Dual functional roles of the MyD88 signaling in colorectal cancer development

Deletion of MyD88 in T Cells Improves Antitumor Activity in Melanoma

Cytotoxic CD8+ T cells are central to the antitumor immune response by releasing cytotoxic granules that kill tumor cells. They are activated by antigen-presenting cells, which become activated by DAMPs (damage associated molecular patterns) through MyD88. However, the suppressive tumor microenvironment promotes T-cell tolerance to tumor antigens, in part by enhancing the activity of immune checkpoint molecules that prevent CD8+ T-cell activation and cytotoxicity. MyD88 limits CD4+ T-cell activation during cardiac adaptation to stress. A similar mechanism is hypothesized to exist in CD8+ T cells that could be modulated to improve antitumor immunity. Herein, adoptive transfer of MyD88-/- CD8+ T cells in melanoma-bearing T-cell-deficient mice resulted in slower tumor growth, greater intratumoral T-cell accumulation, and higher melanoma cell death compared with transfer of wild-type CD8+ T cells. These findings were also observed in T-cell-specific MyD88-/- mice compared with wild-type littermates implanted with melanoma. Mechanistically, deletion of MyD88 enhanced CD8+ T-cell activation and survival, and T-cell receptor induced degranulation of cytotoxic molecules, overall improving the killing of melanoma cells. This enhanced cytotoxicity was retained in mice bearing tumors expressing the specific antigen for which cytotoxic T-cells were restricted. This study's results demonstrate a conserved mechanism for MyD88 in modulating CD8+ T-cell activation and represent a novel target in improving cancer immunotherapy.

MyD88 and Its Inhibitors in Cancer: Prospects and Challenges

The interplay between the immune system and cancer underscores the central role of immunotherapy in cancer treatment. In this context, the innate immune system plays a critical role in preventing tumor invasion. Myeloid differentiation factor 88 (MyD88) is crucial for innate immunity, and activation of MyD88 promotes the production of inflammatory cytokines and induces infiltration, polarization, and immune escape of immune cells in the tumor microenvironment. Additionally, abnormal MyD88 signaling induces tumor cell proliferation and metastasis, which are closely associated with poor prognosis. Therefore, MyD88 could serve as a novel tumor biomarker and is a promising target for cancer therapy. Current strategies targeting MyD88 including inhibition of signaling pathways and protein multimerization, have made substantial progress, especially in inflammatory diseases and chronic inflammation-induced cancers. However, the specific role of MyD88 in regulating tumor immunity and tumorigenic mechanisms remains unclear. Therefore, this review describes the involvement of MyD88 in tumor immune escape and disease therapy. In addition, classical and non-classical MyD88 inhibitors were collated to provide insights into potential cancer treatment strategies. Despite several challenges and complexities, targeting MyD88 is a promising avenue for improving cancer treatment and has the potential to revolutionize patient outcomes.

Exploring the role of sporadic BRAF and KRAS mutations during colorectal cancer pathogenesis: A spotlight on the contribution of the endosome-lysosome system

The highly heterogenous nature of colorectal cancer can significantly hinder its early and accurate diagnosis, eventually contributing to high mortality rates. The adenoma-carcinoma sequence and serrated polyp-carcinoma sequence are the two most common sequences in sporadic colorectal cancer. Genetic alterations in adenomatous polyposis coli (APC), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and tumour protein 53 (TP53) genes are critical in adenoma-carcinoma sequence, whereas v-Raf murine sarcoma viral oncogene homolog B (BRAF) and MutL Homolog1 (MLH1) are driving oncogenes in the serrated polyp-carcinoma sequence. Sporadic mutations in these genes contribute differently to colorectal cancer pathogenesis by introducing distinct alterations in several signalling pathways that rely on the endosome-lysosome system. Unsurprisingly, the endosome-lysosome system plays a pivotal role in the hallmarks of cancer and contributes to specialised colon function. Thus, the endosome-lysosome system might be distinctively influenced by different mutations and these alterations may contribute to the heterogenous nature of sporadic colorectal cancer. This review highlights potential connections between major sporadic colorectal cancer mutations and the diverse pathogenic mechanisms driven by the endosome-lysosome system in colorectal carcinogenesis.

Traversing through the Mechanistic Event Analysis in IL-6 and IL-17 Signaling for a New Therapeutic Paradigm in NSCLC

IL-6 and IL-17 are paradoxical cytokines that progress inflammatory states in chronic diseases, including cancer. In lung cancer, their role has been elucidated to favor cancer development by modulating signaling mechanisms critical to cellular growth. The intrinsic ability of these cytokines to influence macroautophagy is yet another reason to facilitate lung cancer. Here, we employed a systems immunology approach to discover the mechanistic role of these cytokines in cancer development. In a biological system, at later stages, the activation of NFkB stimulates immunosuppressive phenotypes to achieve tolerating effects in a transformed cell. We found that the upregulation of cytokines signaled M2 macrophages to modulate tumor responses through the activation of autophagic intermediates and inflammasome mediators. This caused immune perturbations in the tumor microenvironment, which were associated with cancer inflammation. To address these inflammatory states, we performed triggered event analysis to examine whether overexpressing immune effectors or downregulating immune suppressors may have an effect on cancer reversal. Interestingly, the inhibition of immune regulators opposed the model outcome to an increased immune response. Therefore, IL6-IL17-mediated regulation of lung cancer may address tumor malignancy and potentiate the development of newer therapeutics for NSCLC.

