Role of NOD1/CARD4 and NOD2/CARD15 gene polymorphisms in cancer etiology

Role and molecular mechanism of NOD2 in chronic non-communicable diseases

Nucleotide-binding oligomerization domain containing 2 (NOD2), located in the cell cytoplasm, is a pattern recognition receptor belonging to the innate immune receptor family. It mediates the innate immune response by identifying conserved sequences in bacterial peptide glycans and plays an essential role in maintaining immune system homeostasis. Gene mutations of NOD2 lead to the development of autoimmune diseases such as Crohn's disease and Blau syndrome. Recently, NOD2 has been shown to be associated with the pathogenesis of diabetes, cardiac-cerebral diseases, and cancers. However, the function of NOD2 in these non-communicable diseases (CNCDs) is not well summarized in reviews. Our report mainly discusses the primary function and molecular mechanism of NOD2 as well as its potential clinical significance in CNCDs.

Membrane-associated RING-CH 7 inhibits stem-like capacities of bladder cancer cells by interacting with nucleotide-binding oligomerization domain containing 1

BACKGROUND

Cancer stem-like capacities are major factors contributing to unfavorable prognosis. However, the associated molecular mechanisms underlying cancer stem-like cells (CSCs) maintain remain unclear. This study aimed to investigate the role of the ubiquitin E3 ligase membrane-associated RING-CH 7 (MARCH7) in bladder cancer cell CSCs.

METHODS

Male BALB/c nude mice aged 4-5 weeks were utilized to generate bladder xenograft model. The expression levels of MARCHs were checked in online databases and our collected bladder tumors by quantitative real-time PCR (q-PCR) and immunohistochemistry (IHC). Next, we evaluated the stem-like capacities of bladder cancer cells with knockdown or overexpression of MARCH7 by assessing their spheroid-forming ability and spheroid size. Additionally, we conducted proliferation, colony formation, and transwell assays to validate the effects of MARCH7 on bladder cancer CSCs. The detailed molecular mechanism of MARCH7/NOD1 was validated by immunoprecipitation, dual luciferase, and in vitro ubiquitination assays. Co-immunoprecipitation experiments revealed that nucleotide-binding oligomerization domain-containing 1 (NOD1) is a substrate of MARCH7.

RESULTS

We found that MARCH7 interacts with NOD1, leading to the ubiquitin-proteasome degradation of NOD1. Furthermore, our data suggest that NOD1 significantly enhances stem-like capacities such as proliferation and invasion abilities. The overexpressed MARCH7 counteracts the effects of NOD1 on bladder cancer CSCs in both in vivo and in vitro models.

CONCLUSION

Our findings indicate that MARCH7 functions as a tumor suppressor and inhibits the stem-like capacities of bladder tumor cells by promoting the ubiquitin-proteasome degradation of NOD1. Targeting the MARCH7/NOD1 pathway could be a promising therapeutic strategy for bladder cancer patients.

Microbial ligand-independent regulation of lymphopoiesis by NOD1

Aberrant differentiation of progenitor cells in the hematopoietic system is known to severely impact host immune responsiveness. Here we demonstrate that NOD1, a cytosolic innate sensor of bacterial peptidoglycan, also functions in murine hematopoietic cells as a major regulator of both the generation and differentiation of lymphoid progenitors as well as peripheral T lymphocyte homeostasis. We further show that NOD1 mediates these functions by facilitating STAT5 signaling downstream of hematopoietic cytokines. In steady-state, loss of NOD1 resulted in a modest but significant decrease in numbers of mature T, B and natural killer cells. During systemic protozoan infection this defect was markedly enhanced, leading to host mortality. Lack of functional NOD1 also impaired T cell-dependent anti-tumor immunity while preventing colitis. These findings reveal that, in addition to its classical role as a bacterial ligand receptor, NOD1 plays an important function in regulating adaptive immunity through interaction with a major host cytokine signaling pathway.

Veillonella parvula promotes the proliferation of lung adenocarcinoma through the nucleotide oligomerization domain 2/cellular communication network factor 4/nuclear factor kappa B pathway

Enrichment of Veillonella parvula in the lung microbiota is strongly associated with non-small cell lung cancer (NSCLC) and induces the progression of lung adenocarcinoma in vivo, but its actual role and mechanism remain unexplored. This study analyzed the correlation between NSCLC and V. parvula abundance based on 16 s rRNA sequencing results. The effects of V. parvula on the progression of lung adenocarcinoma were observed in vivo and in vitro using a C57 bl/6j mouse tumor-bearing model, a bacterial cell co-culture model, combined with transcriptome sequencing, and a TCGA database to explore and validate the growth promotion of lung adenocarcinoma by V. parvula and its molecular mechanism. 16 s rRNA sequencing revealed that V. parvula was significantly enriched in lung adenocarcinoma. In vivo, V. parvula promoted the growth of lung adenocarcinoma in mice by suppressing the infiltration of tumor-associated T lymphocytes and peripheral T lymphocytes. It showed a higher affinity for lung adenocarcinoma in vitro and promoted lung adenocarcinoma cell proliferation through adhesion or intracellular invasion. Further analysis of differential gene expression and KEGG enrichment by transcriptome sequencing revealed that V. parvula induced CCN4 expression and activated NOD-like receptor and NF-κB signaling pathway in lung adenocarcinoma cells. Further analysis clarified that V. parvula promoted activation of the NF-κB pathway via Nod2/CCN4 signaling, which promoted lung adenocarcinoma cell proliferation. Thus, V. parvula mediates activation of the Nod2/CCN4/NF-κB signaling pathway to promote non-small cell lung adenocarcinoma progression, thereby providing a potential target for diagnosing and treating lung adenocarcinoma.

Clinical Disease States Related to Mutations of the NOD2 Gene: A Case Report and Literature Review

Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) is a protein encoded by the NOD2 gene and plays an important role in the immune system. NOD2 is an intracellular pattern recognition receptor (PRR) responsible for the recognition of pathogens as well as the activation of many biochemical processes within cells of the host immune system. Mutations of the NOD2 gene can significantly impact the host's immune response against a variety of pathogens. In addition to immunodeficiency, mutations of the NOD2 gene have also been linked with several atopic diseases and autoimmune conditions such as rheumatoid arthritis and Crohn's disease (CD). There is also a distinct set of autoinflammatory conditions that are now classified as NOD2-associated autoinflammatory diseases (NAID). We present a case of a 63-year-old female with common variable immunodeficiency, eosinophilic asthma, and rheumatoid arthritis who was found to have a NOD2 mutation on genetic testing. As genetic testing continues to gain popularity, several disease states that were previously thought to be unrelated are now being recognized as originating from a common genetic defect.

Association of NOD1 and NOD2 Polymorphisms With Susceptibility to Subacute Sclerosing Panencephalitis

Background: Subacute sclerosing panencephalitis is a progressive neurodegenerative disease that is a late complication of measles infection. However, to date, the pathogenesis of subacute sclerosing panencephalitis is still not explained; both viral and host factors seem to be associated. The present study aimed to investigate the relationship between NOD1 and NOD2 gene variants and subacute sclerosing panencephalitis. Methods: The gene variants of NOD1 (rs2075820 and rs2075818) and NOD2 (R334Q and R334W) were explored in 64 subacute sclerosing panencephalitis patients and 70 controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: The frequencies of the AA genotype and A allele of rs2075820 (NOD1; c.796G>A) polymorphism were lower in patients compared with controls (P = .022 and .014, respectively). The presence of the A allele of rs2075820 may be considered as a protective factor for subacute sclerosing panencephalitis. There was a significant difference between the groups in rs2075818 (NOD1 G/C) polymorphism, and the CC genotype increased the risk of subacute sclerosing panencephalitis by 3.471-fold. The carriers of the C allele of rs2075818 (G/C) had a 1.855-fold susceptibility to subacute sclerosing panencephalitis (P = .018). The GC genotype might be associated with subacute sclerosing panencephalitis susceptibility in the patients compared with patients without having that haplotype (P = .03). Conclusions: Thus, we identified an association between subacute sclerosing panencephalitis and the rs2075820 (NOD1 G/A) and rs2075818 (NOD1 G/C) polymorphisms. These findings implicate a possible effect of this genetic polymorphism in susceptibility to subacute sclerosing panencephalitis, which needs to be confirmed in bigger populations.

