IL33 Promotes Colon Cancer Cell Stemness via JNK Activation and Macrophage Recruitment

Interleukin-33 increases the sensitivity of multiple myeloma cells to the proteasome inhibitor bortezomib through reactive oxygen species-mediated inhibition of nuclear factor kappa-B signal and stemness properties

The proteasome inhibitor bortezomib (BTZ) is the first-line therapy for multiple myeloma (MM). BTZ resistance largely limits its clinical application in MM. Interleukin-33 (IL-33) exerts antitumor effects through various mechanisms, including enhancing antitumor immunity and promoting the apoptosis of cancer cells. Here, the synergistic anti-MM effect of IL-33 and BTZ was verified, and the underlying mechanisms were elucidated. Bioinformatic analysis indicated that IL-33 expression levels were downregulated in MM, and that BTZ-treated MM patients with high IL-33 levels had better prognosis than those with low IL-33 levels. Moreover, the patients with high IL-33 levels had a better treatment response to BTZ. Further immune analysis suggested that IL-33 can enhance the anti-MM immunity. IL-33 and BTZ synergistically inhibited proliferation and induced apoptosis of MM cells, which was mediated by the excessive accumulation of cellular reactive oxygen species (ROS). Furthermore, increased ROS hindered the nuclear translocation of NF-κB-p65, thereby decreasing the transcription of target stemness-related genes (SOX2, MYC, and OCT3/4). These effects induced by the combination therapy could be reversed by eliminating ROS by N-acetylcysteine. In conclusion, our results indicated that IL-33 enhanced the sensitivity of MM to BTZ through ROS-mediated inhibition of nuclear factor kappa-B (NF-κB) signal and stemness properties.

The mast cell-T lymphocyte axis impacts cancer: Friend or foe?

Crosstalk between mast cells (MCs) and T lymphocytes (TLs) releases specific signals that create an environment conducive to tumor development. Conversely, they can protect against cancer by targeting tumor cells for destruction. Although their role in immunity and cancer is complex, their potential in anticancer strategies is often underestimated. When peripheral MCs are activated, they can affect cancer development. Tumor-infiltrating TLs may malfunction and contribute to aggressive cancer and poor prognoses. One promising approach for cancer patients is TL-based immunotherapies. Recent reports suggest that MCs modulate TL activity in solid tumors and may be a potential therapeutic layer in multitargeting anticancer strategies. Pharmacologically modulating MC activity can enhance the anticancer cytotoxic TL response in tumors. By identifying tumor-specific targets, it has been possible to genetically alter patients' cells into fully humanized anticancer cellular therapies for autologous transplantation, including the engineering of TLs and MCs to target and kill cancer cells. Hence, recent scientific evidence provides a broader understanding of MC-TL activity in cancer.

Interleukin 33 supports squamous cell carcinoma growth via a dual effect on tumour proliferation, migration and invasion, and T cell activation

Interleukin (IL)-33 is an important cytokine in the tumour microenvironment; it is known to promote the growth and metastasis of solid cancers, such as gastric, colorectal, ovarian and breast cancer. Our group demonstrated that the IL-33/ST2 pathway enhances the development of squamous cell carcinoma (SCC). Conversely, other researchers have reported that IL-33 inhibits tumour progression. In addition, the crosstalk between IL-33, cancer cells and immune cells in SCC remains unknown. The aim of this study was to investigate the effect of IL-33 on the biology of head and neck SCC lines and to evaluate the impact of IL-33 neutralisation on the T cell response in a preclinical model of SCC. First, we identified epithelial and peritumoural cells as a major local source of IL-33 in human SCC samples. Next, in vitro experiments demonstrated that the addition of IL-33 significantly increased the proliferative index, motility and invasiveness of SCC-25 cells, and downregulated MYC gene expression in SCC cell lines. Finally, IL-33 blockade significantly delayed SCC growth and led to a marked decrease in the severity of skin lesions. Importantly, anti-IL-33 monoclonal antibody therapy increase the percentage of CD4+IFNγ+ T cells and decreased CD4+ and CD8+ T cells secreting IL-4 in tumour-draining lymph nodes. Together, these data suggest that the IL-33/ST2 pathway may be involved in the crosstalk between the tumour and immune cells by modulating the phenotype of head and neck SCC and T cell activity. IL-33 neutralisation may offer a novel therapeutic strategy for SCC.

Tumour-associated macrophages and Schwann cells promote perineural invasion via paracrine loop in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is frequently accompanied by perineural invasion (PNI), which is associated with excruciating neuropathic pain and malignant progression. However, the relationship between PNI and tumour stromal cells has not been clarified.

METHODS

The dorsal root ganglia or sciatic nerves nerve model was used to observe the paracrine interaction and the activation effect among Schwann cells, tumour-associated macrophages (TAMs), and pancreatic cancer cells in vitro. Next generation sequencing, enzyme-linked immunosorbent assay and chromatin immunoprecipitation were used to explore the specific paracrine signalling between TAMs and Schwann cells.

RESULTS

We demonstrated that more macrophages were expressed around nerves that have been infiltrated by pancreatic cancer cells compared with normal nerves in murine and human PNI specimens. In addition, high expression of CD68 or GFAP is associated with an increased incidence of PNI and indicates a poor 5-year survival rate in patients with PDAC. Mechanistically, tumour-associated macrophages (TAMs) activate Schwann cells via the bFGF/PI3K/Akt/c-myc/GFAP pathway. Schwann cells secrete IL-33 to recruit macrophages into the perineural milieu and facilitate the M2 pro-tumourigenic polarisation of macrophages.

CONCLUSIONS

Our study demonstrates that the bFGF/IL-33 positive feedback loop between Schwann cells and TAMs is essential in the process of PNI of PDAC. The bFGF/PI3K/Akt/c-myc/GFAP pathway would open potential avenues for targeted therapy of PDAC.

Exploiting innate immunity for cancer immunotherapy

Immunotherapies have revolutionized the treatment paradigms of various types of cancers. However, most of these immunomodulatory strategies focus on harnessing adaptive immunity, mainly by inhibiting immunosuppressive signaling with immune checkpoint blockade, or enhancing immunostimulatory signaling with bispecific T cell engager and chimeric antigen receptor (CAR)-T cell. Although these agents have already achieved great success, only a tiny percentage of patients could benefit from immunotherapies. Actually, immunotherapy efficacy is determined by multiple components in the tumor microenvironment beyond adaptive immunity. Cells from the innate arm of the immune system, such as macrophages, dendritic cells, myeloid-derived suppressor cells, neutrophils, natural killer cells, and unconventional T cells, also participate in cancer immune evasion and surveillance. Considering that the innate arm is the cornerstone of the antitumor immune response, utilizing innate immunity provides potential therapeutic options for cancer control. Up to now, strategies exploiting innate immunity, such as agonists of stimulator of interferon genes, CAR-macrophage or -natural killer cell therapies, metabolic regulators, and novel immune checkpoint blockade, have exhibited potent antitumor activities in preclinical and clinical studies. Here, we summarize the latest insights into the potential roles of innate cells in antitumor immunity and discuss the advances in innate arm-targeted therapeutic strategies.

Immunobiology of cancer stem cells and their immunoevasion mechanisms

Cancer stem cells (CSCs) defined as a small fraction of cells within malignancies have been isolated from tumors with different histological origins with stem related characteristics such as self-replicating potential, tumorigenesis, and therapy resistance. The dynamic communication between CSCs and tumor microenvironment particularly immune cells orchestrates their fate and plasticity as well as the patient outcome. According to recent evidence, it has been reported that they harness different immunological pathways to escape immunosurveillance and express aberrantly immunomodulatory agents or decreased levels of factors forming antigen presenting machinery (APM), subsequently followed by impaired antigen presentation and suppressed immune detection. As effective therapies are expected to be able to eradicate CSCs, mechanistic understanding of such interactions can provide insights into causes of therapy failure particularly in immunotherapy. Also, it can contribute to enhance the practical interventions against CSCs and their immunomodulatory features resulting in CSCs eradication and improving patient clinical outcome. The aim of this review is to explain the present knowledge regarding the immunobiology of CSCs and the immunoevasion mechanisms they use.

ILC1-derived IFN-γ regulates macrophage activation in colon cancer

BACKGROUND

Tumor-associated macrophages (TAMs) are an important subset of innate immune cells in the tumor microenvironment, and they are pivotal regulators of tumor-promoting inflammation and tumor progression. Evidence has proven that TAM numbers are substantially increased in cancers, and most of these TAMs are polarized toward the alternatively activated M2 phenotype; Thus, these TAMs strongly promote the progression of cancer diseases. Type 1 innate lymphocytes (ILC1s) are present in high numbers in intestinal tissues and are characterized by the expression of the transcription factor T-bet and the secretion of interferon (IFN)-γ, which can promote macrophages to polarize toward the classically activated antitumor M1 phenotype. However, the relationship between these two cell subsets in colon cancer remains unclear.