Blocking MyD88 signaling with MyD88 inhibitor prevents colitis-associated colorectal cancer development by maintaining colonic microbiota homeostasis

Certain intestinal microbiota alterations appear to positively correlate with tumorigenesis of CAC due to the disruption of the balance between the host and microorganisms. It is proven that blocking MyD88 signaling can prevent colitis-associated colorectal cancer (CAC) development in mice. We are aim to reveal the role of MyD88 signaling of maintaining colonic microbiota homeostasis for preventing CAC development. We here analyzed the landscape of gut microbiome in the mice model of AOM/DSS-induced CAC with MyD88 inhibitor treatment. PCoA revealed significant reduction in Lactobacillus load and increase in Escherichia load in the mucosal microbial composition of mice with CAC, compared with normal controls (NCs). Inhibitor-treatment led to almost undetectable Proteobacteria (Escherichia) and the retention of the dominance of Firmicutes and Bacteroidota (Muribaculaceae) in the mucosa. RNA sequencing analysis identified genes were up-regulated (Hp, SAA3 and IL-1F9) and down-regulated (CYP3A44, SLC30A10, GPNMB and OTC) in Inhibitor-treated mice (vs. CAC). Meanwhile, Inhibitor-treated mice had higher percentage of MUC2-positive area in colon sections (vs. CAC, which was less than NCs) by IF staining and decreased Escherichia in the mucus layer (vs. CAC) by FISH. And intestinal microbiota from mice with MyD88 inhibitor treatment could lessen the outcome of CAC by fecal microbiota transplantation. The development of CAC was involved in the increasing and ectopic Escherichia in the decreasing colonic mucus layer. MyD88 signaling blockade may maintain the host-microbiota homeostasis by up-regulating MUC2 production, increasing probiotics and their protective effects, and inhibiting the reproduction of Escherichia.

Toll-like receptor-guided therapeutic intervention of human cancers: molecular and immunological perspectives

Toll-like receptors (TLRs) serve as the body's first line of defense, recognizing both pathogen-expressed molecules and host-derived molecules released from damaged or dying cells. The wide distribution of different cell types, ranging from epithelial to immune cells, highlights the crucial roles of TLRs in linking innate and adaptive immunity. Upon stimulation, TLRs binding mediates the expression of several adapter proteins and downstream kinases, that lead to the induction of several other signaling molecules such as key pro-inflammatory mediators. Indeed, extraordinary progress in immunobiological research has suggested that TLRs could represent promising targets for the therapeutic intervention of inflammation-associated diseases, autoimmune diseases, microbial infections as well as human cancers. So far, for the prevention and possible treatment of inflammatory diseases, various TLR antagonists/inhibitors have shown to be efficacious at several stages from pre-clinical evaluation to clinical trials. Therefore, the fascinating role of TLRs in modulating the human immune responses at innate as well as adaptive levels directed the scientists to opt for these immune sensor proteins as suitable targets for developing chemotherapeutics and immunotherapeutics against cancer. Hitherto, several TLR-targeting small molecules (e.g., Pam3CSK4, Poly (I:C), Poly (A:U)), chemical compounds, phytocompounds (e.g., Curcumin), peptides, and antibodies have been found to confer protection against several types of cancers. However, administration of inappropriate doses of such TLR-modulating therapeutics or a wrong infusion administration is reported to induce detrimental outcomes. This review summarizes the current findings on the molecular and structural biology of TLRs and gives an overview of the potency and promises of TLR-directed therapeutic strategies against cancers by discussing the findings from established and pipeline discoveries.

Vancomycin Pretreatment on MPTP-Induced Parkinson's Disease Mice Exerts Neuroprotection by Suppressing Inflammation Both in Brain and Gut

A growing body of evidence implies that gut microbiota was involved in pathogenesis of Parkinson's disease (PD), but the mechanism is still unclear. The aim of this study is to investigate the effects of antibiotics pretreatment on the 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced PD mice. In this study, vancomycin pretreatment was given by gavage once daily with either vancomycin or distilled water for 14 days to mice, then mice were administered with MPTP (20 mg/kg, i.p) for four times in one day to establish an acute PD model. Results show that vancomycin pretreatment significantly improved motor dysfunction of mice in pole and traction tests. Although vancomycin pretreatment had no effect on dopamine (DA) or the process of DA synthesis, it inhibited the metabolism of DA by suppressing the expression of striatal monoamine oxidase B (MAO-B). Furthermore, vancomycin pretreatment reduced the number of astrocytes and microglial cells in the substantia nigra pars compacta (SNpc) to alleviate neuroinflammation, decreased the expression of TLR4/MyD88/NF-κB/TNF-α signaling pathway in both brain and gut. Meanwhile, vancomycin pretreatment changed gut microbiome composition and the levels of fecal short chain fatty acids (SCFAs). The abundance of Akkermansia and Blautia increased significantly after vancomycin pretreatment, which might be related to inflammation and inhibition of TLR4 signaling pathway. In summary, these results demonstrate that the variation of gut microbiota and its metabolites induced by vancomycin pretreatment might decrease dopamine metabolic rate and relieve inflammation in both gut and brain via the microbiota-gut-brain axis in MPTP-induced PD mice. The neuroprotection of vancomycin pretreatment on MPTP-induced Parkinson's disease mice The alterations of gut microbiota and SCFAs induced by vancomycin pretreatment might not only improve motor dysfunction, but also decrease dopamine metabolism and relieve inflammation in both brain and gut via TLR4/MyD88/NF-κB/TNF-α pathway in MPTP-induced PD mice.

Small-Molecule Modulators Targeting Toll-like Receptors for Potential Anticancer Therapeutics

Toll-like receptors (TLRs) are key components of the innate immune system and serve as a crucial link between innate and acquired immunity. In addition to immune function, TLRs are involved in other important pathological processes, including tumorigenesis. TLRs have dual regulatory effects on tumor immunity by activating nuclear factor κ-B signaling pathways, which induce tumor immune evasion or enhance the antitumor immune response. Therefore, TLRs have become a popular target for cancer prevention and treatment, and TLR agonists and antagonists offer considerable potential for drug development. The TLR7 agonist imiquimod (1) has been approved by the U.S. Food and Drug Administration as a treatment for malignant skin cancer. Herein, the structure, signaling pathways, and function of the TLR family are summarized, and the structure-activity relationships associated with TLR selective and multitarget modulators and their potential application in tumor therapy are systematically discussed.

