1.42, 95% CI=1.08, 1.87; p=0.01) than the healthy controls. These findings were still significant after a Bonferroni correction. When stratifying according to the stage of bladder cancer, we found that patients with superficial bladder cancer had a significantly lower frequency of the IL-22 -429 TT genotype (OR=0.48, 95% CI=0.23, 0.98; p=0.04). When stratifying according to the grade and histological type of bladder cancer, we found no statistical association. The IL-22 +1046 T/A and IL-22 +1995 A/C gene polymorphisms were not associated with the risk of bladder cancer.

CONCLUSION

To the authors' knowledge, this is the first report documenting that the IL-22 -429 C/T gene polymorphism is associated with bladder cancer risk. Additional studies are required to confirm this finding.

IL10R2 Overexpression Promotes IL22/STAT3 Signaling in Colorectal Carcinogenesis

The mucosal immune response in the setting of intestinal inflammation contributes to colorectal cancer. IL10 signaling has a central role in gut homeostasis and is impaired in inflammatory bowel disease (IBD). Out of two IL10 receptor subunits, IL10R1 and IL10R2, the latter is shared among the IL10 family of cytokines and activates STAT signaling. STAT3 is oncogenic in colorectal cancer; however, knowledge about IL10 signaling upstream of STAT3 in colorectal cancer is lacking. Here, expression of IL10 signaling genes was examined in matched pairs from normal and tumor tissue from colorectal cancer patients showing overexpression (mRNA, protein) of IL10R2 and STAT3 but not IL10R1. IL10R2 overexpression was related to microsatellite stability. Transient overexpression of IL10R2 in HT29 cells increased proliferation upon ligand activation (IL10 and IL22). IL22, and not IL10, phosphorylated STAT3 along with increased phosphorylation of AKT and ERK. A significantly higher expression of IL22R1 and IL10R2 was also confirmed in a separate cohort of colorectal cancer samples. IL22 expression was elevated in gut mucosa from patients with IBD and colitis-associated cancer, which also exhibited increased expression of IL22R1 but not its coreceptor IL10R2. Overall, these data indicate that overexpression of IL10R2 and STAT3 contributes to colorectal carcinogenesis in microsatellite-stable tumors through IL22/STAT3 signaling.

Antitumor activity of mHSP65-TTL enhanced by administration of low dose cyclophosphamide in pancreatic cancer-bearing mice

Pancreatic cancer remains a lethal malignancy. Despite chemotherapy or/and radiotherapy after the surgery, the improvement on the overall survival of the patients has still been minimal. To develop novel therapeutic approaches, we tried to prepare mHSP65-TTL, a candidate vaccine prepared by mixing the recombinant mycobacterial heat shock protein 65 (mHSP65) with tumor tissue lysate (TTL) of Panc02 pancreatic cancer tissue. The mHSP65-TTL were used to immune the C57BL/6 mice implanted with the Panc02 cancer cells, in combination with or without low dose cyclophosphamide (CY). The results showed that mHSP65-TTL significantly prolonged the survival of the pancreatic cancer bearing mice and low dose CY enhanced the efficacy of the mHSP65-TTL. In addition, we detected mRNA expression of RORγt and IL-17A in spleen cells of mice received mHSP65-TTL or mHSP65-TTL plus CY, and found that mHSP65-TTL up-regulated mRNA expressions of RORγt and IL-17A, CY alone or mHSP65-TTL plus CY up-regulated mRNA expressions of RORγt. The work could provide an insight into a combinational approach for the immunotherapy of pancreatic cancer.

Clinical significance of interleukin-22 in multiple myeloma

OBJECTIVE

Interleukin-22 (IL-22) is a cytokine participating in many aspects of inflammation. Multiple myeloma (MM) is a malignant disease of plasma cells with characteristic immune deregulation. We estimated serum levels of IL-22 in MM patients, both in activity and remission, in order to apprehend its possible participation in MM biology.

METHODS

We measured serum levels of IL-22 along with beta-2 microglobulin (B2M), paraprotein, and interleukin-1beta (IL-1beta), as well as degree of bone marrow infiltration, in 51 patients with active MM and in 22 of them in remission.

RESULTS

We found that IL-22 was higher in active MM patients, compared to both controls and patients in remission, and also in patients in remission compared to controls. Moreover, IL-22 was increasing in parallel with the disease stage and also correlated with B2M, IL1-beta, and degree of infiltration.

