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

Interleukin-22 promotes endometrial carcinoma cell proliferation and cycle progression via ERK1/2 and p38 activation

Endometrial carcinoma (EC) is one of the most common gynecological malignant tumors, but its underlying pathogenic mechanisms are largely obscure. Interleukin-22 (IL-22), one cytokine in the tumor immune microenvironment, was reported to be associated with carcinoma progression. Here, we aimed to investigate the regulation of IL-22 in endometrial carcinoma. Enzyme-linked immunosorbent assay (ELISA) analysis of IL-22 was done in 27 controls and 51 patients with EC. We examined the proliferative potential, cycle progression, and signaling pathways modulated by IL-22 in EC cells. Western blot analysis was performed to investigate the expression of proliferative and cycle-related proteins in EC cells. The effect of IL-22 mediated by interleukin-22 receptor alpha 1 (IL-22RA1) was examined using cell transfection with small interfering RNA (siRNA). In addition, a xenograft tumor model was performed to assess the effect of IL-22 in vivo. We demonstrated significant up-regulation of serum IL-22 concentrations in EC patients (42.59 ± 23.72 pg/mL) compared to the control group (27.47 ± 8.29 pg/mL). High levels of IL-22 concentrations appear to correlate with malignant clinicopathological features of EC. Treatment with IL-22 promoted cell proliferation and G1/S phase progression in Ishikawa and HEC-1B cells. Western blot analysis revealed that c-Myc, cyclin E1, cyclin-dependent kinase (CDK)2, cyclin D1, CDK4, CDK6, p-extracellular signal-regulated kinase1/2 (p-ERK1/2), and p-p38 were highly expressed in EC cells exposed to IL-22. Moreover, in the EC mice model, we found that giving exogenous IL-22 increased tumor volume and weight. Immunohistochemistry showed that intra-tumor Ki-67 expression was up-regulated upon IL-22 treatment. The IL-22-mediated changes in cell proliferation, cycle progression, and protein expression can be effectively inhibited by the ERK1/2 inhibitor U0126 and the p38 inhibitor SB202190. In addition, the role of IL-22 in EC is receptor-dependent. Our findings suggest that IL-22 promotes endometrial carcinoma cell proliferation and G1/S phase progression by activating ERK1/2 and p38 signaling. Therefore, IL-22 may represent a potential therapeutic target for the treatment of endometrial carcinoma.

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.

IL-6/JAK2-dependent G6PD phosphorylation promotes nucleotide synthesis and supports tumor growth

OBJECTIVE

Tumor cells hijack inflammatory mechanisms to promote their own growth. IL-6 is one of the major cytokines, and is frequently upregulated in tumors. The pentose phosphate pathway (PPP) generates the indispensable building blocks to produce various nucleotides. Here we aimed to determine whether and how PPP is timely tuned in response to IL-6 to support tumor growth.

METHODS

Protein expression was examined by immunoblot. Protein interaction was examined by immunoprecipitation. Tumor cell proliferation in in vitro culture was examined by BrdU assay and colony formation assay. Tumor cell proliferation in mouse xenograft model was examined by Ki-67 staining.

RESULTS

Here we show that the metabolic flux of PPP and enzymatic activity of glucose-6-phosphate dehydrogenase (G6PD) is rapidly induced under IL-6 treatment, without obvious changes in G6PD expression level. Mechanistically, Janus kinase 2 (JAK2) phosphorylates G6PD Y437 under IL-6 treatment, which accentuates G6PD enzymatic activity by promoting G6PD binding with its substrate G6P. Further, JAK2-dependent G6PD Y437 phosphorylation is required for IL-6-induced nucleotide biosynthesis and tumor cell proliferation, and is associated with the progression of oral squamous cell carcinoma.

CONCLUSIONS

Our findings report a new mechanism implicated in the crosstalk between tumor cells and inflammatory microenvironment, by which JAK2-dependent activation of G6PD governs nucleotide synthesis to support tumor cell proliferation, thereby highlighting its value as a potential anti-tumor target.

Research progress on Th22 cells and related cytokines in tumors: current status and future perspectives

Th22 cells are a newly identified subpopulation of CD4+ T lymphocytes distinct from Th1, Th2, and Th17 cells, which secretes mainly interleukin-22 (IL-22), in addition to a variety of other cytokines. The function of Th22 cells in tumors is mainly realized through IL-22, which can activate JAK/STAT and MAPK cell signaling pathways, thereby regulating the anti-tumor immune response of the body. 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. In this review, we searched the PubMed and Web of Science databases for articles and reviews published before May 6, 2022, using the keywords "Th22 cells, T helper 22 cells, cancer, tumor", and conducted a comprehensive review of the relevant literature. In addition, this article offers an overview of the relevant findings on the function of Th22 cells in tumors published in recent years, along with a more comprehensive analysis of the functions and mechanisms of Th22 cells in tumors. This article will hopefully inspire new future directions in the research on cancer therapy.

Galactomyces Ferment Filtrate Potentiates an Anti-Inflammaging System in Keratinocytes

Skincare products play a crucial role in preventing the dry skin induced by various causes. Certain ingredients can help to improve the efficacy of skincare products. Galactomyces ferment filtrate (GFF) is such a functional ingredient. Its use originated from the empirical observation that the hands of sake brewers who deal with yeast fermentation retain a beautiful and youthful appearance. Consequently, skincare products based on GFF are widely used throughout the world. Recent studies have demonstrated that GFF activates an aryl hydrocarbon receptor (AHR) and upregulates the expression of filaggrin, a pivotal endogenous source of natural moisturizing factors, in epidermal keratinocytes. It also activates nuclear factor erythroid-2-related factor 2 (NRF2), the antioxidative master transcription factor, and exhibits potent antioxidative activity against oxidative stress induced by ultraviolet irradiation and proinflammatory cytokines, which also accelerate inflammaging. GFF-mediated NRF2 activation downregulates the expression of CDKN2A, which is known to be overexpressed in senescent keratinocytes. Moreover, GFF enhances epidermal terminal differentiation by upregulating the expression of caspase-14, claudin-1, and claudin-4. It also promotes the synthesis of the antiinflammatory cytokine IL-37 and downregulates the expression of proallergic cytokine IL-33 in keratinocytes. In addition, GFF downregulates the expression of the CXCL14 and IL6R genes, which are involved in inflammaging. These beneficial properties might underpin the potent barrier-protecting and anti-inflammaging effects of GFF-containing skin formulae.