Oral IRAK-4 Inhibitor CA-4948 Is Blood-Brain Barrier Penetrant and Has Single-Agent Activity against CNS Lymphoma and Melanoma Brain Metastases

PURPOSE

An ongoing challenge in cancer is the management of primary and metastatic brain malignancies. This is partly due to restrictions of the blood-brain barrier and their unique microenvironment. These challenges are most evident in cancers such as lymphoma and melanoma, which are typically responsive to treatment in systemic locations but resistant when established in the brain. We propose interleukin-1 receptor-associated kinase-4 (IRAK-4) as a potential target across these diseases and describe the activity and mechanism of oral IRAK-4 inhibitor CA-4948.

EXPERIMENTAL DESIGN

Human primary central nervous system lymphoma (PCNSL) and melanoma brain metastases (MBM) samples were analyzed for expression of IRAK-4 and downstream transcription pathways. We next determined the central nervous system (CNS) applicability of CA-4948 in naïve and tumor-bearing mice using models of PCNSL and MBM. The mechanistic effect on tumors and the tumor microenvironment was then analyzed.

RESULTS

Human PCNSL and MBM have high expression of IRAK-4, IRAK-1, and nuclear factor kappa B (NF-κB). This increase in inflammation results in reflexive inhibitory signaling. Similar profiles are observed in immunocompetent murine models. Treatment of tumor-bearing animals with CA-4948 results in the downregulation of mitogen-activated protein kinase (MAPK) signaling in addition to decreased NF-κB. These intracellular changes are associated with a survival advantage.

CONCLUSIONS

IRAK-4 is an attractive target in PCNSL and MBM. The inhibition of IRAK-4 with CA-4948 downregulates the expression of important transcription factors involved in tumor growth and proliferation. CA-4948 is currently being investigated in clinical trials for relapsed and refractory lymphoma and warrants further translation into PCNSL and MBM.

Targeting toll-like receptor 7/8 for immunotherapy: recent advances and prospectives

Toll-like receptors (TLRs) are a large family of proteins that are expressed in immune cells and various tumor cells. TLR7/8 are located in the intracellular endosomes, participate in tumor immune surveillance and play different roles in tumor growth. Activation of TLRs 7 and 8 triggers induction of a Th1 type innate immune response in the highly sophisticated process of innate immunity signaling with the recent research advances involving the small molecule activation of TLR 7 and 8. The wide range of expression and clinical significance of TLR7/TLR8 in different kinds of cancers have been extensively explored. TLR7/TLR8 can be used as novel diagnostic biomarkers, progression and prognostic indicators, and immunotherapeutic targets for various tumors. Although the mechanism of action of TLR7/8 in cancer immunotherapy is still incomplete, TLRs on T cells are involved in the regulation of T cell function and serve as co-stimulatory molecules and activate T cell immunity. TLR agonists can activate T cell-mediated antitumor responses with both innate and adaptive immune responses to improve tumor therapy. Recently, novel drugs of TLR7 or TLR8 agonists with different scaffolds have been developed. These agonists lead to the induction of certain cytokines and chemokines that can be applied to the treatment of some diseases and can be used as good adjutants for vaccines. Furthermore, TLR7/8 agonists as potential therapeutics for tumor-targeted immunotherapy have been developed. In this review, we summarize the recent advances in the development of immunotherapy strategies targeting TLR7/8 in patients with various cancers and chronic hepatitis B.

Network-Based Elaboration of the Efficacy of the Dachangshu (BL25) and Tianshu (ST25) Points in the Treatment of Functional Constipation in Children through Inflammation, Adipocytokine, or Leptin Pathways

Constipation commonly occurs during childhood, and more than 95% of cases are classified as functional constipation. If not effectively treated, 20% of patients with childhood constipation can continue to exhibit symptoms into adulthood, which seriously affects their mental health and quality of life. The main feature of acupuncture or acupoint stimulation, a special branch of traditional Chinese medicine, is the selection of different acupoints for different diseases, and many worthy guidelines have been established for matching acupoints. The back-shu and front-mu point combination adheres to an important acupoint compatibility law that has been used since its proposal 2,500 years ago but has not yet been verified by the modern evidence-based experiments. This study focused on the back-shu and front-mu point combination using the Dachangshu (BL25) and Tianshu (ST25) points as examples to explore possible research methods for network acupoint-based stimulation based on existing evidence and to elucidate the mechanisms induced by BL25 and ST25 in the treatment of functional constipation in children (FCC). The study found that BL25 and ST25 have 20 common targets, namely, AQP8, DRD2, VIP, TAC1, IL6R, TNF, FOS, KIT, CHAT, HTR3A, GAS8, SOD3, TRPV1, MPO, CALCA, IL1B, P2RX7, NPY2R, IL10RA, and TPH1, and these targets may provide a strategy for the combined usage of BL25 and ST25. In addition, BL25 and ST25 can affect FCC treatment through inflammation-relatedTh17-cell differentiation, the NF-kappa B signaling pathway, and the Toll-like receptor signaling pathway. Adipocytokines or leptin may also comprise the mechanism through which BL25 and ST25 regulate FCC. In addition, BL25 and ST25 regulate FCC through 13 core targets, namely, NFKBIA, RELA, TNF, IKBKB, IRAK1, TLR4, MYD88, TNFRSF1A, IL1R1, TLR2, IL1B, TRAF6, and TNFRSF1B. In short, this study provides new ideas and methods for studying the mechanism of acupuncture points.