METHODS

Flow cytometry was used to determine the percentages of M1-like macrophages, M2-like macrophages and ILC1s in colon cancer tissues and paracancerous healthy colon tissues in the AOM/DSS-induced mouse model of colon cancer. Furthermore, ILC1s were isolated and bone marrow-derived macrophages were generated to analyze the crosstalk that occurred between these cells when cocultured in vitro. Moreover, ILC1s were adoptively transferred or inhibited in vivo to explore the effects of ILC1s on tumor-infiltrating macrophages and tumor growth.

RESULTS

We found that the percentages of M1-like macrophages and ILC1s were decreased in colon cancer tissues, and these populations were positively correlated. ILC1s promoted the polarization of macrophages toward the classically activated M1-like phenotype in vitro, and this effect could be blocked by an anti-IFN-γ antibody. The in vivo results showed that the administration of the Group 1 innate lymphocyte-blocking anti-NK1.1 antibody decreased the number of M1-like macrophages in the tumor tissues of MC38 tumor-bearing mice and promoted tumor growth, and adoptive transfer of ILC1s inhibited tumors and increased the percentage of M1-like macrophages in MC38 tumor-bearing mice.

CONCLUSIONS

Our studies preliminarily prove for the first time that ILC1s promote the activation of M1-like macrophages by secreting IFN-γ and inhibit the progression of colon cancer, which may provide insight into immunotherapeutic approaches for colon cancer.

IL-33-ST2 signaling promotes stemness in subtypes of myeloid leukemia cells through the Wnt and Notch pathways

Cell stemness is characterized by quiescence, pluripotency, and long-term self-renewal capacity. Therapy-resistant leukemic stem cells (LSCs) are the primary cause of relapse in patients with chronic and acute myeloid leukemia (CML and AML). However, the same signaling pathways frequently support stemness in both LSCs and normal hematopoietic stem cells (HSCs), making LSCs difficult to therapeutically target. In cell lines and patient samples, we found that interleukin-33 (IL-33) signaling promoted stemness only in leukemia cells in a subtype-specific manner. The IL-33 receptor ST2 was abundant on the surfaces of CD34+ BCR/ABL1 CML and CD34+ AML cells harboring AML1/ETO and DEK/NUP214 translocations or deletion of chromosome 9q [del(9q)]. The cell surface abundance of ST2, which was lower or absent on other leukemia subtypes and HSCs, correlated with stemness, activated Wnt signaling, and repressed Notch signaling. IL-33-ST2 signaling promoted the maintenance and expansion of AML1/ETO-, DEK/NUP214-, and BCR/ABL1-positive LSCs in culture and in mice by activating Wnt, MAPK, and NF-κB signaling. Wnt signaling and its inhibition of the Notch pathway up-regulated the expression of the gene encoding ST2, thus forming a cell-autonomous loop. IL-33-ST2 signaling promoted the resistance of CML cells to the tyrosine kinase inhibitor (TKI) nilotinib and of AML cells to standard chemotherapy. Thus, inhibiting IL-33-ST2 signaling may target LSCs to overcome resistance to chemotherapy or TKIs in these subtypes of leukemia.

Eosinophils in the tumor microenvironment: implications for cancer immunotherapy

Despite being an integral part of the immune response in the tumor microenvironment (TME), few studies have mechanistically elucidated eosinophil functions in cancer outcomes. Eosinophils are a minor population of granulocytes that are mostly explored in asthma and allergic disorders. Their influence on primary and metastatic tumors, however, has recently come to light. Eosinophils' diverse armamentarium of mediators and receptors allows them to participate in innate and adaptive immunity, such as type 1 and type 2 immunity, and shape TME and tumor outcomes. Based on TME cells and cytokines, activated eosinophils drive other immune cells to ultimately promote or suppress tumor growth. Discovering exactly what conditions determine the pro-tumorigenic or anti-tumorigenic role of eosinophils allows us to take advantage of these signals and devise novel strategies to target cancer cells. Here, we first revisit eosinophil biology and differentiation as recognizing eosinophil mediators is crucial to their function in homeostatic and pathological conditions as well as tumor outcome. The bulk of our paper discusses eosinophil interactions with tumor cells, immune cells-including T cells, plasma cells, natural killer (NK) cells-and gut microbiota. Eosinophil mediators, such as IL-5, IL-33, granulocyte-macrophage colony-stimulating factor (GM-CSF), thymic stromal lymphopoietin (TSLP), and CCL11 also determine eosinophil behavior toward tumor cells. We then examine the implications of these findings for cancer immunotherapy approaches, including immune checkpoint blockade (ICB) therapy using immune checkpoint inhibitors (ICIs) and chimeric antigen receptor (CAR) T cell therapy. Eosinophils synergize with CAR T cells and ICB therapy to augment immunotherapies.

Interleukin-33 as a Potential Therapeutic Target in Gastric Cancer Patients: Current Insights

Gastric cancer is a significant global health problem as it is the fifth most prevalent cancer worldwide and the fourth leading cause of cancer-related mortality. While cytotoxic chemotherapy remains the primary treatment for advanced GC, response rates are limited. Recent progresses, focused on molecular signalling within gastric cancer, have ignited new hope for potential therapeutic targets that may improve survival and/or reduce the toxic effects of traditional therapies. Carcinomas are generally initiated when critical regulatory genes get mutated, but the progression to malignancy is usually supported by the non-neoplastic cells that create a conducive environment for transformation and progression to occur. Interleukin 33 (IL-33) functions as a dual activity cytokine as it is also a nuclear factor. IL-33 is usually present in the nuclei of the cells. Upon tissue damage, it is released into the extracellular space and binds to its receptor, suppression of tumorigenicity 2 (ST2) L, which is expressed on the membranes of the target cells. IL-33 signalling activates the T Helper 2 (Th2) immune response among other responses. Although the studies on the role of IL-33 in gastric cancer are still in the early stages, they have revealed potentially important (though sometimes conflicting) functions or roles in cancer development and progression. The pro-tumorigenic roles include induction and the recruitment of tumor-associated immune cells, promoting metaplasia progression, and inducing stem cell like and EMT properties in gastric cancer cells. Therapeutic interventions to disrupt these functions may provide a unique strategy for gastric cancer prevention and treatment. This review aims to provide a summary of the role of IL-33 in GC, state its multiple functions in relation to GC, and show potential avenues for promising therapeutic investigation.

The implication of necroptosis-related lncRNAs in orchestrating immune infiltration and predicting therapeutic efficacy in colon adenocarcinoma: an integrated bioinformatic analysis with preliminarily experimental validation

Background: Necroptosis contributes significantly to colon adenocarcinoma (COAD). We aim to assess the relationship between immunoinfiltration and stemness in COAD patients through the development of a risk score profile using necroptosis-related long noncoding RNAs (NRLs). Methods: Our study was based on gene expression data and relevant clinical information from The Cancer Genome Atlas (TCGA). Necroptosis-related genes (NRGs) were obtained from the Kyoto Encyclopedia of Genes and Genome (KEGG) database. Pearson correlation analysis, Cox regression, and least absolute shrinkage and selection operator (LASSO) regression were used to determine the NRL prognositic signature (NRLPS). NRLs expression was examined using qRT-PCR method. Several algorithms were used to identify relationships between immune cell infiltration and NRLPS risk scores. Further analysis of somatic mutations, tumor stemness index (TSI), and drug sensitivity were also explored. Results: To construct NRLPS, 15 lncRNAs were investigated. Furthermore, NRLPS patients with high-risk subgroups had lower survival rates than that of patients with low-risk subgroups. Using GSEA analysis, NRL was found to be enriched in Notch, Hedgehog and Smoothened pathways. Immune infiltration analysis showed significant differences in CD8+ T cells, dendritic cell DCs, and CD4+ T cells between the two risk groups. In addition, our NRLPS showed a relevance with the regulation of tumor microenvironment, tumor mutation burden (TMB) and stemness. Finally, NRLPS demonstrated potential applications in predicting the efficacy of immunotherapy and chemotherapy in patients with COAD. Conclusion: Based on NRLs, a prognostic model was developed for COAD patients that allows a personalized tailoring immunotherapy and chemotherapy to be tailored.

