A critical role for the regulated wnt-myc pathway in naive T cell survival

Signaling pathways in colorectal cancer implications for the target therapies

Colorectal carcinoma (CRC) stands as a pressing global health issue, marked by the unbridled proliferation of immature cells influenced by multifaceted internal and external factors. Numerous studies have explored the intricate mechanisms of tumorigenesis in CRC, with a primary emphasis on signaling pathways, particularly those associated with growth factors and chemokines. However, the sheer diversity of molecular targets introduces complexity into the selection of targeted therapies, posing a significant challenge in achieving treatment precision. The quest for an effective CRC treatment is further complicated by the absence of pathological insights into the mutations or alterations occurring in tumor cells. This study reveals the transfer of signaling from the cell membrane to the nucleus, unveiling recent advancements in this crucial cellular process. By shedding light on this novel dimension, the research enhances our understanding of the molecular intricacies underlying CRC, providing a potential avenue for breakthroughs in targeted therapeutic strategies. In addition, the study comprehensively outlines the potential immune responses incited by the aberrant activation of signaling pathways, with a specific focus on immune cells, cytokines, and their collective impact on the dynamic landscape of drug development. This research not only contributes significantly to advancing CRC treatment and molecular medicine but also lays the groundwork for future breakthroughs and clinical trials, fostering optimism for improved outcomes and refined approaches in combating colorectal carcinoma.

CMYC-initiated HNF1A-AS1 overexpression maintains the stemness of gastric cancer cells

Cancer stem cells (CSCs) are believed to be responsible for cancer metastasis and recurrence due to their self-renewal ability and resistance to treatment. However, the mechanisms that regulate the stemness of CSCs remain poorly understood. Recently, evidence has emerged suggesting that long non-coding RNAs (lncRNAs) play a crucial role in regulating cancer cell function in different types of malignancies, including gastric cancer (GC). However, the specific means by which lncRNAs regulate the function of gastric cancer stem cells (GCSCs) are yet to be fully understood. In this study, we investigated a lncRNA known as HNF1A-AS1, which is highly expressed in GCSC s and serves as a critical regulator of GCSC stemness and tumorigenesis. Our experiments, both in vitro and in vivo, demonstrated that HNF1A-AS1 maintained the stemness of GC cells. Further analysis revealed that HNF1A-AS1, transcriptionally activated by CMYC, functioned as a competing endogenous RNA by binding to miR-150-5p to upregulate β-catenin expression. This in turn facilitated the entry of β-catenin into the nucleus to activate the Wnt/β-catenin pathway and promote CMYC expression, thereby forming a positive feedback loop that sustained the stemness of GCSCs. We also found that blocking the Wnt/β-catenin pathway effectively inhibited the function of HNF1A-AS1, ultimately resulting in the inhibition of GCSC stemness. Taken together, our results demonstrated that HNF1A-AS1 is a regulator of the stemness of GCSCs and could serve as a potential marker for targeted GC therapy.

Targeting HMGA1 contributes to immunotherapy in aggressive breast cancer while suppressing EMT

Metastasis is an obstacle to the clinical treatment of aggressive breast cancer (BC). Studies have shown that high mobility group A1 (HMGA1) is abnormally expressed in various cancers and mediates tumor proliferation and metastasis. Here, we provided more evidence that HMGA1 mediated epithelial to mesenchymal transition (EMT) through the Wnt/β-catenin pathway in aggressive BC. More importantly, HMGA1 knockdown enhanced antitumor immunity and improved the response to immune checkpoint blockade (ICB) therapy by upregulating programmed cell death ligand 1 (PD-L1) expression. Simultaneously, we revealed a novel mechanism by which HMGA1 and PD-L1 were regulated by the PD-L1/HMGA1/Wnt/β-catenin negative feedback loop in aggressive BC. Taken together, we believe that HMGA1 can serve as a target for the dual role of anti-metastasis and enhancing immunotherapeutic responses.