Knockdown RBM15 Inhibits Colorectal Cancer Cell Proliferation and Metastasis Via N6-Methyladenosine (m6A) Modification of MyD88 mRNA

Colorectal cancer (CRC) is one of the most common cancers worldwide. In this study, we explored the role of RNA binding motif protein 15 (RBM15)-mediated MyD88 mRNA N6-methyladenosine (m6A) in CRC development. Cell proliferation, apoptosis, and invasion were detected by EdU, Annexin V-FITC/PI staining, and Transwell assays, respectively. RBM15 and MyD88 expression was detected by RT-qPCR and Western blot. RNA-seq, RIP-seq, and MeRIP-seq were used for RBM15 downstream target gene prediction and expression detection. In this research, we confirmed that RBM15 was highly expressed in CRC tissues and was negatively correlated with overall and disease-free survival rate. Silencing RBM15 significantly inhibited the proliferative and invasive abilities and promoted cell apoptosis in the CRC cell lines (SW480 and HCT116). Moreover, tumor growth and CRC liver metastasis were inhibited by silencing RBM15 in vivo. m6A methylation level was decreased in RBM15-silenced SW480 and HCT116 cells. MyD88 was the target mRNA of RBM15-mediated m6A methylation in CRC. MyD88 was lowly expressed in CRC and negatively correlated with RBM15 expression. Taken together, RBM15 silencing inhibited the CRC growth and metastasis in vitro and in vivo. RBM15 mediated m6A methylation modification of MyD88 mRNA in CRC cells.

Dysbiosis of human tumor microbiome and aberrant residence of Actinomyces in tumor-associated fibroblasts in young-onset colorectal cancer

Colorectal cancer (CRC) is the third most common form of cancer, and the incidence of sporadic young-onset colorectal cancer (yCRC) has been increasing. Microbiota residing in the tumor microenvironment are emerging tumor components. The colonic microbiome differs between patients with CRC and healthy controls; however, few studies have investigated the role of the tumor microbiota in disease diagnosis and tumorigenesis of yCRC. We performed 16S rRNA sequencing analysis to identify the microbiome in CRC and found that tumor microbial diversity decreased in yCRC. Proteobacteria and Firmicutes were the most abundant phyla in all CRC samples, and Actinomyces and Schaalia cardiffensis were the key microbiota in the yCRC group. Correlation analysis revealed that Actinomyces co-occurred with various pro-tumor microbial taxa, including Bacteroidia, Gammaproteobacteria, and Pseudomonas. An independent cohort was used to validate the results. The Actinomyces in CRC was co-localized with cancer-associated fibroblasts and activated the TLR2/NF-κB pathway and reduces CD8+ T lymphocyte infiltration in CRC microenvironment. This study suggests that tumoral microbiota plays an important role in promoting tumorigenesis and therefore has potential as a promising non-invasive tool and intervention target for anti-tumor therapy.

Toll-Like Receptor 3 in Cardiovascular Diseases

Toll-like receptor 3 (TLR3) is an important member of the innate immune response receptor toll-like receptors (TLRs) family, which plays a vital role in regulating immune response, promoting the maturation and differentiation of immune cells, and participating in the response of pro-inflammatory factors. TLR3 is activated by pathogen-associated molecular patterns and damage-associated molecular patterns, which support the pathophysiology of many diseases related to inflammation. An increasing number of studies have confirmed that TLR3, as a crucial medium of innate immunity, participates in the occurrence and development of cardiovascular diseases (CVDs) by regulating the transcription and translation of various cytokines, thus affecting the structure and physiological function of resident cells in the cardiovascular system, including vascular endothelial cells, vascular smooth muscle cells, cardiomyocytes, fibroblasts and macrophages. The dysfunction and structural damage of vascular endothelial cells and proliferation of vascular smooth muscle cells are the key factors in the occurrence of vascular diseases such as pulmonary arterial hypertension, atherosclerosis, myocardial hypertrophy, myocardial infarction, ischaemia/reperfusion injury, and heart failure. Meanwhile, cardiomyocytes, fibroblasts, and macrophages are involved in the development of CVDs. Therefore, the purpose of this review was to explore the latest research published on TLR3 in CVDs and discuss current understanding of potential mechanisms by which TLR3 contributes to CVDs. Even though TLR3 is a developing area, it has strong treatment potential as an immunomodulator and deserves further study for clinical translation.

Inflammation as a Key Outcome Pathway in Particle Induced Effects in the Lung

Inflammation is considered a key event in the pathology of many chronic diseases, including pulmonary and systemic particle induced effects. In addition, inflammation is now considered as the key response in standard setting for poorly-soluble low toxicity (PSLT) particles and also the critical endpoint to screen for in OECD based sub-chronic animal inhalation testing protocols. During Particles & Health 2021, an afternoon session was dedicated to the subject and a brief summary of the most important messages are summarized in this paper. In the first part of this session, two speakers (Prof. Lison and Dr Duffin) provided state of the art insight into different aspects and sequels to (persistent) inflammation as a protective or adverse response. Most recent insights on the role of different macrophage cell types were presented as well as perspectives and data provided by inflammatory pathways in humans, such as in asthma and COPD. A brief review of the expert workshop on PSLT particles focusing on the regulatory impact of using persistent inflammation as a key outcome was provided by Kevin Driscoll. The second part of the session focused on the outcomes that are associated with inflammation in animal studies, with an emphasis by Drs. Harkema (Michigan State) and Weber (Anapath) on cell proliferation and other pathologies that need to be considered when comparing human and animal responses, such as outcomes from 14- or 28 day inhalation studies used for specific target organ toxicity classification.

Immunomodulation by Gut Microbiome on Gastrointestinal Cancers: Focusing on Colorectal Cancer

Simple Summary

A symbiotic relationship with the host gut microbiome influences the immune system’s development, functions, and activities. In the mucosa, the gut microbiome mediates several immune activities such as the induction of naïve T-cells differentiation, production of cytokines, and myeloid cells activation. The gut-immune interaction and GI cancer development were investigated more recently. Understanding the interaction’s underlying mechanism provides insight to use them as potential anti-cancer targets. Even though multiple reports support the role of gut-immune interactions in targeting cancer-related pathways such as inflammation, apoptosis, and cellular proliferation, efforts are required to assess their interaction and impact on current treatment options.