Regulation of Immune Homeostasis via Muramyl Peptides-Low Molecular Weight Bioregulators of Bacterial Origin

Metabolites and fragments of bacterial cells play an important role in the formation of immune homeostasis. Formed in the course of evolution, symbiotic relationships between microorganisms and a macroorganism are manifested, in particular, in the regulation of numerous physiological functions of the human body by the innate immunity receptors. Low molecular weight bioregulators of bacterial origin have recently attracted more and more attention as drugs in the prevention and composition of complex therapy for a wide range of diseases of bacterial and viral etiology. Signaling networks show cascades of causal relationships of deterministic phenomena that support the homeostasis of multicellular organisms at different levels. To create networks, data from numerous biomedical and clinical research databases were used to prepare expert systems for use in pharmacological and biomedical research with an emphasis on muramyl dipeptides. Muramyl peptides are the fragments of the cell wall of Gram-positive and Gram-negative bacteria. Binding of muramyl peptides with intracellular NOD2 receptors is crucial for an immune response on pathogens. Depending on the microenvironment and duration of action, muramyl peptides possess positive or negative regulation of inflammation. Other factors, such as genetic, pollutions, method of application and stress also contribute and should be taken into account. A system biology approach should be used in order to systemize all experimental data for rigorous analysis, with the aim of understanding intrinsic pathways of homeostasis, in order to define precise medicine therapy and drug design.

Context-dependent functions of pattern recognition receptors in cancer

The immune system plays a critical role in shaping all facets of cancer, from the early initiation stage through to metastatic disease and resistance to therapy. Our understanding of the importance of the adaptive arm of the immune system in antitumour immunity has led to the implementation of immunotherapy with immune checkpoint inhibitors in numerous cancers, albeit with differing efficacy. By contrast, the clinical utility of innate immunity in cancer has not been exploited, despite dysregulated innate immunity being a feature of at least one-third of all cancers associated with tumour-promoting chronic inflammation. The past two decades have seen innate immune pattern recognition receptors (PRRs) emerge as critical regulators of the immune response to microbial infection and host tissue damage. More recently, it has become apparent that in many cancer types, PRRs play a central role in modulating a vast array of tumour-inhibiting and tumour-promoting cellular responses both in immune cells within the tumour microenvironment and directly in cancer cells. Herein, we provide a comprehensive overview of the fast-evolving field of PRRs in cancer, and discuss the potential to target PRRs for drug development and biomarker discovery in a wide range of oncology settings.

Peptidoglycan-Like Components in Z-100, Extracted from Mycobacterium tuberculosis Strain Aoyama B, Increase IL-12p40 via NOD2

Background. Z-100 is a hot-water extract of the human-type Mycobacterium tuberculosis strain Aoyama B. While Z-100’s macrophage-mediated immunomodulatory effects have been reported, the mechanistic details have not been fully clarified. Here, we studied the immunomodulatory effects of Z-100 on mouse bone marrow-derived cells, human CD14+ cells, and skin. Methods. Mouse bone marrow-derived cells and CD14+ cells were cultured in the presence of granulocyte-macrophage colony-stimulating factor, differentiated into macrophage-like cells, and then stimulated with Z-100. Furthermore, since Z-100 is subcutaneously administered clinically, we injected Z-100 into mice and measured gene expression in the skin. Results. While Z-100 stimulation increased the production of interleukin- (IL-) 12p40 and IL-1β in mouse bone marrow-derived macrophages, levels of IL-1β were low. In contrast, TNF-α production did not increase. Meanwhile, stimulation of human CD14+ cells with Z-100 increased production of IL-12p40, TNF-α, and IL-1β. Because Z-100 appeared to have the most stable effect on IL-12p40, we examined the components of Z-100 that induce IL-12p40 production. We found that Z-100 contained peptidoglycan-like components. In addition, an siRNA study showed that Z-100 increased the production of IL-12p40 via nucleotide-binding oligomerization domain 2 (NOD2). Further, subcutaneous administration of Z-100 to mice significantly elevated expression of IL-12p40 and IL-1β and showed a trend towards increasing TNF-α in the skin. Conclusion. Z-100 induced the production of immunomodulatory cytokines from various types of macrophages and specifically increased IL-12p40 production through peptidoglycan-like components via NOD2.

Bladder cancer survival in patients with NOD2 or CDKN2A variants

Purpose: The association between the NOD2 c.3020insC allele and CDKN2A missense variant c.442G>A (p.P.A148T) and survival of patients with bladder or kidney cancer remains controversial.

Materials and Methods: We compared the allele frequencies of NOD2 c.3020insC and CDKN2A p.A148T allele in 706 patients with bladder cancer, 410 cases with kidney cancer against two control groups. The Cox proportional hazards model was used to determine whether there were any survival differences between carriers of the NOD2 c.3020insC or the CDKN2A p.A148T variant.

Results: Among the three patient subgroups: patients under 60 years of age, non-smokers and a third with histological features of low grade noninvasive papillary bladder cancer, we observed that the c.3020insC allele had a nominal statistically significant effect on survival. We also observed that the NOD2 c.3020insC variant was more frequent in patients with bladder cancer aged between 51 and 60 years.

There was some nominal evidence that the CDKN2A p.A148T polymorphism reduced survival in the subgroup of bladder cancer patients under 60 years of age. We observed that in kidney cancer patients, the incidence of the NOD2 variant appeared to be lower in the group aged between 60 and 70 years, however, this was not statistically significant. In addition, in patients with histological features of grade III chromophobic kidney cancer, the c.3020insC allele also appeared to be over-represented but this too was not statistically significant.

Conclusion: We have shown that the NOD2 c.3020insC allele and the CDKN2A p.A148T polymorphism does not play a role in the survival of patients with bladder cancer.

Polymorphisms in autophagy genes are genetic susceptibility factors in glioblastoma development

Background

Glioblastoma is the most aggressive and common malignant primary brain tumor in adults. Many genetic, epigenetic and genomic mutations have been identified in this tumor, but no driving cause has been identified yet for glioblastoma pathogenesis. Autophagy has proved to be deregulated in different diseases such as cancer where it has a dual role, acting as a tumor suppression mechanism during the first steps of tumor development and promoting cancer cells survival in stablished tumors.

Methods

Here, we aimed to assess the potential association between several candidate polymorphisms in autophagy genes (ATG2B rs3759601, ATG16L1 rs2241880, ATG10 rs1864183, ATG5 rs2245214, NOD2 rs2066844 and rs2066845) and glioblastoma susceptibility.

Results

Our results showed a significant correlation between ATG2B rs3759601, ATG10 rs1864183 and NOD2 rs2066844 variants and higher risk to suffer glioblastoma. In addition, the relationship between the different clinical features listed in glioblastoma patients and candidate gene polymorphisms was also investigated, finding that ATG10 rs1864183 might be a promising prognosis factor for this tumor.

Conclusions

This is the first report evaluating the role of different variants in autophagy genes in modulating glioblastoma risk and our results emphasize the importance of autophagy in glioblastoma development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09214-y.

Therapeutic Interventions Targeting Innate Immune Receptors: A Balancing Act

The innate immune system is an organism's first line of defense against an onslaught of internal and external threats. The downstream adaptive immune system has been a popular target for therapeutic intervention, while there is a relative paucity of therapeutics targeting the innate immune system. However, the innate immune system plays a critical role in many human diseases, such as microbial infection, cancer, and autoimmunity, highlighting the need for ongoing therapeutic research. In this review, we discuss the major innate immune pathways and detail the molecular strategies underpinning successful therapeutics targeting each pathway as well as previous and ongoing efforts. We will also discuss any recent discoveries that could inform the development of novel therapeutic strategies. As our understanding of the innate immune system continues to develop, we envision that therapies harnessing the power of the innate immune system will become the mainstay of treatment for a wide variety of human diseases.

Salmonella enterica subsp. enterica host-pathogen interactions and their implications in gallbladder cancer

BACKGROUND

Several studies have linked chronic typhoid infection with gallbladder carcinoma without completely understood mechanism. This study was performed in order to understand role of Salmonella in gallbladder cancer etiology.

METHODS

Known Salmonella host-pathogen interactions were screened from database in addition to known gallbladder carcinoma targets. Host-pathogen interaction map of S. enterica was prepared and screened for interactions with gallbladder carcinoma targets. Further functional overrepresentation analysis was performed to understand the role of human targets involved in Salmonella host-pathogen interactions in gallbladder carcinoma.