IL-33's role in the gut immune system: A comprehensive review of its crosstalk and regulation

The intestinal tract is the largest immune organ in the human body, comprising a complex network of immune cells and epithelial cells that perform a variety of functions such as nutrient absorption, digestion, and waste excretion. Maintenance of homeostasis and effective responses to injury in the colonic epithelium are crucial for maintaining homeostasis between these two cell types. The onset and perpetuation of gut inflammation, characterizing inflammatory bowel diseases (IBD), are triggered by constitutive dysregulation of cytokine production. IL-33 is a newly characterized cytokine that has emerged as a critical modulator of inflammatory disorders. IL-33 is constitutively expressed in the nuclei of different cell types such as endothelial, epithelial, and fibroblast-like cells. Upon tissue damage or pathogen encounter, IL-33 is released as an alarmin and signals through a heterodimer receptor that consists of serum Stimulation-2 (ST2) and IL-1 receptor accessory protein (IL-1RAcP). IL-33 has the ability to induce Th2 cytokine production and enhance both Th1 and Th2, as well as Th17 immune responses. Exogenous administration of IL-33 in mice caused pathological changes in most mucosal tissues such as the lung and the gastrointestinal (GI) tract associated with increased production of type 2 cytokines and chemokines. In vivo and in vitro, primary studies have exhibited that IL-33 can activate Th2 cells, mast cells, or basophils to produce type 2 cytokines such as IL-4, IL-5, and IL-13. Moreover, several novel cell populations, collectively referred to as "type 2 innate lymphoid cells," were identified as being IL-33 responsive and are thought to be important for initiating type 2 immunity. Nevertheless, the underlying mechanisms by which IL-33 promotes type 2 immunity in the GI tract remain to be fully understood. Recently, it has been discovered that IL-33 plays important roles in regulatory immune responses. Highly suppressive ST2 + FoxP3+ Tregs subsets regulated by IL-33 were identified in several tissues, including lymphoid organs, gut, lung, and adipose tissues. This review aims to comprehensively summarize the current knowledge on IL-33's role in the gut immune system, its crosstalk, and regulation. The article will provide insights into the potential applications of IL-33-based therapies in the treatment of gut inflammatory disorders.

Promising Modulatory Effects of Cenicriviroc on the Progression of Mouse Colorectal Cancer through Inhibition of CCR2_CCL2 Signaling Pathway

The study was designed to assay the efficacy of cenicriviroc (CVC) on the progression of mouse colorectal cancer by downregulation of CCR2_CCL2. In this study, CVC was used to inhibit the CCR2 receptor. Next, an MTT assay was performed to evaluate the cytotoxic effects of CVC on the CT26 cell line. CT26 cells were implanted subcutaneously in BALB/c mice. After tumor implantation, one group of animals received 20 mg/kg of CVC several times. The mRNA levels of CCR2, CCL2, VEGF, NF-κB, c-Myc, vimentin, and IL33 were determined in the CT26 cell line and then tumor tissues (after 21 days), by qRT-PCR. Protein levels of the above-mentioned targets were determined by western blot and ELISA. Flow cytometry was performed to assess the changes in apoptosis. Tumor growth inhibition was measured on the 1st, 7th, and 21st days after the first treatment. In both cell line and tumor cells treated with CVC, expression levels of the markers of our interest in mRNA and protein levels were significantly reduced compared to controls. A significantly higher apoptotic index was observed in CVC-treated groups. The rates of tumor growth were significantly decreased on the 7th and 21st days after the first injection. To our knowledge, this was the first time that we demonstrated the promising effect of CVC on the development of CRC through inhibition of the CCR2_CCL2 signaling and its downstream biomarkers.

Interleukin-33: Friend or Foe in Gastrointestinal Tract Cancers?

Accumulating evidence suggests that Interleukin-33 (IL-33), a member of the IL-1 family, has crucial roles in tissue homeostasis and repair, type 2 immunity, inflammation, and viral infection. IL-33 is a novel contributing factor in tumorigenesis and plays a critical role in regulating angiogenesis and cancer progression in a variety of human cancers. The partially unraveled role of IL-33/ST2 signaling in gastrointestinal tract cancers is being investigated through the analysis of patients' samples and by studies in murine and rat models. In this review, we discuss the basic biology and mechanisms of release of the IL-33 protein and its involvement in gastrointestinal cancer onset and progression.

How the interplay among the tumor microenvironment and the gut microbiota influences the stemness of colorectal cancer cells

Colorectal cancer (CRC) remains the third most prevalent cancer disease and involves a multi-step process in which intestinal cells acquire malignant characteristics. It is well established that the appearance of distal metastasis in CRC patients is the cause of a poor prognosis and treatment failure. Nevertheless, in the last decades, CRC aggressiveness and progression have been attributed to a specific cell population called CRC stem cells (CCSC) with features like tumor initiation capacity, self-renewal capacity, and acquired multidrug resistance. Emerging data highlight the concept of this cell subtype as a plastic entity that has a dynamic status and can be originated from different types of cells through genetic and epigenetic changes. These alterations are modulated by complex and dynamic crosstalk with environmental factors by paracrine signaling. It is known that in the tumor niche, different cell types, structures, and biomolecules coexist and interact with cancer cells favoring cancer growth and development. Together, these components constitute the tumor microenvironment (TME). Most recently, researchers have also deepened the influence of the complex variety of microorganisms that inhabit the intestinal mucosa, collectively known as gut microbiota, on CRC. Both TME and microorganisms participate in inflammatory processes that can drive the initiation and evolution of CRC. Since in the last decade, crucial advances have been made concerning to the synergistic interaction among the TME and gut microorganisms that condition the identity of CCSC, the data exposed in this review could provide valuable insights into the biology of CRC and the development of new targeted therapies.

The role and metabolic adaptations of neutrophils in premetastatic niches

It has been found that tumor cells create microenvironments in distant organs that promote their survival and growth in advance of their arrival. These predetermined microenvironments are referred to as "pre-metastatic niches". Increasing attention is being paid to neutrophils' role in forming the pre-metastatic niche. As major components of the pre-metastatic niche, tumor-associated neutrophils (TANs) play an important role in the formation of the pre-metastatic niche through communication with multiple growth factors, chemokines, inflammatory factors, and other immune cells, which together create a pre-metastatic niche well suited for tumor cell seeding and growth. However, how TANs modulate their metabolism to survive and exert their functions in the process of metastasis remains largely to be discovered. Accordingly, the objective of this review is to assess the role that neutrophils play in the formation of pre-metastatic niche and to explore the metabolism alteration of neutrophils in cancer metastasis. A better understanding of the role of TANs in pre-metastatic niche will help us discover new mechanisms of metastasis and develop new therapies targeting TANs.

Enhanced binding of β-catenin and β-TrCP mediates LMPt's anti-CSCs activity in colorectal cancer

Cancer stem cells (CSCs), a subpopulation of tumor cells with the features of self-renewal, tumor initiation, and insensitivity to common physical and chemical agents, are the key to cancer relapses, metastasis, and resistance. Accessible CSCs inhibitory strategies are primarily based on small molecule drugs, yet toxicity limits their application. Here, we report a liposome loaded with low toxicity and high effectiveness of miriplatin, lipo-miriplatin (LMPt) with high miriplatin loading, and robust stability, exhibiting a superior inhibitory effect on CSCs and non-CSCs. LMPt predominantly inhibits the survival of oxaliplatin-resistant (OXA-resistant) cells composed of CSCs. Furthermore, LMPt directly blocks stemness features of self-renewal, tumor initiation, unlimited proliferation, metastasis, and insensitivity. In mechanistic exploration, RNA sequencing (RNA-seq) revealed that LMPt downregulates the levels of pro-stemness proteins and that the β-catenin-mediated stemness pathway is enriched. Further research shows that either in adherent cells or 3D-spheres, the β-catenin-OCT4/NANOG axis, the vital pathway to maintain stemness, is depressed by LMPt. The consecutive activation of the β-catenin pathway induced by mutant β-catenin (S33Y) and OCT4/NANOG overexpression restores LMPt's anti-CSCs effect, elucidating the key role of the β-catenin-OCT4/NANOG axis. Further studies revealed that the strengthened binding of β-catenin and β-TrCP initiates ubiquitination and degradation of β-catenin induced by LMPt. In addition,the Apc^Min/+transgenicmouse model, in which colon tumors are spontaneously formed, demonstrates LMPt's potent anti-non-CSCs activity in vivo.