Abstract

Gastrointestinal cancer (GI) is a global health disease with a huge burden on a patient’s physical and psychological aspects of life and on health care providers. It is associated with multiple disease related challenges which can alter the patient’s quality of life and well-being. GI cancer development is influenced by multiple factors such as diet, infection, environment, and genetics. Although activating immune pathways and components during cancer is critical for the host’s survival, cancerous cells can target those pathways to escape and survive. As the gut microbiome influences the development and function of the immune system, research is conducted to investigate the gut microbiome–immune interactions, the underlying mechanisms, and how they reduce the risk of GI cancer. This review addresses and summarizes the current knowledge on the major immune cells and gut microbiome interactions. Additionally, it highlights the underlying mechanisms of immune dysregulation caused by gut microbiota on four major cancerous pathways, inflammation, cellular proliferation, apoptosis, and metastasis. Overall, gut-immune interactions might be a key to understanding GI cancer development, but further research is needed for more detailed clarification.

Toll-Like Receptors Serve as Biomarkers for Early Diagnosis and Prognosis Assessment of Kidney Renal Clear Cell Carcinoma by Influencing the Immune Microenvironment: Comprehensive Bioinformatics Analysis Combined With Experimental Validation

Background: Toll-like receptors (TLRs) are important initiators of innate and acquired immune responses. However, its role in kidney renal clear cell carcinoma (KIRC) remains unclear.

Methods: TLRs and their relationships with KIRC were studied in detail by ONCOMINE, UALCAN, GEPIA, cBioPortal, GeneMANIA, FunRich, LinkedOmics, TIMER and TRRUST. Moreover, we used clinical samples to verify the expressions of TLR3 and TLR4 in early stage of KIRC by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), flow cytometry (FC) and immunohistochemistry (IHC).

Results: The expression levels of TLRs in KIRC were generally different compared with adjacent normal tissues. Moreover, the expressions of TLR3 and TLR4 elevated significantly in the early stage of KIRC. Overexpressions of TLR1, TLR3, TLR4 and TLR8 in KIRC patients were associated with longer overall survival (OS), while inhibition of TLR9 expression was related to longer OS. Additionally, overexpressions of TLR1, TLR3 and TLR4 in KIRC patients were associated with longer disease free survival (DFS). There were general genetic alterations and obvious co-expression correlation of TLRs in KIRC. The PPI network between TLRs was rather complex, and the key gene connecting the TLRs interaction was MYD88. The GO analysis and KEGG pathway analysis indicated that TLRs were closely related to adaptive immunity, innate immunity and other immune-related processes. RELA, NFKB1, IRF8, IRF3 and HIF1A were key transcription factors regulating the expressions of TLRs. What’s more, the expression levels of all TLRs in KIRC were positively correlated with the infiltration levels of dendritic cells, macrophages, neutrophils, B cells, CD4⁺ T cells and CD8⁺ T cells. Finally, the results of RT-qPCR, FC and IHC confirmed that TLR3 and TLR4 were significantly elevated in the early stage of KIRC.

Conclusion: The occurrence and development of KIRC are closely related to TLRs, and TLRs have the potential to be early diagnostic biomarkers of KIRC and biomarkers for judging the prognosis and immune status of KIRC. This study may provide new insights into the selection of KIRC immunotherapy targets.

MicroRNA-7-5p Inhibits Migration, Invasion and Metastasis of Intrahepatic Cholangiocarcinoma by Inhibiting MyD88

BACKGROUND AND AIMS

Intrahepatic cholangiocarcinoma (ICC) is a malignant tumor derived from intrahepatic bile duct epithelial cells. Accumulating studies report that microRNAs are widely involved in tumor migration and metastasis by regulation of target genes. miR-7-5p has been confirmed to inhibit tumor metastasis and to be related to prognosis for several malignant tumors. Our study investigated the underlying functions of miR-7-5p in ICC.

METHODS

The expression of miR-7-5p in ICC tissues but also in ICC cell lines was analyzed by real-time PCR. By analyzing the relationship between the clinicopathological parameters of 60 ICC patients and the expression level of miR-7-5p, the effect of miR-7-5p on the prognosis was clarified. After transfected with miR-7-5p mimics or miR-7-5p inhibitor, cell counting kit-8 assay was applied to evaluate the cells proliferation, flow cytometry was applied to analyze the cells apoptosis, wound healing assay and transwell chamber assay were applied to analyze the cell invasion and migration. A luciferase reporter assay was identified the relationship of miR-7-5p and myeloid differentiation factor 88 (MyD88). Western blotting was used to analyze the proteins expression. And immunochemistry was performed to determine the expression of MYD88 in ICC tissues.

RESULTS

Our data showed the expression of miR-7-5p was down-regulated not only in ICC tissues but also in ICC cell lines compared with normal controls. Low expression of miR-7-5p was notably associated with poor prognosis in ICC patients. miR-7-5p negatively regulated cell proliferation, migration, invasion and apoptosis in ICC cells. We further verified that MyD88 was a novel target of miR-7-5p and was significantly overexpressed in ICC tissues. Overexpression of MyD88 counteracted the effects of miR-7-5p in ICC cells.

CONCLUSIONS

The present findings suggest that miR-7-5p plays a pivotal role in ICC invasion by regulating MyD88. Ampliative insight into the key factors of ICC invasion may result in the development of new treatment options for ICC.

A Potential Role for Integrin-Linked Kinase in Colorectal Cancer Growth and Progression via Regulating Senescence and Immunity

Integrin-linked kinase (ILK) has been implicated as a molecular driver and mediator in both inflammation and tumorigenesis of the colon. ILK functions as an adaptor and mediator protein linking the extracellular matrix with downstream signaling pathways. ILK is broadly expressed in many human tissues and cells. It is also overexpressed in many cancers, including colorectal cancer (CRC). Inflammation, as evidenced by inflammatory bowel disease (IBD), is one of the highest risk factors for initiating CRC. This has led to the hypothesis that targeting ILK therapeutically could have potential in CRC, as it regulates different cellular processes associated with CRC development and progression as well as inflammation in the colon. A number of studies have indicated an ILK function in senescence, a cellular process that arrests the cell cycle while maintaining active metabolism and transcription. Senescent cells produce different secretions collectively known as the senescence-associated secretory phenotype (SASP). The SASP secretions influence infiltration of different immune cells, either positively for clearing senescent cells or negatively for promoting tumor growth, reflecting the dual role of senescence in cancer. However, a role for ILK in senescence and immunity in CRC remains to be determined. In this review, we discuss the possible role for ILK in senescence and immunity, paying particular attention to the relevance of ILK in CRC. We also examine how activating Toll-like receptors (TLRs) and their agonists in CRC could trigger immune responses against cancer, as a combination therapy with ILK inhibition.