Suppression of Tumor or Host Intrinsic CMTM6 Drives Antitumor Cytotoxicity in a PD-L1-Independent Manner

CKLF-like MARVEL transmembrane domain-containing protein 6 (CMTM6) is known to be a regulator of membranal programmed death ligand 1 (PD-L1) stability and a factor associated with malignancy progression, but the effects and mechanisms of CMTM6 on tumor growth, as well as its potential as a target for therapy, are still largely unknown. Here, we show that CMTM6 expression increased with tumor progression in both patients and mice. Ablation of CMTM6 significantly reduced human and murine tumor growth in a manner dependent on T-cell immunity. Tumor CMTM6 suppression broke resistance to immune-checkpoint inhibitors and remodeled the tumor immune microenvironment, as specific antitumor cytotoxicity was enhanced and contributed primarily to tumor inhibition. Without the PD-1/PD-L1 axis, CMTM6 suppression still significantly dampened tumor growth dependent on cytotoxic cells. Furthermore, we identified that CMTM6 was widely expressed on immune cells. T-cell CMTM6 levels increased with sustained immune activation and intratumoral immune exhaustion and affected T cell-intrinsic PD-L1 levels. Host CMTM6 knockout significantly restrained tumor growth in a manner dependent on CD8+ T cells and not entirely dependent on PD-L1. Thus, we developed and evaluated the antitumor efficacy of CMTM6-targeting adeno-associated virus (AAV), which effectively mobilized antitumor immunity and could be combined with various antitumor drugs. Our findings reveal that both tumor and host CMTM6 are involved in antitumor immunity with or without the PD-1/PD-L1 axis and that gene therapy targeting CMTM6 is a promising strategy for cancer immunotherapy.

Colorectal cancer immunotherapy-Recent progress and future directions

Compared with conventional chemotherapy and targeted therapy, immunotherapy has changed the treatment prospects of various solid tumors and has recently become the main treatment method for metastatic or recurrent solid tumors, including malignant melanoma, non-small-cell lung cancer, and renal cell carcinoma. The application of immune checkpoint inhibitor (ICI)-based immunotherapy in patients with colorectal cancer (CRC) has yielded satisfactory results in terms of safety and efficacy, and several immunotherapeutic agents, including pembrolizumab, nivolumab, and ipilimumab, have been approved for the treatment of advanced CRC. The advent of other immunotherapies, such as chimeric antigen receptor-modified T (CAR-T) cells or cancer vaccines, have also contributed to the development of immunotherapy for CRC. Here, we summarize the findings of recent clinical trials on the efficacy of immunotherapy in CRC and briefly describe the mechanisms associated with tumor-intrinsic resistance to ICIs. We then discuss potential biomarkers for predicting the efficacy of immunotherapy.

Wnt signaling pathway in cancer immunotherapy

Wnt/β-catenin signaling is a highly conserved pathway that regulates cell proliferation, differentiation, apoptosis, stem cell self-renewal, tissue homeostasis, and wound healing. Dysregulation of the Wnt pathway is intricately involved in almost all stages of tumorigenesis in various cancers. Through direct and/or indirect effects on effector T cells, T-regulatory cells, T-helper cells, dendritic cells, and other cytokine-expressing immune cells, abnormal activation of Wnt/β-catenin signaling benefits immune exclusion and hinders T-cell-mediated antitumor immune responses. Activation of Wnt signaling results in increased resistance to immunotherapies. In this review, we summarize the process by which Wnt signaling affects cancer and immune surveillance, and the potential for targeting the Wnt-signaling pathway via cancer immunotherapy.

Single-cell transcriptomics reveals opposing roles of Shp2 in Myc-driven liver tumor cells and microenvironment

The mechanisms of Myc-driven liver tumorigenesis are inadequately understood. Herein we show that Myc-driven hepatocellular carcinoma (HCC) is dramatically aggravated in mice with hepatocyte-specific Ptpn11/Shp2 deletion. However, Myc-induced tumors develop selectively from the rare Shp2-positive hepatocytes in Shp2-deficent liver, and Myc-driven oncogenesis depends on an intact Ras-Erk signaling promoted by Shp2 to sustain Myc stability. Despite a stringent requirement of Shp2 cell autonomously, Shp2 deletion induces an immunosuppressive environment, resulting in defective clearance of tumor-initiating cells and aggressive tumor progression. The basal Wnt/β-catenin signaling is upregulated in Shp2-deficient liver, which is further augmented by Myc transfection. Ablating Ctnnb1 suppresses Myc-induced HCC in Shp2-deficient livers, revealing an essential role of β-catenin. Consistently, Myc overexpression and CTNNB1 mutations are frequently co-detected in HCC patients with poor prognosis. These data elucidate complex mechanisms of liver tumorigenesis driven by cell-intrinsic oncogenic signaling in cooperation with a tumor-promoting microenvironment generated by disrupting the specific oncogenic pathway.