RESULTS

Salmonella interact with several human proteins involved in gallbladder carcinoma. MAPK and RAC1 are the most important human proteins based on node degree value among all GBC associated interactors identified in current data search. Functional over-representation analysis reveals that Salmonella can induce adenocarcinoma which constitutes 85% of gallbladder cancer.

CONCLUSION

Though, the role of MAPK/ERK and PI3K/AKT/mTOR pathway is already suggested for Salmonella mediated gallbladder cancer, but current data based approach indicate several new insight for exploration of the role of Salmonella in gallbladder cancer etiology. The results indicate about several other processes including CREB/SP-1 and BSG(CD147) signaling, that must be given consideration for understanding the role of Salmonella in gallbladder cancer.

Cell death as part of innate immunity: Cause or consequence?

Regulated or programmed cell death plays a critical role in the development and tissue organization and function. In addition, it is intrinsically connected with immunity and host defence. An increasing cellular and molecular findings cause a change in the concept of cell death, revealing an expanding network of regulated cell death modalities and their biochemical programmes. Likewise, recent evidences demonstrate the interconnection between cell death pathways and how they are involved in different immune mechanisms. This work provides an overview of the main cell death programmes and their implication in innate immunity not only as an immunogenic/inflammatory process, but also as an active defence strategy during immune response and at the same time as a regulatory mechanism.

Seven-gene signature on tumor microenvironment for predicting the prognosis of patients with pancreatic cancer

Background

The aim of the present study was to construct a novel gene signature on the tumor microenvironment (TME) to predict the prognosis of patients with pancreatic ductal adenocarcinoma (PDAC).

Methods

We downloaded gene expression profiles and clinical information of PDAC from The Cancer Genome Atlas (TCGA) datasets, as well as Gene Expression Omnibus (GEO) datasets (GSE78229, GSE62452, and GSE28735). Differentially expressed genes were generated by comparing high versus low score groups of immune/stromal subgroups based on the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data algorithm. Subsequently, a prognostic risk score model was constructed and validated through univariate and multivariate Cox regression analyses. Finally, functional enrichment analysis and protein-protein interactions were performed to predict the functional implication of the prognostic model.

Results

We picked out 1,797 upregulated genes in immune groups and stromal groups. Through further analysis, we constructed a 7-gene signature on the TME. The risk score from the model effectively differentiated patients into high-risk and low-risk groups with different overall survival and was validated by GEO datasets. A functional analysis suggested that 7 selected genes and their co-expressed genes were mainly enriched in immune response, extracellular structure organization, and cell adhesion molecule binding.

Conclusions

Our results showed that the 7-gene model on the TME can be used to assess the prognosis of patients with PDAC.

Recognition of DAP and activation of NF-κB by cytosolic sensor NOD1 in Oreochromis niloticus

As a lower vertebrate, the immune defense mechanism of fish mainly depends on the innate immune system. Nucleotide-binding oligomerization domain-like receptors (NLRs) are an important class of pattern recognition receptors in the innate immune system. In this study, NOD1 gene was cloned and characterized in Nile tilapia (Oreochromis niloticus). The ORF of Nile tilapia NOD1 gene was 2826 bp long and encoded 941 amino acid residues with a structure of CARD-NACHT-LRRs that was similar to the other counterparts in mammals and fishes. Phylogenetic and synteny analysis showed that NOD1 was conserved among different fishes and existed at least in the early stage of fish evolution. Expression pattern revealed that NOD1 mRNA was constitutively expressed in the tested tissues, while had high expression level in main immune organs and mucosal immune tissues (liver, head kidney, spleen, blood, gill, and intestine). Following Streptococcus agalactiae challenge, Nile tilapia NOD1 mRNA expression levels were altered in immune organs (liver, head kidney, spleen, blood), and the expression pattern was similar in liver, spleen and blood. Furthermore, the ligand recognition and signaling pathway of Nile tilapia NOD1 were also analyzed, it showed that NOD1 could recognize Tri-DAP intracellularly and activated NF-κB signaling pathway. In summary, our results indicated that the Nile tilapia NOD1 may play an important role in innate immune system and provided a basis for the functional study of NOD1 in teleost.

Emerging Autophagy Functions Shape the Tumor Microenvironment and Play a Role in Cancer Progression - Implications for Cancer Therapy

The tumor microenvironment (TME) is a complex environment where cancer cells reside and interact with different types of cells, secreted factors, and the extracellular matrix. Additionally, TME is shaped by several processes, such as autophagy. Autophagy has emerged as a conserved intracellular degradation pathway for clearance of damaged organelles or aberrant proteins. With its central role, autophagy maintains the cellular homeostasis and orchestrates stress responses, playing opposite roles in tumorigenesis. During tumor development, autophagy also mediates autophagy-independent functions associated with several hallmarks of cancer, and therefore exerting several effects on tumor suppression and/or tumor promotion mechanisms. Beyond the concept of degradation, new different forms of autophagy have been described as modulators of cancer progression, such as secretory autophagy enabling intercellular communication in the TME by cargo release. In this context, the synthesis of senescence-associated secretory proteins by autophagy lead to a senescent phenotype. Besides disturbing tumor treatment responses, autophagy also participates in innate and adaptive immune signaling. Furthermore, recent studies have indicated intricate crosstalk between autophagy and the epithelial-mesenchymal transition (EMT), by which cancer cells obtain an invasive phenotype and metastatic potential. Thus, autophagy in the cancer context is far broader and complex than just a cell energy sensing mechanism. In this scenario, we will discuss the key roles of autophagy in the TME and surrounding cells, contributing to cancer development and progression/EMT. Finally, the potential intervention in autophagy processes as a strategy for cancer therapy will be addressed.

Molecular Association of Medulloblastoma and Sarcoidosis: Case Report and Review of the Literature

BACKGROUND

Medulloblastoma (MB) is a malignant tumor of the central nervous system (CNS), and sarcoidosis is a chronic inflammatory disease of many organ systems, commonly affecting the lungs. No association between MB and sarcoidosis was described in the literature. MB and sarcoidosis have mutual molecular and signaling pathways that may predispose patients with sarcoidosis to develop MB. We describe a patient with sarcoidosis who developed MB.

CASE DESCRIPTION

The patient is a 36-year-old diagnosed with pulmonary sarcoidosis presented with ataxia, bilateral horizontal nystagmus, diplopia, and bilateral upper limb dysmetria was found to have a cerebellar mass on magnetic resonance imaging (MRI). He was initially treated with corticosteroids as a case of neurosarcoidosis. The patient's symptoms worsened, and repeat MRI showed an increase in the tumor size with hydrocephalus. External ventricular drain insertion plus midline suboccipital craniotomy and resection of the tumor was performed. Pathology revealed MB classic type, sonic hedgehog-activated. There was no cerebrospinal fluid dissemination. He received craniospinal radiation and chemotherapy. Follow-up 20 months after radiation revealed residual neurologic symptoms and no recurrence on MRI brain.

CONCLUSIONS

The exceedingly rare coexistence of adult MB and sarcoidosis may have a causal relationship based on specific common molecules. Leukotrienes, stimulation of astrocytes and Purkinje neurons, and the sonic hedgehog signaling pathway can be considered. Further genetic and molecular studies are merited.

Genetic variation in NOD1/CARD4 and NOD2/CARD15 immune sensors and risk of osteoporosis

The present study was aimed to investigate the relationship between NOD1/CARD4 and NOD2/CARD15 gene polymorphisms and osteoporosis in the Turkish population. The first time we thought that the functional polymorphisms in NOD1/CARD4 and NOD2/CARD15 genes might have triggered the development of osteoporosis. The objective of our study was to determine the relationship between NOD1/CARD4 and NOD2/CARD15 SNPs and osteoporosis. The NOD1/CARD4 (rs5743336) and NOD2/CARD15 (rs2066847) SNPs were analyzed by PCR restriction fragment length polymorphism (PCR-RFLP) in 94 healthy controls and 164 subjects with osteoporosis. PCR products were digested with restriction enzymes AvaI for NOD1/CARD4 and ApaI for NOD2/CARD15. We found that NOD1/CARD4 genotype distribution of AA, GA and GG were 15, 44 and 41% for patients and 17, 46 and 37% for controls, respectively. NOD2/CARD15 mutation was found only in three patients (1.8%) as heterozygote. The results did not show any statistical difference between NOD1/CARD4 and NOD2/CARD15 genotype distribution of patients and healthy groups (χ² = 1.740, P=0.187; χ² = 1.311, P=0.519). However, the most frequent AG genotype (46%) of NOD1/CARD4 was observed in healthy controls, GG genotype (44%) of NOD1/CARD4 was observed as the most frequent in osteoporotic patients. NOD2/CARD15 WT/WT genotype, the most frequent genotype, was observed in both groups. Statistical analysis revealed that NOD1/CARD4 and NOD2/CARD15 polymorphisms are not associated with osteoporosis. However, a definite judgement is difficult to be made due to restricted number of patients and small size of control group. Further research is sorely warranted in this direction.