DISCUSSION

We suggest that the elevated levels of IL-22 in active MM patients, in parallel with disease activity, and in positive correlation with IL-1beta, may represent the inflammatory element of the disease. This increased occurrence of IL-22 may enhance myeloma proliferation and growth, and moreover, may participate in the mechanisms of immune deregulation.

IL22/IL-22R pathway induces cell survival in human glioblastoma cells

Interleukin-22 (IL-22) is a member of the IL-10 cytokine family that binds to a heterodimeric receptor consisting of IL-22 receptor 1 (IL-22R1) and IL-10R2. IL-22R expression was initially characterized on epithelial cells, and plays an essential role in a number of inflammatory diseases. Recently, a functional receptor was detected on cancer cells such as hepatocarcinoma and lung carcinoma, but its presence was not reported in glioblastoma (GBM). Two GBM cell lines and 10 primary cell lines established from patients undergoing surgery for malignant GBM were used to investigate the expression of IL-22 and IL-22R by using quantitative RT-PCR, western blotting and confocal microscopy studies. The role of IL-22 in proliferation and survival of GBM cell lines was investigated in vitro by BrdU and ELISA cell death assays. We report herein that the two subunits of the IL-22R complex are expressed on human GBM cells. Their activation, depending on exogenous IL-22, induced antiapoptotic effect and cell proliferation. IL-22 treatment of GBM cells resulted in increased levels of phosphorylated Akt, STAT3 signaling protein and its downstream antiapoptotic protein Bcl-xL and decreased level of phosphorylated ERK1/2. In addition, IL-22R subunits were expressed in all the 10 tested primary cell lines established from GBM tumors. Our results showed that IL-22R is expressed on GBM established and primary cell lines. Depending on STAT3, ERK1/2 and PI3K/Akt pathways, IL-22 induced GBM cell survival. These data are consistent with a potential role of IL-22R in tumorigenesis of GBM. Since endogenous IL-22 was not detected in all studied GBM cells, we hypothesize that IL-22R could be activated by immune microenvironmental IL-22 producing cells.

[Potential relationship and clinical significance of miRNAs and Th17 related cytokines in patients with multiple myeloma]

目的

探讨miRNA和Th17相关细胞因子在多发性骨髓瘤(MM)患者发病中的作用机制。

方法

收集27例MM患者骨髓标本，以8名健康人为正常对照，应用荧光实时定量PCR(qRT-PCR)法检测其miR-15a/16、-34a、-194-2-192簇、-181a/b的表达情况，采用ELISA法检测患者血清Th17相关细胞因子IL-17、IL-21、IL-22、IL-23、IL-27的表达水平。分析miRNA与Th17相关细胞因子表达的相关性。

结果

与对照组比较，MM患者组miR-15a/16、-34a、-194-2-192簇表达水平降低，而miR-181a/b表达水平升高，差异均有统计学意义（P值均<0.05）；MM患者血清IL-17、IL-21、IL-27的表达水平升高，IL-22表达水平降低，差异均有统计学意义（P值均<0.05）；IL-23表达水平与对照组相比差异无统计学意义（P>0.05)。ISS分期Ⅲ期患者的miR-181a/b和IL-17、IL-21、IL-23、IL-27表达水平高于Ⅰ期患者，而miR-15a/16、-34a、-194和IL-22的表达水平则低于后者，差异均有统计学意义（P值均< 0.05）。miR-34a与IL-21，miR-181a与IL-23，miR-192与IL-21、IL-27，miR-194与IL-27的表达水平均呈正相关，而miR-192与IL-21呈负相关（P值均<0.05）。

结论

miRNA和Th17相关细胞因子在MM患者中均存在异常表达，其表达水平与MM患者的ISS分期有关，同时两者之间也存在密切的联系，提示失调的miRNA可能影响Th17细胞的分化进而参与MM的发生、发展。