The multifaceted role of STAT3 pathway and its implication as a potential therapeutic target in oral cancer

Oral cancer is one of the leading causes of cancer-related deaths, and it has become a matter of serious concern due to the alarming rise in its incidence rate worldwide. Despite recent advancements in oral cancer treatment strategies, there are no significant improvements in patient's survival rate. Among the numerous cell signaling pathways involved in oral cancer development and progression, STAT3 is known to play a multifaceted oncogenic role in shaping the tumor pathophysiology. STAT3 hyperactivation in oral cancer contributes to survival, proliferation, invasion, epithelial to mesenchymal transition, metastasis, immunosuppression, chemoresistance, and poor prognosis. A plethora of pre-clinical and clinical studies have documented the role of STAT3 in the initiation and development of oral cancer and showed that STAT3 inhibition holds significant potential in the prevention and treatment of this cancer. However, to date, targeting STAT3 activation mainly involves inhibiting the upstream signaling molecules such as JAK and IL-6 receptors. The major challenge in targeting STAT3 lies in the complexity of its phosphorylation- and dimerization-independent functions, which are not affected by disrupting the upstream regulators. The present review delineates the significance of the STAT3 pathway in regulating various hallmarks of oral cancer. In addition, it highlights the STAT3 inhibitors identified to date through various preclinical and clinical studies that can be employed for the therapeutic intervention in oral cancer treatment.

The origin of bladder cancer from mucosal field effects

Whole-organ mapping was used to study molecular changes in the evolution of bladder cancer from field effects. We identified more than 100 dysregulated pathways, involving immunity, differentiation, and transformation, as initiators of carcinogenesis. Dysregulation of interleukins signified the involvement of inflammation in the incipient phases of the process. An aberrant methylation/expression of multiple HOX genes signified dysregulation of the differentiation program. We identified three types of mutations based on their geographic distribution. The most common were mutations restricted to individual mucosal samples that targeted uroprogenitor cells. Two types of mutations were associated with clonal expansion and involved large areas of mucosa. The α mutations occurred at low frequencies while the β mutations increased in frequency with disease progression. Modeling revealed that bladder carcinogenesis spans 10-15 years and can be divided into dormant and progressive phases. The progressive phase lasted 1-2 years and was driven by β mutations.

Increased expression of interleukin-22 and its receptor is relevant to poor prognosis in laryngeal squamous cell carcinoma: A case control trial

ABSTRACT

To detect the expression of interlerukin-22 (IL-22) and associated genes and to evaluate their relationship with clinicopathological features and prognosis in laryngeal squamous cell carcinoma (LSCC).The expression of IL-22 and associated genes were evaluated by immunohistochemistry and real time polymerase chain reaction in LSCC tissues from 30 patients and adjacent non-tumor tissues. A statistical analysis was implemented to assess the relationship among levels of expression, clinicopathological factors, and overall survival.The expression of IL-22 and interleukin 22 receptor 1 (IL-22R1) was mainly located in the cytoplasm, and the expression of LSCC was significantly higher than in controls. The expression of aryl hydrocarbon receptor and signal transducer and activator of transcription 3 distributed in the cell nucleus, which was significantly higher in LSCC than in controls. The expression of IL-22 and IL-22R1 was associated with metastasis of lymph node and clinical stage of LSCC. Overall survival of LSCC was significantly poorer with higher expression of IL-22 and IL-22R1 than in those with lower expression.The present research indicated that the increased level of IL-22 and IL-22R1 may be related to the pathogenesis and prognosis of LSCC. IL-22 may be the important biomarker, which need further research.

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.

Molecular Pathogenesis of Psoriasis and Biomarkers Reflecting Disease Activity

Psoriasis is a chronic inflammatory skin disease induced by multifactorial causes and is characterized by bothersome, scaly reddish plaques, especially on frequently chafed body parts, such as extensor sites of the extremities. The latest advances in molecular-targeted therapies using biologics or small-molecule inhibitors help to sufficiently treat even the most severe psoriatic symptoms and the extra cutaneous comorbidities of psoriatic arthritis. The excellent clinical effects of these therapies provide a deeper understanding of the impaired quality of life caused by this disease and the detailed molecular mechanism in which the interleukin (IL)-23/IL-17 axis plays an essential role. To establish standardized therapeutic strategies, biomarkers that define deep remission are indispensable. Several molecules, such as cytokines, chemokines, antimicrobial peptides, and proteinase inhibitors, have been recognized as potent biomarker candidates. In particular, blood protein markers that are repeatedly measurable can be extremely useful in daily clinical practice. Herein, we summarize the molecular mechanism of psoriasis, and we describe the functions and induction mechanisms of these biomarker candidates.

Role of Th22 Cells in the Pathogenesis of Autoimmune Diseases

Upon antigenic stimulation, naïve CD4+T cells differentiate into different subsets and secrete various cytokines to exert biological effects. Th22 cells, a newly identified CD4+T cell subset,are distinct from the Th1, Th2 and Th17 subsets. Th22 cells secrete certain cytokines such as IL-22, IL-13 and TNF-α, but not others, such as IL-17, IL-4, or interferon-γ (IFN-γ), and they express chemokine receptors CCR4, CCR6 and CCR10. Th22 cells were initially found to play a role in skin inflammatory diseases, but recent studies have demonstrated their involvement in the development of various autoimmune diseases. Here, we review research advances in the origin, characteristics and effector mechanisms of Th22 cells, with an emphasis on the role of Th22 cells and their main effector cytokine IL-22 in the pathogenesis of autoimmune diseases. The findings presented here may facilitate the development of new therapeutic strategies for targeting these diseases.