Alarmin IL-33 orchestrates antitumoral T cell responses to enhance sensitivity to 5-fluorouracil in colorectal cancer

Rationale: Resistance to 5-fluorouracil (5-FU) chemotherapy remains the main barrier to effective clinical outcomes for patients with colorectal cancer (CRC). A better understanding of the detailed mechanisms underlying 5-FU resistance is needed to increase survival. Interleukin (IL)-33 is a newly discovered alarmin-like molecule that exerts pro- and anti-tumorigenic effects in various cancers. However, the precise role of IL-33 in CRC progression, as well as in the development of 5-FU resistance, remains unclear. Methods: High-quality RNA-sequencing analyses were performed on matched samples from patients with 5-FU-sensitive and 5-FU-resistant CRC. The clinical and biological significance of IL-33, including its effects on both T cells and tumor cells, as well as its relationship with 5-FU chemotherapeutic activity were examined in ex vivo, in vitro and in vivo models of CRC. The molecular mechanisms underlying these processes were explored. Results: IL-33 expressed by tumor cells was a dominant mediator of antitumoral immunity in 5-FU-sensitive patients with CRC. By binding to its ST2 receptor, IL-33 triggered CD4+ (Th1 and Th2) and CD8+ T cell responses by activating annexin A1 downstream signaling cascades. Mechanistically, IL-33 enhanced the sensitivity of CRC cells to 5-FU only in the presence of T cells, which led to the activation of both tumor cell-intrinsic apoptotic and immune killing-related signals, thereby synergizing with 5-FU to induce apoptosis of CRC cells. Moreover, injured CRC cells released more IL-33 and the T cell chemokines CXCL10 and CXCL13, forming a positive feedback loop to further augment T cell responses. Conclusions: Our results identified a previously unrecognized connection between IL-33 and enhanced sensitivity to 5-FU. IL-33 created an immune-active tumor microenvironment by orchestrating antitumoral T cell responses. Thus, IL-33 is a potential predictive biomarker for 5-FU chemosensitivity and favorable prognosis and has potential as a promising adjuvant immunotherapy to improve the clinical benefits of 5-FU-based therapies in the treatment of CRC.

Tumor microenvironment enriches the stemness features: the architectural event of therapy resistance and metastasis

Cancer divergence has many facets other than being considered a genetic term. It is a tremendous challenge to understand the metastasis and therapy response in cancer biology; however, it postulates the opportunity to explore the possible mechanism in the surrounding tumor environment. Most deadly solid malignancies are distinctly characterized by their tumor microenvironment (TME). TME consists of stromal components such as immune, inflammatory, endothelial, adipocytes, and fibroblast cells. Cancer stem cells (CSCs) or cancer stem-like cells are a small sub-set of the population within cancer cells believed to be a responsible player in the self-renewal, metastasis, and therapy response of cancer cells. The correlation between TME and CSCs remains an enigma in understanding the events of metastasis and therapy resistance in cancer biology. Recent evidence suggests that TME dictates the CSCs maintenance to arbitrate cancer progression and metastasis. The immune, inflammatory, endothelial, adipocyte, and fibroblast cells in the TME release growth factors, cytokines, chemokines, microRNAs, and exosomes that provide cues for the gain and maintenance of CSC features. These intricate cross-talks are fueled to evolve into aggressive, invasive, migratory phenotypes for cancer development. In this review, we have abridged the recent developments in the role of the TME factors in CSC maintenance and how these events influence the transition of tumor progression to further translate into metastasis and therapy resistance in cancer.

Non-kinase targeting of oncogenic c-Jun N-terminal kinase (JNK) signaling: the future of clinically viable cancer treatments

c-Jun N-terminal Kinases (JNKs) have been identified as key disease drivers in a number of pathophysiological settings and central oncogenic signaling nodes in various cancers. Their roles in driving primary tumor growth, positively regulating cancer stem cell populations, promoting invasion and facilitating metastatic outgrowth have led JNKs to be considered attractive targets for anti-cancer therapies. However, the homeostatic, apoptotic and tumor-suppressive activities of JNK proteins limit the use of direct JNK inhibitors in a clinical setting. In this review, we will provide an overview of the different JNK targeting strategies developed to date, which include various ATP-competitive, non-kinase and substrate-competitive inhibitors. We aim to summarize their distinct mechanisms of action, review some of the insights they have provided regarding JNK-targeting in cancer, and outline the limitations as well as challenges of all strategies that target JNKs directly. Furthermore, we will highlight alternate drug targets within JNK signaling complexes, including recently identified scaffold proteins, and discuss how these findings may open up novel therapeutic options for targeting discrete oncogenic JNK signaling complexes in specific cancer settings.

Cancer secretome: finding out hidden messages in extracellular secretions

Secretome analysis has gained popularity recently as a very well-designed proteomic approach that is being used to study various interactions and their effects on cellular activity. This analysis is especially helpful while studying the effects of the cells on their microenvironment, paracrine and autocrine processes, their therapeutic purposes, and as a new diagnostic perspective. Cancer is a condition rather than a specific type of disease and is still yet to be fully understood. Cancer secretome is a fairly new concept that is being implemented to examine the interactions taking place in the tumor microenvironment and can help to understand the phenomena like induction of tumorigenesis, stimulation of immune cells, etc. The secretome analysis helps to gain a different perspective on the existing knowledge on cancer and its effects. The recent advances in secretome studies are directed toward secreted components as drug targets, biomarkers, and companion tools for diagnostic and prognostic purposes in cancer. This review aims to find the interactors in different types of cancer and understand the existing unstructured secretome data and its application in prognosis, diagnosis, and in biomarker study.

Development and validation of a predictive model for immune-related genes in patients with tongue squamous cell carcinoma

The present study involved building a model of immune-related genes (IRGs) that can predict the survival outcomes of tongue squamous cell carcinoma (TSCC). Using the TCGA database, we collected the gene expression profiles of patients with TSCC and analyzed the differences in IRGs obtained from the ImmPort database. Subsequently, we constructed a predictive model. Transcription factors and differentially expressed IRGs can be used to construct TSCC regulatory network. CIBERSORT tool was used to analyze the relative proportion of 22 tumor-infiltrating immune cells in TSCC samples. Finally, a prognostic model is constructed. We established an IRG model formed by seven genes. The receiver operating characteristic value of the prognostic model based on IRGs is 0.739. After the analysis of the correlation between IRGs and clinical and pathological conditions, we found that Gast was related to grade, IRF9, LTB, and T stage. Among the 22 tumor-infiltrating immune cells, the resting natural killer (NK) cells were found to be related to the 5-year survival rate. This study constructed a prognostic model formed by seven IRGs and discussed the tumor-infiltrating immune cells, which are related to the survival outcome, reflecting the potential regulatory role of TSCC tumor immune microenvironment that could potentially promote individualized treatment.

Targeting cancer-related inflammation with non-steroidal anti-inflammatory drugs: Perspectives in pharmacogenomics

Inflammatory processes are essential for innate immunity and contribute to carcinogenesis in various malignancies, such as colorectal cancer, esophageal cancer and lung cancer. Pharmacotherapies targeting inflammation have the potential to reduce the risk of carcinogenesis and improve therapeutic efficacy of existing anti-cancer treatment. Non-steroidal anti-inflammatory drugs (NSAIDs), comprising a variety of structurally different chemicals that can inhibit cyclooxygenase (COX) enzymes and other COX-independent pathways, are originally used to treat inflammatory diseases, but their preventive and therapeutic potential for cancers have also attracted researchers' attention. Pharmacogenomic variability, including distinct genetic characteristics among different patients, can significantly affect pharmacokinetics and effectiveness of NSAIDs, which might determine the preventive or therapeutic success for cancer patients. Hence, a more comprehensive understanding in pharmacogenomic characteristics of NSAIDs and cancer-related inflammation would provide new insights into this appealing strategy. In this review, the up-to-date advances in clinical and experimental researches targeting cancer-related inflammation with NSAIDs are presented, and the potential of pharmacogenomics are discussed as well.

How do pre-pregnancy endometrial macrophages contribute to pregnancy?

Macrophages are professional phagocytes with a wide distribution in all tissues throughout the body. Macrophages play a crucial role in homeostasis and numerous physiological processes beyond innate and adaptive immunity, including cellular debris removal, metabolic regulation, tissue repair, and tissue remodeling. Uterine macrophages are a heterogeneous and highly plastic subset of immune cells regulated by the local microenvironment and, in addition to their anti-inflammatory and anti-infective functions, support the establishment and maintenance of pregnancy. Comprehensive reviews have summarized the role of decidual macrophages during pregnancy. However, the distribution of macrophages in the endometrium prior to pregnancy, their functional remodeling, and the knock-on effects on subsequent pregnancies have not been elucidated. In this review, we focus on 1) how the phenotypes of endometrial macrophages and their interactions with other endometrial cells indicate or contribute to the subsequent pregnancy, 2) the adaptive switching of endometrial macrophages during the initial establishment of pregnancy, 3) and the pregnancy complications and pregnancy-related disorders associated with endometrial macrophages.

Cytokine-mediated crosstalk between cancer stem cells and their inflammatory niche from the colorectal precancerous adenoma stage to the cancerous stage: Mechanisms and clinical implications

The majority of colorectal cancers (CRCs) are thought to arise from precancerous adenomas. Upon exposure to diverse microenvironmental factors, precancerous stem cells (pCSCs) undergo complex genetic/molecular changes and gradually progress to form cancer stem cells (CSCs). Accumulative evidence suggests that the pCSC/CSC niche is an inflammatory dominated milieu that contains different cytokines that function as the key communicators between pCSCs/CSCs and their niche and have a decisive role in promoting CRC development, progression, and metastasis. In view of the importance and increasing data about cytokines in modulating pCSCs/CSC stemness properties and their significance in CRC, this review summarizes current new insights of cytokines, such as interleukin (IL)-4, IL-6, IL-8, IL-17A, IL-22, IL-23, IL-33 and interferon (IFN)-γ, involving in the modulation of pCSC/CSC properties and features in precancerous and cancerous lesions and discusses the possible mechanisms of adenoma progression to CRCs and their therapeutic potential.