Association of interleukin 22 polymorphisms with gastric cancer risk

Interleukin (IL)-22 has been implicated in inflammation and tumorigenesis. To date, no studies have investigated the role of IL-22 polymorphism in the carcinogenesis of gastric cancer (GC). In this study, we aimed to investigate the association of IL-22 polymorphisms with the risk of GC in a Chinese population. One hundred eight GC patients and 110 healthy controls were included in the study. IL-22 rs1179251, rs2227485, and rs2227473 polymorphisms were determined by PCR amplification and DNA sequencing. Haplotypes were constructed, and a possible association of these haplotypes with GC was assessed. The distribution of IL-22 rs1179251 polymorphism with clinical parameters was also analyzed. The IL-22 rs1179251 polymorphism was significantly associated with an increased risk of GC (p < 0.05). Stratified analysis revealed that rs1179251 was associated with advanced stages, lymph node metastases, and distant metastases of GC (p < 0.05). No associations were found between rs2227485 and rs2227473 and the risk of GC (p > 0.05). Three possible haplotypes (C(rs1179251)-C(rs2227485)-G(rs2227485), C(rs1179251)-T(rs2227485)-G(rs2227485), and G(rs1179251)-T(rs2227485)-A(rs2227485)) were identified, but no associations were found between these and the risk of GC (p > 0.05). In summary, our study demonstrates that the rs1179251 polymorphism of IL-22 was associated with an increased risk of GC and may influence the progression of GC. Future larger studies with other ethnic populations are required to confirm these findings.

Potential relationship and clinical significance of miRNAs and Th17 cytokines in patients with multiple myeloma

We evaluated the potential relationship between miRNAs and Th17 cytokines in multiple myeloma (MM) patients. Twenty-seven newly diagnosed myeloma patients and eight normal donors were studied. We determined that the relative expression levels of miR-15a/16, miR-34a, miR-194 in MM patients were significantly lower than those in the healthy controls with exception for miR-181a/b, which showed significantly higher in MM patients (P<0.05). In contrast, the levels of IL-17, IL-21 and IL-27 were up-regulated in MM patients compared to healthy controls while IL-22 was down-regulated (P<0.05). The expression patterns of them were differentially present in various groups according to the International Staging System (ISS) criteria. Up-regulated IL-17, IL-21 and IL-27 may potentially down-regulate the expression of several miRNAs in MM patients. Establishment of the relationship may be useful for understanding the pathogenesis of MM and for clinical diagnosis of the disease.

The frequency of Th17 and Th22 cells in patients with colorectal cancer at pre-operation and post-operation

T helper 17 (Th17) and Th22 cells regulate the development of tumors. However, their roles in the development of colorectal cancer (CRC) are still unclear. A total of 49 patients with CRC and 18 healthy controls (HC) were evaluated for the percentages of circulating Th17 and Th22 cells by flow cytometry. The concentrations of serum interleukin-17A (IL-17A), IL-22 and carcinoembryonic antigen (CEA) were examined. The levels of IL-17A and IL-22 in tumors were determined by real-time PCR. We found that the percentages of Th17 and Th22 cells in the CRC patients were significantly lower than that in the HC and were associated negatively with the pathological stages of CRC. The levels of IL-17A and IL-22 mRNA transcripts were lower in the tumor tissues, particularly in the advanced CRC. After the tumor resection, the percentages of circulating Th17 and Th22 cells increased. These data suggest that decreased Th17 and Th22 responses may be associated with the development of CRC.

Th17 cells in cancer: the ultimate identity crisis

T helper 17 (Th17) cells play a complex and controversial role in tumor immunity and have been found to exhibit a fluctuating identity within the context of cancer. The recent, expanding literature on these cells attests to their puzzling nature, either promoting or suppressing tumor growth depending on the malignancy and course of therapeutic intervention investigated. This review addresses several newly appreciated factors that may help delineate Th17 cells' immunological properties in the context of cancer. Several reports suggest that inflammatory signals induced in the tumor milieu regulate the functional fate and antitumor activity of Th17 cells. Recent findings also point to significant alterations in Th17 cells due to their interplay with regulatory T lymphocytes and cytotoxic CD8(+) T cells within the tumor microenvironment. Finally, an appreciation for the stem cell-like properties of Th17 cells that augment their persistence and activity emerges from recent reports. The impact of these factors on Th17 cells' antitumor efficacy and how these factors may be exploited to improve cancer therapies will be discussed.