NOD2 inhibits tumorigenesis and increases chemosensitivity of hepatocellular carcinoma by targeting AMPK pathway

Nucleotide binding oligomerization domain 2 (NOD2) is a recognized innate immune sensor which can initiate potent immune response against pathogens. Many innate immune sensors have been reported to be of great importance in carcinogenesis. However, the role of NOD2 in cancer is not well understood. Here we investigated the role of NOD2 in the development of hepatocellular carcinoma (HCC). We demonstrated that NOD2 deficiency promoted hepatocarcinogenesis in N-nitrosodiethylamine (DEN)/carbon tetrachloride (CCl₄) induced HCC mice model and xenograft tumor model. In vitro investigation showed that NOD2 acted as a tumor suppressor and inhibited proliferation, colony formation and invasion of HCC cells. Clinical investigation showed that NOD2 expression was completely lost or significantly downregulated in clinical HCC tissues, and loss of NOD2 expression was significantly correlated with advanced disease stages. Further investigation showed that NOD2 exerted its anti-tumor effect through activating adenosine 5'-monophosphate (AMP) -activated protein kinase (AMPK) signaling pathway, and NOD2 significantly enhanced the sensitivity of HCC cells to sorafenib, lenvatinib and 5-FU treatment through activating AMPK pathway induced apoptosis. Moreover, we demonstrated that NOD2 activated AMPK pathway by directly binding with AMPKα-LKB1 complex, which led to autophagy-mediated apoptosis of HCC cells. Altogether, this study showed that NOD2 acted as a tumor suppressor as well as a chemotherapeutic regulator in HCC cells by directly activating AMPK pathway, which indicated a potential therapeutic strategy for HCC treatment by upregulating NOD2-AMPK signaling axis.

NOD1 inhibits proliferation and enhances response to chemotherapy via suppressing SRC-MAPK pathway in hepatocellular carcinoma

NOD1 is an innate immune sensor playing an important role in fighting against infection. However, its role in cancer is far from being clarified, and whether NOD1 plays a role in the progression of hepatocellular carcinoma (HCC) has never been reported. Here, we found that NOD1 expression was significantly decreased in hepatocellular carcinoma tissues and overexpression of NOD1 significantly inhibited tumorigenesis in vivo. In vitro experiments demonstrated that NOD1 inhibited proliferation of HCC cells by directly targeting proto-oncogene SRC and inducing cell cycle arrest at G1 phase. Further investigation showed that NOD1 exerted its antitumor effect by inhibiting SRC activation and further suppressing SRC/MAPK axis in hepatocellular carcinoma cells. Moreover, NOD1 dramatically enhanced the response of HCC cells to chemotherapy via inhibition of SRC-MAPK axis both in vitro and in vivo. Collectively, these data indicated that NOD1 suppressed proliferation and enhanced response to sorafenib or 5-FU treatment through inhibiting SRC-MAPK axis in hepatocellular carcinoma. KEY MESSAGES: NOD1 significantly inhibited tumorigenesis of HCC in cellular and animal models. NOD1 inhibited proliferation of HCC cells by inducing cell cycle arrest. NOD1 exerted its antitumor effect on HCC by directly interacting with SRC and inhibiting SRC-MAPK axis. NOD1 significantly enhanced the chemosensitivity of HCC cells to chemotherapeutic drugs.

Emerging Roles for NLRC5 in Immune Diseases

Innate immunity activates the corresponding immune response relying on multiple pattern recognition receptors (PRRs) that includes pattern recognition receptors (PRRs), like NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and C-type lectin receptors (CLRs), which could accurately recognize invasive pathogens. In particular, NLRs belong to a large protein family of pattern recognition receptors in the cytoplasm, where they are highly correlated with activation of inflammatory response system followed by rapid clearance of invasive pathogens. Among the NLRs family, NLRC5, also known as NOD4 or NOD27, accounts for a large proportion and involves in immune responses far and wide. Notably, in the above response case of inflammation, the expression of NLRC5 remarkably increased in immune cells and immune-related tissues. However, the evidence for higher expression of NLRC5 in immune disease still remains controversial. It is noted that the growing evidence further accounts for the participation of NLRC5 in the innate immune response and inflammatory diseases. Moreover, NLRC5 has also been confirmed to exert a critical role in the control of regulatory diverse signaling pathways. Together with its broad participation in the occurrence and development of immune diseases, NLRC5 can be consequently treated as a potential therapeutic target. Nevertheless, the paucity of absolute understanding of intrinsic characteristics and underlying mechanisms of NLRC5 still make it hard to develop targeting drugs. Therefore, current summary about NLRC5 information is indispensable. Herein, current knowledge of NLRC5 is summarized, and research advances in terms of NLRC5 in characteristics, biological function, and regulatory mechanisms are reviewed.

NOD-like receptor signaling in inflammation-associated cancers: From functions to targeted therapies

BACKGROUND

Recently, many studies have reported that some botanicals and natural products were able to regulate NOD-like receptor signaling. NOD-like receptors (NLRs) have been established as crucial regulators in inflammation-associated tumorigenesis, angiogenesis, cancer cell stemness and chemoresistance. NLRs specifically sense pathogen-associated molecular patterns and respond by activating other signaling regulators, including Rip2 kinase, NF-κB, MAPK and ASC/caspase-1, leading to the secretion of various cytokines.

PURPOSE

The aim of this article is to review the molecular mechanisms of NOD-like receptor signaling in inflammation-associated cancers and the NLRs-targeted botanicals and synthetic small molecules in cancer intervention.

RESULTS

Aberrant activation of NLRs occurs in various cancers, orchestrating the tissue microenvironment and potentiating neoplastic risk. Blocking NLR inflammasome activation by botanicals or synthetic small molecules may be a valuable way to prevent cancer progression. Moreover, due to the roles of NLRs in regulating cytokine production, NLR signaling may be correlated with senescence-associated secretory phenotype.

CONCLUSION

In this review, we discuss how NLR signaling is involved in inflammation-associated cancers, and highlight the NLR-targeted botanicals and synthetic small molecules in cancer intervention.

NOD-like receptors: major players (and targets) in the interface between innate immunity and cancer

Innate immunity comprises several inflammation-related modulatory pathways which receive signals from an array of membrane-bound and cytoplasmic pattern recognition receptors (PRRs). The NLRs (NACHT (NAIP (neuronal apoptosis inhibitor protein), C2TA (MHC class 2 transcription activator), HET-E (incompatibility locus protein from Podospora anserina) and TP1 (telomerase-associated protein) and Leucine-Rich Repeat (LRR) domain containing proteins) relate to a large family of cytosolic innate receptors, involved in detection of intracellular pathogens and endogenous byproducts of tissue injury. These receptors may recognize pathogen-associated molecular patterns (PAMPs) and/or danger-associated molecular patterns (DAMPs), activating host responses against pathogen infection and cellular stress. NLR-driven downstream signals trigger a number of signaling circuitries, which may either initiate the formation of inflammasomes and/or activate nuclear factor κB (NF-κB), stress kinases, interferon response factors (IRFs), inflammatory caspases and autophagy. Disruption of those signals may lead to a number of pro-inflammatory conditions, eventually promoting the onset of human malignancies. In this review, we describe the structures and functions of the most well-defined NLR proteins and highlight their association and biological impact on a diverse number of cancers.

Expression of Nod-like Receptors and Clinical Correlations in Patients With Dry Eye Disease

PURPOSE

To investigate the expression pattern of nucleotide-binding oligomerization domain (Nod)-like receptors that detects "danger" intracellular signaling and its correlation with clinical dry eye (DE) markers.

DESIGN

Cross-sectional study.

