Activated macrophages promote Wnt signalling through tumour necrosis factor-alpha in gastric tumour cells

PC4 promotes bladder cancer progression and stemness by directly interacting with Sp1 to transcriptionally activate the Wnt5a/β-catenin pathway

Bladder cancer is a common malignancy with a poor prognosis worldwide. Positive cofactor 4 (PC4) is widely reported to promote malignant phenotypes in various tumors. Nonetheless, the biological function and mechanism of PC4 in bladder cancer remain unclear. Here, for the first time, we report that PC4 is elevated in bladder cancer and is associated with patient survival. Moreover, PC4 deficiency obviously inhibited bladder cancer cell proliferation and metastasis by reducing the expression of genes related to cancer stemness (CD44, CD47, KLF4 and c-Myc). Through RNA-seq and experimental verification, we found that activation of the Wnt5a/β-catenin pathway is involved in the malignant function of PC4. Mechanistically, PC4 directly interacts with Sp1 to promote Wnt5a transcription. Thus, our study furthers our understanding of the role of PC4 in cancer stemness regulation and provides a promising strategy for bladder cancer therapy.

Gastric cancer immunosuppressive microenvironment heterogeneity: implications for therapy development

Although immunotherapy has revolutionized solid tumor treatment, durable responses in gastric cancer (GC) remain limited. The heterogeneous tumor microenvironment (TME) facilitates immune evasion, contributing to resistance to conventional and immune therapies. Recent studies have highlighted how specific TME components in GC acquire immune escape capabilities through cancer-specific factors. Understanding the underlying molecular mechanisms and targeting the immunosuppressive TME will enhance immunotherapy efficacy and patient outcomes. This review summarizes recent advances in GC TME research and explores the role of the immune-suppressive system as a context-specific determinant. We also provide insights into potential treatments beyond checkpoint inhibition.

Targeted knockdown of PGAM5 in synovial macrophages efficiently alleviates osteoarthritis

Osteoarthritis (OA) is a common degenerative disease worldwide and new therapeutics that target inflammation and the crosstalk between immunocytes and chondrocytes are being developed to prevent and treat OA. These attempts involve repolarizing pro-inflammatory M1 macrophages into the anti-inflammatory M2 phenotype in synovium. In this study, we found that phosphoglycerate mutase 5 (PGAM5) significantly increased in macrophages in OA synovium compared to controls based on histology of human samples and single-cell RNA sequencing results of mice models. To address the role of PGAM5 in macrophages in OA, we found conditional knockout of PGAM5 in macrophages greatly alleviated OA symptoms and promoted anabolic metabolism of chondrocytes in vitro and in vivo. Mechanistically, we found that PGAM5 enhanced M1 polarization via AKT-mTOR/p38/ERK pathways, whereas inhibited M2 polarization via STAT6-PPARγ pathway in murine bone marrow-derived macrophages. Furthermore, we found that PGAM5 directly dephosphorylated Dishevelled Segment Polarity Protein 2 (DVL2) which resulted in the inhibition of β-catenin and repolarization of M2 macrophages into M1 macrophages. Conditional knockout of both PGAM5 and β-catenin in macrophages significantly exacerbated osteoarthritis compared to PGAM5-deficient mice. Motivated by these findings, we successfully designed mannose modified fluoropolymers combined with siPGAM5 to inhibit PGAM5 specifically in synovial macrophages via intra-articular injection, which possessed desired targeting abilities of synovial macrophages and greatly attenuated murine osteoarthritis. Collectively, these findings defined a key role for PGAM5 in orchestrating macrophage polarization and provides insights into novel macrophage-targeted strategy for treating OA.

A Protective Role of Canonical Wnt/β-Catenin Pathway in Pathogenic Bacteria-Induced Inflammatory Responses

Inflammation is a complex host defensive response against various disease-associated pathogens. A baseline extent of inflammation is supposed to be tightly associated with a sequence of immune-modulated processes, resulting in the protection of the host organism against pathogen invasion; however, as a matter of fact is that an uncontrolled inflammatory cascade is the main factor responsible for the host damage, accordingly suggesting a significant and indispensable involvement of negative feedback mechanism in modulation of inflammation. Evidence accumulated so far has supported a repressive effect of the canonical Wnt/β-catenin pathway on microbial-triggered inflammation via diverse mechanisms, although that consequence is dependent on the cellular context, types of stimuli, and cytokine environment. It is of particular interest and importance to comprehend the precise way in which the Wnt/β-catenin pathway is activated, due to its essential anti-inflammatory properties. It is assumed that an inflammatory milieu is necessary for initiating and activating this signaling, implying that Wnt activity is responsible for shielding tissues from overwhelming inflammation, thus sustaining a balanced physiological condition against bacterial infection. This review gathers the recent efforts to elucidate the mechanistic details through how Wnt/β-catenin signaling modulates anti-inflammatory responses in response to bacterial infection and its interactions with other inflammatory signals, which warrants further study for the development of specific interventions for the treatment of inflammatory diseases. Further clinical trials from different disease settings are required.

Porphyromonas gingivalis Lipopolysaccharide Damages Mucosal Barrier to Promote Gastritis-Associated Carcinogenesis

BACKGROUND

Recent epidemiological studies suggested correlation between gastric cancer (GC) and periodontal disease.

AIMS

We aim to clarify involvement of lipopolysaccharide of Porphyromonas gingivalis (Pg.), one of the red complex periodontal pathogens, in the GC development.

METHODS

To evaluate barrier function of background mucosa against the stimulations, we applied biopsy samples from 76 patients with GC using a Ussing chamber system (UCs). K19-Wnt1/C2mE transgenic (Gan) mice and human GC cell-lines ± THP1-derived macrophage was applied to investigate the role of Pg. lipopolysaccharide in inflammation-associated carcinogenesis.

RESULTS

In the UCs, Pg. lipopolysaccharide reduced the impedance of metaplastic and inflamed mucosa with increases in mRNA expression of toll-like receptor (TLR) 2, tumor necrosis factor (TNF) α, and apoptotic markers. In vitro, Pg. lipopolysaccharide promoted reactive oxidative stress (ROS)-related apoptosis as well as activated TLR2-β-catenin-signaling on MKN7, and it increased the TNFα production on macrophages, respectively. TNFα alone activated TLR2-β-catenin-signaling in MKN7, while it further increased ROS and TNFα in macrophages. Under coculture with macrophages isolated after stimulation with Pg. lipopolysaccharide, β-catenin-signaling in MKN7 was activated with an increase in supernatant TNFα concentration, both of which were decreased by adding a TNFα neutralization antibody into the supernatant. In Gan mice with 15-week oral administration of Pg. lipopolysaccharide, tumor enlargement with β-catenin-signaling activation were observed with an increase in TNFα with macrophage infiltration.

CONCLUSIONS

Local exposure of Pg. lipopolysaccharide may increase ROS on premalignant gastric mucosa to induce apoptosis-associated barrier dysfunction and to secrete TNFα from activated macrophages, and both stimulation of Pg. lipopolysaccharide and TNFα might activate TLR2-β-catenin-signaling in GC.

Association between new plasma inflammatory markers and risk of colorectal neoplasms in individuals over 50 years old

OBJECTIVE(S)

The prognostic value of systemic cytokine profiles and inflammatory markers in colorectal cancer were explored by several studies. We want to know more about inflammatory biomarkers in colorectal adenoma and early cancer.

METHOD

The level of 38 inflammatory markers in the plasma of 112 adenoma patients, 72 Tis-T1 staging of colorectal carcinoma patients, 34 T2-T4 staging of colorectal carcinoma patients and 53 normal subjects were detected and compared.

RESULT(S)

Eight inflammatory biomarkers (Eotaxin, GCSF, IL-4, IL-5, IL-17E, MCP-1, TNF-α and VEGF-A) have higher plasma concentrations in colorectal adenoma and cancer patients compared with normal participants over 50 years old.

CONCLUSION(S)

Inflammatory markers may have the prognostic value for colorectal adenoma and early-stage carcinoma.