Stress-activated kinases as therapeutic targets in pancreatic cancer

Pancreatic cancer is a dismal disease with high incidence and poor survival rates. With the aim to improve overall survival of pancreatic cancer patients, new therapeutic approaches are urgently needed. Protein kinases are key regulatory players in basically all stages of development, maintaining physiologic functions but also being involved in pathogenic processes. c-Jun N-terminal kinases (JNK) and p38 kinases, representatives of the mitogen-activated protein kinases, as well as the casein kinase 1 (CK1) family of protein kinases are important mediators of adequate response to cellular stress following inflammatory and metabolic stressors, DNA damage, and others. In their physiologic roles, they are responsible for the regulation of cell cycle progression, cell proliferation and differentiation, and apoptosis. Dysregulation of the underlying pathways consequently has been identified in various cancer types, including pancreatic cancer. Pharmacological targeting of those pathways has been the field of interest for several years. While success in earlier studies was limited due to lacking specificity and off-target effects, more recent improvements in small molecule inhibitor design against stress-activated protein kinases and their use in combination therapies have shown promising in vitro results. Consequently, targeting of JNK, p38, and CK1 protein kinase family members may actually be of particular interest in the field of precision medicine in patients with highly deregulated kinase pathways related to these kinases. However, further studies are warranted, especially involving in vivo investigation and clinical trials, in order to advance inhibition of stress-activated kinases to the field of translational medicine.

A Novel Ferroptosis-Related Pathway for Regulating Immune Checkpoints in Clear Cell Renal Cell Carcinoma

Ferroptosis is a novel form of cell death and plays a role in various diseases, especially tumors. It has been reported that ferroptosis is involved in the growth and progression of clear cell renal cell carcinoma (ccRCC); however, the specific molecular mechanisms are still unclear. In this study, we constructed a four-gene signature (FeSig) of ferroptosis-related genes via Cox regression analysis. ROC and survival analyses indicated that FeSig had good diagnostic and prognostic value. Further analysis revealed that ferroptosis was associated with tumor immunity in ccRCC. Next, weighted gene co-expression network analysis was performed to identify the potential regulatory mechanisms. Combined with correlation and survival analyses, the TAZ/WNT10B axis was identified as a tumor immune-related regulatory pathway. In conclusion, these findings suggest that ferroptosis is correlated with tumor immunity. The TAZ/WNT10B axis may be a novel biomarker and therapeutic target for immunotherapy in ccRCC.

MYC deficiency impairs the development of effector/memory T lymphocytes

In the thymus, T cell progenitors differentiate in order to generate naive T lymphocytes which migrate in the periphery where they will fulfill their function in the adaptive immune response. During thymopoiesis, genomic alterations in thymocytes can promote leukemia development. Among recurrent alteration is PTEN inactivation, which is associated to MYC overexpression. Herein, we used conditional Pten and Myc knockout mouse models and single-cell RNA-sequencing approach, to investigate the impact of MYC loss on physio-pathological development of PTEN-proficient or PTEN-deficient T lymphocytes. First, our results confirm that MYC is mandatory for PTEN loss-mediated leukemogenesis, while it is not required for terminal steps of thymopoiesis. In contrast, we uncovered that Myc ablation in CD4⁺CD8⁺ thymocytes disrupts T lymphocytes homeostasis in the spleen, notably by drastically reducing the number of MYC-deficient effector/memory T cells. Collectively, our data show that besides naive T cells proliferation, MYC is essential for effector/memory differentiation.

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MYC is essential for PTEN loss-mediated T cell leukemogenesis

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MYC is required for effector/memory T cell differentiation

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Expansion of splenic CD8⁺TCRγδ⁺ cells in MYC-deficient background

Disruption of Wnt/β-catenin Pathway Elevates the Sensitivity of Gastric Cancer Cells to PD-1 Antibody

BACKGROUND

Gastric cancer (GC) is the fifth most common malignancy tumor and the third cause of cancer-related death around the world. Immune checkpoint inhibitors (ICIs) such as programmed cell death-1 (PD-1) antibodies play an active role in tumor therapy. A recent study reveals that the Wnt/β-catenin signaling pathway is negatively correlated with T-cell infiltration in the tumor microenvironment (TME), thereby influencing the therapeutic efficacy of the PD-1 antibody.