METHODS

A total of 50 participants with 50 eyes were included: 23 eyes with Sjögren syndrome (SS)-DE, 14 eyes with non-SS-DE, and 13 healthy controls with non-DE. Ocular Surface Disease Index (OSDI) was self-answered and clinical tests including the tear film breakup time (TBUT), Schirmer test, and corneal fluorescein staining (CFS) were performed. Specimens for expression pattern analysis were obtained by conjunctival impression cytology and biopsy. Nod-1, inhibitor kappa B kinase-alpha (IκKα), and nuclear factor kappa B (NF-κB) expression was determined by reverse transcription quantitative real-time polymerase chain reaction and Western blot. Correlations between Nod-1 and ocular surface parameters were determined.

RESULTS

Patients with SS-DE had significantly higher OSDI and CFS scores and lower TBUT and Schirmer test scores than those with non-SS-DE patients (all P < .05). Compared with the control group, both the SS-DE and non-SS-DE groups showed significant upregulation in mRNA expression levels of Nod-1 (relative 3.48-fold and 1.72-fold upregulation, respectively, P < .01), IκKα (relative 1.83-fold and 1.24-fold upregulation, respectively, P < .01), and NF-κB (relative 1.84-fold and 1.32-fold upregulation, respectively, P < .01). Western blot analysis showed that Nod-1 protein expression increased in both the SS-DE and non-SS-DE groups (relative 2.71-fold and 1.64-fold upregulation, respectively, P < .05) compared with that in the control group. Similar findings were observed for IκKα and NF-κB. In DE participants, the expression of Nod-1 significantly correlated with the OSDI (R² = 0.61, r = 0.78, P < .01), Schirmer test score (R² = 0.44, r = -0.66, P < .01), and CFS (R² = 0.46, r = 0.68, P < .01) but did not significantly correlate with TBUT (R² < 0.01, r = 0.08, P = .66).

CONCLUSIONS

Nod-1 expression was increased in the conjunctiva of DE, especially SS-DE, and was associated with disease severity. Expression of Nod-like receptors might play an important role in initiating the inflammatory response in DE.

Proteome profiling of triple negative breast cancer cells overexpressing NOD1 and NOD2 receptors unveils molecular signatures of malignant cell proliferation

Background

Triple negative breast cancer (TNBC) is a malignancy with very poor prognosis, due to its aggressive clinical characteristics and lack of response to receptor-targeted drug therapy. In TNBC, immune-related pathways are typically upregulated and may be associated with a better prognosis of the disease, encouraging the pursuit for immunotherapeutic options. A number of immune-related molecules have already been associated to the onset and progression of breast cancer, including NOD1 and NOD2, innate immune receptors of bacterial-derived components which activate pro-inflammatory and survival pathways. In the context of TNBC, overexpression of either NOD1or NOD2 is shown to reduce cell proliferation and increase clonogenic potential in vitro. To further investigate the pathways linking NOD1 and NOD2 signaling to tumorigenesis in TNBC, we undertook a global proteome profiling of TNBC-derived cells ectopically expressing each one of these NOD receptors.

Results

We have identified a total of 95 and 58 differentially regulated proteins in NOD1- and NOD2-overexpressing cells, respectively. We used bioinformatics analyses to identify enriched molecular signatures aiming to integrate the differentially regulated proteins into functional networks. These analyses suggest that overexpression of both NOD1 and NOD2 may disrupt immune-related pathways, particularly NF-κB and MAPK signaling cascades. Moreover, overexpression of either of these receptors may affect several stress response and protein degradation systems, such as autophagy and the ubiquitin-proteasome complex. Interestingly, the levels of several proteins associated to cellular adhesion and migration were also affected in these NOD-overexpressing cells.

Conclusions

Our proteomic analyses shed new light on the molecular pathways that may be modulating tumorigenesis via NOD1 and NOD2 signaling in TNBC. Up- and downregulation of several proteins associated to inflammation and stress response pathways may promote activation of protein degradation systems, as well as modulate cell-cycle and cellular adhesion proteins. Altogether, these signals seem to be modulating cellular proliferation and migration via NF-κB, PI3K/Akt/mTOR and MAPK signaling pathways. Further investigation of altered proteins in these pathways may provide more insights on relevant targets, possibly enabling the immunomodulation of tumorigenesis in the aggressive TNBC phenotype.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5523-6) contains supplementary material, which is available to authorized users.

Innate Immune Stimulation in Cancer Therapy

The innate immune system has evolved as a first line of defense against invading pathogens and acts via classes of germline-encoded receptor systems to respond with proinflammatory cytokines. Innate immune cells, predominantly cells of the myeloid compartment, are capable of providing a potent basis for boosting adaptive immunity in malignant diseases. The authors review their current understanding of the molecular mechanisms whereby innate pattern recognition receptors participate in immunosurveillance of cancer cells. They discuss how innate effector mechanisms are currently being targeted pharmacologically and how improved understanding of the biology of these pathways is leading to novel immunotherapies of cancer.

Harnessing the untapped potential of nucleotide-binding oligomerization domain ligands for cancer immunotherapy

In the last decade, cancer immunotherapy has emerged as an effective alternative to traditional therapies such as chemotherapy and radiation. In contrast to the latter, cancer immunotherapy has the potential to distinguish between cancer and healthy cells, and thus to avoid severe and intolerable side‐effects, since the cancer cells are effectively eliminated by stimulated immune cells. The cytosolic nucleotide‐binding oligomerization domains 1 and 2 receptors (NOD1 and NOD2) are important components of the innate immune system and constitute interesting targets in terms of strengthening the immune response against cancer cells. Many NOD ligands have been synthesized, in particular NOD2 agonists that exhibit favorable immunostimulatory and anticancer activity. Among them, mifamurtide has already been approved in Europe by the European Medicine Agency for treating patients with osteosarcoma in combination with chemotherapy after complete surgical removal of the primary tumor. This review is focused on NOD receptors as promising targets in cancer immunotherapy as well as summarizing current knowledge of the various NOD ligands exhibiting antitumor and even antimetastatic activity in vitro and in vivo.

The deubiquitinase MYSM1 dampens NOD2-mediated inflammation and tissue damage by inactivating the RIP2 complex

NOD2 is essential for antimicrobial innate immunity and tissue homeostasis, but require tight regulation to avert pathology. A focal point of NOD2 signaling is RIP2, which upon polyubiquitination nucleates the NOD2:RIP2 complex, enabling signaling events leading to inflammation, yet the precise nature and the regulation of the polyubiquitins coordinating this process remain unclear. Here we show that NOD2 signaling involves conjugation of RIP2 with lysine 63 (K63), K48 and M1 polyubiquitin chains, as well as with non-canonical K27 chains. In addition, we identify MYSM1 as a proximal deubiquitinase that attenuates NOD2:RIP2 complex assembly by selectively removing the K63, K27 and M1 chains, but sparing the K48 chains. Consequently, MYSM1 deficient mice have unrestrained NOD2-mediated peritonitis, systemic inflammation and liver injury. This study provides a complete overview of the polyubiquitins in NOD2:RIP2 signaling and reveal MYSM1 as a central negative regulator restricting these polyubiquitins to prevent excessive inflammation.

The innate immune receptor NOD2 is tightly regulated to ensure beneficial antimicrobial immunity. Here the authors show that the H2A deubiquitinase MYSM1 restrains NOD2 signaling by removing lysine 63 (K63), K27, M1 but not K48 polyubiquitin chains from its downstream adaptor protein RIP2.

New use for CETSA: monitoring innate immune receptor stability via post-translational modification by OGT

O-GlcNAcylation is a dynamic and functionally diverse post-translational modification shown to affect thousands of proteins, including the innate immune receptor nucleotide-binding oligomerization domain-containing protein 2 (Nod2). Mutations of Nod2 (R702W, G908R and 1007 fs) are associated with Crohn's disease and have lower stabilities compared to wild type. Cycloheximide (CHX)-chase half-life assays have been used to show that O-GlcNAcylation increases the stability and response of both wild type and Crohn's variant Nod2, R702W. A more rapid method to assess stability afforded by post-translational modifications is necessary to fully comprehend the correlation between NLR stability and O-GlcNAcylation. Here, a recently developed cellular thermal shift assay (CETSA) that is typically used to demonstrate protein-ligand binding was adapted to detect shifts in protein stabilization upon increasing O-GlcNAcylation levels in Nod2. This assay was used as a method to predict if other Crohn's associated Nod2 variants were O-GlcNAcylated, and also identified the modification on another NLR, Nod1. Classical immunoprecipitations and NF-κB transcriptional assays were used to confirm the presence and effect of this modification on these proteins. The results presented here demonstrate that CETSA is a convenient method that can be used to detect the stability effect of O-GlcNAcylation on O-GlcNAc-transferase (OGT) client proteins and will be a powerful tool in studying post-translational modification.