Expression of Nutrient Transporters on NK Cells During Murine Cytomegalovirus Infection Is MyD88-Dependent

Natural killer (NK) cells are the predominant innate lymphocytes that provide early defense against infections. In the inflammatory milieu, NK cells modify their metabolism to support high energy demands required for their proliferation, activation, and functional plasticity. This metabolic reprogramming is usually accompanied by the upregulation of nutrient transporter expression on the cell surface, leading to increased nutrient uptake required for intense proliferation. The interleukin-1 family members of inflammatory cytokines are critical in activating NK cells during infection; however, their underlying mechanism in NK cell metabolism is not fully elucidated. Previously, we have shown that IL-18 upregulates the expression of solute carrier transmembrane proteins and thereby induces a robust metabolic boost in NK cells. Unexpectedly, we found that IL-18 signaling is dispensable during viral infection in vivo, while the upregulation of nutrient transporters is primarily MyD88-dependent. NK cells from Myd88-/- mice displayed significantly reduced surface expression of nutrient receptors and mTOR activity during MCMV infection. We also identified that IL-33, another cytokine employing MyD88 signaling, induces the expression of nutrient transporters but requires a pre-exposure to IL-12. Moreover, signaling through the NK cell activating receptor, Ly49H, can also promote the expression of nutrient transporters. Collectively, our findings revealed multiple pathways that can induce the expression of nutrient transporters on NK cells while highlighting the imperative role of MyD88 in NK cell metabolism during infection.

Three plasma-based microRNAs as potent diagnostic biomarkers for endometrial cancer

BACKGROUND

MicroRNAs (miRNAs), with noticeable stability and unique expression pattern in plasma of patients with various diseases, are powerful non-invasive biomarkers for cancer detection including endometrial cancer (EC).

OBJECTIVE

The objective of this study was to identify promising miRNA biomarkers in plasma to assist the clinical screening of EC.

METHODS

A total of 93 EC and 79 normal control (NC) plasma samples were analyzed using Quantitative Real-time Polymerase Chain Reaction (qRT-PCR) in this four-stage experiment. The receiver operating characteristic curve (ROC) analysis was conducted to evaluate the diagnostic value. Additionally, the expression features of the identified miRNAs were further explored in tissues and plasma exosomes samples.

RESULTS

The expression of miR-142-3p, miR-146a-5p, and miR-151a-5p was significantly overexpressed in the plasma of EC patients compared with NCs. Areas under the ROC curve of the 3-miRNA signature were 0.729, 0.751, and 0.789 for the training, testing, and external validation phases, respectively. The diagnostic performance of the identified signature proved to be stable in the three public datasets and superior to the other miRNA biomarkers in EC diagnosis. Moreover, the expression of miR-151a-5p was significantly elevated in EC plasma exosomes.

CONCLUSIONS

A signature consisting of 3 plasma miRNAs was identified and showed potential for the non-invasive diagnosis of EC.

Immunotherapy in Solid Tumors and Gut Microbiota: The Correlation-A Special Reference to Colorectal Cancer

Simple Summary

Immunotherapy and immune checkpoint inhibitors have become the breakthrough treatment with extended responses and survival rates in various neoplasms. They use the immune system to defeat cancer, while gut microbiota seems to play a significant role in that attempt. To date, colorectal cancer patients have gained little benefit from immunotherapy. Only mismatch repair-deficient/microsatellite-unstable tumors seem to respond positively to immunotherapy. However, gut microbiota could be the key to expanding the use of immunotherapy to a greater range of colorectal cancer patients. In the current review study, the authors aimed to present and analyze the mechanisms of action and resistance of immunotherapy and the types of immune checkpoint inhibitors (ICIs) as well as their correlation to gut microbiota. A special reference will be made in the association of immunotherapy and gut microbiota in the colorectal cancer setting.

Abstract

Over the last few years, immunotherapy has been considered as a key player in the treatment of solid tumors. Immune checkpoint inhibitors (ICIs) have become the breakthrough treatment, with prolonged responses and improved survival results. ICIs use the immune system to defeat cancer by breaking the axes that allow tumors to escape immune surveillance. Innate and adaptive immunity are involved in mechanisms against tumor growth. The gut microbiome and its role in such mechanisms is a relatively new study field. The presence of a high microbial variation in the gut seems to be remarkably important for the efficacy of immunotherapy, interfering with innate immunity. Metabolic and immunity pathways are related with specific gut microbiota composition. Various studies have explored the composition of gut microbiota in correlation with the effectiveness of immunotherapy. Colorectal cancer (CRC) patients have gained little benefit from immunotherapy until now. Only mismatch repair-deficient/microsatellite-unstable tumors seem to respond positively to immunotherapy. However, gut microbiota could be the key to expanding the use of immunotherapy to a greater range of CRC patients.

The suppressive role of miR-362-3p in epithelial ovarian cancer

Ovarian cancer is a common cancer worldwide. Epithelial ovarian cancer (EOC) is the most common subtype of ovarian cancer. This study was designed to explore the function of miR-362-3p in EOC. QRT-PCR analysis was used to test miR-362-3p levels in EOC tissues and cell lines. Cell viability was tested via MTT assay. Transwell systems were applied to assay cell migration. The target gene of miR-362-3p was evaluated using dual luciferase reporter assays. The MyD88 protein in EOC cells was tested via western blot. Our data showed that miR-362-3p was expressed at low levels in EOC tissues and cells. miR-362-3p inhibited cell proliferation and migration, bound the 3′-untranslated region (UTR) of MyD88, and inhibited MyD88 expression. MyD88 was inversely correlated with miR-362-3p in EOC, and MyD88 overexpression partly reduced the anti-proliferative effect of miR-362-3p in EOC cells. In conclusion, our data showed that miR-362-3p has an anti-proliferative effect on EOC.