Tumor necrosis factor-α knockout mitigates intestinal inflammation and tumorigenesis in obese Apc1638N mice

Strong evidence from observational studies shows that having body fatness is associated with an individual's risk of developing colorectal cancer (CRC), but the causality between obesity and CRC remains inadequately elucidated. Our previous studies have shown diet-induced obesity is associated with elevated TNF-α and enhanced activation of Wnt-signaling, yet the causal role of TNF-α on intestinal tumorigenesis has not been precisely studied. The present study aims to examine the functionality of TNF-α in the development of CRC associated with obesity. We first examined the extent to which diet-induced obesity elevates intestinal tumorigenesis by comparing Apc^1638N mice fed a low fat diet (LFD, 10 kcal% fat) with those fed a high fat diet (HFD, 60 kcal% fat), and then investigated the degree that the genetic ablation of TNF-α attenuates the effect by crossing the TNF-α^-/- mice with Apc^1638N mice and feeding them with the same HFD (TNF-α KO HFD). After 16-weeks of feeding, the HFD significantly increased intestinal tumorigenesis, whereas the deletion of TNF-α attenuated the effect (p < 0.05). Accompanying the changes in macroscopic tumorigenesis, HFD significantly elevated intestinal inflammation and pro-carcinogenic Wnt-signaling, whereas abolishment of TNF-α mitigated the magnitude of these elevations (p < 0.05). In summary, our findings demonstrate that the knockout of TNF-α attenuates obesity-associated intestinal tumorigenesis by decreasing intestinal inflammation and thereby the Wnt-signaling, indicating that TNF-α signaling is a potential target that can be utilized to reduce the risk of CRC associated with obesity.

Infliximab Inhibits Colitis Associated Cancer in Model Mice by Downregulating Genes Associated with Mast Cells and Decreasing Their Accumulation

Inflammatory bowel diseases (IBDs), such as Crohn’s disease or ulcerative colitis, can be treated with anti TNF-alpha (TNF-α) antibodies (Abs), but they also put patients with IBDs at risk of cancer. We aimed to determine whether the anti TNF-α Ab induces colon cancer development in vitro and in vivo, and to identify the genes involved in colitis-associated cancer. We found that TNF-α (50 ng/mL) inhibited the proliferation, migration, and invasion of HCT8 and COLO205 colon cancer cell lines and that anti TNF-α Ab neutralized TNF-α inhibition in vitro. The effects of anti TNF-α Ab, infliximab (10 mg/kg) were investigated in mouse models of colitis-associated cancer induced by intraperitoneally injected azoxymethane (AOM: 10 mg/kg)/orally administered dextran sodium sulfate (DSS: 2.5%) (AOM/DSS) in vivo. Infliximab significantly attenuated the development of colon cancer in these mice. Microarray analyses and RT-qPCR revealed that mast cell protease 1, mast cell protease 2, and chymase 1 were up-regulated in cancer tissue of AOM/DSS mice; however, those mast cell related genes were downregulated in cancer tissue of AOM/DSS mice with infliximab. These results suggested that mast cells play a pivotal role in the development of cancer associated with colitis in AOM/DSS mice.

Cold atmospheric plasma: Novel opportunities for tumor microenvironment targeting

With mounting preclinical and clinical evidences on the prominent roles of the tumor microenvironment (TME) played during carcinogenesis, the TME has been recognized and used as an important onco-therapeutic target during the past decade. Delineating our current knowledge on TME components and their functionalities can help us recognize novel onco-therapeutic opportunities and establish treatment modalities towards desirable anti-cancer outcome. By identifying and focusing on primary cellular components in the TME, that is, tumor-infiltrating lymphocytes, tumor-associated macrophages, cancer-associated fibroblasts and mesenchymal stem cells, we decomposed their primary functionalities during carcinogenesis, categorized current therapeutic approaches utilizing traits of these components, and forecasted possible benefits that cold atmospheric plasma, a redox modulating tool with selectivity against cancer cells, may convey by targeting the TME. Our insights may open a novel therapeutic avenue for cancer control taking advantages of redox homeostasis and immunostasis.

Latent membrane protein 1 and macrophage-derived TNFα synergistically activate and mobilize invadopodia to drive invasion of nasopharyngeal carcinoma

Invadopodia are actin-rich membrane protrusions that digest the matrix barrier during cancer metastasis. Since the discovery of invadopodia, they have been visualized as localized and dot-like structures in different types of cancer cells on top of a 2D matrix. In this investigation of Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC), a highly invasive cancer frequently accompanied by neck lymph node and distal organ metastases, we revealed a new form of invadopodium with mobilizing features. Integration of live-cell imaging and molecular assays revealed the interaction of macrophage-released TNFα and EBV-encoded latent membrane protein 1 (LMP1) in co-activating the EGFR/Src/ERK/cortactin and Cdc42/N-WASP signaling axes for mobilizing the invadopodia with lateral movements. This phenomenon endows the invadopodia with massive degradative power, visualized as a shift of focal dot-like digestion patterns on a 2D gelatin to a dendrite-like digestion pattern. Notably, single stimulation of either LMP1 or TNFα could only enhance the number of ordinary dot-like invadopodia, suggesting that the EBV infection sensitizes the NPC cells to form mobilizing invadopodia when encountering a TNFα-rich tumor microenvironment. This study unveils the interplay of EBV and stromal components in driving the invasive potential of NPC via unleashing the propulsion of invadopodia in overcoming matrix hurdles. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Relationships among microbiota, gastric cancer, and immunotherapy

Currently, conventional neoadjuvant therapy or postoperative adjuvant therapy, such as chemotherapy and radiation therapy, can only bring limited survival benefits to gastric cancer (GC). Median survival after palliative chemotherapy is also low, at about 8–10 months. Immunotargeting is a new option for the treatment of GC, but has not been widely replicated. The highly immunosuppressed tumor microenvironment (TME) discounts the efficacy of immunotherapy for GC. Therefore, new strategies are needed to enhance the immune response of the TME. This paper reviewed the relationship between microorganisms and GC, potential links between microorganisms and immunotherapy and research of microorganisms combined immunotherapy.

Sanguinarine Regulates Tumor-Associated Macrophages to Prevent Lung Cancer Angiogenesis Through the WNT/β-Catenin Pathway

Tumor-associated macrophage (TAM)-mediated angiogenesis in the tumor microenvironment is a prerequisite for lung cancer growth and metastasis. Therefore, targeting TAMs, which block angiogenesis, is expected to be a breakthrough in controlling the growth and metastasis of lung cancer. In this study, we found that Sanguinarine (Sang) inhibits tumor growth and tumor angiogenesis of subcutaneously transplanted tumors in Lewis lung cancer mice. Furthermore, Sanguinarine inhibited the proliferation, migration, and lumen formation of HUVECs and the expression of CD31 and VEGF by regulating the polarization of M2 macrophages in vitro. However, the inhibitory effect of Sanguinarine on angiogenesis remained in vivo despite the clearance of macrophages using small molecule drugs. Further high-throughput sequencing suggested that WNT/β-Catenin signaling might represent the underlying mechanism of the beneficial effects of Sanguinarine. Finally, the β-Catenin activator SKL2001 antagonized the effect of Sanguinarine, indicating that Sanguinarine can regulate M2-mediated angiogenesis through the WNT/β-Catenin pathway. In conclusion, this study presents the first findings that Sanguinarine can function as a novel regulator of the WNT/β-Catenin pathway to modulate the M2 macrophage polarization and inhibit angiogenesis, which has potential application value in immunotherapy and antiangiogenic therapy for lung cancer.

Intracellular complement C5a/C5aR1 stabilizes β-catenin to promote colorectal tumorigenesis

Complement is operative in not only the extracellular but also the intracellular milieu. However, little is known about the role of complement activation inside tumor cells. Here, we report that intracellular C5 is cleaved by cathepsin D (CTSD) to produce C5a in lysosomes and endosomes of colonic cancer cells. After stimulation by C5a, intracellular C5aR1 assembles a complex with KCTD5/cullin3/Roc-1 and β-catenin to promote the switch of polyubiquitination of β-catenin from K48 to K63, which enhances β-catenin stability. Genetic loss or pharmacological blockade of C5aR1 dramatically impedes colorectal tumorigenesis at least by destabilizing β-catenin. In human colorectal cancer specimens, high levels of C5aR1, C5a, and CTSD are closely correlated with elevated β-catenin levels and a poor prognosis. Importantly, intracellular C5a/C5aR1-mediated β-catenin stabilization is also observed ubiquitously in other cell types. Collectively, we identify a machinery for β-catenin activation and provide a potential target for tumor prevention and treatment.