OBJECTIVE

In this study, we aimed to uncover the relationship of the Wnt/β-catenin pathway to CD8+ T cell activity as well as its effect on anti-PD-1 therapeutic efficacy in GC.

METHODS

We first collected clinical samples and went through an immunohistochemical analysis and found that a high β-catenin expression in GC tissues was often associated with a significant absence of CD8+ T-cell infiltration.

RESULTS

In addition, our data further indicated that disruption of the Wnt/β-catenin pathway in GC cells inhibited their migratory and invasive ability. Meanwhile, enhanced sensitivity of GC cells to PD-1 blockade therapy was evident by decreased Jurkat cell apoptosis rate and increased GC cell apoptosis rate in a tumor and Jurkat cells co-culture system with the presence of Wnt/β-catenin pathway inhibition.

CONCLUSION

Collectively, these findings indicated that the Wnt/β-catenin pathway might play a significant role in modulating the activity of Jurkat cells, and downregulation of Wnt/β-catenin may enhance the sensitivity of GC cells to PD-1 antibody in vitro. This result further indicated that β-catenin and PD-1 targeted inhibition might become a potential and effective therapy for GC patients.

Single cell analysis reveals distinct immune landscapes in transplant and primary sarcomas that determine response or resistance to immunotherapy

Immunotherapy fails to cure most cancer patients. Preclinical studies indicate that radiotherapy synergizes with immunotherapy, promoting radiation-induced antitumor immunity. Most preclinical immunotherapy studies utilize transplant tumor models, which overestimate patient responses. Here, we show that transplant sarcomas are cured by PD-1 blockade and radiotherapy, but identical treatment fails in autochthonous sarcomas, which demonstrate immunoediting, decreased neoantigen expression, and tumor-specific immune tolerance. We characterize tumor-infiltrating immune cells from transplant and primary tumors, revealing striking differences in their immune landscapes. Although radiotherapy remodels myeloid cells in both models, only transplant tumors are enriched for activated CD8+ T cells. The immune microenvironment of primary murine sarcomas resembles most human sarcomas, while transplant sarcomas resemble the most inflamed human sarcomas. These results identify distinct microenvironments in murine sarcomas that coevolve with the immune system and suggest that patients with a sarcoma immune phenotype similar to transplant tumors may benefit most from PD-1 blockade and radiotherapy.

Coordinating Cytoskeleton and Molecular Traffic in T Cell Migration, Activation, and Effector Functions

Dynamic localization of receptors and signaling molecules at the plasma membrane and within intracellular vesicular compartments is crucial for T lymphocyte sensing environmental cues, triggering membrane receptors, recruiting signaling molecules, and fine-tuning of intracellular signals. The orchestrated action of actin and microtubule cytoskeleton and intracellular vesicle traffic plays a key role in all these events that together ensure important steps in T cell physiology. These include extravasation and migration through lymphoid and peripheral tissues, T cell interactions with antigen-presenting cells, T cell receptor (TCR) triggering by cognate antigen–major histocompatibility complex (MHC) complexes, immunological synapse formation, cell activation, and effector functions. Cytoskeletal and vesicle traffic dynamics and their interplay are coordinated by a variety of regulatory molecules. Among them, polarity regulators and membrane–cytoskeleton linkers are master controllers of this interplay. Here, we review the various ways the T cell plasma membrane, receptors, and their signaling machinery interplay with the actin and microtubule cytoskeleton and with intracellular vesicular compartments. We highlight the importance of this fine-tuned crosstalk in three key stages of T cell biology involving cell polarization: T cell migration in response to chemokines, immunological synapse formation in response to antigen cues, and effector functions. Finally, we discuss two examples of perturbation of this interplay in pathological settings, such as HIV-1 infection and mutation of the polarity regulator and tumor suppressor adenomatous polyposis coli (Apc) that leads to familial polyposis and colorectal cancer.

Targeting the immune milieu in gastrointestinal cancers

Gastrointestinal (GI) cancers are among the most common and lethal solid tumors worldwide. Unlike in malignancies such as lung, renal and skin cancers, the activity of immunotherapeutic agents in GI cancers has, on the whole, been much less remarkable and do not apply to the majority. Furthermore, while incremental progress has been made and approvals for use of immune checkpoint inhibitors (ICIs) in specific subsets of patients with GI cancers are coming through, in a population of 'all-comers', it is frequently unclear as to who may benefit most due to the relative lack of reliable predictive biomarkers. For most patients with newly diagnosed advanced or metastatic GI cancer, the mainstay of treatment still involves chemotherapy and/or a targeted agent however, beyond the second-line this paradigm confers minimal patient benefit. Thus, current research efforts are concentrating on broadening the applicability of ICIs in GI cancers by combining them with agents designed to beneficially remodel the tumor microenvironment (TME) for more effective anti-cancer immunity with intention of improving patient outcomes. This review will discuss the currently approved ICIs available for the treatment of GI cancers, the strategies underway focusing on combining ICIs with agents that target the TME and touch on recent progress toward identification of predictors of sensitivity to immune checkpoint blockade in GI cancers.