Expression and in vitro assessment of tumorigenicity for NOD1 and NOD2 receptors in breast cancer cell lines

OBJECTIVE

Immune-related pathways have been frequently associated to tumorigenesis. NOD1 and NOD2 are innate immune receptors responsible for sensing a subset of bacterial-derived components, and to further translate these pathogenic signals through pro-inflammatory and survival pathways. NOD1 and NOD2 have been further associated with tumorigenesis, particularly in gastrointestinal cancers. NOD1 has also been suggested to be a tumor suppressor gene in a model of estrogen receptor-dependent breast cancer. Contrarily, NOD2 polymorphisms are associated with higher risk of breast cancer, with no tumor suppressor role being reported. To better delineate this issue, we investigated NOD1 and NOD2 expression in a panel of breast cancer cell lines, as well as their potential impact in breast tumorigenesis based on in vitro assays.

RESULTS

The highly invasive Hs578T breast cell line presented the second highest NOD1 expression and the lowest NOD2 expression in our panel. Therefore, we investigated whether NOD1 and/or NOD2 might act as a tumor suppressor in this cell model. Our studies indicate that overexpression of either NOD1 or NOD2 reduces cell proliferation and increases clonogenic potential in vitro. Elucidation of NOD1 and NOD2 effects on tumor cell viability and proliferation may unveil potential targets for future therapeutic intervention.

Identification of laryngeal cancer prognostic biomarkers using an inflammatory gene-related, competitive endogenous RNA network

Competitive endogenous RNAs (ceRNAs) act as molecular sponges for microRNAs (miRNAs), and are associated with tumorigenesis in various cancers, including laryngeal cancer (LC). In this work, we constructed an LC-specific inflammatory gene-related ceRNA network (IceNet). In IceNet, ceRNAs targeting inflammation-related genes tended to be network hubs. Additionally, the betweenness centralities of these hub ceRNAs were higher than those of the inflammation-related genes themselves, indicating that the hub ceRNAs in this study played critical roles in communication between IceNet molecules. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses indicated that IceNet molecules are associated with multiple cancer-related functions and signaling pathways. Using cFinder software and survival analyses, we identified a potential prognostic module within IceNet that contains 18 mRNAs and a long non-coding RNA (lncRNA), and we effectively stratified patients into high- and low-risk subgroups with different survival outcomes, independent of patient age and tumor grade. This 18-mRNA and one-lncRNA module provides a novel mechanism for potentially improving LC patient prognostic predictions. Applying the module clinically to differentiate high- and low-risk patients could inform therapeutic decision making and ultimately improve patient outcomes. In addition, these results demonstrate the potential importance of IceNet hub ceRNAs in LC development and progression.

NOD2 and inflammation: current insights

The nucleotide-binding oligomerization domain (NOD) protein, NOD2, belonging to the intracellular NOD-like receptor family, detects conserved motifs in bacterial peptidoglycan and promotes their clearance through activation of a proinflammatory transcriptional program and other innate immune pathways, including autophagy and endoplasmic reticulum stress. An inactive form due to mutations or a constitutive high expression of NOD2 is associated with several inflammatory diseases, suggesting that balanced NOD2 signaling is critical for the maintenance of immune homeostasis. In this review, we discuss recent developments about the pathway and mechanisms of regulation of NOD2 and illustrate the principal functions of the gene, with particular emphasis on its central role in maintaining the equilibrium between intestinal microbiota and host immune responses to control inflammation. Furthermore, we survey recent studies illustrating the role of NOD2 in several inflammatory diseases, in particular, inflammatory bowel disease, of which it is the main susceptibility gene.

Autophagy-associated immune responses and cancer immunotherapy

Autophagy is an evolutionarily conserved catabolic process by which cellular components are sequestered into a double-membrane vesicle and delivered to the lysosome for terminal degradation and recycling. Accumulating evidence suggests that autophagy plays a critical role in cell survival, senescence and homeostasis, and its dysregulation is associated with a variety of diseases including cancer, cardiovascular disease, neurodegeneration. Recent studies show that autophagy is also an important regulator of cell immune response. However, the mechanism by which autophagy regulates tumor immune responses remains elusive. In this review, we will describe the role of autophagy in immune regulation and summarize the possible molecular mechanisms that are currently well documented in the ability of autophagy to control cell immune response. In addition, the scientific and clinical hurdles regarding the potential role of autophagy in cancer immunotherapy will be discussed.

10H-3,6-Diazaphenothiazine induces G2/M phase cell cycle arrest and caspase-dependent apoptosis and inhibits cell invasion of A2780 ovarian carcinoma cells through the regulation of NF-κB and (BIRC6-XIAP) complexes

The asymptomatic properties and high treatment resistance of ovarian cancer result in poor treatment outcomes and high mortality rates. Although the fundamental chemotherapy provides promising anticancer activities, it is associated with severe side effects. The derivative of phenothiazine, namely, 10H-3,6-diazaphenothiazine (PTZ), was synthesized and reported with ideal anticancer effects in a previous paper. In this study, detailed anticancer properties of PTZ was examined on A2780 ovarian cancer cells by investigating the cytotoxicity profiles, mechanism of apoptosis, and cell invasion. Research outcomes revealed PTZ-induced dose-dependent inhibition on A2780 cancer cells (IC₅₀ =0.62 µM), with significant less cytotoxicity toward HEK293 normal kidney cells and H9C2 normal heart cells. Generation of reactive oxygen species (ROS) and polarization of mitochondrial membrane potential (ΔΨm) suggests PTZ-induced cell death through oxidative damage. The RT² Profiler PCR Array on apoptosis pathway demonstrated PTZ-induced apoptosis via intrinsic (mitochondria-dependent) and extrinsic (cell death receptor-dependent) pathway. Inhibition of NF-κB and subsequent inhibition of (BIRC6-XIAP) complex activities reduced the invasion rate of A2780 cancer cells penetrating through the Matrigel™ Invasion Chamber. Lastly, the cell cycle analysis hypothesizes that the compound is cytostatic and significantly arrests cell proliferation at G₂/M phase. Hence, the exploration of the underlying anticancer mechanism of PTZ suggested its usage as promising chemotherapeutic agent.

Diverse gene expression patterns in response to anticancer drugs between human and mouse cell lines revealed by a comparative transcriptomic analysis

The aim of the present study was to perform comparative genomics using gene expression profile datasets of mice and humans who had been treated with anticancer drugs, to determine the similarities and differences in the antitumor mechanisms in the two mammals. This involved data mining of antitumor gene expression regulation, and screening of genetic loci from experimental mouse models of antitumor targets, to provide a theoretical basis of drug design. Subsequently, 9 overlapping genes with opposite expression patterns were identified across mouse and human cell lines that were treated with a specific cyclin-dependent kinase 4/6 inhibitor, PD0332991. These genes included LIM homeobox 2, adenomedullin, bone marrow stromal cell antigen 1, caveolin 1, histone cluster 1 (HIST1) H2B family member C, HIST1 H3 family member F, low density lipoprotein-receptor related protein 11, prolyl 4-hydroxylase subunit α1 and torsin family 3 member A. In addition, the janus kinase-signal transducer and activator of transcription signaling pathway, Toll-like receptor signaling pathway, T cell receptor signaling pathway and the nucleotide-binding oligomerization domain-like receptor signaling pathway were identified as candidate pathways for explaining antitumor mechanisms.

Molecular Interactions of Autophagy with the Immune System and Cancer

Autophagy is a highly conserved catabolic mechanism that mediates the degradation of damaged cellular components by inducing their fusion with lysosomes. This process provides cells with an alternative source of energy for the synthesis of new proteins and the maintenance of metabolic homeostasis in stressful environments. Autophagy protects against cancer by mediating both innate and adaptive immune responses. Innate immune receptors and lymphocytes (T and B) are modulated by autophagy, which represent innate and adaptive immune responses, respectively. Numerous studies have demonstrated beneficial roles for autophagy induction as well as its suppression of cancer cells. Autophagy may induce either survival or death depending on the cell/tissue type. Radiation therapy is commonly used to treat cancer by inducing autophagy in human cancer cell lines. Additionally, melatonin appears to affect cancer cell death by regulating programmed cell death. In this review, we summarize the current understanding of autophagy and its regulation in cancer.