Tissue Damage in Radiation-Induced Oral Mucositis Is Mitigated by IL-17 Receptor Signaling

Oral mucositis (OM) is a treatment-limiting adverse side effect of radiation and chemotherapy. Approximately 80% of patients undergoing radiotherapy (RT) for head and neck cancers (HNC) develop OM, representing a major unmet medical condition. Our understanding of the immunopathogenesis of OM is limited, due in part to the surprising paucity of information regarding healing mechanisms in the oral mucosa. RNAseq of oral tissue in a murine model that closely mimics human OM, showed elevated expression of IL-17 and related immune pathways in response to head and neck irradiation (HNI). Strikingly, mice lacking the IL-17 receptor (IL-17RA) exhibited markedly more severe OM. Restoration of the oral mucosa was compromised in Il17ra-/- mice and components associated with healing, including matrix metalloproteinase 3, 10 and IL-24 were diminished. IL-17 is typically associated with recruitment of neutrophils to mucosal sites following oral infections. Unexpectedly, in OM the absence of IL-17RA resulted in excessive neutrophil recruitment and immunopathology. Instead, neutrophil activation was IL-1R-driven in Il17ra-/- mice. Blockade of IL-1R and depletion of neutrophils lessened the severity of damage in these mice. Overall, we show IL-17 is protective in OM through multiple mechanisms including restoration of the damaged epithelia and control of the neutrophil response. We also present a clinically relevant murine model of human OM to improve mechanistic understanding and develop rational translational therapeutics.

Establishment and characterization of a primary cell culture derived from external auditory canal squamous cell carcinoma

There are no human cancer cell lines of external auditory canal origin available for research use. This report describes the establishment of a culture condition for external auditory canal squamous cell carcinoma, derived from human tumor tissue. Successive squamous cell carcinoma colonies were dissociated by trypsin, subcultured, and maintained on a feeder layer (MMC‐TIG‐1‐20), yielding a clonally proliferating cell culture. Two morphological types of colony were observed: (a) densely packed colonies and (b) colonies with indistinct boundaries characterized by cell–cell complexes with fibroblast feeder cells. The SCC‐like characteristics of these cells were evidenced by positivity for p53, SCCA1/2, cytokeratin, and vimentin, and cancer stem cell properties were indicated by positivity for CD44, CD133, Oct3/4, and alkaline phosphatase (ALP). One of the unique properties of cell cultures is their tendency to form steric colonies in vitro on feeder layer cells. In addition, in the presence of fresh macrophages, the cells very slowly transform to break away from colonies as free cells, a process that resembles the epidermal–mesenchymal transition, whereby cell–cell interactions are weakened and migration activity is enhanced. These factors are purported to play a key role in cancer cell metastasis.

MicroRNA-1278 ameliorates the inflammation of cardiomyocytes during myocardial ischemia by targeting both IL-22 and CXCL14

AIMS

This study aimed to elucidate the role of microRNAs (miRNAs) during myocardial infarction (MI) development in vivo and in vitro.

MAIN METHODS

Differentially expressed miRNAs between heart tissue from the MI mouse model and the control mouse were identified via microarray. Quantitative PCR (qPCR) and western blotting (WB) were performed to examine the expression levels of miRNAs and proteins, respectively. EdU-staining and colony formation assay were performed to assess cell viability and growth. Annexin V- and PI-staining-based flow cytometry was used to assess cell apoptosis. An MI mouse model was also established to study the function of miR-1278 in vivo.

KEY FINDINGS

The levels of miR-1278 were reduced in the infarct regions of heart tissues of the MI mouse model and in H2O2-treated newborn murine ventricular cardiomyocytes (NMVCs) compared to those in the heart tissues of healthy mice and non-treated NMVCs. H2O2 treatment suppressed the proliferation of NMVCs, while miR-1278 upregulation improved it. Moreover, we found that miR-1278 inhibited the upregulation of IL-22 and CXCL14 expression in H2O2-treated NMVCs by directly binding with the 3'-UTRs of both IL-22 and CXCL14. Furthermore, restoration of IL-22 and CXCL14 in H2O2-treated NMVCs promoted miR-1278-induced inflammation and apoptosis. Administration of agomiR-1278 to the MI mouse model significantly improved cardiac activity.

SIGNIFICANCE

Collectively, our findings illustrate that the expression of miR-1278 is low in H2O2-treated NMVCs and post-MI cardiac tissues, and the overexpression of miR-1278 in these protects against cell death by modulating IL-22 and CXCL14 expression.

Identification of oral squamous cell carcinoma markers MUC2 and SPRR1B downstream of TANGO

PURPOSE

Transport and Golgi organization protein 1 (TANGO) promotes angiogenesis and lymphangiogenesis in oral squamous cell carcinoma (OSCC). To elucidate the underlying mechanisms, this study aims to identify and characterize elements downstream of TANGO that mediate its involvement in OSCC.

METHODS

In this study, microarray analysis compared gene expression between control and TANGO-repressed HSC3 cells. Protein expression in 213 OSCC tissue samples was analyzed immunohistochemically.

RESULTS

TANGO repression decreased or increased expression of Mucin 20 (MUC20) and small proline-rich protein 1B (SPRR1B), respectively. MUC20 increased the growth and invasiveness of OSCC cells via altered matrix metalloproteinase (MMP)-2 and E-cadherin expression and c-met phosphorylation. MUC20 induced angiogenesis and lymphangiogenesis by activating vascular endothelial growth factors A and C. In well-differentiated OSCC, SPRR1B expression was high (P = 0.0091) and correlated with keratinization markers and promoted proliferation by inducing mitogen-activated protein kinase p38 phosphorylation. MUC20 expression correlated significantly with clinical stage (P = 0.0024), lymph node metastasis (P = 0.0036), and number of blood and lymph vessels (P < 0.0001). MUC20-expressing cases had a significantly worse prognosis than non-expressing cases (P < 0.0001).

CONCLUSION

MUC20 and SPRR1B located downstream of TANGO may be useful molecular markers for OSCC.