Cooperation Between MYC and β-Catenin in Liver Tumorigenesis Requires Yap/Taz

BACKGROUND AND AIMS

Activation of MYC and catenin beta-1 (CTNNB1, encoding β-catenin) can co-occur in liver cancer, but how these oncogenes cooperate in tumorigenesis remains unclear.

APPROACH AND RESULTS

We generated a mouse model allowing conditional activation of MYC and WNT/β-catenin signaling (through either β-catenin activation or loss of APC - adenomatous polyposis coli) upon expression of CRE recombinase in the liver and monitored their effects on hepatocyte proliferation, apoptosis, gene expression profiles, and tumorigenesis. Activation of WNT/β-catenin signaling strongly accelerated MYC-driven carcinogenesis in the liver. Both pathways also cooperated in promoting cellular transformation in vitro, demonstrating their cell-autonomous action. Short-term induction of MYC and β-catenin in hepatocytes, followed by RNA-sequencing profiling, allowed the identification of a "Myc/β-catenin signature," composed of a discrete set of Myc-activated genes whose expression increased in the presence of active β-catenin. Notably, this signature enriched for targets of Yes-associated protein (Yap) and transcriptional coactivator with PDZ-binding motif (Taz), two transcriptional coactivators known to be activated by WNT/β-catenin signaling and to cooperate with MYC in mitogenic activation and liver transformation. Consistent with these regulatory connections, Yap/Taz accumulated upon Myc/β-catenin activation and were required not only for the ensuing proliferative response, but also for tumor cell growth and survival. Finally, the Myc/β-catenin signature was enriched in a subset of human hepatocellular carcinomas characterized by comparatively poor prognosis.

CONCLUSIONS

Myc and β-catenin show a strong cooperative action in liver carcinogenesis, with Yap and Taz serving as mediators of this effect. These findings warrant efforts toward therapeutic targeting of Yap/Taz in aggressive liver tumors marked by elevated Myc/β-catenin activity.

Casein Kinase 1α as a Regulator of Wnt-Driven Cancer

Wnt signaling regulates numerous cellular processes during embryonic development and adult tissue homeostasis. Underscoring this physiological importance, deregulation of the Wnt signaling pathway is associated with many disease states, including cancer. Here, we review pivotal regulatory events in the Wnt signaling pathway that drive cancer growth. We then discuss the roles of the established negative Wnt regulator, casein kinase 1α (CK1α), in Wnt signaling. Although the study of CK1α has been ongoing for several decades, the bulk of such research has focused on how it phosphorylates and regulates its various substrates. We focus here on what is known about the mechanisms controlling CK1α, including its putative regulatory proteins and alternative splicing variants. Finally, we describe the discovery and validation of a family of pharmacological CK1α activators capable of inhibiting Wnt pathway activity. One of the important advantages of CK1α activators, relative to other classes of Wnt inhibitors, is their reduced on-target toxicity, overcoming one of the major impediments to developing a clinically relevant Wnt inhibitor. Therefore, we also discuss mechanisms that regulate CK1α steady-state homeostasis, which may contribute to the deregulation of Wnt pathway activity in cancer and underlie the enhanced therapeutic index of CK1α activators.

LMBR1L regulates lymphopoiesis through Wnt/β-catenin signaling

Precise control of Wnt signaling is necessary for immune system development. In this study, we detected severely impaired development of all lymphoid lineages in mice, resulting from an N-ethyl-N-nitrosourea-induced mutation in the limb region 1-like gene (Lmbr1l), which encodes a membrane-spanning protein with no previously described function in immunity. The interaction of LMBR1L with glycoprotein 78 (GP78) and ubiquitin-associated domain-containing protein 2 (UBAC2) attenuated Wnt signaling in lymphocytes by preventing the maturation of FZD6 and LRP6 through ubiquitination within the endoplasmic reticulum and by stabilizing "destruction complex" proteins. LMBR1L-deficient T cells exhibited hallmarks of Wnt/β-catenin activation and underwent apoptotic cell death in response to proliferative stimuli. LMBR1L has an essential function during lymphopoiesis and lymphoid activation, acting as a negative regulator of the Wnt/β-catenin pathway.