Dysregulation of signaling pathways associated with innate antibacterial immunity in patients with pancreatic cancer

Disorders of innate antibacterial response are of fundamental importance in the development of gastrointestinal cancers, including pancreatic cancer. Multi-regulatory properties of the Toll-like receptors (TLRs) (e.g., regulation of proliferation, the activity of NF-κB, gene transcription of apoptosis proteins, regulation of angiogenesis, HIF-1α protein expression) are used in experimental studies to better understand the pathogenesis of pancreatic cancer, for early diagnosis, and for more effective therapeutic intervention. There are known numerous examples of TLR agonists (e.g., TLR2/5 ligands, TLR6, TLR9) of antitumor effect. The direction of these studies is promising, but a small number of them does not allow for an accurate assessment of the impact of TLR expression disorders, proteins of these signaling pathways, or attempts to block or stimulate them, on the results of treatment of pancreatic cancer patients. It is known, however, that the expression disorders of proteins of innate antibacterial response signaling pathways occur not only in tumor tissue but also in peripheral blood leukocytes of pancreatic cancer patients (e.g., increased expression of TLR4, NOD1, TRAF6), which is one of the most important factors facilitating further tumor development. This review mainly focuses on the genetic aspects of signaling pathway disorders associated with innate antibacterial response in the pathogenesis and diagnosis of pancreatic cancer.

Inflammatory pathway genes associated with inter-individual variability in the trajectories of morning and evening fatigue in patients receiving chemotherapy

Fatigue, a highly prevalent and distressing symptom during chemotherapy (CTX), demonstrates diurnal and interindividual variability in severity. Little is known about the associations between variations in genes involved in inflammatory processes and morning and evening fatigue severity during CTX. The purposes of this study, in a sample of oncology patients (N=543) with breast, gastrointestinal (GI), gynecological (GYN), or lung cancer who received two cycles of CTX, were to determine whether variations in genes involved in inflammatory processes were associated with inter-individual variability in initial levels as well as in the trajectories of morning and evening fatigue. Patients completed the Lee Fatigue Scale to determine morning and evening fatigue severity a total of six times over two cycles of CTX. Using a whole exome array, 309 single nucleotide polymorphisms SNPs among the 64 candidate genes that passed all quality control filters were evaluated using hierarchical linear modeling (HLM). Based on the results of the HLM analyses, the final SNPs were evaluated for their potential impact on protein function using two bioinformational tools. The following inflammatory pathways were represented: chemokines (3 genes); cytokines (12 genes); inflammasome (11 genes); Janus kinase/signal transducers and activators of transcription (JAK/STAT, 10 genes); mitogen-activated protein kinase/jun amino-terminal kinases (MAPK/JNK, 3 genes); nuclear factor-kappa beta (NFkB, 18 genes); and NFkB and MAP/JNK (7 genes). After controlling for self-reported and genomic estimates of race and ethnicity, polymorphisms in six genes from the cytokine (2 genes); inflammasome (2 genes); and NFkB (2 genes) pathways were associated with both morning and evening fatigue. Polymorphisms in six genes from the inflammasome (1 gene); JAK/STAT (1 gene); and NFkB (4 genes) pathways were associated with only morning fatigue. Polymorphisms in three genes from the inflammasome (2 genes) and the NFkB (1 gene) pathways were associated with only evening fatigue. Taken together, these findings add to the growing body of evidence that suggests that morning and evening fatigue are distinct symptoms.

Effects of genetic variations in the genes encoding NOD1 and NOD2 on type 2 diabetes mellitus and insulin resistance

WHAT IS KNOWN AND OBJECTIVE

Nucleotide-binding oligomerization domain (NOD) 1 and NOD 2 are members of the NOD-like receptor (NLR) family and contain a caspase recruitment domain. NLRs are located in the cytosol, bind bacterial and viral ligands and play a key role in the realization of innate and adaptive immune response, inflammation, apoptosis and reactive oxygen species generation. Insulin resistance (IR) is a leading cause of type 2 diabetes mellitus (T2DM) and associated with obesity, inflammation and pro-inflammatory responses. NOD1 and NOD2 gene variants may affect the risk of chronic inflammation, insulin resistance and T2DM by shifting the balance between pro- and anti-inflammatory cytokines. The aim of our study was to determine whether the NOD1/2 gene variants might contribute to the risk of T2DM and IR.

METHODS

The rs5743336 variant of NOD1 and rs2066847 variant of NOD2 were analysed by PCR-RFLP analysis in 200 subjects (T2DM: n = 100; healthy controls: n = 100) of Turkish origin. PCR products were digested with the AvaI and ApaI restriction enzymes. For the NOD1 site, the presence of the G allele was indicated by cleavage of the 379 bp amplified PCR product that yielded 209-bp and 170-bp fragments. For the NOD2 site, 151-bp PCR products were cleaved and yielded 130-bp and 21-bp fragments when the WT-insC mutation was present. Comparisons of the genotypes between controls and patients were performed by chi-square tests.

RESULTS AND DISCUSSION

The genotypes of the rs5743336 variant of NOD1 and the rs2066847 variant of NOD2 are presented, and no significant differences were observed in the genotype frequencies of the NOD1 and NOD2 variants between the healthy controls and T2DM patients (P > 0·05). According to our preliminary data, NOD1/2 gene variants are not linked with T2DM and IR.

WHAT IS NEW AND CONCLUSION

This study is the first to look for possible association of the genotype frequencies of NOD1 and NOD2 genes with T2DM and IR. The significant finding of this report is that the rs5743336 and rs2066847 variations in the NOD1/2 gene are not associated with T2DM and IR risk in patients of Turkish origin.

Inflammatory-Related Genetic Variants in Non-Muscle-Invasive Bladder Cancer Prognosis: A Multimarker Bayesian Assessment

BACKGROUND

Increasing evidence points to the role of tumor immunologic environment on urothelial bladder cancer prognosis. This effect might be partly dependent on the host genetic context. We evaluated the association of SNPs in inflammation-related genes with non-muscle-invasive bladder cancer (NMIBC) risk-of-recurrence and risk-of-progression.

METHODS

We considered 822 NMIBC included in the SBC/EPICURO Study followed-up >10 years. We selected 1,679 SNPs belonging to 251 inflammatory genes. The association of SNPs with risk-of-recurrence and risk-of-progression was assessed using Cox regression single-marker (SMM) and multimarker methods (MMM) Bayes A and Bayesian LASSO. Discriminative abilities of the models were calculated using the c index and validated with bootstrap cross-validation procedures.

RESULTS

While no SNP was found to be associated with risk-of-recurrence using SMM, three SNPs in TNIP1, CD5, and JAK3 showed very strong association with posterior probabilities >90% using MMM. Regarding risk-of-progression, one SNP in CD3G was significantly associated using SMM (HR, 2.69; P = 1.55 × 10(-5)) and two SNPs in MASP1 and AIRE, showed a posterior probability ≥80% with MMM. Validated discriminative abilities of the models without and with the SNPs were 58.4% versus 60.5% and 72.1% versus 72.8% for risk-of-recurrence and risk-of-progression, respectively.

CONCLUSIONS

Using innovative analytic approaches, we demonstrated that SNPs in inflammatory-related genes were associated with NMIBC prognosis and that they improve the discriminative ability of prognostic clinical models for NMIBC.

IMPACT

This study provides proof of concept for the joint effect of genetic variants in improving the discriminative ability of clinical prognostic models. The approach may be extended to other diseases. Cancer Epidemiol Biomarkers Prev; 25(7); 1144-50. ©2016 AACR.

NLR-regulated pathways in cancer: opportunities and obstacles for therapeutic interventions

NLRs (nucleotide-binding domain, leucine-rich repeat containing receptors) are pattern recognition receptors associated with immunity and inflammation in response to endogenous and exogenous pathogen and damage associated molecular patterns (PAMPs and DAMPs respectively). Dysregulated NLR function is associated with several diseases including cancers, metabolic diseases, autoimmune disorders and autoinflammatory syndromes. In the last decade, distinct cell and organ specific roles for NLRs have been identified however; their roles in cancer initiation, development and progression remain controversial. This review summarizes the emerging role of NLRs in cancer and their possible future as targets for cancer therapeutics.

NOD2 mutations and colorectal cancer - Where do we stand?