Intestinal microbiota: a new force in cancer immunotherapy

Cancer displays high levels of heterogeneity and mutation potential, and curing cancer remains a challenge that clinicians and researchers are eager to overcome. In recent years, the emergence of cancer immunotherapy has brought hope to many patients with cancer. Cancer immunotherapy reactivates the immune function of immune cells by blocking immune checkpoints, thereby restoring the anti-tumor activity of immune cells. However, immune-related adverse events are a common complication of checkpoint blockade, which might be caused by the physiological role of checkpoint pathways in regulating adaptive immunity and preventing autoimmunity. In this context, the intestinal microbiota has shown great potential in the immunotherapy of cancer. The intestinal microbiota not only regulates the immune function of the body, but also optimizes the therapeutic effect of immune checkpoint inhibitors, thus reducing the occurrence of complications. Therefore, manipulating the intestinal microbiota is expected to enhance the effectiveness of immune checkpoint inhibitors and reduce adverse reactions, which will lead to new breakthroughs in immunotherapy and cancer management. Video abstract.

Intestinal Flora and Disease Mutually Shape the Regional Immune System in the Intestinal Tract

The intestinal tract is the largest digestive organ in the human body. It is colonized by, and consistently exposed to, a myriad of microorganisms, including bifidobacteria, lactobacillus, Escherichia coli, enterococcus, clostridium perfringens, and pseudomonas. To protect the body from potential pathogens, the intestinal tract has evolved regional immune characteristics. These characteristics are defined by its unique structure, function, and microenvironment, which differ drastically from those of the common central and peripheral immune organs. The intestinal microenvironment created by the intestinal flora and its products significantly affects the immune function of the region. In turn, specific diseases regulate and influence the composition of the intestinal flora. A constant interplay occurs between the intestinal flora and immune system. Further, the intestinal microenvironment can be reconstructed by probiotic use or microbiota transplantation, functioning to recalibrate the immune homeostasis, while also contributing to the treatment or amelioration of diseases. In this review, we summarize the relationship between the intestinal flora and the occurrence and development of diseases as an in-turn effect on intestinal immunity. We also discuss improved immune function as it relates to non-specific and specific immunity. Further, we discuss the proliferation, differentiation and secretion of immune cells, within the intestinal region following remodeling of the microenvironment as a means to ameliorate and treat diseases. Finally, we suggest strategies for improved utilization of intestinal flora.

Interactions between the MicroRNAs and Microbiota in Cancer Development: Roles and Therapeutic Opportunities

The human microbiota is made up of the fungi, bacteria, protozoa and viruses cohabiting within the human body. An altered microbiota can provoke diseases such as cancer. The mechanisms by which a modified microbiota can intervene in the onset and progression of neoplastic diseases are manifold. For instance, these include the effects on the immune system and the onset of obesity. A different mechanism seems to be constituted by the continuous and bidirectional relationships existing between microbiota and miRNAs. MiRNAs emerged as a novel group of small endogenous non-coding RNAs from that control gene expression. Several works seem to confirm the presence of a close connection between microbiota and miRNAs. Although the main literature data concern the correlations between microbiota, miRNAs and colon cancer, several researches have revealed the presence of connections with other types of tumour, including the ovarian tumour, cervical carcinoma, hepatic carcinoma, neoplastic pathologies of the central nervous system and the possible implication of the microbiota-miRNAs system on the response to the treatment of neoplastic pathologies. In this review, we summarise the physiological and pathological functions of the microbiota on cancer onset by governing miRNA production. A better knowledge of the bidirectional relationships existing between microbiota and miRNAs could provide new markers for the diagnosis, staging and monitoring of cancer and seems to be a promising approach for antagomir-guided approaches as therapeutic agents.

Expression and Significance of MyD88 in Patients With Gastric Cardia Cancer in a High-Incidence Area of China

Background: Gastric cardia cancer (GCC) arises in the area of the stomach adjoining the esophageal-gastric junction and has unique risk factors. It was suggested that the involvement of Helicobacter pylori is associated with GCC from high-risk population. Myeloid differentiation factor 88 (MyD88) is a crucial adaptor molecule in Toll-like signaling pathway recognizing H. pylori. Its role in GCC has not been elucidated yet. In this study, our purpose is to investigate the expression and significance of MyD88 in GCC tissue. Methods: Expression of MyD88 and nuclear factor κB (NF-κB) p105/p50 and infection of H. pylori were detected by immunohistochemistry in gastric cardia tissue. The correlation of MyD88 expression to NF-κB p105/p50 expression, H. pylori infection, and clinicopathologic characteristics in gastric cardia tissue was analyzed. The involvement of MyD88 in patient prognosis was also analyzed. Results: Our data showed that the expression of MyD88 elevated from normal mucosa to inflammation (p = 0.071). The expression of MyD88 was enhanced in GCC tissues by contrast to non-malignant cardia mucosa (p = 0.025). What's more, overexpression of MyD88 was detected in intestinal-type adenocarcinoma with inflammation. Patients with high MyD88 staining revealed a better differentiation (p = 0.02). MyD88 also positively correlated with NF-κB p105/p50 expression (p = 0.012) in cancer tissue. Expression of MyD88 was increased but not significantly in biopsies with H. pylori infection compared with non-infected biopsies. Multivariate analyses revealed lymph node metastasis but not MyD88 expression was an independent predictor for patient survival. Conclusion: These findings provide pathological evidence that upregulating MyD88 and inducing inflammation might be involved in gastric cardia carcinogenesis in high-risk population. MyD88 plays a role in gastric cardia carcinogenesis with NF-κB pathway activation. Higher MyD88 expression is not a major prognostic determinant in GCC, but it may relate to the tumor cell differentiation.