Multiple Targets of the Canonical WNT/β-Catenin Signaling in Cancers

Canonical WNT/β-catenin signaling is involved in most of the mechanisms that lead to the formation and development of cancer cells. It plays a central role in three cyclic processes, which are the cell division cycle, the immune cycle, and circadian rhythms. When the canonical WNT pathway is upregulated as in cancers, the increase in β-catenin in the nucleus leads to activation of the expression of numerous genes, in particular CYCLIN D1 and cMYC, where the former influences the G1 phase of the cell division cycle, and the latter, the S phase. Every stage of the immune cycle is disrupted by the canonical WNT signaling. In numerous cancers, the dysfunction of the canonical WNT pathway is accompanied by alterations of the circadian genes (CLOCK, BMAL1, PER). Induction of these cyclic phenomena leads to the genesis of thermodynamic mechanisms that operate far from equilibrium, and that have been called “dissipative structures.” Moreover, upregulation of the canonical WNT/β-catenin signaling is important in the myofibroblasts of the cancer stroma. Their differentiation is controlled by the canonical WNT /TGF-β1 signaling. Myofibroblasts present ultraslow contractile properties due to the presence of the non-muscle myosin IIA. Myofibroblats also play a role in the inflammatory processes, often found in cancers and fibrosis processes. Finally, upregulated canonical WNT deviates mitochondrial oxidative phosphorylation toward the Warburg glycolysis metabolism, which is characteristic of cancers. Among all these cancer-generating mechanisms, the upregulated canonical WNT pathway would appear to offer the best hope as a therapeutic target, particularly in the field of immunotherapy.

Wnt Signaling Protects against Paclitaxel-Induced Spiral Ganglion Neuron Damage in the Mouse Cochlea In Vitro

It has been reported that paclitaxel administration could cause sensorineural hearing loss, and Wnt activation is important for the development and cell protection of mouse cochlea. However, the effect of Wnt signaling in spiral ganglion neurons (SGNs) damage induced by paclitaxel has not yet been elucidated. In this study, we explored the effect of paclitaxel on SGNs in the mouse cochlea and the neuroprotective effects of Wnt signaling pathway against paclitaxel-induced SGN damage by using Wnt agonist/antagonists in vitro. We first found that paclitaxel treatment resulted in a degenerative change and reduction of cell numbers in SGNs and induced caspase-mediated apoptosis in SGNs. The expression levels of β-catenin and C-myc were increased, thus indicating Wnt signaling was activated in SGNs after paclitaxel treatment. The activation of Wnt signaling pathway protected against SGN loss after exposure to paclitaxel, whereas the suppression of Wnt signaling in SGNs made them more vulnerable to paclitaxel treatment. We also showed that activation of Wnt signaling in SGNs inhibited caspase-mediated apoptosis. Our findings demonstrated that Wnt signaling had an important role in protecting SGNs against paclitaxel-induced damage and thus might be an effective therapeutic target for the prevention of paclitaxel-induced SGN death.

Serum microRNA Profiles Serve as Novel Biomarkers for Autoimmune Diseases

Autoimmune diseases involve a complex dysregulation of immunity. Autoimmune diseases include many members [e.g., rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE)], and most of them are classified according to what organs and tissues are targeted by the damaging immune response. Many studies have focused on finding specific biomarkers for single autoimmune diseases, but so far, there are no universal biomarkers for detecting almost all autoimmune diseases. Serum miRNAs have served as potential biomarkers for detecting various diseases. The purpose of this study was to find a universal biomarker for diagnosing autoimmune diseases. Regulatory T cells (Tregs) play a crucial role in protecting an individual from autoimmunity, and depletion of Tregs in mice is considered a representative animal model of autoimmune disease. Two mouse models for Treg depletion, in which Treg was depleted by CD25mAb (in C57 mice) or by diphtheria toxin (DT) (in Foxp3^DTR mice), were investigated, and 381 miRNAs were identified in the serum of mice with Treg depletion. A distinctive circulating miRNA profile was identified in Treg-depleted mice and in patients with autoimmune disease. QRT-PCR confirmation and ROC curve analysis determined that six miRNAs (miR-551b, miR-448, miR-9, miR-124, miR-148, and miR-34c) in the Treg-depleted mouse models and three miRNAs [miR-551b (specificity 73.5%, sensitivity 88.4%), miR-448 (specificity 82.4%, sensitivity 91.3%), and miR-124 (specificity 76.5%, sensitivity 91.3%)] in patients with RA, SLE, Sjogren's syndrome (SS), and ulcerative colitis (UC) could serve as valuable specific biomarkers. These circulating miRNAs may represent potential universal biomarkers for autoimmune diseases diagnosis and prognosis.