The role of the IL-22/IL-22R1 axis in cancer

Interleukin-22 (IL-22) is an IL-10 family cytokine produced by T cells and innate lymphoid cells. The IL-22 signaling pathway orchestrates mucosal immune defense and tissue regeneration through pleiotropic effects including pro-survival signaling, cell migration, dysplasia and angiogenesis. While these functions can prevent initial establishment of tumors, they can also be hijacked by aggressive cancers to enhance tumor growth and metastasis. Thus, the role of the IL-22/IL-22R1 axis in cancer is complex and context-specific. Evidence of IL-22 involvement manifests as dysregulation of IL-22 expression and signaling in patients with many common cancers including those of the gut, skin, lung and liver. Unlike other cancer-associated cytokines, IL-22 has restricted tissue specificity as its unique receptor IL-22R1 is exclusively expressed on epithelial and tissue cells, but not immune cells. This makes it an attractive target for therapy as there is potential achieve anti-tumor immunity with fewer side effects. This review summarizes current findings on functions of IL-22 in association with general mechanisms for tumorigenesis as well as specific contributions to particular cancers, and ponders how best to approach further research in the field.

The multifaceted role of Th17 lymphocytes and their associated cytokines in cancer

While the role of T helper 17 lymphocytes (Th17) in the pathogenesis of autoimmune diseases and in infectious immunity has been relatively well defined, the impact of these cells and their associated cytokines on cancer development is still under debate. Although multiple reports have indicated that Th17 can promote anticancer immunity, others have argued that these cells may exhibit tumor-promoting properties. This dichotomy in the function of Th17 lymphocytes in cancer may be related to the versatile nature of these cells, being capable of differentiating into either proinflammatory Th1 or suppressive FoxP3-expressing Treg cells or hybrid T cell subsets depending on the underlying environmental conditions. In the current review, we examine the role of Th17 lymphocytes and Th17-associated cytokines in cancer and discuss how factors that control their final lineage commitment decision may influence the balance between their tumor-promoting versus tumor-suppressing properties.

Identification and functional annotation of genome-wide ER-regulated genes in breast cancer based on ChIP-Seq data

Estrogen receptor (ER) is a crucial molecule symbol of breast cancer. Molecular interactions between ER complexes and DNA regulate the expression of genes responsible for cancer cell phenotypes. However, the positions and mechanisms of the ER binding with downstream gene targets are far from being fully understood. ChIP-Seq is an important assay for the genome-wide study of protein-DNA interactions. In this paper, we explored the genome-wide chromatin localization of ER-DNA binding regions by analyzing ChIP-Seq data from MCF-7 breast cancer cell line. By integrating three peak detection algorithms and two datasets, we localized 933 ER binding sites, 92% among which were located far away from promoters, suggesting long-range control by ER. Moreover, 489 genes in the vicinity of ER binding sites were identified as estrogen response elements by comparison with expression data. In addition, 836 single nucleotide polymorphisms (SNPs) in or near 157 ER-regulated genes were found in the vicinity of ER binding sites. Furthermore, we annotated the function of the nearest-neighbor genes of these binding sites using Gene Ontology (GO), KEGG, and GeneGo pathway databases. The results revealed novel ER-regulated genes pathways for further experimental validation. ER was found to affect every developed stage of breast cancer by regulating genes related to the development, progression, and metastasis. This study provides a deeper understanding of the regulatory mechanisms of ER and its associated genes.

Interleukin 22-producing CD4+ T cells in malignant pleural effusion

Th22 cells have been reported to be involved in human cancers. However, differentiation and immune regulation of Th22 cells in malignant pleural effusion (MPE) remain unknown. We noted that Th22 cell numbers were increased in MPE, and that IL-22 substantially promoted the proliferation and migratory activity of A549 cells. Moreover, IL-22 could strongly facilitate intercellular adhesion of A549 cells to pleural mesothelial cell monolayers. Our data revealed that the increase in Th22 cells in MPE was due to pleural cytokines and chemokines, and that Th22 exerted an important immune regulation on cancer cells in human pleural malignant environment.