Interleukin-22 promotes the migration and invasion of oral squamous cell carcinoma cells

The roles of interleukin-22 (IL-22) in carcinogenesis have been proposed in various neoplasms. Increased expression of IL-22 has been observed in oral squamous cell carcinoma (OSCC) lesions as well as in other cancers. OSCC is still associated with poor prognosis and a high mortality rate because of its invasiveness and frequent lymph node metastasis. In the present study, we investigated the effects of IL-22 on OSCC cells. The human OSCC cell lines Ca9-22 and SAS were stimulated with IL-22 (1-10 ng/mL), and their migration abilities were examined using a cell scratch assay. A Matrigel invasion assay was performed to evaluate the invasion abilities of OSCC cells. Signal transducer and activator of transcription 3 (STAT3) phosphorylation, matrix metalloproteinase (MMP) and epithelial-mesenchymal transition (EMT)-related genes and proteins were also examined. IL-22 treatment promoted the migration and invasion abilities of OSCC cells without increasing their viability. IL-22 stimulation also induced STAT3 phosphorylation, MMP-9 activity and EMT-related genes and proteins. Our findings suggest that IL-22 has possible roles in the development of OSCC.

Interleukin-22 enhances chemoresistance of lung adenocarcinoma cells to paclitaxel

The chemoresistance of tumors is the main barrier to cancer treatment. Interleukin-22 (IL-22) plays an important role in the chemoresistance of multi-cancers; however, the roles of IL-22 in the paclitaxel resistance of lung adenocarcinoma cells remain to be investigated. The present study aims to investigate the potential mechanisms of IL-22 enhancing the chemoresistance of lung adenocarcinoma cells to paclitaxel. We cultured A549, H358, and A549/PTX cell lines. qRT-PCR and western blot assays were performed to examine the mRNA and/or protein levels of IL-22 in A549, A549/PTX, H358, and H358/PTX. Moreover, cells were transfected with IL-22 siRNA1, IL-22 siRNA2, and siRNA NC, and treated with paclitaxel, and the proliferation rate of lung adenocarcinoma cells was evaluated by MTT assay. Flow cytometry was conducted to determine the apoptosis rate of lung adenocarcinoma cells. The results showed that the expression of IL-22 in lung adenocarcinoma tissues was higher than that in normal tissues, and the expression of IL-22 was higher in A549/PTX and H358/PTX compared with A549 and H358 cells. Meanwhile, the expression of IL-22 was strongly correlated with smoking history and TMN stage, as well. Furthermore, IL-22 siRNA inhibited the proliferation and promoted the apoptosis of A549/PTX and H358/PTX cells, and IL-22 siRNA also suppressed the expression levels of AKT and Bcl-2 and increased the expression levels of Bax and cleaved caspase 3. To sum up, IL-22 may mediate the chemosensitivity of lung adenocarcinoma cells to paclitaxel through inhibiting the AKT signaling pathways.

Effects of IL-22 on cardiovascular diseases

Interleukin-22 (IL-22), which belongs to the IL-10 family, is an alpha helix cytokine specifically produced by many lymphocytes, such as Th1, Th17, Th22, ILCs, CD4+ and CD8+ T cells. In recent years, more and more studies have demonstrated that IL-22 has an interesting relationship with various cardiovascular diseases, including myocarditis, myocardial infarction, atherosclerosis, and other cardiovascular diseases, and IL-22 signal may play a dual role in cardiovascular diseases. Here, we summarize the recent progress on the source, function, regulation of IL-22 and the effects of IL-22 signal in cardiovascular diseases. The study of IL-22 will suggest more specific strategies to maneuver these functions for the effective treatment of cardiovascular diseases and future clinical treatment.

Interleukin-22 receptor 1 upregulation and activation in hypoxic endothelial cells improves perfusion recovery in experimental peripheral arterial disease

OBJECTIVE

Inflammation induced by muscle ischemia is involved in tissue repair and perfusion recovery in peripheral arterial disease (PAD) patients. Interleukin (IL)-22 is an inflammatory cytokine discovered in recent years and shows versatile functions; however, its role in PAD remains unknown. Here, we test whether IL-22 and its receptors are involved in angiogenesis in experimental PAD.

METHODS AND RESULTS

Both IL-22 and its receptor-IL-22 receptor 1(IL-22R1) were upregulated in muscle and endothelial cells after ischemia. In experimental PAD models, blocking IL-22 using IL-22 monoclonal antibody impaired perfusion recovery and angiogenesis; on the other hand, IL-22 treatment improved perfusion recovery. Ischemic muscle tissue was harvested 3 days after experimental PAD for biochemical test, IL-22 antagonism resulted in decreased Signal Transducer and Activator of Transcription (STAT3) phosphorylation, but did not alter the levels of VEGF-A or cyclic guanine monophosphate (cGMP) levels in ischemic muscle. In cultured endothelial cells, IL-22R1 was upregulated under simulated ischemic conditions, and IL-22 treatment increased STAT3 phosphorylation, endothelial cell survival and tube formation. Knock down of IL-22R1 or treatment with STAT3 inhibitor blunted IL-22-induced endothelial cell survival or tube formation.

CONCULSION

Ischemia-induced IL-22 and IL-22R1 upregulation improves angiogenesis in PAD by inducing STAT3 phosphorylation in endothelial cells. IL-22R1 may serve as a new therapeutic target for PAD.

STAT3 activation by E6 is essential for the differentiation-dependent HPV18 life cycle