Wnt7a induces a unique phenotype of monocyte-derived macrophages with lower phagocytic capacity and differential expression of pro- and anti-inflammatory cytokines

The variation of macrophage functions suggests the involvement of multiple signalling pathways in fine tuning their differentiation. Macrophages that originate from monocytes in the blood migrate to tissue in response to homeostatic or 'danger' signals and undergo substantial morphological and functional modifications to meet the needs of the dominant signals in the microenvironment. Wnts are secreted glycoproteins that play a significant role in organ and cell differentiation, yet their impact on monocyte differentiation is not clear. In this study, we assessed the role of Wnt1 and Wnt7a on the differentiation of monocytes and the subsequent phenotype and function of monocyte-derived macrophages (MDMs). We show that Wnt7a decreased the expression of CD14, CD11b, CD163 and CD206, whereas Wnt1 had no effect. The Wnt7a effect on CD11b was also observed in the brain and spleen of Wnt7a^-/- adult brain mouse tissue and in embryonic Wnt7a^-/- tissue. Wnt7a reduced the phagocytic capacity of M-MDMs, decreased interleukin-10 (IL-10) and IL-12 secretion and increased IL-6 secretion. Collectively, these findings demonstrate that Wnt7a generates an MDM phenotype with both pro-inflammatory and alternative MDM cytokine profiles and reduced phagocytic capacity. As such, Wnt7a can have a significant impact on macrophage responses in health and disease.

Impairment of Wnt/β-catenin signaling in blood cells of patients with severe cavitary pulmonary tuberculosis

Tuberculosis (TB) remains as a leading infectious disease worldwide. Our previous study showed interferon (IFN)-γ and CD3 T cell impairment in patients with severe cavitary pulmonary TB (PTB). However, the cause of the change in immune responses during the progression of TB is still poorly understood. In this study, eight newly diagnosed patients with severe cavitary and mild lesion non-cavity PTB were recruited, and three healthy volunteers were recruited as the control. RNA extracted from blood was tested by whole genome oligo microarrays. A PCR array was used to further test the same samples. Two additional groups of patients were recruited according to the same criteria with healthy control(HC) recruited as well and subjected to peripheral blood mononuclear cell isolation (PBMC)and analysis of TCF-7, β-catenin, cyclin D2, IFN-γ, and tumor necrosis factor (TNF)-α expression in CD14- cells (lymphocytes) and CD14+ cells by quantitative PCR. The changes of expression of β-catenin, CD69+ and IFN-γ by CD3+, CD14- and CD14+ cells in vitro with stimulation of LiCl were tested by flow cytometry. Whole genome oligo microarrays showed a significant decrease in expression of the Wnt signaling pathway in severe PTB patients. Further analysis of the Wnt pathway by PCR array indicated that TCF-7, β-catenin, and cyclin D2 expression was significantly reduced in severe PTB patients compared with mild PTB patients. In the additionally recruited patients, TCF-7, β-catenin, and cyclin D2 were expressed in both CD14+ and CD14- cells, while β-catenin was decreased significantly in CD14- cells compared with CD14+ cells in severe PTB patients, and IFN-γ and TNF-α expression in CD14- cells was also reduced significantly in severe PTB patients. β-catenin can directly trigger T cell activation and IFN-γsecretion in PBMCs stimulated for 24 hours. These findings indicate that Wnt pathway and its key genes, such as β-catenin, were impaired in blood cells of patients with severe PTB. Therefore, Wnt/β-catenin pathway is closely associated with T cell proliferation and TB lesion deterioration.