Integrated DNA and RNA sequencing reveals early drivers involved in metastasis of gastric cancer

Gastric cancer (GC) is the second cause of cancer-related death and metastasis is an important cause of death. Considering difficulties in searching for metastatic driver mutations, we tried a novel strategy here. We conducted an integrative genomic analysis on GC and identified early drivers lead to metastasis. Whole-exome sequencing (WES), transcriptomes sequencing and targeted-exome sequencing (TES) were performed on tumors and matched normal tissues from 432 Chinese GC patients, especially the comparative analysis between higher metastatic-potential (HMP) group with T1 stage and lymph-node metastasis, and lower metastatic-potential (LMP) group without lymph-nodes or distant metastasis. HMP group presented higher mutation load and heterogeneity, enrichment in immunosuppressive signaling, more immune cell infiltration than LMP group. An integrated mRNA-lncRNA signature based on differentially expressed genes was constructed and its prognostic value was better than traditional TNM stage. We identified 176 candidate prometastatic mutations by WES and selected 8 genes for following TES. Mutated TP53 and MADCAM1 were significantly associated with poor metastasis-free survival. We further demonstrated that mutated MADCAM1 could not only directly promote cancer cells migration, but also could trigger tumor metastasis by establishing immunosuppressive microenvironment, including promoting PD-L1-mediated immune escape and reprogramming tumor-associated macrophages by regulating CCL2 through Akt/mTOR axis. In conclusion, GCs with different metastatic-potential are distinguishable at the genetic level and we revealed a number of potential metastatic driver mutations. Driver mutations in early-onset metastatic GC could promote metastasis by establishing an immunosuppressive microenvironment. This study provided possibility for future target therapy of GC.

The effects of ellagic acid and other pomegranate (Punica granatum L.) derivatives on human gastric cancer AGS cells

Although surgery with or without (neo)adjuvant chemo/radiotherapy, as the standard treatments, can be suitable therapeutic strategies for gastric cancer, side effects and drug resistance are two main treatment obstacles. It has been discovered that pomegranate and its natural derivatives, especially ellagic acid (EA), offer significant anti-cancer effects while causing trivial side effects. In this study, we aimed to explore the anti-cancer effects of EA on a human gastric adenocarcinoma cell line (AGS) as well as in immunocompromised mice bearing human gastric tumors, for the first time. HPLC was used for determining EA in samples. MTT assay, apoptosis and scratch assay, gelatin zymography, and quantitative RT-PCR were used to determine the anti-cancer properties of different concentrations of pomegranate fruit juice, pomegranate peel extract, and EA. Furthermore, the effects of these compounds were investigated on immunosuppressed C57BL/6 mice carrying human gastric cancer tumors. EA could inhibit the proliferation and migration of gastric cancer cells. It also had significant effects on reducing both expression and activity of MMP-2 and MMP-9. Further, it was demonstrated that with alterations in the expression of genes involved in apoptosis and inflammation including P53, BAX, APAF1, BCL2, iNOS, NF-κB, IL-8, and TNF-α, EA treatment led to increased cancer cell death and reduced inflammation. Furthermore, its use in mice bearing gastric tumors resulted in a significant reduction in tumor volume without any obvious side effects. Ellagic acid exhibited anti-cancer effects on gastric adenocarcinoma, and can be considered as a safe anti-cancer agent for further preclinical studies on this cancer.

Canonical Wnt Signaling in the Pathology of Iron Overload-Induced Oxidative Stress and Age-Related Diseases

Iron accumulates in the vital organs with aging. This is associated with oxidative stress, inflammation, and mitochondrial dysfunction leading to age-related disorders. Abnormal iron levels are linked to neurodegenerative diseases, liver injury, cancer, and ocular diseases. Canonical Wnt signaling is an evolutionarily conserved signaling pathway that regulates many cellular functions including cell proliferation, apoptosis, cell migration, and stem cell renewal. Recent evidences indicate that iron regulates Wnt signaling, and iron chelators like deferoxamine and deferasirox can inhibit Wnt signaling and cell growth. Canonical Wnt signaling is implicated in the pathogenesis of many diseases, and there are significant efforts ongoing to develop innovative therapies targeting the aberrant Wnt signaling. This review examines how intracellular iron accumulation regulates Wnt signaling in various tissues and their potential contribution in the progression of age-related diseases.

Cancer Stem Cells and the Tumor Microenvironment in Gastric Cancer

Gastric cancer (GC) remains one of the leading causes of cancer-related death worldwide. Cancer stem cells (CSCs) might be responsible for tumor initiation, relapse, metastasis and treatment resistance of GC. The tumor microenvironment (TME) comprises tumor cells, immune cells, stromal cells and other extracellular components, which plays a pivotal role in tumor progression and therapy resistance. The properties of CSCs are regulated by cells and extracellular matrix components of the TME in some unique manners. This review will summarize current literature regarding the effects of CSCs and TME on the progression and therapy resistance of GC, while emphasizing the potential for developing successful anti-tumor therapy based on targeting the TME and CSCs.

Neutrophil-to-Lymphocyte Ratio as a Prognostic Biomarker for Patients With Metastatic Renal Cell Carcinoma Treated With Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis

There is increasing evidence to suggest that the neutrophil-to-lymphocyte ratio (NLR) is related to the prognosis of patients with renal cell carcinoma (RCC) treated with immune checkpoint inhibitors (ICIs). However, these findings are inconsistent. The present study was performed with the aim of exploring the utility of NLR in patients with RCC treated with ICIs. For this purpose, a comprehensive search of PubMed, Web of Science, and Embase was performed to find studies evaluating the prognostic value of NLR. The overall survival (OS) and progression-free survival (PFS) were the assessed clinical outcomes. All statistical analysis was performed using Stata version 12.0 software. The combined hazard ratios (HRs) and 95% confidence intervals (CIs) of NLR for OS and PFS were calculated using the random-effect models. Heterogeneity was evaluated based on the I ² value and Cochran's Q test. Egger's and Begg's tests were applied to precisely assess the publication bias. The "trim and fill" method was adopted to perform the sensitivity analysis to determine whether the results were stable. In total, 12 studies encompassing 1,275 patients were included in the final analysis. The results revealed that a high NLR at baseline or pre-therapy was associated with a poor OS (HR, 2.23; 95% CI, 1.84-2.70; p < 0.001) and PFS (HR, 1.78; 95% CI, 1.72-2.09; p < 0.001). During the course of treatment, a decrease in the NLR was associated with a significantly longer OS (HR, 0.34; 95% CI, 0.20-0.56; p < 0.001) and PFS (HR, 0.44; 95% CI, 0.30-0.63; p < 0.001) compared to an increase in NLR. As a preliminary screening of other risk factors, age, sex, race, and IMDC risk may have a certain prognostic value for RCC treated with ICIs. People over 70 years old had better OS compared to people younger than 70 (HR, 0.65; 95% CI, 0.48-0.89). Non-Caucasians treated with immunotherapy had a worse OS (HR, 8.67; 95% CI, 2.87-26.2) and PFS (HR, 2.65; 95% CI, 1.28-5.48) than Caucasians. Males had a worse OS than females (HR, 1.48; 95% CI, 1.14-1.93). Compared with the IMDC favorable risk group, the OS of the IMDC poor risk group was worse (HR, 2.59; 95% CI, 1.56-4.32). There was no significant publication bias or heterogeneity observed in the present study. On the whole, the present study demonstrated that an elevated NLR is associated with an adverse OS and PFS in patients with RCC treated with ICIs. The NLR may thus be used as a readily available prognostic biomarker for these patients. Age, sex, race, and IMDC risk may have potential predictive value for the prognosis of RCC treated with ICIs. However, further investigations are warranted to validate these results.

Tumor Necrosis Factor Family Member Profile Predicts Prognosis and Adjuvant Chemotherapy Benefit for Patients With Small-Cell Lung Cancer

Tumor necrosis factor (TNF) family members participate in the body's antitumor immunity response and influence tumor prognosis and treatment response. However, little is known about the roles of TNF family members in small cell lung cancer (SCLC). Therefore, we conducted the first comprehensive investigation of TNF family members in patients with SCLC, with the goal of using them to predict prognosis and chemotherapy benefit. Abnormal genetic alterations and expression of TNF family members were found to be widespread in SCLC patients. Using LASSO Cox regression analysis, we constructed a TNF family-based signature that separated SCLC patients in the training set (n=77) into high- and low-risk groups with distinct survival and chemotherapy benefit, and the signature was well-validated in the validation set (n=137) by RT-qPCR. Importantly, the signature exhibited superior predictive performance and was identified as a novel independent prognostic factor. Additionally, different immune phenotypes were found between the low-risk and high-risk groups, and high-risk patients had higher CMTM6 expression, suggesting that these patients could benefit from therapeutic methods targeting CMTM6. We constructed the first clinically applicable TNF family-based signature for predicting prognosis and chemotherapy benefit for patients with SCLC. The findings reported here provide a new method for predicting the prognosis of SCLC patients and optimizing clinical management.