Anti-Metastatic Effect of Pyruvate Dehydrogenase Kinase 4 Inhibition in Bladder Cancer via the ERK, SRC, and JNK Pathways

Bladder cancer is a common global cancer with a high percentage of metastases and high mortality rate. Thus, it is necessary to identify new biomarkers that can be helpful in diagnosis. Pyruvate dehydrogenase kinase 4 (PDK4) belongs to the PDK family and plays an important role in glucose utilization in living organisms. In the present study, we evaluated the role of PDK4 in bladder cancer and its related protein changes. First, we observed elevated PDK4 expression in high-grade bladder cancers. To screen for changes in PDK4-related proteins in bladder cancer, we performed a comparative proteomic analysis using PDK4 knockdown cells. In bladder cancer cell lines, PDK4 silencing resulted in a lower rate of cell migration and invasion. In addition, a PDK4 knockdown xenograft model showed reduced bladder cancer growth in nude mice. Based on our results, PDK4 plays a critical role in the metastasis and growth of bladder cancer cells through changes in ERK, SRC, and JNK.

Emerging roles for IL-25 and IL-33 in colorectal cancer tumorigenesis

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide, and is largely refractory to current immunotherapeutic interventions. The lack of efficacy of existing cancer immunotherapies in CRC reflects the complex nature of the unique intestinal immune environment, which serves to maintain barrier integrity against pathogens and harmful environmental stimuli while sustaining host-microbe symbiosis during homeostasis. With their expression by barrier epithelial cells, the cytokines interleukin-25 (IL-25) and IL-33 play key roles in intestinal immune responses, and have been associated with inappropriate allergic reactions, autoimmune diseases and cancer pathology. Studies in the past decade have begun to uncover the important roles of IL-25 and IL-33 in shaping the CRC tumour immune microenvironment, where they may promote or inhibit tumorigenesis depending on the specific CRC subtype. Notably, both IL-25 and IL-33 have been shown to act on group 2 innate lymphoid cells (ILC2s), but can also stimulate an array of other innate and adaptive immune cell types. Though sometimes their functions can overlap they can also produce distinct phenotypes dependent on the differential distribution of their receptor expression. Furthermore, both IL-25 and IL-33 modulate pathways previously known to contribute to CRC tumorigenesis, including angiogenesis, tumour stemness, invasion and metastasis. Here, we review our current understanding of IL-25 and IL-33 in CRC tumorigenesis, with specific focus on dissecting their individual function in the context of distinct subtypes of CRC, and the potential prospects for targeting these pathways in CRC immunotherapy.

Lipocalin-2 inhibits pancreatic cancer stemness via the AKT/c-Jun pathway

Cancer stem cells (CSCs) are involved in cancer recurrence and metastasis owing to their self-renewal properties and drug-resistance capacity. Lipocalin-2 (Lcn2) of the lipocalin superfamily is highly expressed in pancreatic cancer. Nevertheless, reports on the involvement of Lcn2 in the regulation of pancreatic CSC properties are scant. This study is purposed to investigate whether Lcn2 plays a crucial role in CSC renewal and stemness maintenance in pancreatic carcinoma. Immunohistochemistry results of tumor tissue chips together with Gene Expression Omnibus sequencing files confirmed that Lcn2 is highly expressed in pancreatic carcinoma compared with that in normal tissues. The exogenous expression of Lcn2 attenuated CSC-associated SOX2, CD44, and EpCAM expression and suppressed sarcosphere formation and tumorigenesis in the pancreatic carcinoma cell line PANC-1, which showed low expression of Lcn2. However, Lcn2 knockout in BxPC-3 cell line, which presented high Lcn2 expression, promoted CSC stemness, further enhancing sarcosphere formation and tumorigenesis. Moreover, Lcn2 was found to regulate stemness in pancreatic cancer depending on the activation of AKT and c-Jun. Lcn2 suppresses stemness properties in pancreatic carcinoma by activating the AKT-c-Jun pathway, and thus, it may be a novel candidate to suppress the stemness of pancreatic cancer. This study provides a new insight into disease progression.

M2-like tumor-associated macrophages transmit exosomal miR-27b-3p and maintain glioblastoma stem-like cell properties

There is growing evidence supporting the implications of exosomes-shuttled microRNAs (miRs) in the phenotypes of glioblastoma stem cells (GSCs), whilst the role of exosomal miR-27b-3p remains to be established. Herein, the aim of this study was to investigate the effect of M2 tumor-associated macrophage (TAM)-derived exosomal miR-27b-3p on the function of GSCs. Clinical glioblastoma (GBM) specimens were obtained and GSCs and M2-TAMs were isolated by fluorescence-activated cell sorting (FACS), and exosomes were separated from M2-TAMs. It was observed that M2-TAM-derived exosomes promoted the stem-like properties of GSCs. Gain- and loss- of function assays were then conducted to explore the effects of exosomal miR-27b-3p and the miR-27b-3p/MLL4/PRDM1 axis on GSC phenotypes. A xenograft tumor model of GBM was further established for in vivo substantiation. Inhibition of miR-27b-3p in M2-TAMs reduced exosomal miR-27b-3p transferred into GSCs and consequently diminished GSC viability in vitro and tumor-promoting effects of GSCs in vivo. The interaction among miR-27b-3p, mixed linked leukemia 4 (MLL4), positive regulatory domain I (PRDM1) was validated by dual-luciferase and ChIP assays. MLL4 positively regulated PRDM1 expression by inducing methylation in the PRDM1 enhancer region and ultimately reduced IL-33 expression. miR-27b-3p targeted MLL4/PRDM1 to activate IL-33 and maintain the stem-like function of GSCs. In conclusion, our study elucidated that M2-TAM-derived exosomal miR-27b-3p enhanced the tumorigenicity of GSCs through the MLL4/PRDM1/IL-33 axis.

IL-33 biology in cancer: An update and future perspectives

Interleukin-33 (IL-33) is a member of the IL-1 family of cytokines that is constitutively expressed in the nucleus of epithelial, endothelial and fibroblast-like cells. Upon cell stress, damage or necrosis, IL-33 is released into the cytoplasm to exert its prime role as an alarmin by binding to its specific receptor moiety, ST2. IL-33 exhibits pleiotropic function in inflammatory diseases and particularly in cancer. IL-33 may play a dual role as both a pro-tumorigenic and anti-tumorigenic cytokine, dependent on tumor and cellular context, expression levels, bioactivity and the nature of the inflammatory environment. In this review, we discuss the differential contribution of IL-33 to malignant or inflammatory conditions, its multifaceted effects on the tumor microenvironment, while providing possible explanations for the discrepant findings described in the literature. Additionally, we examine the emerging and divergent functions of IL-33 in the nucleus, and aspects of IL-33 biology that are currently under-addressed.

Macrophages Are a Double-Edged Sword: Molecular Crosstalk between Tumor-Associated Macrophages and Cancer Stem Cells

Cancer stem cells (CSCs) are a subset of highly tumorigenic cells in tumors. They have enhanced self-renewal properties, are usually chemo-radioresistant, and can promote tumor recurrence and metastasis. They can recruit macrophages into the tumor microenvironment and differentiate them into tumor-associated macrophages (TAMs). TAMs maintain CSC stemness and construct niches that are favorable for CSC survival. However, how CSCs and TAMs interact is not completely understood. An understanding on these mechanisms can provide additional targeting strategies for eliminating CSCs. In this review, we comprehensively summarize the reported mechanisms of crosstalk between CSCs and TAMs and update the related signaling pathways involved in tumor progression. In addition, we discuss potential therapies targeting CSC–TAM interaction, including targeting macrophage recruitment and polarization by CSCs and inhibiting the TAM-induced promotion of CSC stemness. This review also provides the perspective on the major challenge for developing potential therapeutic strategies to overcome CSC-TAM crosstalk.

Roles for macrophage-polarizing interleukins in cancer immunity and immunotherapy

Macrophages are the most abundant and one of the most critical cells of tumor immunity. They provide a bridge between innate and adaptive immunity through releasing cytokines into the tumor microenvironment (TME). A number of interleukin (IL) cytokine family members is involved in shaping the final phenotype of macrophages toward either a classically-activated pro-inflammatory M1 state with anti-tumor activity or an alternatively-activated anti-inflammatory M2 state with pro-tumor activity. Shaping TME macrophages toward the M1 phenotype or recovering this phenotypic state may offer a promising therapeutic approach in patients with cancer. Here, we focus on the impact of macrophage-polarizing ILs on immune cells and IL-mediated cellular cross-interactions within the TME. The key aim of this review is to define therapeutic schedules for addressing ILs in cancer immunotherapy based on their multi-directional impacts in such a milieu. Gathering more knowledge on this area is also important for defining adverse effects related to cytokine therapy and addressing them for reinforcing the efficacy of immunotherapy against cancer.