Due to the overwhelming burden of colorectal cancer (CRC), great effort has been placed on identifying genetic mutations that contribute to disease development and progression. One of the most studied polymorphisms that could potentially increase susceptibility to CRC involves the nucleotide-binding and oligomerization-domain containing 2 (NOD2) gene. There is growing evidence that the biological activity of NOD2 is far greater than previously thought and a link with intestinal microbiota and mucosal immunity is increasingly sought after. In fact, microbial composition may be an important contributor not only to inflammatory bowel diseases (IBD) but also to CRC. Recent studies have showed that deficient NOD2 function confers a communicable risk of colitis and CRC. Despite the evidence from experimental models, population-based studies that tried to link certain NOD2 polymorphisms and an increase in CRC risk have been described as conflicting. Significant geographic discrepancies in the frequency of such polymorphisms and different interpretations of the results may have limited the conclusions of those studies. Since being first associated to IBD and CRC, our understanding of the role of this gene has come a long way, and it is tempting to postulate that it may contribute to identify individuals with susceptible genetic background that may benefit from early CRC screening programs or in predicting response to current therapeutic tools. The aim of this review is to clarify the status quo of NOD2 mutations as genetic risk factors to chronic inflammation and ultimately to CRC. The use of NOD2 as a predictor of certain phenotypic characteristics of the disease will be analyzed as well.

NOD2 Arg702Trp Polymorphism in Romanian Patients with Gastric Cancer

Purpose. Our study aimed to assess a possible correlation between NOD2 Arg702Trp (rs2066844) polymorphism and gastric cancer risk in a Romanian population. Material/Methods. A total of 322 subjects (72 patients with gastric adenocarcinoma and 250 healthy controls) were included. Genomic DNA was extracted from blood leukocytes and NOD2 Arg702Trp polymorphism was genotyped by Real-Time PCR using specific TaqMan probes. Results. No statistically significant difference was observed between gastric cancer patients and controls when we compared one genotype with other genotype (the CC genotype serves as reference) (OR 0.45, 95% CI: 0.10 - 2.05) or when we compared allele frequencies (the C allele serves as reference) (OR 0.46, 95% CI: 0.11 - 2.04). We examined separately the association of this polymorphism with tumor site and histologic type and no correlation was found. Conclusion. NOD2 Arg702Trp polymorphism is not associated with gastric cancer risk and further investigations are needed to elucidate the contribution of NOD2 gene in gastric carcinogenesis.

The role of NOD1/CARD4 and NOD2/CARD15 genetic variations in lung cancer risk

BACKGROUND AND AIM

NOD1/CARD4 and NOD2/CARD15 are members of the Nod-like receptor (NLR) family, and they contain a caspase recruitment domain (CARD). NLRs are located in the cytosol where they bind bacterial and viral ligands and play a key role in the innate and adaptive immune response, apoptosis, autophagy, and reactive oxygen species generation. NLR gene polymorphisms may shift the balance between pro- and anti-inflammatory cytokines and modulate the risk of infection, chronic inflammation, and cancer. NOD1/CARD4 and NOD2/CARD15 gene polymorphisms may also be associated with altered risks for many cancer types. The aim of our study was to evaluate the potential associations between lung cancer and NOD1/CARD4 and NOD2/CARD15 polymorphisms.

METHOD

The NOD1/CARD4 (rs5743336) and NOD2/CARD15 (rs2066847) SNPs were analyzed by PCR restriction fragment-length polymorphism analysis (PCR-RFLP) in 260 subjects (lung cancer patients: n = 160; healthy controls: n = 100) of Turkish origin. PCR products were digested with AvaI for rs5743336 and ApaI for rs2066847 and then visualized.

RESULTS

Comparisons of the genotypes between control and lung cancer patients were performed by Chi-square tests. We found a significant difference in the genotypic distribution of the rs5743336 variant of NOD1/CARD4 between lung cancer patients and controls (p = 0.010, χ (2) = 9.220). However, we did not identify any statistically significant difference for the p.Leu1007fsX1008 (rs2066847) genotype of NOD2/CARD15 between groups (p > 0.05).

CONCLUSION

According to our data, the rs5743336 variant of the NOD1/CARD4 gene may influence the diagnosis and treatment of lung cancer, whereas the rs2066847 variant of the NOD2/CARD15 gene is not associated with lung cancer risk in the Turkish population.

NOD1 and NOD2 Genetic Variants in Association with Risk of Gastric Cancer and Its Precursors in a Chinese Population

BACKGROUND

Genetic variants of nucleotide-binding oligomerization domain-containing protein (NOD) may influence the outcome of Helicobacter pylori (H. pylori) infection and gastric carcinogenesis. To explore genetic variants of NOD1 and NOD2 in association with gastric cancer (GC) and its precursors, a population-based study was conducted in Linqu County, China.

METHODS

TagSNPs of NOD1 and NOD2 were genotyped by Sequenom MASS array in 132 GCs, and 1,198 subjects with precancerous gastric lesions, and were correlated with evolution of gastric lesions in 766 subjects with follow-up data.

RESULTS

Among seven tagSNPs, NOD1 rs2709800 and NOD2 rs718226 were associated with gastric lesions. NOD1 rs2709800 TG genotype carriers had a decreased risk of intestinal metaplasia (IM, OR: 0.53; 95% CI: 0.31-0.92), while NOD2 rs718226 G allele (AG/GG) showed increased risks of dysplasia (DYS, OR: 2.96; 95% CI: 1.86-4.71) and GC (OR: 2.35; 95% CI: 1.24-4.46). Moreover, an additive interaction between rs718226 and H. pylori was found in DYS or GC with synergy index of 3.08 (95% CI: 1.38-6.87) or 3.99 (95% CI: 1.55-10.22), respectively. The follow-up data indicated that NOD2 rs2111235 C allele (OR: 0.52; 95% CI: 0.32-0.83) and rs7205423 G allele (OR: 0.56; 95% CI: 0.35-0.89) were associated with decreased risk of progression in H. pylori-infected subjects.

CONCLUSIONS

NOD1 rs2709800, NOD2 rs718226, rs2111235, rs7205423 and interaction between rs718226 and H. pylori infection may be related to risk of gastric lesions.

NOD-like receptors: versatile cytosolic sentinels

Nucleotide binding oligomerization domain (NOD)-like receptors are cytoplasmic pattern-recognition receptors that together with RIG-I-like receptor (retinoic acid-inducible gene 1), Toll-like receptor (TLR), and C-type lectin families make up the innate pathogen pattern recognition system. There are 22 members of NLRs in humans, 34 in mice, and even a larger number in some invertebrates like sea urchins, which contain more than 200 receptors. Although initially described to respond to intracellular pathogens, NLRs have been shown to play important roles in distinct biological processes ranging from regulation of antigen presentation, sensing metabolic changes in the cell, modulation of inflammation, embryo development, cell death, and differentiation of the adaptive immune response. The diversity among NLR receptors is derived from ligand specificity conferred by the leucine-rich repeats and an NH2-terminal effector domain that triggers the activation of different biological pathways. Here, we describe NLR genes associated with different biological processes and the molecular mechanisms underlying their function. Furthermore, we discuss mutations in NLR genes that have been associated with human diseases.

The NLR-related protein NWD1 is associated with prostate cancer and modulates androgen receptor signaling

Prostate cancer (PCa) is among the leading causes of cancer-related death in men. Androgen receptor (AR) signaling plays a seminal role in prostate development and homeostasis, and dysregulation of this pathway is intimately linked to prostate cancer pathogenesis and progression. Here, we identify the cytosolic NLR-related protein NWD1 as a novel modulator of AR signaling. We determined that expression of NWD1 becomes elevated during prostate cancer progression, based on analysis of primary tumor specimens. Experiments with cultured cells showed that NWD1 expression is up-regulated by the sex-determining region Y (SRY) family proteins. Gene silencing procedures, in conjunction with transcriptional profiling, showed that NWD1 is required for expression of PDEF (prostate-derived Ets factor), which is known to bind and co-regulate AR. Of note, NWD1 modulates AR protein levels. Depleting NWD1 in PCa cell lines reduces AR levels and suppresses activity of androgen-driven reporter genes. NWD1 knockdown potently suppressed growth of androgen-dependent LNCaP prostate cancer cells, thus showing its functional importance in an AR-dependent tumor cell model. Proteomic analysis suggested that NWD1 associates with various molecular chaperones commonly related to AR complexes. Altogether, these data suggest a role for tumor-associated over-expression of NWD1 in dysregulation of AR signaling in PCa.