Interleukin-22 protects rat PC12 pheochromocytoma cells from serum deprivation-induced cell death

Interleukin-22 (IL-22), an IL-10 family cytokine, mediates the crosstalk between leukocytes and epithelial cells. Previous studies reported that IL-22 expresses in mouse brain, and the rat PC12 cells are responsive to IL-22 stimulation. However, the biological roles of IL-22 in neuronal cells remain largely unknown. We show here that IL-22 activates Stat3, p38 mitogen-activated protein kinases (MAPK), and Akt pathways and inhibits Erk/MAPK pathway in naïve PC12 cells. We further demonstrate that IL-22 protects naïve PC12 cells from serum starvation-induced cell death via the Jak1/Stat3 and Akt pathways. We also show that IL-22 has no effects on naïve PC12 cell proliferation and cannot protect naïve PC12 cells from 1-methyl-4-phenylpyridinium (MPP(+))-induced cytotoxicity. However, IL-22 exerts a dose-dependent protective effect on MPP(+)-induced neurodegeneration in nerve growth factor-differentiated PC12 cells. Overall, our data suggest that IL-22 might play a role in neurological processes. To our knowledge, this is the first report showing that IL-22 confers a neuroprotective function, which may provide a new therapeutic option for treatment of neurodegenerative diseases.

STAT3 signal transduction through interleukin-22 in oral squamous cell carcinoma

Interleukin (IL)-22 is a member of the IL-10 family. Its main targets are epithelial cells, not immune cells. We examined IL-22 signal transduction in oral squamous cell carcinoma (OSCC) cells. Immunohistochemical staining revealed that IL-22R was expressed more highly in OSCC compared to normal regions. An IL-22R signal was also observed in metastatic OSCC cells in the lymph node. RT-PCR showed that the human OSCC cell lines MISK81-5, HSC-3, HSC-4, SAS and SQUU-B expressed IL-22 receptor chains. Immunoblotting showed that IL-22 induced a transient tyrosine phosphorylation of STAT3 (pY705-STAT3) in MISK81-5 cells. The change in the serine phosphorylation of STAT3 was subtle during the examination periods. Simultaneously, pY705-STAT3 activation in HSC-3 cells was undetectable after IL-22 stimulation. Immunocytochemistry demonstrated that IL-22 induced the translocation of phosphorylated STAT3 into the nucleus of MISK81-5 cells. IL-22 temporarily upregulated the expression of anti-apoptotic and mitogenic genes such as Bcl-x, survivin and c-Myc, as well as SOCS3. IL-22 transiently activated ERK1/2 and induced a delayed phosphorylation of p38 MAP kinase, but negligibly involved the activation of NF-κB in MISK81-5 cells. MISK81-5 and SQUU-B cells treated with IL-22 showed mild cellular proliferation. MISK81-5, HSC-4 and SAS cells treated with IL-22 downregulated the keratinocyte differentiation-related genes compared with unstimulated cells. Conversely, STAT3 suppression by STAT3 siRNA strongly disrupted the downregulation of these genes by IL-22, but it did not significantly affect the activation of ERK1/2 by IL-22. The OSCC cells used in this study upregulated the expression of SERPINB3/4 (SCCA1/2), well-known SCC markers, following treatment with IL-22. These results indicate that IL-22 differentially activates the STAT3 signaling system depending on the type of OSCC. IL-22 may therefore play a role in tumor growth, cell differentiation and progression through STAT3-dependent and -independent pathways.

Controversies on the role of Th17 in cancer: a TGF-β-dependent immunosuppressive activity?

The immune system has important roles in limiting the spread of cancer and shaping the tumor microenvironment. Although the contributions of T helper 17 (Th17) cells (a subtype of CD4(+) T lymphocytes) to autoimmunity and allergy response are well known, their roles in cancer remain ambiguous. Despite adoptive transfer studies indicating that mouse Th17 cells support anticancer immunity, the Th17 cells that naturally infiltrate experimental tumors appear to have a tumor-promoting effect. These contradictory properties can be related to the high degree of plasticity inherent in Th17 cells and their capacity to differentiate into tumoricidal Th1-like cells. Mouse Th17 cells induced by transforming growth factor-β (TGF-β) express CD39 and CD73 ectonucleotidases on their surfaces, which leads to adenosine release and suppression of T cell immunity. Here, we discuss how TGF-β acts as a molecular switch controlling the immunoregulatory properties of Th17 cells.