MicroRNA-21 Plays Multiple Oncometabolic Roles in Colitis-Associated Carcinoma and Colorectal Cancer via the PI3K/AKT, STAT3, and PDCD4/TNF-α Signaling Pathways in Zebrafish

Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. Patients with inflammatory bowel disease (IBD) have a high risk of developing CRC. Inflammatory cytokines are regulated by complex gene networks and regulatory RNAs, especially microRNAs. MicroRNA-21 (miR-21) is amongst the most frequently upregulated microRNAs in inflammatory responses and cancer development. miR-21 has become a target for genetic and pharmacological regulation in various diseases. However, the association between inflammation and tumorigenesis in the gut is largely unknown. Hence, in this study, we generated a zebrafish model (ImiR-21) with inducible overexpression of miR-21 in the intestine. The results demonstrate that miR-21 can induce CRC or colitis-associated cancer (CAC) in ImiR-21 through the PI3K/AKT, PDCD4/TNF-α, and IL-6/STAT3 signaling network. miR-21 activated the PI3K/AKT and NF-κB signaling pathways, leading to initial inflammation; thereafter, miR-21 and TNF-α repressed PDCD4 and its tumor suppression activity. Eventually, active STAT3 stimulated a strong inflammatory response and activated the invasion/metastasis process of tumor cells. Hence, our findings indicate that miR-21 is critical for the development of CRC/CAC via the PI3K/AKT, STAT3, and PDCD4/TNF-α signaling networks.

Microenvironmental modulation of the developing tumour: an immune-stromal dialogue

Successful establishment of a tumour relies on a cascade of interactions between cancer cells and stromal cells within an evolving microenvironment. Both immune and nonimmune cellular components are key factors in this process, and the individual players may change their role from tumour elimination to tumour promotion as the microenvironment develops. While the tumour-stroma crosstalk present in an established tumour is well-studied, aspects in the early tumour or premalignant microenvironment have received less attention. This is in part due to the challenges in studying this process in the clinic or in mouse models. Here, we review the key anti- and pro-tumour factors in the early microenvironment and discuss how understanding this process may be exploited in the clinic.

Exploring the Crosstalk between Inflammation and Epithelial-Mesenchymal Transition in Cancer

Tumor cells undergo invasion and metastasis through epithelial-to-mesenchymal cell transition (EMT) by activation of alterations in extracellular matrix (ECM) protein-encoding genes, enzymes responsible for the breakdown of ECM, and activation of genes that drive the transformation of the epithelial cell to the mesenchymal type. Inflammatory cytokines such as TGFβ, TNFα, IL-1, IL-6, and IL-8 activate transcription factors such as Smads, NF-κB, STAT3, Snail, Twist, and Zeb that drive EMT. EMT drives primary tumors to metastasize in different parts of the body. T and B cells, dendritic cells (DCs), and tumor-associated macrophages (TAMs) which are present in the tumor microenvironment induce EMT. The current review elucidates the interaction between EMT tumor cells and immune cells under the microenvironment. Such complex interactions provide a better understanding of tumor angiogenesis and metastasis and in defining the aggressiveness of the primary tumors. Anti-inflammatory molecules in this context may open new therapeutic options for the better treatment of tumor progression. Targeting EMT and the related mechanisms by utilizing natural compounds may be an important and safe therapeutic alternative in the treatment of tumor growth.

The prognostic role of the pre-treatment neutrophil to lymphocyte ratio (NLR) and tumor depth of invasion (DOI) in early-stage squamous cell carcinomas of the oral tongue

The appropriate surgical management of early-stage oral tongue squamous cell carcinoma (OTSCC) remains a debated topic. The aim of this study is to investigate the role of the pre-treatment neutrophil to lymphocyte ratio (NLR) and tumor depth of invasion (DOI) in predicting the presence of occult neck metastases in early-stage OTSCC. A retrospective analysis of patients affected by early-stage (cT1-T2 cN0) OTSCC who were submitted to elective neck dissection (END) was performed. Tumors were classified retrospectively according to the 8th TNM classification, the DOI was assessed on the pre-operative magnetic resonance imaging, and the pre-treatment NLR was calculated for each patient. A logistic regression model to estimate the probability π (x) of cervical metastases by studying the NLR and DOI was carried out. Next, the correlation between the two variables, the NLR and DOI, was preliminarily studied. A cohort of 110 patients was analyzed (mean age, 62 years old; male to female ratio 1.2:1). The patients were staged as cT1 in 53 cases and cT2 in 57 cases. A DOI greater than 5.4 mm and a NLR greater than 2.93 are associated with an increased risk of presenting occult cervical metastases. Furthermore, the variables NLR and DOI are linearly associated with a positive correlation, proved by Spearman's rank correlation coefficient rho of 0.64, with a unitary increase in the DOI of 1 mm directly associated with an increase of 0.47 in the NLR. The DOI and NLR can be effectively used to predict the occurrence of occult neck metastasis and therefore to plan an END in early-stage OTSCC.

Association Between Helicobacter pylori and Gastric Carcinoma

Gastric carcinoma is the third leading cause of cancer mortality worldwide. In 2018, the incidence of gastric carcinoma worldwide was over 1,000,000 new cases, with approximately 783,000 deaths. The rate of new cases is noticeably increased in Eastern Asia. Helicobacter pylori is responsible for the increased incidence of gastric cancer. In the year 2015, H. pylori had an approximate prevalence of 4.4 billion positive cases worldwide, with the most positive cases found within the region of Africa, Latin America and the Caribbean, and of Asia. H. pylori is known to have multiple strains which allow it to survive in the host cell epithelium chronically. Research has shown many factors which play a significant role in developing infection and thereafter its progression to gastric carcinoma. After H. pylori colonizes the gastric mucosa, its effects can be potentiated by virulence factors, host factors, and environmental factors. H. pylori contains virulence factors that aid in the adhesion, translocation, inflammation, and infectivity of the host gastric epithelium. It alters the functions of the host immune response and cytokines, utilizing these factors to invade and persist in the gastric epithelium for a long period of time. The human body will identify H. pylori to be foreign and will exacerbate an inflammatory response in an effort to eradicate the bacterium. Consequently, this will cause H. pylori to induce a serious infection which may progress to cancer. In this review, we will discuss the various factors involved in the infectious process of H. pylori and how they help the infection progress to gastric carcinoma. This will allow us to better understand and modulate treatments to effectively eradicate this bacterium before it triggers the body into developing cancer.

Activation of GSK3 Prevents Termination of TNF-Induced Signaling

Background

Termination of TNF-induced signaling plays a key role in the resolution of inflammation with dysregulations leading to severe pathophysiological conditions (sepsis, chronic inflammatory disease, cancer). Since a recent phospho-proteome analysis in human monocytes suggested GSK3 as a relevant kinase during signal termination, we aimed at further elucidating its role in this context.

Materials and Methods

For the analyses, THP-1 monocytic cells and primary human monocytes were used. Staurosporine (Stauro) was applied to activate GSK3 by inhibiting kinases that mediate inhibitory GSK3α/β-Ser21/9 phosphorylation (eg, PKC). For GSK3 inhibition, Kenpaulone (Ken) was used. GSK3- and PKC-siRNAs were applied for knockdown experiments. Protein expression and phosphorylation were assessed by Western blot or ELISA and mRNA expression by qPCR. NF-κB activation was addressed using reporter gene assays.

Results

Constitutive GSK3β and PKCβ expression and GSK3α/β-Ser21/9 and PKCα/βII-Thr638/641 phosphorylation were not altered during TNF long-term incubation. Stauro-induced GSK3 activation (demonstrated by Bcl3 reduction) prevented termination of TNF-induced signaling as reflected by strongly elevated IL-8 expression (used as an indicator) following TNF long-term incubation. A similar increase was observed in TNF short-term-exposed cells, and this effect was inhibited by Ken. PKCα/β-knockdown modestly increased, whereas GSK3α/β-knockdown inhibited TNF-induced IL-8 expression. TNF-dependent activation of two NF-κB-dependent indicator plasmids was enhanced by Stauro, demonstrating transcriptional effects. A TNF-induced increase in p65-Ser536 phosphorylation was further enhanced by Stauro, whereas IκBα proteolysis and IKKα/β-Ser176/180 phosphorylation were not affected. Moreover, PKCβ-knockdown reduced levels of Bcl3. A20 and IκBα mRNA, both coding for signaling inhibitors, were dramatically less affected under our conditions when compared to IL-8, suggesting differential transcriptional effects.