Research Progress of Mechanisms and Drug Therapy For Atherosclerosis on Toll-Like Receptor Pathway

Recent reports have established atherosclerosis (AS) as a major factor in the pathogenetic process of cardiovascular diseases such as ischemic stroke and coronary heart disease. Although the possible pathogenesis of AS remains to be elucidated, a large number of investigations strongly suggest that the inhibition of toll-like receptors (TLRs) alleviates the severity of AS to some extent by suppressing vascular inflammation and the formation of atherosclerotic plaques. As pattern recognition receptors, TLRs occupy a vital position in innate immunity, mediating various signaling pathways in infective and sterile inflammation. This review summarizes the available data on the research progress of AS and the latest antiatherosclerotic drugs associated with TLR pathway.

MyD88 mediates colorectal cancer cell proliferation, migration and invasion via NF‑κB/AP‑1 signaling pathway

The role of myeloid differentiation factor 88 (MyD88) in malignant tumors is largely unknown. Therefore, in this study, we aimed to examine the function and underlying mechanism of MyD88 in colorectal carcinoma in vitro using SW480 and HCT116 cell lines and in vivo using a nude mouse model. SW480 and HCT116 cells were infected with a lentiviral-based effective MyD88 siRNA virus. CCK-8 and colony formation assay were used to assess cell proliferation. Transwell and scratch assays were used to test the migration of colorectal cancer cells, and the Transwell assay was further used to analyze the invasiveness of colorectal cancer cells. Western blotting was performed to analyze the underlying mechanism of MyD88 regulation. In vitro experiments demonstrated that silencing MyD88 in SW480 and HCT116 cells markedly suppressed growth and invasion. Furthermore, MyD88 knockdown affected the MyD88-NF-κB/AP-1 signaling pathways in SW480 and HCT116 cells. In vivo, MyD88 knockdown inhibited tumor growth in a HCT116 cell subcutaneous nude model. We found that knockdown of the MyD88 gene can affect proliferation, invasion, and migration of colorectal cancer cells. We further verified that MyD88 knockdown can reduce the activity of NF-κB and AP-1 pathways. These results show that MyD88 gene plays an important role in promoting colorectal cancer, and thus can be exploited as a potential diagnostic and prognostic biomarker for colorectal cancer.

The Role of TLRs in Anti-cancer Immunity and Tumor Rejection

In recent years, a lot of scientific interest has focused on cancer immunotherapy. Although chronic inflammation has been described as one of the hallmarks of cancer, acute inflammation can actually trigger the immune system to fight diseases, including cancer. Toll-like receptor (TLR) ligands have long been used as adjuvants for traditional vaccines and it seems they may also play a role enhancing efficiency of tumor immunotherapy. The aim of this perspective is to discuss the effects of TLR stimulation in cancer, expression of various TLRs in different types of tumors, and finally the role of TLRs in anti-cancer immunity and tumor rejection.

Toll-like receptor-induced cytokines as immunotherapeutic targets in cancers and autoimmune diseases

Immune cells of the myeloid and lymphoid lineages express Toll-like receptors (TLRs) to recognize pathogenic components or cellular debris and activate the immune system through the secretion of cytokines. Cytokines are signaling molecules that are structurally and functionally distinct from one another, although their secretion profiles and signaling cascades often overlap. This situation gives rise to pleiotropic cell-to-cell communication pathways essential for protection from infections as well as cancers. Nonetheless, deregulated signaling can have detrimental effects on the host, in the form of inflammatory or autoimmune diseases. Because cytokines are associated with numerous autoimmune and cancerous conditions, therapeutic strategies to modulate these molecules or their biological responses have been immensely beneficial over the years. There are still challenges in the regulation of cytokine function in patients, even in those who take approved biological therapeutics. In this review, our purpose is to discuss the differential expression patterns of TLR-regulated cytokines and their cell type specificity that is associated with cancers and immune-system-related diseases. In addition, we highlight key structural features and molecular recognition of cytokines by receptors; these data have facilitated the development and approval of several biologics for the treatment of autoimmune diseases and cancers.

Low KISS1 expression predicts poor prognosis for patients with colorectal cancer: A meta-analysis

KISS1 and KISS1R, a novel pair of metastasis suppressors, are likely to be associated with the prognosis of colorectal cancer (CRC). Here, a meta-analysis was performed to study the role of KISS1 and KISS1R in CRC. Heterogeneity, stability and publication bias were all estimated. Six publications describing a total of 559 CRC patients were included in the present study. Low KISS1 expression predicted 70% higher risk of poor prognosis for general patients (HR, 1.71; 95% CI, 1.28-2.29) and 99% higher risk for East Asian patients (HR, 1.99; 95% CI, 1.46-2.72). Limited evidence indicated that decreased KISS1R expression might predict poor outcome (HR, 2.96; 95% CI, 1.51-5.82). Neither heterogeneity nor publication bias was identified. The current analyses suggest that low KISS1 expression predicts poor overall survival among East Asian patients with CRC. Evidence on other races and KISS1R are still insufficient, and additional studies are required to clarify the risk of CRC associated with KISS1R by race.

The Cancer Prevention, Anti-Inflammatory and Anti-Oxidation of Bioactive Phytochemicals Targeting the TLR4 Signaling Pathway

Toll-like receptors (TLRs) are a well-known family of pattern recognition receptors that play an important role in a host immune system. TLR triggering leads to the induction of pro-inflammatory cytokines and chemokines, driving the activation of both innate and adaptive immunity. Recently, an increasing number studies have shown the link between TLRs and cancer. Among them, the toll-like receptor 4 (TLR4) signaling pathway is associated with inflammatory response and cancer progression. Dietary phytochemicals are potential modulators of immunological status with various pharmacological properties including anti-cancer, anti-oxidant and anti-inflammatory. Curcumin, 6-gingerol, 6-shogaol, 1-dehydro-10-gingerdione, epigallocatechin gallate (EGCG), luteolin, quercetin, resveratrol, caffeic acid phenethyl ester, xanthohumol, genistein, berberine, and sulforaphane can inhibit TLR4 activation. The aim of the present review is to describe the role of the TLR4 signaling pathway between inflammatory response and cancer progression. We further introduce bioactive phytochemicals with potential anti-inflammation and chemoprevention by inhibiting TLR activation.