An Immune-Related Gene Signature for Predicting Neoadjuvant Chemoradiotherapy Efficacy in Rectal Carcinoma

Background

Locally advanced rectal cancers (LARC) show a highly variable response to neoadjuvant chemoradiotherapy (nCRT), and the impact of the tumor immune response in this process is poorly understood. This study aimed to characterize the immune-related gene expression profiles (GEP), pathways, and cell types associated with response or resistance to neoadjuvant chemoradiotherapy.

Methods

The transcriptomic and clinical data of Rectal carcinoma from the Gene Expression Omnibus database and Immune-related genes (IRGs) from ImmPort were downloaded to identify the differentially expressed immune-related genes (DEIRGs) between responder and non-responder to neoadjuvant chemoradiotherapy. Gene set enrichment analyses were performed to uncover significantly enriched GO terms and KEGG pathways. Immune cell infiltration was estimated from RNA-sequencing data using ImmuCellAI. Afterward, we constructed an immune-related gene-based predictive model (IRGPM) by Support Vector Machine and validated it in an external cohort.

Result

A 15-gene signature (HLA-DPB1, HLA-DQA1, CXCL9, CXCL10, TAP2, INHBB, BMP2, CD74, IL33, CCL11, CXCL11, DEFB1, HLA-DPA1, CCN3, STAT1) was identified as DEIRGs and found to be significantly associated with nCRT outcomes. Gene set enrichment analyses indicated that the 15 genes play active roles in inflammation-related biological processes. In addition, ImmuCellAI revealed that CD4 naive T cells, Tex, Th1 were significantly up-regulated (p=0.035, p=0.02, p=0.0086, respectively), while Tfh were significantly down-regulated (p=0.015) in responder subgroup. Finally, a novel predictive model was developed by SVM based on DEIRGs with an AUC of 80% (internal validation) and 73.5% (external validation).

Conclusion

Our team conducted a genomic study of the relationship between gene expression profile and response to nCRT in LARC. Our data suggested that the DEIRGs signature could help predict the efficacy of nCRT. And a DEIRGs‐based SVM model was developed to monitor the outcomes of nCRT in LARC.

Framework of Intrinsic Immune Landscape of Dormant Prostate Cancer

Androgen deprivation therapy (ADT) is the standard therapy for men with advanced prostate cancer (PCa). PCa often responds to ADT and enters a dormancy period, which can be recognized clinically as a minimal residual disease. However, the majority of these patients will eventually experience a relapse in the form of castration-resistant PCa with poor survival. Therefore, ADT-induced dormancy is a unique time window for treatment that can provide a cure. The study of this well-recognized phase of prostate cancer progression is largely hindered by the scarcity of appropriate clinical tissue and clinically relevant preclinical models. Here, we report the utility of unique and clinically relevant patient-derived xenograft models in the study of the intrinsic immune landscape of dormant PCa. Using data from RNA sequencing, we have reconstructed the immune evasion mechanisms that can be utilized by dormant PCa cells. Since dormant PCa cells need to evade the host immune surveillance for survival, our results provide a framework for further study and for devising immunomodulatory mechanisms that can eliminate dormant PCa cells.

Crosstalk between macrophage-derived PGE2 and tumor UHRF1 drives hepatocellular carcinoma progression

Background: Tumor-associated macrophages (TAMs) and dysregulated tumor epigenetics contribute to hepatocellular carcinoma (HCC) progression. However, the mechanistic interactions between TAMs and tumor epigenetics remain poorly understood. Methods: Immunohistochemistry and multiplexed fluorescence staining were performed to evaluate the correlation between TAMs numbers and UHRF1 expression in human HCC tissues. PGE2 neutralizing antibody and COX-2 inhibitor were used to analyze the regulation of TAMs isolated from HCC tissues on UHRF1 expression. Multiple microRNA prediction programs were employed to identify microRNAs that target UHRF1 3'UTR. Luciferase reporter assay was applied to evaluate the regulation of miR-520d on UHRF1 expression. Chromatin immunoprecipitation (ChIP) assays were performed to assess the abundance of H3K9me2 in the KLF6 promoter and DNMT1 in the CSF1 promoter regulated by UHRF1. The functional roles of TAM-mediated oncogenic network in HCC progression were verified by in vitro colony formation assays, in vivo xenograft experiments and analysis of clinical samples. Results: Here, we find that TAMs induce and maintain high levels of HCC UHRF1, an oncogenic epigenetic regulator. Mechanistically, TAM-derived PGE2 stimulates UHRF1 expression by repressing miR-520d that targets the 3'-UTR of UHRF1 mRNA. In consequence, upregulated UHRF1 methylates H3K9 to diminish tumor KLF6 expression, a tumor inhibitory transcriptional factor that directly transcribes miR-520d. PGE2 reduces KLF6 occupancy in the promoter of miR-520d, dampens miR-520d expression, and sustains robust UHRF1 expression. Moreover, UHRF1 promotes CSF1 expression by inducing DNA hypomethylation of the CSF1 promoter and supports TAM accumulation. Conclusions: Capitalizing on studies on HCC cells and tissues, animal models, and clinical information, we reveal a previously unappreciated TAM-mediated oncogenic network via multiple reciprocal enforcing molecular nodes. Targeting this network may be an approach to treat HCC patients.

IL25 Enhanced Colitis-Associated Tumorigenesis in Mice by Upregulating Transcription Factor GLI1

Interleukin-25 (IL17E/IL25) plays a critical role in colitis and intestinal homeostasis. However, the expression and biological role of IL25 in colorectal cancer is not properly understood. In this study, we show that IL25 is mainly expressed by cancer stem cells in the colorectal cancer microenvironment. Genetic deletion of IL25 inhibited tumor formation and growth and prolonged survival in AOM/DSS-treated mice. IL25 stimulated cancer organoid and cancer cells sphere formation and prevented the tumor from chemotherapy-induced apoptosis. Mechanistically, IL25 upregulated stem cell genes LGR5, CD133, and ABC transporters via activating the Hedgehog signaling pathway. IL25 inhibited phosphorylation of AMPK and promoted GLI1 accumulation to maintain cancer stem cells. Moreover, IL25 expression was associated with poor survival in patients with metastatic colorectal cancer. Taken together, our work reveals an immune-associated mechanism that intrinsically confers cancer cell stemness properties. Our results first demonstrated that IL25, as a new potent endogenous Hedgehog pathway agonist, could be an important prognostic factor and therapeutic target for CRC.

Downregulated cytotoxic CD8+ T-cell identifies with the NKG2A-soluble HLA-E axis as a predictive biomarker and potential therapeutic target in keloids

Keloids are an abnormal fibroproliferative wound-healing disease with a poorly understood pathogenesis, making it difficult to predict and prevent this disease in clinical settings. Identifying disease-specific signatures at the molecular and cellular levels in both the blood circulation and primary lesions is urgently needed to develop novel biomarkers for risk assessment and therapeutic targets for recurrence-free treatment. There is mounting evidence of immune cell dysregulation in keloid scarring. In this study, we aimed to profile keloid scar tissues and blood cells and found that downregulation of cytotoxic CD8+ T cells is a keloid signature in the peripheral blood and keloid lesions. Single-cell RNA sequencing revealed that the NKG2A/CD94 complex was specifically upregulated, which might contribute to the significant reduction in CTLs within the scar tissue boundary. In addition, the NKG2A/CD94 complex was associated with high serum levels of soluble human leukocyte antigen-E (sHLA-E). We subsequently measured sHLA-E in our hospital-based study cohort, consisting of 104 keloid patients, 512 healthy donors, and 100 patients with an interfering disease. The sensitivity and specificity of sHLA-E were 83.69% (87/104) and 92.16% (564/612), respectively, and hypertrophic scars and other unrelated diseases exhibited minimal interference with the test results. Furthermore, intralesional therapy with triamcinolone combined with 5-fluorouracil drastically decreased the sHLA-E levels in keloid patients with better prognostic outcomes, while an incomplete reduction in the sHLA-E levels in patient serum was associated with higher recurrence. sHLA-E may effectively serve as a diagnostic marker for assessing the risk of keloid formation and a prognostic marker for the clinical outcomes of intralesional treatment.