Conclusion

Our results suggest that GSK3 activation is involved in preventing the termination of TNF-induced signaling. Our data demonstrate that activation of GSK3 – either pathophysiologically or pharmacologically induced – may destroy the finely balanced condition necessary for the termination of inflammation-associated signaling.

The Sensitivity Prediction of Neoadjuvant Chemotherapy for Gastric Cancer

The overall efficacy of neoadjuvant chemoradiotherapy (NACT) for locally advanced gastric cancer (LAGC) has been recognized. However, the response rate of NACT is limited due to tumor heterogeneity. For patients who are resistant to NACT, not only the operation timing will be postponed, patients will also suffer from the side effects of it. Thus, it is important to develop a comprehensive strategy and screen out patients who may be sensitive to NACT. This article summarizes the related research progress on the sensitivity prediction of NACT for GC in the following aspects: microRNAs, metabolic enzymes, exosomes, other biomarkers; inflammatory indicators, and imageological assessments. The results showed that there were many studies on biomarkers, but no unified conclusion has been drawn. The inflammatory indicators are related to the survival and prognosis of patients under NACT. For imageological assessments such as CT, MRI, and PET, with careful integration and optimization, they will have unique advantages in early screening for patients who are sensitive to NACT.

The Tumour Microenvironment and Circulating Tumour Cells: A Partnership Driving Metastasis and Glycan-Based Opportunities for Cancer Control

Circulating tumour cells (CTC) are rare cells that actively detach or are shed from primary tumours into the lymph and blood. Some CTC subpopulations gain the capacity to survive, home and colonize distant locations, forming metastasis. This results from a multifactorial process in which cancer cells optimize motility, invasion, immune escape and cooperative relationships with microenvironmental cues. Here we present evidences of a self-fuelling molecular crosstalk between cancer cells and the tumour stroma supporting the main milestones leading to metastasis. We discuss how the tumour microenvironment supports pre-metastatic niches and CTC development and ultimately dictates CTC fate in targeted organs. Finally, we highlight the key role played by protein glycosylation in metastasis development, its prompt response to microenvironmental stimuli and the tremendous potential of glycan-based molecular signatures for liquid biopsies and targeted therapeutics.

A small sustained increase in NOD1 abundance promotes ligand-independent inflammatory and oncogene transcriptional responses

Small, genetically determined differences in transcription [expression quantitative trait loci (eQTLs)] are implicated in complex diseases through unknown molecular mechanisms. Here, we showed that a small, persistent increase in the abundance of the innate pathogen sensor NOD1 precipitated large changes in the transcriptional state of monocytes. A ~1.2- to 1.3-fold increase in NOD1 protein abundance resulting from loss of regulation by the microRNA cluster miR-15b/16 lowered the threshold for ligand-induced activation of the transcription factor NF-κB and the MAPK p38. An additional sustained increase in NOD1 abundance to 1.5-fold over basal amounts bypassed this low ligand concentration requirement, resulting in robust ligand-independent induction of proinflammatory genes and oncogenes. These findings reveal that tight regulation of NOD1 abundance prevents this sensor from exceeding a physiological switching checkpoint that promotes persistent inflammation and oncogene expression. Furthermore, our data provide insight into how a quantitatively small change in protein abundance can produce marked changes in cell state that can serve as the initiator of disease.

CD206+ M2-Like Macrophages Are Essential for Successful Implantation

Macrophages (MΦs) play important roles in implantation. Depletion of CD11b+ pan-MΦs in CD11b-diphtheria-toxin-receptor (DTR) mice is reported to cause implantation failure due to decreased progesterone production in the corpus luteum. However, of the M1 and M2, the type of MΦs that is important for implantation is unknown. In this study, we investigated the role of M2 MΦ in implantation using CD206-DTR mice. To deplete M2-MΦ, female CD206-DTR C57/BL6 mice were injected with DT before implantation. These M2-MΦ depleted mice (M2(-)) were naturally mated with Balb/C mice. As the control group, female C57/BL6 wild type (WT) mice injected with DT were mated with male Balb/C mice. The number of implantation sites and plasma progesterone levels at implantation were examined. Implantation-related molecule expression was determined using quantitative-PCR and immunohistochemistry of uterine tissues. The mRNA expression in the endometrial tissues of 38 patients with implantation failure was examined during the implantation window. In WT mice, CD206+M2-like MΦs accumulated in the endometrium at the implantation period, on embryonic (E) 4.5. In M2(-), the implantation number was significantly lower than that in control (p < 0.001, 7.8 ± 0.8 vs. 0.2 ± 0.4), although the plasma progesterone levels were not changed. Leukemia inhibitory factor (LIF) and CD206 mRNA expression was significantly reduced (p < 0.01), whereas the levels of TNFα were increased on E4.5 (p < 0.05). In M2(-), the number of Ki-67+ epithelial cells was higher than that in control at the pre-implantation period. Accelerated epithelial cell proliferation was confirmed by significantly upregulated uterine fibroblast growth factor (FGF)18 mRNA (P < 0.05), and strong FGF18 protein expression in M2(-) endometrial epithelial cells. Further, M2(-) showed upregulated uterine Wnt/β-catenin signals at the mRNA and protein levels. In the non-pregnant group, the proportion of M2-like MΦ to pan MΦ, CD206/CD68, was significantly reduced (p < 0.05) and the TNFα mRNA expression was significantly increased (p < 0.05) in the endometrial tissues compared to those in the pregnant group. CD206+ M2-like MΦs may be essential for embryo implantation through the regulation of endometrial proliferation via Wnt/β-catenin signaling.

Analysis of β-catenin association with obesity in African Americans with premalignant and malignant colorectal lesions

BACKGROUND

African Americans (AA) are at high risk for Colorectal Cancer (CRC). Studies report a 30-60% increase in CRC risk with physical inactivity, obesity and metabolic syndrome. Activation of the WNT/β-catenin (CTNNB1) signaling pathway plays a critical role in colorectal carcinogenesis. Accumulating evidence also indicates a role of WNT-CTNNB1 signaling in obesity and metabolic diseases.

AIM

To examine the association between obesity, β-Catenin expression and colonic lesions in African Americans.

METHODS

We reviewed the pathology records of 152 colorectal specimens from 2010 to 2012 (46 CRCs, 74 advanced adenomas and 32 normal colon tissues). Tissue Microarrays (TMA) were constructed from these samples. Immunohistochemistry (IHC) for CTNNB1 (β-Catenin; clone β-Catenin-1) was performed on the constructed TMAs. The IHC results were evaluated by 2 pathologists and the nuclear intensity staining was scored from 0 to 4. BMI, sex, age, location of the lesion and other demographic data were obtained.

RESULTS

Positive nuclear staining in normal, advanced adenoma and CRC was 0, 24 and 41%, respectively (P < 0.001). CRC was asso ciated with positive status for nuclear CTNNB1 intensity (adjusted OR: 3.40, 95%CI = 1.42-8.15, P = 0.006 for positive nuclear staining) compared to non-CRC samples (Normal or advanced adenoma). Nuclear staining percentage has a fair diagnostic ability for CRC with an AUC of 0.63 (95%CI = 0.55-0.71). Overweight/obese patients (BMI > 25) did not show a significant difference in (p = 0.3) nuclear CTNNB1 staining (17% positive in normal weight vs. 27% positive in overweight/obese). The association between nuclear intensity and CRC was not different between normal and overweight patients (P for interaction = 0.6). The positive nuclear CTNNB1status in CRC stage III and IV (35% of all CRC) was not different from stage I and II (50% vs. 36%, respectively, P = 0.4).

CONCLUSION

In our study, advanced adenoma and CRC were associated with activation of β-catenin in physically fit, overweight and obese patients. Thus, obesity and WNT/β-Catenin pathway seem to be independent in African American patients. WNT/β-Catenin signaling pathway has a potential to be used as an effector in colon carcinogenic transformation. Whether or not BMI is a modifier of this pathway needs to be investigated further.