Human papillomaviruses (HPV) activate a number of host factors to control their differentiation-dependent life cycles. The transcription factor signal transducer and activator of transcription (STAT)-3 is important for cell cycle progression and cell survival in response to cytokines and growth factors. STAT3 requires phosphorylation on Ser727, in addition to phosphorylation on Tyr705 to be transcriptionally active. In this study, we show that STAT3 is essential for the HPV life cycle in undifferentiated and differentiated keratinocytes. Primary human keratinocytes containing high-risk HPV18 genomes display enhanced STAT3 phosphorylation compared to normal keratinocytes. Expression of the E6 oncoprotein is sufficient to induce the dual phosphorylation of STAT3 at Ser727 and Tyr705 by a mechanism requiring Janus kinases and members of the MAPK family. E6-mediated activation of STAT3 induces the transcription of STAT3 responsive genes including cyclin D1 and Bcl-xL. Silencing of STAT3 protein expression by siRNA or inhibition of STAT3 activation by small molecule inhibitors, or by expression of dominant negative STAT3 phosphorylation site mutants, results in blockade of cell cycle progression. Loss of active STAT3 impairs HPV gene expression and prevents episome maintenance in undifferentiated keratinocytes and upon differentiation, lack of active STAT3 abolishes virus genome amplification and late gene expression. Organotypic raft cultures of HPV18 containing keratinocytes expressing a phosphorylation site STAT3 mutant display a profound reduction in suprabasal hyperplasia, which correlates with a loss of cyclin B1 expression and increased differentiation. Finally, increased STAT3 expression and phosphorylation is observed in HPV positive cervical disease biopsies compared to control samples, highlighting a role for STAT3 activation in cervical carcinogenesis. In summary, our data provides evidence of a critical role for STAT3 in the HPV18 life cycle.

Bcl-3 induced by IL-22 via STAT3 activation acts as a potentiator of psoriasis-related gene expression in epidermal keratinocytes

IL-22 induces STAT3 phosphorylation and mediates psoriasis-related gene expression. However, the signaling mechanism leading from pSTAT3 to the expression of these genes remains unclear. We focused on Bcl-3, which is induced by STAT3 activation and mediates gene expression. In cultured human epidermal keratinocytes, IL-22 increased Bcl-3, which was translocated to the nucleus with p50 via STAT3 activation. The increases in CXCL8, S100As and human β-defensin 2 mRNA expression caused by IL-22 were abolished by siRNA against Bcl-3. Although CCL20 expression was also augmented by IL-22, the knockdown of Bcl-3 increased its level. Moreover, the combination of IL-22 and IL-17A enhanced Bcl-3 production, IL-22-induced gene expression, and the expression of other psoriasis-related genes, including those encoding IL-17C, IL-19, and IL-36γ. The expression of these genes (except for CCL20) was also suppressed by the knockdown of Bcl-3. Bcl-3 overexpression induced CXCL8 and HBD2 expression but not S100As expression. We also compared Bcl-3 expression between psoriatic skin lesions and normal skin. Immunostaining revealed strong signals for Bcl-3 and p50 in the nucleus of epidermal keratinocytes from psoriatic skin. The IL-22-STAT3-Bcl-3 pathway may be important in the pathogenesis of psoriasis.

The regulatory role of Fos related antigen‑1 in inflammatory bowel disease

The etiology of inflammatory bowel disease (IBD) remains unclear. The ratio of Fos related antigen‑1 (Fra‑1)‑positive intestinal mucosa epithelial cells is significantly increased in active IBD. This study intends to explore the regulatory role of Fra‑1 in IBD. The Fra‑1 eukaryotic expression vector was constructed and stably transfected to establish the Fra‑1 overexpression HCT‑116 (116‑Fra‑1) intestinal epithelial cell line. The impact of Fra‑1 overexpression on intestinal mucosal epithelial cell damage repair function was tested using a scratch assay. The role of Fra‑1 overexpression on intestinal mucosal epithelial cell proliferation was evaluated using a Cell Counting Kit-8 assay. Apoptosis related proteins, B‑cell lymphoma 2 (Bcl‑2), c‑Myc, Survivin and Bcl‑extra large (Bcl‑xL), expression levels were detected by western blotting. Fra‑1 suppressed intestinal mucosal epithelial cell damage repair and proliferation. Fra‑1 inhibited the protein levels of Bcl‑2, c‑Myc, Survivin, and Bcl‑xL. Fra‑1 overexpression in intestinal mucosal epithelial cells may restrain damage repair after intestinal mucosal injury in IBD remittent period through weakening the protective effect of intestinal mucosa, thus increasing the risk of recurrence. Therefore, suppressing Fra‑1 expression in intestinal mucosal epithelial cells may contribute to IBD remittent maintenance and recurrence delay.

IL-22 suppresses the infection of porcine enteric coronaviruses and rotavirus by activating STAT3 signal pathway

Interleukin-22 (IL-22), a member of the IL-10 superfamily, plays essential roles in fighting against mucosal microbial infection and maintaining mucosal barrier integrity within the intestine. However, little knowledge exists on the ability of porcine IL-22 (pIL-22) to fight against viral infection in the gut. In this study, we found that recombinant mature pIL-22 (mpIL-22) inhibited the infection of multiple diarrhea viruses, including alpha coronavirus, porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), and porcine rotavirus (PoRV), in the intestinal porcine epithelial cell line J2 (IPEC-J2) cells. mpIL-22 up-regulated the expression of the antimicrobial peptide beta-defensin (BD-2), cytokine IL-18 and IFN-λ. Furthermore, we found that mpIL-22 induced phosphorylation of STAT3 on Ser727 and Tyr705 in IPEC-J2 cells. Inhibition of STAT3 phosphorylation by S3I-201 abrogated the antiviral ability of mpIL-22 and the mpIL-22-induced expression of BD-2, IL-18, and IFN-λ. Together, mpIL-22 inhibited the infection of PoRV and enteric coronaviruses, and up-regulated the expression of antimicrobial genes in IPEC-J2, which were mediated by the activation of the STAT3 signal pathway. The significant antiviral activity of IL-22 to curtail multiple enteric diarrhea viruses in vitro suggests that pIL-22 could be a novel therapeutic against devastating viral diarrhea in piglets.