The Merkel Cell Polyomavirus T-Antigens and IL-33/ST2-IL1RAcP Axis: Possible Role in Merkel Cell Carcinoma

Merkel cell polyomavirus (MCPyV) is a causal factor in Merkel cell carcinoma (MCC). The oncogenic potential is mediated through its viral oncoproteins large T-antigen (LT) and small T-antigen (sT). Cytokines produced by tumor cells play an important role in cancer pathogenesis, and viruses affect their expression. Therefore, we compared human cytokine and receptor transcript levels in virus positive (V+) and virus negative (V−) MCC cell lines. Increased expression of IL-33, a potent modulator of tumor microenvironment, was observed in V+ MCC cell lines when compared to V− MCC-13 cells. Transient transfection studies with luciferase reporter plasmids demonstrated that LT and sT stimulated IL-33, ST2/IL1RL1 and IL1RAcP promoter activity. The induction of IL-33 expression was confirmed by transfecting MCC-13 cells with MCPyV LT. Furthermore, recombinant human cytokine domain IL-33 induced activation of MAP kinase and NF-κB pathways, which could be blocked by a ST2 receptor antibody. Immunohistochemical analysis demonstrated a significantly stronger IL-33, ST2, and IL1RAcP expression in MCC tissues compared to normal skin. Of interest, significantly higher IL-33 and IL1RAcP protein levels were observed in MCC patient plasma compared to plasma from healthy controls. Previous studies have demonstrated the implication of the IL-33/STL2 pathway in cancer. Because our results revealed a T-antigens-dependent induction of the IL-33/ST2 axis, IL-33/ST2 may play a role in the tumorigenesis of MCPyV-positive MCC. Therefore, neutralizing the IL-33/ST2 axis may present a novel therapeutic approach for MCC patients.

DOT1L affects colorectal carcinogenesis via altering T cell subsets and oncogenic pathway

Chronic inflammation and oncogenic pathway activation are key-contributing factors in colorectal cancer pathogenesis. However, colorectal intrinsic mechanisms linking these two factors in cancer development are poorly defined. Here, we show that intestinal epithelial cell (IEC)-specific deletion of Dot1l histone methyltransferase (Dot1l^ΔIEC) reduced H3K79 dimethylation (H3K79me2) in IECs and inhibited intestinal tumor formation in Apc^Min- and AOM-DSS-induced colorectal cancer models. IEC-Dot1l abrogation was accompanied by alleviative colorectal inflammation and reduced Wnt/β-catenin signaling activation. Mechanistically, Dot1l deficiency resulted in an increase in Foxp3⁺RORϒ⁺ regulatory T (Treg) cells and a decrease in inflammatory Th17 and Th22 cells, thereby reducing local inflammation in the intestinal tumor microenvironment. Furthermore, Dot1l deficiency caused a reduction of H3K79me2 occupancies in the promoters of the Wnt/β-catenin signaling genes, thereby diminishing Wnt/β-catenin oncogenic signaling pathway activation in colorectal cancer cells. Clinically, high levels of tumor H3K79me2 were detected in patients with colorectal carcinomas as compared to adenomas, and negatively correlated with RORϒ⁺FOXP3⁺ Treg cells. Altogether, we conclude that DOT1L is an intrinsic molecular node connecting chronic immune activation and oncogenic signaling pathways in colorectal cancer. Our work suggests that targeting the DOT1L pathway may control colorectal carcinogenesis. Significance: IEC-intrinsic DOT1L controls T cell subset balance and key oncogenic pathway activation, impacting colorectal carcinogenesis.

Innate lymphoid cells in colorectal cancer

Innate lymphoid cells (ILC) can be viewed as the innate counterparts of T cells. In contrast to T cells, ILCs exert their functions in antigen‐independent manners, relying on tissue‐derived signals from other immune cells, stroma and neurons. Natural killer (NK) cells have been known for their antitumour effects for decades. However, the roles of other ILC subtypes in cancer immunity are just now starting to be unravelled. ILCs contribute to both homeostasis and inflammation in the intestinal mucosa. Intestinal inflammation predisposes the intestine for the development of colonic dysplasia and colorectal cancer (CRC). Recent data from mouse models and human studies indicate that ILCs play a role in CRC, exerting both protumoural and antitumoural functions. Studies also suggest that intratumoural ILC frequencies and expression of ILC signature genes can predict disease progression and response to PD‐1 checkpoint therapy in CRC. In this mini‐review, we focus on such recent insights and their implications for understanding the immunobiology of CRC. We also identify knowledge gaps and research areas that require further work.

DeepTI: A deep learning-based framework decoding tumor-immune interactions for precision immunotherapy in oncology

BACKGROUND

Increasing evidence suggests the immunomodulatory potential of genes in oncology. But the identification of immune attributes of genes is costly and time-consuming, which leads to an urgent demand to develop a prediction model.

METHOD

We developed a deep learning-based model to predict the immune properties of genes. This model is trained in 70% of samples and evaluated in 30% of samples. Furthermore, it uncovers 60 new immune-related genes. We analyzed the expression perturbation and prognostic value of these genes in gastric cancer. Finally, we validated these genes in immunotherapy-related datasets to check the predictive potential of immunotherapeutic sensitivity.

RESULT

This model classifies genes as immune-promoted or immune-inhibited based on the human PPI network and it achieves an accuracy of 0.68 on the test set. It uncovers 60 new immune-related genes, most of which are validated in the published literature. These genes are found to be downregulated in gastric cancer and significantly associated with the immune microenvironment in gastric cancer. Analysis of immunotherapy shows that these genes can discriminate between responder and non-responder.

CONCLUSION

This model can facilitate the identification of immune properties of genes, decoding tumor-immune interactions for precision immunotherapy in oncology.

Targeting the Epithelium-Derived Innate Cytokines: From Bench to Bedside

When epithelial cells are exposed to potentially threatening external stimuli such as allergens, bacteria, viruses, and helminths, they instantly produce "alarmin" cytokines, namely, IL-33, IL-25, and TSLP. These alarmins alert the immune system about these threats, thereby mobilizing host immune defense mechanisms. Specifically, the alarmins strongly stimulate type-2 immune cells, including eosinophils, mast cells, dendritic cells, type-2 helper T cells, and type-2 innate lymphoid cells. Given that the alarm-raising role of IL-33, IL-25, and TSLP was first detected in allergic and infectious diseases, most studies on alarmins focus on their role in these diseases. However, recent studies suggest that alarmins also have a broad range of effector functions in other pathological conditions, including psoriasis, multiple sclerosis, and cancer. Therefore, this review provides an update on the epithelium-derived cytokines in both allergic and non-allergic diseases. We also review the progress of clinical trials on biological agents that target the alarmins and discuss the therapeutic potential of these agents in non-allergic diseases.

Multi-Omics Analysis for Transcriptional Regulation of Immune-Related Targets Using Epigenetic Data: A New Research Direction

Background

Currently, a comprehensive method for exploration of transcriptional regulation has not been well established. We explored a novel pipeline to analyze transcriptional regulation using co-analysis of RNA sequencing (RNA-seq), assay for transposase-accessible chromatin using sequencing (ATAC-seq), and chromatin immunoprecipitation with high-throughput sequencing (ChIP-seq).

Methods

The G protein-coupled receptors (GPCRs) possibly associated with macrophages were further filtered using a reduced-Cox regression model. ATAC-seq profiles were used to map the chromatin accessibility of the GPRC5B promoter region. Pearson analysis was performed to identify the transcription factor (TF) whose expression was correlated with open chromatin regions of GPRC5B promoter. ChIP-seq profiles were obtained to confirm the physical binding of GATA4 and its predicted binding regions. For verification, quantitative polymerase chain reaction (qPCR) and multidimensional database validations were performed.

Results

The reduced-Cox regression model revealed the prognostic value of GPRC5B. A novel pipeline for TF exploration was proposed. With our novel pipeline, we first identified chr16:19884686-19885185 as a reproducible open chromatin region in the GPRC5B promoter. Thereafter, we confirmed the correlation between GATA4 expression and the accessibility of this region, confirmed its physical binding, and proved in vitro how its overexpression could regulate GPRC5B. GPRC5B was significantly downregulated in colon adenocarcinoma (COAD) as seen in 28 patient samples. The correlation between GPRC5B and macrophages in COAD was validated using multiple databases.

Conclusion

GPRC5B, correlated with macrophages, was a key GPCR affecting COAD prognosis. Further, with our novel pipeline, TF GATA4 was identified as a direct upstream of GPRC5B. This study proposed a novel pipeline for TF exploration and provided a theoretical basis for COAD therapy.

Paradoxical role of interleukin-33/suppressor of tumorigenicity 2 in colorectal carcinogenesis: Progress and therapeutic potential

Colorectal cancer (CRC) is presently the second most prevalent global mortality-inducing cancer. CRC carcinogenesis is a multifactorial process involving internal genetic mutations and the external environment. In addition, non-neoplastic cell activities within tumor microenvironments for CRC development have been established. However, interleukin (IL)-33, secreted by such cell types, plays a pivotal role in cancer progression due to interaction with cellular constituents within the tumor-inflammation microenvironment. IL-33 belongs to the IL-1 cytokine family and acts as binding attachments for the suppressor of tumorigenicity (ST)2 receptor. Therefore, how to coordinate tumor microenvironment, design and optimize treatment strategies suitable for CRC, based on IL-33/ST2 signal is a challenge. Even though it has established influences upon immunity-linked conditions, IL-33 effects on CRC progression and prevention and related mechanisms are still controversial. Our review depicts controversial activities for IL-33/ST2 within carcinogenesis and cancer prevention. Moreover, IL-33/ST2 signaling is a potential therapeutic target for CRC.