Tumor microenvironment in gastric cancers

The tumor microenvironment favors the growth and expansion of cancer cells. Many cell types are involved in the tumor microenvironment such as inflammatory cells, fibroblasts, nerves, and vascular endothelial cells. These stromal cells contribute to tumor growth by releasing various molecules to either directly activate the growth signaling in cancer cells or remodel surrounding areas. This review introduces recent advances in findings on the interactions within the tumor microenvironment such as in cancer-associated fibroblasts (CAFs), immune cells, and endothelial cells, in particular those established in mouse gastric cancer models. In mice, myofibroblasts in the gastric stroma secrete R-spondin and support normal gastric stem cells. Most CAFs promote tumor growth in a paracrine manner, but CAF population appears to be heterogeneous in terms of their function and origin, and include both tumor-promoting and tumor-restraining populations. Among immune cell populations, tumor-associated macrophages, including M1 and M2 macrophages, and myeloid-derived suppressor cells (MDSCs), are reported to directly or indirectly promote gastric tumorigenesis by secreting soluble factors or modulating immune responses. Endothelial cells or blood vessels not only fuel tumors with nutrients, but also interact with cancer stem cells and immune cells by secreting chemokines or cytokines, and act as a cancer niche. Understanding these interactions within the tumor microenvironment would contribute to unraveling new therapeutic targets.

Pretreatment Neutrophil-to-Lymphocyte Ratio (NLR) May Predict the Outcomes of Advanced Non-small-cell Lung Cancer (NSCLC) Patients Treated With Immune Checkpoint Inhibitors (ICIs)

Background: Recent studies have demonstrated the predictive value of pretreatment neutrophil-to-lymphocyte ratio (NLR) in advanced cancers; however, the role of NLR in patients with advanced non-small-cell lung cancer (NSCLC) treated with immune checkpoint inhibitors (ICIs) remained to be explored. Thus, we aimed to investigate whether pretreatment NLR was associated with the outcomes of advanced NSCLC patients treated with ICIs.

Methods: A comprehensive literature research was first conducted in PubMed, the Cochrane Central Library, and Embase for studies that evaluated the association between pretreatment NLR and survival of advanced NSCLC patients with ICIs treatment. We then conducted a retrospective study in Chinese People's Liberation Army (PLA) General Hospital (Beijing, China) to validate these findings.

Results: A total of 17 eligible studies with 2,106 patients were included in our meta-analysis, of which, 12 studies reported progression-free survival (PFS), and 13 studies reported overall survival (OS). The pooled results showed that high pretreatment NLR was significantly associated with poorer PFS (HR = 1.44, 95% CI 1.26–1.65; P < 0.001) and OS (HR = 2.86, 95% CI 2.11–3.87; P < 0.001) compared with those with low pretreatment NLR. Subgroup analysis demonstrated that the association between baseline NLR and PFS remained significant except that the cut-off value of NLR was 3 (HR = 1.48, 95% CI 0.93–2.37; P = 0.098) and region of Asia (HR = 1.55, 95% CI 1.00–2.39; P = 0.051). These results were further validated in our retrospective study that patients with pretreatment NLR ≥ 6.0 had shorter PFS (median: 5.0 vs. 9.1 months, HR = 1.39; 95% CI 1.01–1.91; P = 0.02) and OS (median: 10.0 vs. 17.3 months, HR = 1.71; 95% CI 1.18–2.46; P < 0.001) compared with those with NLR < 6.0. The associations between NLR and survival were consistent in subgroup analysis stratified by age, gender, ECOG PS, histology, stage, smoking history, treatment, and prior lines of therapy. Dynamics of NLR (dNLR) that increased ≥3.0 from baseline was also significantly associated with worse PFS (median: 3.1 vs. 9.1 months; P = 0.01) and OS (median: 6.8 vs. 17.0 months; P < 0.0001).

Conclusions: Our study demonstrates that pretreatment NLR and dNLR from baseline are associated with the outcomes of advanced NSCLC patients treated with ICIs; however, it warrants further prospective studies.

The roles of tumor-associated macrophages in tumor angiogenesis and metastasis

Tumor associated macrophages (TAMs) are the most frequent immune cells within tumor microenvironment (TME). There is growing evidence that TAMs are involved in tumor progression via multiple mechanisms. TAMs create an immunosuppressive TME by producing growth factors, chemokines, and cytokines which modulate recruitment of immune cells and inhibit anti-tumor responses. They also serve as angiogenesis promoting cells by production of pro-angiogenic factors and matrix metalloproteinases (MMPs) and vascular constructing which guarantee supplying oxygen and nutrients to solid tumor cells. Furthermore, TAMs play important functions in tumor metastasis through contributing to invasion, extravasation, survival, intravasation, and colonization of tumor cells. In this review, we summarized macrophage classification, TAMs polarization, and mechanisms underlying TAM-promoting angiogenesis and metastasis.

Inflammatory Responses during Tumour Initiation: From Zebrafish Transgenic Models of Cancer to Evidence from Mouse and Man

The zebrafish is now an important model organism for cancer biology studies and provides unique and complementary opportunities in comparison to the mammalian equivalent. The translucency of zebrafish has allowed in vivo live imaging studies of tumour initiation and progression at the cellular level, providing novel insights into our understanding of cancer. Here we summarise the available transgenic zebrafish tumour models and discuss what we have gleaned from them with respect to cancer inflammation. In particular, we focus on the host inflammatory response towards transformed cells during the pre-neoplastic stage of tumour development. We discuss features of tumour-associated macrophages and neutrophils in mammalian models and present evidence that supports the idea that these inflammatory cells promote early stage tumour development and progression. Direct live imaging of tumour initiation in zebrafish models has shown that the intrinsic inflammation induced by pre-neoplastic cells is tumour promoting. Signals mediating leukocyte recruitment to pre-neoplastic cells in zebrafish correspond to the signals that mediate leukocyte recruitment in mammalian tumours. The activation state of macrophages and neutrophils recruited to pre-neoplastic cells in zebrafish appears to be heterogenous, as seen in mammalian models, which provides an opportunity to study the plasticity of innate immune cells during tumour initiation. Although several potential mechanisms are described that might mediate the trophic function of innate immune cells during tumour initiation in zebrafish, there are several unknowns that are yet to be resolved. Rapid advancement of genetic tools and imaging technologies for zebrafish will facilitate research into the mechanisms that modulate leukocyte function during tumour initiation and identify targets for cancer prevention.

GSK3: A Kinase Balancing Promotion and Resolution of Inflammation

GSK3 has been implicated for years in the regulation of inflammation and addressed in a plethora of scientific reports using a variety of experimental (disease) models and approaches. However, the specific role of GSK3 in the inflammatory process is still not fully understood and controversially discussed. Following a detailed overview of structure, function, and various regulatory levels, this review focusses on the immunoregulatory functions of GSK3, including the current knowledge obtained from animal models. Its impact on pro-inflammatory cytokine/chemokine profiles, bacterial/viral infections, and the modulation of associated pro-inflammatory transcriptional and signaling pathways is discussed. Moreover, GSK3 contributes to the resolution of inflammation on multiple levels, e.g., via the regulation of pro-resolving mediators, the clearance of apoptotic immune cells, and tissue repair processes. The influence of GSK3 on the development of different forms of stimulation tolerance is also addressed. Collectively, the role of GSK3 as a kinase balancing the initiation/perpetuation and the amelioration/resolution of inflammation is highlighted.

Monocytes and Macrophages in Cancer: Unsuspected Roles

The behavior of cancer is undoubtedly affected by stroma. Macrophages belong to this microenvironment and their presence correlates with reduced survival in most cancers. After a tumor-induced "immunoediting", these monocytes/macrophages, originally the first line of defense against tumor cells, undergo a phenotypic switch and become tumor-supportive and immunosuppressive.The influence of these tumor-associated macrophages (TAMs) on cancer is present in all traits of carcinogenesis. These cells participate in tumor initiation and growth, migration, vascularization, invasion and metastasis. Although metastasis is extremely clinically relevant, this step is always reliant on the angiogenic ability of tumors. Therefore, the formation of new blood vessels in tumors assumes particular importance as a limiting step for disease progression.Herein, the once unsuspected roles of macrophages in cancer will be discussed and their importance as a promising strategy to treat this group of diseases will be reminded.