Interleukin 22 attenuated angiotensin II induced acute lung injury through inhibiting the apoptosis of pulmonary microvascular endothelial cells

Apoptosis of pulmonary microvascular endothelial cells (PMVECs) was considered to be closely related to the pathogenesis of acute lung injury (ALI). We aim to investigate whether IL-22 plays protective roles in lung injury through inhibiting the apoptosis of PMVECs. ALI model was induced through subcutaneous infusion of angiotensin II (Ang II). Lung injury and infiltration of inflammatory cells were evaluated by determining the PaO2/FiO2, calculation of dry to weight ratio in lung, and immunohistochemisty analysis. Apoptosis of PMVECs was determined using TUNEL assay and flow cytometry, respectively. Immunofluorescence and Western blot analysis were used to determine the expression and localization of STAT3, as well as the nucleus transmission of STAT3 from cytoplasm after IL22 treatment. Pathological findings showed ALI was induced 1 week after AngII infusion. IL22 inhibited the AngII-induced ALI, attenuated the edema in lung and the infiltration of inflammatory cells. Also, it contributed to the apoptosis of PMVECs induced by AngII. Meanwhile, significant increase was noticed in the expression of STAT3, phosphorylation of Y705-STAT3, and migration from cytoplasm to the nucleus after IL-22 treatment (P < 0.05). The activation of STAT3 by IL22 showed significant attenuation after AG490 treatment. Our data indicated that IL22 showed protective effects on lung injury through inhibiting the AngII-induced PMVECs apoptosis and PMVEC barrier injury by activating the JAK2/STAT3 signaling pathway.

SOCS3 inhibits the pathological effects of IL-22 in non-melanoma skin tumor-derived keratinocytes

Basal cell carcinomas (BCC) and squamous-cell carcinomas (SCC) are common malignancies in humans, caused by neoplastic transformation of keratinocytes of the basal or suprabasal layers of epidermis, respectively. Tumor-infiltrating lymphocytes (TILs) are frequently found in BCC and SCC, and functionally promote epithelial carcinogenesis. TILs secreting IL-22, in particular, participate to BCC and SCC growth by inducing keratinocyte proliferation and migration, as well as the expression of inflammatory, anti-apoptotic and pro-angiogenic genes.In this study, we identified SOCS3 as a valid candidate to be manipulated for suppressing tumorigenic functions in BCC and SCC. We found that SOCS3 and SOCS1 expression was reduced in vivo, in tumor lesions of BCC and SCC, as compared to other skin inflammatory conditions such as psoriasis, despite the high number of IL-22-secreting TILs. Moreover, IL-22 was not able to induce in vitro the transcriptional expression of SOCS3 in BCC-or SCC-derived keratinocytes, contrarily to healthy cells. Aimed at rescuing SOCS3 activity in these tumor contexts, a SOCS3-derived peptide, named KIR-ESS, was synthesized, and its ability in suppressing IL-22-induced responses was evaluated in healthy and transformed keratinocytes. We found that KIR-ESS peptide efficiently suppressed the IL-22 molecular signaling in keratinocytes, by acting on STAT3 and Erk1/2 cascade, as well as on the expression of STAT3-dependent downstream genes. Interestingly, after treatment with peptide, both healthy and transformed keratinocytes could no longer aberrantly proliferate and migrate in response to IL-22. Finally, treatment of athymic nude mice bearing SCC xenografts with KIR-ESS peptide concomitantly reduced tumor growth and activated STAT3 levels. As a whole, these data provides the rationale for the use in BCC and SCC skin tumors of SOCS3 mimetics, being able to inhibit the deleterious effects of IL-22 in these contexts.

Role of tumour-associated macrophages in oral squamous cells carcinoma progression: an update on current knowledge

BACKGROUND

Oral squamous cell carcinoma (OSCC) accounts over 90% of malignant neoplasms of the oral cavity. This pathological entity is associated to a high mortality rate that has remained unchanged over the past decades. Tumour-associated macrophages (TAMs) are believed to have potential involvement in OSCC progression. However, the molecular networks involved in communication between stroma and cancer cells have not yet been fully elucidated.

MAIN BODY

The role of M2 polarized cells in oral carcinogenesis is supported by a correlation between TAMs accumulation into OSCC stroma and poor clinical outcome. Signalling pathways such as the NF-κB and cytokines released in the tumour microenvironment promote a bidirectional cross-talk between M2 and OSCC cells. These interactions consequently result in an increased proliferation of malignant cells and enhances aggressiveness, thus reducing patients' survival time.

CONCLUSIONS

Here, we present a comprehensive review of the role of interleukin (IL)-1, IL-4, IL-6, IL-8, IL-10 and the receptor tyrosine kinase Axl in macrophage polarization to an M2 phenotype and OSCC progression. Understanding the molecular basis of oral carcinogenesis and metastatic spread of OSCC would promote the development of targeted treatment contributing to a more favourable prognosis.

JNK1/2 expression and modulation of STAT3 signaling in oral cancer

Mitogen-activated protein kinases (MAPKs) are a family of protein kinases that link extracellular stimuli with intracellular responses and participate in numerous cellular processes such as growth, proliferation, differentiation, inflammation and apoptosis. Persistent activation of signal transducer and activator of transcription 3 (STAT3), which is accompanied by increases in STAT3 tyrosine phosphorylation, is associated with cell proliferation, differentiation and apoptosis in oral squamous cell carcinoma (OSCC). The role and significance of the activation of MAPKs, particularly of c-Jun N-terminal kinase (JNK), on STAT3 signaling in OSCC have not been thoroughly investigated. The present study examines the effects of JNK1/2 modulation on STAT3 signaling and cellular activities in OSCC cells. The expression levels of STAT3 [total, tyrosine phosphorylated (p-Tyr) and serine phosphorylated (p-Ser)], JNK, c-Jun and cyclin D1 were assessed in the OSCC cell lines SCC25 and SCC9. Inhibition of JNK1/2 was achieved by pharmacological agents (SP600125) and by small interfering RNA (siRNA) silencing, while JNK1/2 was induced by active MAPK kinase 7. Cell proliferation and viability rates were also evaluated. Inhibition of JNK1/2 with either SP600125 treatment or specific siRNA silencing resulted in decreased levels of p-Ser STAT3 and increased levels of p-Tyr STAT3 and cyclin D1 in both cell lines. Furthermore, JNK1/2 inhibition resulted in a dose-dependent increase in cell growth and viability in both cell lines. Opposite results were observed with JNK1/2 induction in both cell lines. The present results are supportive of a potential tumor suppressive role of JNK1/2 signaling in OSCC, which may be mediated through negative crosstalk with the oncogenic STAT3 signaling pathway. The possible therapeutic implications of JNK1/2 inhibition for patients with OSCC require to be investigated.