Clinical significance of circulating interleukin-23 as a prognostic factor in breast cancer patients

Little is known about specific IL-23 alterations associated with breast cancer and the data available are still controversial. Therefore, the evaluation of changes in serum IL-23 levels may add further information on the role of this cytokine in breast cancer patients. The aim of this study was to evaluate prospectively the prognostic importance of circulating IL-23 in patients with untreated breast cancer, respect to healthy controls, and the association with clinico-pathological variables. The study involved 50 women diagnosed with stages I-IV breast cancer and 38 healthy controls. Of the 50 breast cancer patients, 37 women were recruited prior to their initial adjuvant chemotherapy and 13 prior to receive first line chemotherapy for metastatic disease. Adjuvant chemotherapy patients were at least in their 4th week post-surgery. IL-23 serum concentrations were measured by a quantitative enzyme immunoassay technique. We found a statistically significant higher systemic cytokine value in women with cancer in comparison with the control group (14.52±11.39 pg/ml vs. 6.35±4.63 pg/ml, P<0.0001). Patients with shorter overall survival presented higher IL-23 values, suggesting a negative prognostic correlation. There was no significant differences in IL-23 levels among patients according to the biomolecular characteristics, the different subtypes and the presence of metastatic disease. This work investigated, for the first time, the role of IL-23 in breast cancer patients showing a significant increase respect the control group. However, further validations are needed in larger studies to better investigate the implications of IL-23 increase in these patients.

High fat diet induces formation of spontaneous liposarcoma in mouse adipose tissue with overexpression of interleukin 22

Interleukin 22 (IL-22) is a T-cell secreted cytokine that modulates inflammatory response in nonhematopoietic tissues such as epithelium and liver. The function of IL-22 in adipose tissue is currently unknown. We generated a transgenic mouse model with overexpression of IL-22 specifically in adipose tissue. The IL-22 transgenic mice had no apparent changes in obesity and insulin resistance after feeding with high fat diet (HFD). Unexpectedly, all the IL-22 transgenic mice fed with HFD for four months developed spontaneous tumors in epididymal adipose tissue. Histological analysis indicated that the tumors were well-differentiated liposarcomas with infiltration of inflammatory cells. IL-22 overexpression promotes production of inflammatory cytokines such as IL-1β and IL-10 and stimulates ERK phosphorylation in adipose tissue. Furthermore, IL-22 treatment in differentiated 3T3-L1 adipocytes could induce IL-1β and IL-10 expression, together with stimulation of ERK phosphorylation. Taken together, our study not only established a novel mouse model with spontaneous liposarcoma, but also revealed that IL-22 overexpression may collaborate with diet-induced obesity to impact on tumor development in mouse.

Regulation and functions of the IL-10 family of cytokines in inflammation and disease

The IL-10 family of cytokines consists of nine members: IL-10, IL-19, IL-20, IL-22, IL-24, IL-26, and the more distantly related IL-28A, IL-28B, and IL-29. Evolutionarily, IL-10 family cytokines emerged before the adaptive immune response. These cytokines elicit diverse host defense mechanisms, especially from epithelial cells, during various infections. IL-10 family cytokines are essential for maintaining the integrity and homeostasis of tissue epithelial layers. Members of this family can promote innate immune responses from tissue epithelia to limit the damage caused by viral and bacterial infections. These cytokines can also facilitate the tissue-healing process in injuries caused by infection or inflammation. Finally, IL-10 itself can repress proinflammatory responses and limit unnecessary tissue disruptions caused by inflammation. Thus, IL-10 family cytokines have indispensable functions in many infectious and inflammatory diseases.

Interleukins, from 1 to 37, and interferon-γ: receptors, functions, and roles in diseases

Advancing our understanding of mechanisms of immune regulation in allergy, asthma, autoimmune diseases, tumor development, organ transplantation, and chronic infections could lead to effective and targeted therapies. Subsets of immune and inflammatory cells interact via ILs and IFNs; reciprocal regulation and counter balance among T(h) and regulatory T cells, as well as subsets of B cells, offer opportunities for immune interventions. Here, we review current knowledge about ILs 1 to 37 and IFN-γ. Our understanding of the effects of ILs has greatly increased since the discoveries of monocyte IL (called IL-1) and lymphocyte IL (called IL-2); more than 40 cytokines are now designated as ILs. Studies of transgenic or knockout mice with altered expression of these cytokines or their receptors and analyses of mutations and polymorphisms in human genes that encode these products have provided important information about IL and IFN functions. We discuss their signaling pathways, cellular sources, targets, roles in immune regulation and cellular networks, roles in allergy and asthma, and roles in defense against infections.