Genetic ablation of tumor necrosis factor-alpha attenuates the promoted colonic Wnt signaling in high fat diet-induced obese mice

Obesity is an established risk factor for colorectal cancer, but the mechanisms responsible for this relationship are not adequately delineated. Using a TNF-α^-/- mouse model, the present study aimed to test the causal role of TNF-α in mediating the promotion of tumorigenic Wnt signaling by high-fat diet-induced obesity. A 2×2 factorial study was performed with wild-type and TNF-α^-/- mice on a 60 kcal% high-fat diet or a 10 kcal% low-fat diet. The inflammatory cytokine profile and genes within the Wnt signaling pathway were measured by electrochemiluminescence assay, real-time PCR, Western blotting or immunohistochemistry. The high-fat diet increased body weights in both wild-type and TNF-α^-/- animals (P<.05), but males were more sensitive to high-fat diet-induced weight gain and increases of colonic TNF-α than females (P<.05). Genetic ablation of TNF-α suppressed the obesity-promoted elevation of Wnt signaling, as indicated by decreased levels of phospho-GSK3β and active β-catenin, two key components within the Wnt pathway (P<.05). The transcriptional expression of several Wnt signaling targets (C-myc, Cyclin D1 and Axin 2) and cell proliferation, as indicated by Ki-67 staining, were attenuated by the deletion of TNF-α in the high-fat-fed TNF-α^-/- animals comparing with the wild-type animals (P<.05). Our data collectively showed that the genetic deletion of TNF-α attenuated the tumorigenic Wnt signaling, which was otherwise elevated by high-fat diet-induced obesity, and demonstrated a causal role of TNF-α in mediating obesity-associated Wnt signaling, which indicates a potential mechanism of inflammation-driven Wnt signaling for obesity-associated colorectal carcinogenesis.

Macrophages as an Emerging Source of Wnt Ligands: Relevance in Mucosal Integrity

The Wnt signaling pathway is a conserved pathway involved in important cellular processes such as the control of embryonic development, cellular polarity, cellular migration, and cell proliferation. In addition to playing a central role during embryogenesis, this pathway is also an essential part of adult homeostasis. Indeed, it controls the proliferation of epithelial cells in different organs such as intestine, lung, and kidney, and guarantees the maintenance of the mucosa in physiological conditions. The origin of this molecular pathway is the binding between Wnt ligands (belonging to a family of 19 different homologous secreted glycoproteins) and their specific membrane receptors, from the Frizzled receptor family. This specific interaction triggers the activation of the signaling cascade, which in turn activates or suppresses the expression of different genes in order to change the behavior of the cell. On the other hand, alterations of this pathway have been described in pathological conditions such as inflammation, fibrosis, and cancer. In recent years, macrophages-among other cell types-have emerged as a potential source of Wnt ligands. Due to their high plasticity, macrophages, which are central to the innate immune response, are capable of adopting different phenotypes depending on their microenvironment. In the past, two different phenotypes were described: a proinflammatory phenotype-M1 macrophages-and an anti-inflammatory phenotype-M2 macrophages-and a selective expression of Wnt ligands has been associated with said phenotypes. However, nowadays it is assumed that macrophages in vivo move through a continual spectrum of functional phenotypes. In both physiological and pathological (inflammation, fibrosis and cancer) conditions, the accumulation and polarization of macrophages conditions the future of the tissue, facilitating various scenarios, such as resolution of inflammation, activation of fibrosis, and cancer development due to the modulation of the Wnt signaling pathway, in autocrine and paracrine manner. In this work, we provide an overview of studies that have explored the role of macrophages and how they act as a source of Wnt ligands and as mediators of mucosal integrity.

Helminth-derived molecules inhibit colitis-associated colon cancer development through NF-κB and STAT3 regulation

Inflammation is currently considered a hallmark of cancer and plays a decisive role in different stages of tumorigenesis, including initiation, promotion, progression, metastasis and resistance to antitumor therapies. Colorectal cancer is a disease widely associated with local chronic inflammation. Additionally, extrinsic factors such as infection may beneficially or detrimentally alter cancer progression. Several reports have noted the ability of various parasitic infections to modulate cancer development, favoring tumor progression in many cases and inhibiting tumorigenesis in others. The aim of our study was to determine the effects of excreted/secreted products of the helminth Taenia crassiceps (TcES) as a treatment in a murine model of colitis-associated colon cancer (CAC). Here, we found that after inducing CAC, treatment with TcES was able to reduce inflammatory cytokines such as IL-1β, TNF-α, IL-33 and IL-17 and significantly attenuate colon tumorigenesis. This effect was associated with the inhibition of signal transducer and activator of transcription 3 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) phosphorylation. Furthermore, we determined that TcES interfered with LPS-induced NF-κB p65 activation in human colonic epithelial cell lines in a Raf-1 proto-oncogene-dependent manner. Moreover, in three-dimensional cultures, TcES promoted reorganization of the actin cytoskeleton, altering cell morphology and forming colonospheres, features associated with a low grade of aggressiveness. Our study demonstrates a remarkable effect of helminth-derived molecules on suppressing ongoing colorectal cancer by downregulating proinflammatory and protumorigenic signaling pathways.

Turmeronol A and turmeronol B from Curcuma longa prevent inflammatory mediator production by lipopolysaccharide-stimulated RAW264.7 macrophages, partially via reduced NF-κB signaling

Chronic inflammation depends on inflammatory mediators produced by activated macrophages and is the common pathological basis for various diseases. Turmeronol is a sesquiterpenoid found in the spice turmeric (Curcuma longa), which is known to have anti-inflammatory activity. To elucidate the anti-inflammatory mechanism of turmeronol, we investigated the influence of turmeronol A and turmeronol B in mouse macrophages (RAW264.7 cells) stimulated with lipopolysaccharide (LPS). Pretreatment of RAW264.7 cells with either turmeronol A or B significantly inhibited LPS-induced production of prostaglandin E₂ and nitric oxide, as well as expression of mRNAs for the corresponding synthetic enzymes. In addition, the turmeronols significantly inhibited LPS-induced upregulation of interleukin-1β, interleukin-6, and tumor necrosis factor-α at the mRNA and protein levels. Both turmeronols also inhibited nuclear translocation of nuclear factor κB (NF-κB), with a similar time course to the NF-κB inhibitor pyrrolidine dithiocarbamate, but not curcumin (another NF-κB inhibitor). Thus, both turmeronols prevented activation of macrophages and inflammatory mediator production, possibly by suppressing activation of NF-κB, and therefore have potential for use in preventing chronic inflammatory diseases.

Inflammatory Cytokine TNFα Promotes the Long-Term Expansion of Primary Hepatocytes in 3D Culture

In the healthy adult liver, most hepatocytes proliferate minimally. However, upon physical or chemical injury to the liver, hepatocytes proliferate extensively in vivo under the direction of multiple extracellular cues, including Wnt and pro-inflammatory signals. Currently, liver organoids can be generated readily in vitro from bile-duct epithelial cells, but not hepatocytes. Here, we show that TNFα, an injury-induced inflammatory cytokine, promotes the expansion of hepatocytes in 3D culture and enables serial passaging and long-term culture for more than 6 months. Single-cell RNA sequencing reveals broad expression of hepatocyte markers. Strikingly, in vitro-expanded hepatocytes engrafted, and significantly repopulated, the injured livers of Fah^-/- mice. We anticipate that tissue repair signals can be harnessed to promote the expansion of otherwise hard-to-culture cell-types, with broad implications.

Wnt Signaling in Cancer: Not a Binary ON:OFF Switch

In the March 1 issue of Cancer Research, we identified the Wnt receptor Fzd7 as an attractive therapeutic target for the treatment of gastric cancer. In summary, we showed that pharmacological inhibition of Wnt receptors, or genetic deletion of Fzd7, blocks the initiation and growth of gastric tumors. Inhibiting Fzd receptors, specifically Fzd7, inhibits the growth of gastric cancer cells even in the presence of adenomatous polyposis coli (Apc) mutation. Apc is located in the cytoplasm downstream of Fzd7 in the Wnt signaling cascade and APC mutations activate Wnt/β-catenin signaling, therefore, this result seems counterintuitive. Here, we analyze this result in greater detail in the context of current knowledge of Wnt signaling and discuss the wider implications of this aspect of Wnt signaling in other cancers.

Microbial osteoporosis: The interplay between the gut microbiota and bones via host metabolism and immunity

The complex relationship between intestinal microbiota and host is a novel field in recent years. A large number of studies are being conducted on the relationship between intestinal microbiota and bone metabolism. Bone metabolism consisted of bone absorption and formation exists in the whole process of human growth and development. The nutrient components, inflammatory factors, and hormone environment play important roles in bone metabolism. Recently, intestinal microbiota has been found to influence bone metabolism via influencing the host metabolism, immune function, and hormone secretion. Here, we searched relevant literature on Pubmed and reviewed the effect of intestinal microbiota on bone metabolism through the three aspects, which may provide new ideas and targets for the clinical treatment of osteoporosis.