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.

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.

Interleukin-22 Signaling in the Regulation of Intestinal Health and Disease

Interleukin (IL)-22 is a member of the IL-10 family of cytokines that has been extensively studied since its discovery in 2000. This review article aims to describe the cellular sources and signaling pathways of this cytokine as well as the functions of IL-22 in the intestine. In addition, this article describes the roles of IL-22 in the pathogenesis of several gastrointestinal diseases, including inhibition of inflammation and barrier defense against pathogens within the intestine. Since many of the functions of IL-22 in the intestine are incompletely understood, this review is meant to assess our current understanding of the roles of IL-22 and provide new opportunities for inquiry to improve human intestinal health and disease.

Prognostic Significance of Serine-Phosphorylated STAT3 Expression in pT1-T2 Oral Tongue Carcinoma

Objectives

Phosphorylated (activated) STAT3 (pSTAT3) is a regulator of numerous genes that play an essential part in the onset, development and progression of cancer; it is involved in cell proliferation and preventing apoptosis, and in invasion, angiogenesis, and the evasion of immune surveillance. This study aimed mainly to investigate the potential prognostic role of pSTAT3 expression in oral tongue squamous cell carcinoma (SCC).

Methods

Phospho-ser727 STAT3 immunolabeling was correlated with prognostic parameters in 34 consecutive cases of pT1-T2 tongue SCCs undergoing primary surgery. Computer-based image analysis was used for the immunohistochemical reactions analysis.

Results

Statistical analysis showed a difference in disease-free survival (DFS) when patients were stratified by pN status (P=0.031). Most tumors had variable degrees (mean±SD, 80.7%±23.8%) of intense nuclear immunoreaction to pSTAT3. Our findings rule out any significant association of serine-phosphorylated nuclear STAT3 expression with tumor stage, grade, lymph node metastasis, recurrence rate, or DFS.

Conclusion

In spite of these results, it is worth further investigating the role of pSTAT3 (serine- and tyrosine-pSTAT3) in oral tongue SCC in larger series because preclinical models are increasingly showing that several anticancer strategies would benefit from STAT3 phosphorylation inhibition.

Th22 cell accumulation is associated with colorectal cancer development

AIM

To investigate the expression of Th22 cells and related cytokines in colorectal cancer (CRC) tissues, and the probably mechanism.

METHODS

CRC tumor and paratumor tissues were collected to detect the expression levels of Th22 cells and of related cytokines by immunohistochemistry, flow cytometry and real-time quantitative polymerase chain reaction (RT-qPCR). Interleukin (IL)-22 alone or with a STAT3 inhibitor was co-cultured with RKO cells in vitro to study the effects of IL-22 on colon cancer cells. IL-22 alone or with a STAT3 inhibitor was injected into a BALB/c nude mouse model with subcutaneously transplanted RKO cells to study the effects of IL-22 on colon cancer growth.

RESULTS

The percentage of Th22 cells in the CD4(+) T subset was significantly higher in tumor tissues compared with that in paratumor tissues (1.47% ± 0.083% vs 1.23% ± 0.077%, P < 0.05) as determined by flow cytometry. RT-qPCR analysis revealed that the mRNA expression levels of IL-22, aryl hydrocarbon receptor, CCL20 and CCL22 were significantly higher in tumor tissues compared with those in paratumor tissues. CCL27 mRNA also displayed a higher expression level in tumor tissues compared with that in paratumor tissues; however, these levels were not significantly different (2.58 ± 0.93 vs 2.30 ± 0.78, P > 0.05). IL-22 enhanced colon cancer cell proliferation in vitro and displayed anti-apoptotic effects; these effects were blocked by adding a STAT3 inhibitor. IL-22 promoted tumor growth in BALB/c nude mice; however, this effect was reversed by adding a STAT3 inhibitor.

CONCLUSION

Th22 cells that accumulate in CRC may be associated with the chemotactic effect of the tumor microenvironment. IL-22 is associated with CRC development, most likely via STAT3 activation.

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.

Interleukin-17 and interleukin-22 promote tumor progression in human nonmelanoma skin cancer

Interleukin-17 (IL-17) and IL-22 have been reported to play critical roles in autoimmunity and inflammation but information about their role in cancer is limited. In this study, we investigated the role of IL-17 and IL-22 in the progression of human skin basal-cell carcinoma (BCC) and squamous-cell carcinoma (SCC). We found that both tumor types are infiltrated with an high number of IL-17(+) and IL-22(+) T lymphocytes, as demonstrated by immunohistochemistry and by FACS analysis performed on peritumoral T-cell lines isolated from skin biopsies. In vitro studies demonstrated that proliferation and migration of the BCC- and SCC-cell lines M77015 and CAL27 were increased by IL-17 and IL-22. Moreover, IL-17, alone or in combination with TNF-α, was able to induce the production of two cytokines important for tumor progression, IL-6 and IL-8, in CAL27. We also showed that IL-17 upregulated NF-κB signaling, while IL-22 activated the STAT3 pathway and the antiapoptotic AKT protein in M77015 and CAL27. Finally, in vivo experiments demonstrated that IL-17 and IL-22 enhanced tumor growth in nude mice injected with CAL27. Altogether, our findings indicate that high levels of IL-22 and IL-17 in the BCC and SCC microenvironment promote tumor progression.

Interleukin-22: immunobiology and pathology

Interleukin-22 (IL-22) is a recently described IL-10 family cytokine that is produced by T helper (Th) 17 cells, γδ T cells, NKT cells, and newly described innate lymphoid cells (ILCs). Knowledge of IL-22 biology has evolved rapidly since its discovery in 2000, and a role for IL-22 has been identified in numerous tissues, including the intestines, lung, liver, kidney, thymus, pancreas, and skin. IL-22 primarily targets nonhematopoietic epithelial and stromal cells, where it can promote proliferation and play a role in tissue regeneration. In addition, IL-22 regulates host defense at barrier surfaces. However, IL-22 has also been linked to several conditions involving inflammatory tissue pathology. In this review, we assess the current understanding of this cytokine, including its physiologic and pathologic effects on epithelial cell function.