1810011o10 Rik Inhibits the Antitumor Effect of Intratumoral CD8+ T Cells through Suppression of Notch2 Pathway in a Murine Hepatocellular Carcinoma Model

The mechanisms by which tumor-responsive CD8⁺ T cells are regulated are important for understanding the tumor immunity and for developing new therapeutic strategies. In current study, we identified the expression of 1810011o10 Rik, which is the homolog of human thyroid cancer 1, in intratumoral activated CD8⁺ T cells in a murine hepatocellular carcinoma (HCC) implantation model. To investigate the role of 1810011o10 Rik in the regulation of antitumor activity of CD8⁺ T cells, normal CD8⁺ T cells were transduced with 1810011o10 Rik-expressing lentiviruses. Although 1810011o10 Rik overexpression did not influence agonistic antibody-induced CD8⁺ T cell activation in vitro, it inhibited the cytotoxic efficacy of CD8⁺ T cells on HCC cells in vivo. 1810011o10 Rik overexpression impeded CD8⁺ T cell-mediated HCC cell apoptosis and favored tumor cell growth in vivo. Further investigation revealed that 1810011o10 Rik blocked the nuclear translocation of Notch2 intracellular domain, which is crucial for CD8⁺ T cell activity. Furthermore, a brief in vitro experiment suggested that both antigen-presenting cells and TGF-β might be necessary for the upregulation of Rik expression in activated CD8⁺ T cells. In general, our study disclosed a novel mechanism underlying the negative regulation of antitumor CD8⁺ T cells during HCC progression.

DNA hypermethylation of CD3(+) T cells from cord blood of infants exposed to intrauterine growth restriction

AIMS/HYPOTHESIS

Intrauterine growth restriction (IUGR) is associated with increased susceptibility to obesity, metabolic syndrome and type 2 diabetes. Although the mechanisms underlying the developmental origins of metabolic disease are poorly understood, evidence suggests that epigenomic alterations play a critical role. We sought to identify changes in DNA methylation patterns that are associated with IUGR in CD3(+) T cells purified from umbilical cord blood obtained from male newborns who were appropriate for gestational age (AGA) or who had been exposed to IUGR.

METHODS

CD3(+) T cells were isolated from cord blood obtained from IUGR and AGA infants. The genome-wide methylation profile in eight AGA and seven IUGR samples was determined using the HELP tagging assay. Validation analysis using targeted bisulfite sequencing and bisulfite massARRAY was performed on the original cohort as well as biological replicates consisting of two AGA and four IUGR infants. The Segway algorithm was used to identify methylation changes within regulatory regions of the genome.

RESULTS

A global shift towards hypermethylation in IUGR was seen compared with AGA (89.8% of 4,425 differentially methylated loci), targeted to regulatory regions of the genome, specifically promoters and enhancers. Pathway analysis identified dysregulation of pathways involved in metabolic disease (type 2 diabetes mellitus, insulin signalling, mitogen-activated protein kinase signalling) and T cell development, regulation and activation (T cell receptor signalling), as well as transcription factors (TCF3, LEF1 and NFATC) that regulate T cells. Furthermore, bump-hunting analysis revealed differentially methylated regions in PRDM16 and HLA-DPB1, genes important for adipose tissue differentiation, stem cell maintenance and function and T cell activation.

CONCLUSIONS/INTERPRETATION

Our findings suggest that the alterations in methylation patterns observed in IUGR CD3(+) T cells may have functional consequences in targeted genes, regulatory regions and transcription factors. These may serve as biomarkers to identify those at 'high risk' for diminished attainment of full health potential who can benefit from early interventions.

ACCESS TO RESEARCH MATERIALS

HELP tagging data: Gene Expression Omnibus database (GSE77268), scheduled to be released on 25 January 2019.

Take the Wnt out of the inflammatory sails: modulatory effects of Wnt in airway diseases

Bronchial asthma and chronic obstructive pulmonary disease (COPD) are chronic diseases that are associated with inflammation and structural changes in the airways and lungs. Recent findings have implicated Wnt pathways in critically regulating inflammatory responses, especially in asthma. Furthermore, canonical and noncanonical Wnt pathways are involved in structural changes such as airway remodeling, goblet cell metaplasia, and airway smooth muscle (ASM) proliferation. In COPD, Wnt pathways are not only associated with structural changes in the airways but also involved in the development of emphysema. The present review summarizes the role and function of the canonical and noncanonical Wnt pathway with regard to airway inflammation and structural changes in asthma and COPD. Further identification of the role and function of different Wnt molecules and pathways could help to develop novel therapeutic options for these diseases.