Periodontal ligament stem cells promote polarization of M2 macrophages

Macrophages are widely distributed in a variety of tissues, and the different state of macrophages polarization is closely related to the occurrence, development, and prognosis of inflammation, including periodontitis, a chronic inflammatory disease leading to tooth loss worldwide. Periodontal ligament stem cells (PDLSCs) play a key role in immune regulation and periodontal tissues regeneration, contributing to cell-based therapy of periodontitis. However, the interactions between PDLSCs and macrophages are still elusive. The purpose of present study is to investigate the effect of PDLSCs conditioned medium (PDLSCs-CM) on the macrophage polarization and the possible mechanism. PDLSCs were isolated using tissue explant methods and characterized via multipotent differentiation test and examination of expression profiles of mesenchymal stem cells (MSCs) markers. The supernatant of PDLSCs was collected, centrifuged, filtered, and used as PDLSCs-CM. Then, PDLSCs-CM was cocultured with M0 macrophages or IL-4- and IL-13-induced M2 macrophages. The level of surface markers of M1/M2 macrophages and production of several proinflammatory or anti-inflammatory factors were evaluated by flow cytometric analysis and enzyme-linked immunosorbent assay, respectively. The associated genes and proteins involved in the JNK pathway were investigated to explore the potential mechanism that may regulate PDLSCs-CM-mediated macrophage polarization. PDLSCs expressed MSCs markers, including STRO-1, CD146, CD90, and CD73, and were negative for CD34 and CD45, could undergo osteogenic and adipogenic differentiation when cultured in defined medium. After incubation with PDLSCs-CM, no significant increase of CD80+ and HLA-DR+ M1 macrophages was shown while evaluated CD209+ and CD206+ M2 macrophages were observed. In addition, the levels of anti-inflammatory factors such as IL-10, TGF-β, and CCL18 were increased instead of proinflammatory factors such as IL-1β, TNF-α with PDLSC-CM treatment. There was a decrease of JNK expression on M0 macrophages by qRT-PCR analysis and an increase of protein phosphorylation on M0 macrophages after incubation with PDLSCs-CM. Furthermore, as for the enhancement of IL-4- and IL-13-mediated M2 polarization by PDLSCs-CM, the mRNA level of JNK decreased, and the protein phosphorylation level of JNK increased. In addition, the treatment of JNK pathway inhibitor, SP600125, could inhibit the expression and secretion level of anti-inflammatory factor such as IL-10 in M2 polarization induced by PDLSCs-CM. Collectively, PDLSCs were able to induce M2 macrophage polarization instead of M1 polarization, and capable of enhancing M2 macrophage polarization induced by IL-4 and IL-13. The JNK pathway was involved in the promotion of M2 macrophage polarization.

Korean Red Ginseng Enhances Immunotherapeutic Effects of NK Cells via Eosinophils in Metastatic Liver Cancer Model

Metastasis decreases the survival rate of patients with liver cancer. Therefore, novel anti-metastatic strategies are needed. Korean Red Ginseng (KRG) is often ingested as a functional food with an immune-boosting effect. We investigated a combination of KRG and natural killer (NK) cells as a novel immunotherapy approach. SK-Hep1 cells were injected into the tail vein of NRGA mice to establish an experimental metastasis model. KRG, NK cells, or a combination of KRG and NK cells were administered. Tumor growth was observed using an in vivo imaging system, and metastatic lesions were evaluated by histological analysis and immunohistochemistry. Bioluminescence intensity was lower in the KRG and NK cell combination group than in the other groups, indicating that the combination treatment suppressed the progression of metastasis. CD56 expression was used as a NK cell marker and hematological analysis was performed. The combination treatment also decreased the expression of matrix metalloproteinases and the area of metastatic lesions in liver and bone tissues, as well as increased the eosinophil count. Expression of cytokines-related eosinophils and NK cells was determined by Western blotting analysis. The expression of interleukin 33 (IL33) was induced by the combination of KRG and NK cells. High IL33 expression was associated with prolonged overall survival in the Kaplan–Meier plotter. Our results suggest that KRG enhances the immune activity of NK cells by IL-33 through eosinophils and suppresses metastatic liver cancer progression.

Neutrophil Extracellular Traps (NETs) in Cancer Metastasis

Metastasis is the leading cause of cancer related morbidity and mortality. The metastatic process involves several identifiable biological stages, including tumor cell dissemination, intravasation, and the extravasation of circulating cancer cells to facilitate colonization at a distant site. Immune cell infiltration and inflammation within the tumor microenvironment coincide with tumor progression and metastatic spread and are thought to be the key mediators of this complex process. Amongst many infiltrating cells, neutrophils have recently emerged as an important player in fueling tumor progression, both in animal models and cancer patients. The production of Neutrophil Extracellular Traps (NETs) is particularly important in the pathogenesis of the metastatic cascade. NETs are composed of web-like DNA structures with entangled proteins that are released in response to inflammatory cues in the environment. NETs play an important role in driving tumor progression both in experimental and clinical models. In this review, we aim to summarize the current advances in understanding the role of NETs in cancer, with a specific focus on their role in promoting premetastatic niche formation, interaction with circulating cancer cells, and in epithelial to mesenchymal transition during cancer metastasis. We will furthermore discuss the possible role and different treatment options for targeting NETs to prevent tumor progression.

Elevated DLL3 in stomach cancer by tumor-associated macrophages enhances cancer-cell proliferation and cytokine secretion of macrophages

Background

The notch signal pathway is important in the development of both tumor-associated macrophages (TAMs) and stomach cancer, but how Notch signaling affects TAMs in stomach cancer is barely understood.

Methods

The expressions of Notch1, Notch2, Notch3, Notch4, hes family bHLH transcription factor 1 (Hes1), and delta-like canonical Notch ligand 3 (DLL3) were detected by Western blot and the expressions of interleukin (IL)-10, IL-12, and IL1-β were detected using enzyme-linked immunosorbent assay after the co-culture of macrophages and stomach-cancer cells. The proliferation and migration of cancer cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and scratch assay, respectively, and the cell cycle was detected using Annexin V/propidium iodide assay. The protein interactions with DLL3 were detected using co-immunoprecipitation and mass spectrometry.

Results

The co-culture of macrophages and stomach-cancer cells MKN45 and BGC823 could enhance cell proliferation accompanied by the activation of Notch1/Notch2 signaling and upregulation of DLL3. Notch signaling gamma-secretase inhibitor (DAPT) blocked this process. The overexpression of DLL3 in stomach-cancer cells could promote the proliferation of cancer cells, enhance the activation of Notch1/Notch2 signaling, induce the expression of IL-33, lead to the degradation of galectin-3–binding protein (LG3BP) and heat shock cognate 71 kDa protein (HSPA8), and result in elevated IL-1β, IL-12, and IL-10 secretion by macrophages. Higher expression of DLL3 or IL-33 could lead to a lower survival rate based on University of California, Santa Cruz Xena Functional Genomics Explorer and The Cancer Genome Atlas data set.

Conclusions

This is evidence that DLL3 regulates macrophages in stomach cancer, suggesting that DLL3 may be a novel and potential target for stomach-cancer therapy.

Extracellular vesicles: General features and usefulness in diagnosis and therapeutic management of colorectal cancer

In the world, among all type of cancers, colorectal cancer (CRC) is the third most commonly diagnosed in males and the second in females. In most of cases, (RP1) patients’ prognosis limitation with malignant tumors can be attributed to delayed diagnosis of the disease. Identification of patients with early-stage disease leads to more effective therapeutic interventions. Therefore, new screening methods and further innovative treatment approaches are mandatory as they may lead to an increase in progression-free and overall survival rates. For the last decade, the interest in extracellular vesicles (EVs) research has exponentially increased as EVs generation appears to be a universal feature of every cell that is strongly involved in many mechanisms of cell-cell communication either in physiological or pathological situations. EVs can cargo biomolecules, such as lipids, proteins, nucleic acids and generate transmission signal through the intercellular transfer of their content. By this mechanism, tumor cells can recruit and modify the adjacent and systemic microenvironment to support further invasion and dissemination. This review intends to cover the most recent literature on the role of EVs production in colorectal normal and cancer tissues. Specific attention is paid to the use of EVs for early CRC diagnosis, follow-up, and prognosis as EVs have come into the spotlight of research as a high potential source of ‘liquid biopsies’. The use of EVs as new targets or nanovectors as drug delivery systems for CRC therapy is also summarized.