Genetic polymorphisms and plasma levels of interleukin-22 contribute to the development of nonsmall cell lung cancer

Interleukin (IL)-22, a relatively new member of the IL-10 family, has been implicated in inflammation and tumorigenesis. The aim of this study was to identify genetic polymorphisms in IL-22 and to measure plasma levels of IL-22 in patients with nonsmall cell lung cancer (NSCLC). Patients with NSCLC had a significantly higher frequency of IL-22 rs2227484 CT genotype (odds ratio [OR]=1.917, 95% confidence interval [CI] 1.001-3.670, p=0.038) and T allele (OR=1.878, 95% CI 1.010-3.491, p=0.049) as compared with controls. The rs2227484 genotype was associated with a 2.263-fold increased risk for advanced NSCLC (p=0.041). Among different subtypes of NSCLC, these associations were more obvious in the adenocarcinoma. Moreover, patients with high frequencies of genotypic polymorphisms had high plasma levels of IL-22. IL-22 polymorphisms and corresponding high levels of IL-22 in plasma may contribute to the development of NSCLC, especially adenocarcinoma.

IL-22 produced by cancer-associated fibroblasts promotes gastric cancer cell invasion via STAT3 and ERK signaling

BACKGROUND

Interleukin-22 (IL-22) has been recently highlighted owing to its biological significance in the modulation of tissue responses during inflammation. However, the role of IL-22 in carcinogenesis has remained unclear. Here, we investigated the pathophysiological significance of IL-22 expression in gastric cancer tissues and examined the mechanism by which IL-22 promotes gastric cancer cell invasion.

METHODS

Human gastric cancer specimens were analysed by immunohistochemistry for expression of IL-22 and IL-22 receptor 1 (IL-22R1). The effects of IL-22-induced STAT3 and ERK signalling on invasive ability of gastric cancer cells were examined using a small-interfering RNA system and specific inhibitors. AGS cells were co-cultured with cancer-associated fibroblasts (CAFs) from human gastric cancer tissues and assessed by invasion assay.

RESULTS

Interleukin-22 and its receptor were expressed in α-smooth muscle actin-positive stromal cells and tumour cells at the invasive front of gastric cancer tissues, respectively. The expression of IL-22 and IL-22R1 was significantly related to lymphatic invasion. Interleukin-22 treatment promoted the invasive ability of gastric cancer cells through STAT3 and ERK activation. The invasive ability of gastric cancer cells was significantly enhanced by co-culture with IL-22-expressing CAFs.

CONCLUSIONS

Interleukin-22 produced by CAFs promotes gastric cancer cell invasion via STAT3 and ERK signalling.

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.

Chemoresistance to concanamycin A1 in human oral squamous cell carcinoma is attenuated by an HDAC inhibitor partly via suppression of Bcl-2 expression

V-ATPase is involved in the acidification of the microenvironment around/in solid tumors, such as oral squamous cell carcinoma (OSCC). V-ATPase is thought to induce tumor invasion and multi-drug resistance in several malignant tumors, and it also contributes to maintaining the intracellular pH under an acidic microenvironment by inducing proton extrusion into the extracellular medium. However, there is little information regarding the effects of V-ATPase inhibitors on OSCCs. In this study, the effects of a V-ATPase inhibitor, concanamycin A1 (CMA), on the proliferation and apoptosis of OSCC were investigated in vitro. We used four OSCC cell lines, MISK81-5, SAS, HSC-4 and SQUU-B. Acridine orange staining revealed that the red fluorescence was reduced in all of the low concentration CMA-treated OSCC cells, indicating that the acidification of vesicular organelles in the OSCCs was prevented by the treatment with low-concentration of CMA. CMA treatment induced apoptosis in MISK81-5, SAS and HSC-4 cells, but not in SQUU-B cells. The p-p38 expression was not altered in CMA-treated SQUU-B cells, but their levels were increased in the other cells. The Bax/Bcl-2 ratio in CMA-treated SQUU-B cells was dramatically decreased in comparison with that in the other cell lines treated with CMA. However, when the SQUU-B cells were treated with CMA and a histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), the SQUU-B cells became more susceptible to the CMA-induced apoptosis. SAHA treatment led to a significantly decrease in the Bcl-2 expression in CMA-treated SQUU-B cells, resulting in a dramatically increased Bax/Bcl-2 ratio in comparison with that observed in the SQUU-B cells treated with CMA alone. These findings suggest that CMA could have an anti-tumor effect on OSCCs. In addition, combination of CMA with other agents, such as SAHA, could help improve the pro-apoptotic effects of CMA even in CMA-resistant OSCC cells.

Integrative genomic analyses of recepteur d'origine nantais and its prognostic value in cancer

Recepteur d'origine nantais (RON) is a receptor tyrosine kinase (RTK) normally expressed at low levels in epithelial cells. RON is a 180-kDa heterodimeric protein composed of a 40-kDa α-chain and a 150-kDa transmembrane β-chain with intrinsic tyrosine kinase activity. The extracellular sequences of RON contain several domains including an N-terminal semaphorin (sema) domain, followed by the plexin, semaphorin, integrin (PSI) domain, and four immunoglobulin, plexin, transcription factor (IPT) domains. Here, we identified RON genes from 14 vertebrate genomes and found that RON exists in all types of vertebrates including fish, amphibians, birds and mammals. We found that the human RON gene showed predominant expression in the liver, lymph node, thymus, intestine, lung, mammary gland, bone marrow, brain, heart, placenta, bladder, cortex, cervix, skin, kidney and prostate. When searched in the PrognoScan database, human RON was also found to be expressed in bladder, blood, breast, glioma, esophageal, colorectal, head and neck, ovarian, lung and skin cancer. The relationship between the expression of RON and prognosis was found to vary in different cancer types, even in the same cancer from different databases. This suggests that the function of RON in these tumors may be multidimensional, not just as a tumor suppressor or oncogene. Six available single-nucleotide polymorphisms (SNPs) disrupting existing exonic splicing enhancers were identified in RON. This may contribute to the generation of active RON variants by alternative splicing, which is frequently observed in primary tumors.