Interleukin 1 Up-regulates MicroRNA 135b to Promote Inflammation-Associated Gastric Carcinogenesis in Mice

BACKGROUND & AIMS

Gastritis is associated with development of stomach cancer, but little is known about changes in microRNA expression patterns during gastric inflammation. Specific changes in gene expression in epithelial cells are difficult to monitor because of the heterogeneity of the tissue. We investigated epithelial cell-specific changes in microRNA expression during gastric inflammation and gastritis-associated carcinogenesis in mice.

METHODS

We used laser microdissection to enrich epithelial cells from K19-C2mE transgenic mice, which spontaneously develop gastritis-associated hyperplasia, and Gan mice, which express activated prostaglandin E2 and Wnt in the gastric mucosa and develop gastric tumors. We measured expression of epithelial cell-enriched microRNAs and used bioinformatics analyses to integrate data from different systems to identify inflammation-associated microRNAs. We validated our findings in gastric tissues from mice and evaluated protein functions in gastric cell lines (SNU-719, SNU-601, SNU-638, AGS, and GIF-14) and knockout mice. Organoids were cultured from gastric corpus tissues of wild-type and miR-135b-knockout C57BL/6 mice. We measured levels of microRNAs in pairs of gastric tumors and nontumor mucosa from 28 patients in Japan.

RESULTS

We found microRNA 135b (miR-135B) to be the most overexpressed microRNA in gastric tissues from K19-C2mE and Gan mice: levels increased during the early stages of gastritis-associated carcinogenesis. Levels of miR-135B were also increased in gastric tumor tissues from gp130^F/F mice and patients compared with nontumor tissues. In gastric organoids and immortalized cell lines, expression of miR-135B was induced by interleukin 1 signaling. K19-C2mE mice with disruption of Mir-135b developed hyperplastic lesions that were 50% smaller than mice without Mir-135b disruption and had significant reductions in cell proliferation. Expression of miR-135B in gastric cancer cell lines increased their colony formation, migration, and sphere formation. We identified FOXN3 and RECK messenger RNAs (mRNAs) as targets of miR-135B; their knockdown reduced migration of gastric cancer cell lines. Levels of FOXN3 and RECK mRNAs correlated inversely with levels of miR-135B in human gastric tumors and in inflamed mucosa from K19-C2mE mice.

CONCLUSIONS

We found expression of miR-135B to be up-regulated by interleukin L1 signaling in gastric cancer cells and organoids. miR-135B promotes invasiveness and stem-cell features of gastric cancer cells in culture by reducing FOXN3 and RECK messenger RNAs. Levels of these messenger RNA targets, which encode tumor suppressor, are reduced in human gastric tumors.

Hypoxia and the Metastatic Niche

Metastasis is considered the latest stage of cancer development; however, metastasis occurs earlier than it can be detected. Metastatic sites are actively remodeled by secretory factors including growth factors, chemokines and cytokines, extracellular matrix (ECM) enzymes, and exosomes produced by the primary cancer tissues. Many of the associated-secretory factors are abundantly induced by inflammation and hypoxia. These secretory factors modify the ECM, immune composition, and blood vessel permeability of the future metastatic sites, a process termed 'metastatic niche formation.' In general, ECM is modified to enhance the attachment of other cell types or cancer cells to establish a growth-factor rich metastatic niche. Immune-suppressive cells such as tumor-associated macrophages (TAMs) and regulatory T cells (Tregs) dominate the metastatic niche to allow metastatic cancer cells to bypass immune surveillance and propagate. Endothelial cell-to-cell junctions of blood vessels are loosened to enhance the penetrance of metastatic cancer cells to the metastatic sites. Different metastatic tissues have unique ECM constituents, resident immune cells, and anatomical positions linked with the circulatory system; therefore, many cancer types have their own metastatic pattern, and they favor metastasis to specific organs. Some of the remodeling events represent the earliest step of metastasis, even preceding the detachment of cancer cells from the primary tumor site. Understanding how the metastatic niche is formed is important for the development of drugs to prevent the earliest step of metastasis and advance our understanding of organotrophic metastasis. This review summarizes the major findings in the field of metastatic niche highlighting the role of hypoxia.

Deletion of Stearoyl-CoA Desaturase-1 From the Intestinal Epithelium Promotes Inflammation and Tumorigenesis, Reversed by Dietary Oleate

BACKGROUND & AIMS

The enzyme stearoyl-coenzyme A desaturase 1 (SCD or SCD1) produces monounsaturated fatty acids by introducing double bonds into saturated bonds between carbons 9 and 10, with oleic acid as the main product. SCD1 is present in the intestinal epithelium, and fatty acids regulate cell proliferation, so we investigated the effects of SCD1-induced production of oleic acid in enterocytes in mice.

METHODS

We generated mice with disruption of Scd1 selectively in the intestinal epithelium (iScd1^-/- mice) on a C57BL/6 background; iScd1^+/+ mice were used as controls. We also generated iScd1^-/-Apc^Min/+ mice and studied cancer susceptibility. Mice were fed a chow, oleic acid-deficient, or oleic acid-rich diet. Intestinal tissues were collected and analyzed by histology, reverse transcription quantitative polymerase chain reaction, immunohistochemistry, and mass spectrometry, and tumors were quantified and measured.

RESULTS

Compared with control mice, the ileal mucosa of iScd1^-/- mice had a lower proportion of palmitoleic (C16:1 n-7) and oleic acids (C18:1 n-9), with accumulation of stearic acid (C18:0); this resulted a reduction of the Δ9 desaturation ratio between monounsaturated (C16:1 n-7 and C18:1 n-9) and saturated (C16:0 and C18:0) fatty acids. Ileal tissues from iScd1^-/- mice had increased expression of markers of inflammation activation and crypt proliferative genes compared with control mice. The iScd1^-/-Apc^Min/+ mice developed more and larger tumors than iScd1^+/+Apc^Min/+ mice. iScd1^-/-Apc^Min/+ mice fed the oleic acid-rich diet had reduced intestinal inflammation and significantly lower tumor burden compared with mice fed a chow diet.

CONCLUSIONS

In studies of mice, we found intestinal SCD1 to be required for synthesis of oleate in the enterocytes and maintenance of fatty acid homeostasis. Dietary supplementation with oleic acid reduces intestinal inflammation and tumor development in mice.

Incremental Elevations in TNFα and IL6 in the Human Colon and Procancerous Changes in the Mucosal Transcriptome Accompany Adiposity

BACKGROUND

Obesity, a risk factor for colorectal cancer, raises systemic levels of proinflammatory mediators. Whether increased levels also reside in the colons of obese individuals and are accompanied by procancerous alterations in the mucosal transcriptome is unknown.

METHODS

Concentrations of TNFα, IL1β, and IL6 in blood and colonic mucosa of 16 lean and 26 obese individuals were examined. Differences in the mucosal transcriptome between the two groups were defined.

RESULTS

Plasma IL6 and TNFα were 1.4- to 3-fold elevated in obese subjects [body mass index (BMI) ≥ 34 kg/m²] compared with the lean controls (P < 0.01). Among individuals with BMI ≥ 34 kg/m² colonic concentrations of IL6 and TNFα were 2- to 3-fold greater than in lean subjects (P < 0.03). In a general linear model, adjusted for NSAID use, colonic IL6 (partial r = 0.41; P < 0.01) and TNFα (partial r = 0.41; P = 0.01) increased incrementally over the entire range of BMIs (18.1-45.7). Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) was associated with a reduction in colonic IL6 (β = -0.65, P < 0.02). RNA sequencing (NSAID users excluded) identified 182 genes expressed differentially between lean and obese subjects. The two gene networks most strongly linked to changes in expression included several differentially expressed genes known to regulate the procarcinogenic signaling pathways, NFκB and ERK 1/2, in a pattern consistent with upregulation of each in the obese subjects.

CONCLUSIONS

Incremental increases in two major proinflammatory colonic cytokines are associated with increasing BMI, and in the obese state are accompanied by procancerous changes in the transcriptome.

IMPACT

These observations delineate means by which an inflammatory milieu may contribute to obesity-promoted colon cancer.