MicroRNA-3178 ameliorates inflammation and gastric carcinogenesis promoted by Helicobacter pylori new toxin, Tip-α, by targeting TRAF3

FOSL1 regulates hyperproliferation and NLRP3-mediated inflammation of psoriatic keratinocytes through the NF-kB signaling via transcriptionally activating TRAF3

Psoriasis is a common and immune-mediated skin disease related to keratinocytes hyperproliferation and inflammation. Fos-like antigen-1 (FOSL1) is an important transcription factor involved in various diseases. FOSL1 has been reported to be differentially expressed in psoriasis. However, the roles and mechanism of FOSL1 in psoriasis progression remain largely unknown. FOSL1 is an upregulated transcription factor in psoriasis and increased in M5-treated HaCaT cells. FOSL1 had a diagnostic value in psoriasis, and positively associated with PASI score, TNF-α and IL-6 levels in psoriasis patients. FOSL1 silencing attenuated M5-induced HaCaT cell hyperproliferation through decreasing cell viability and proliferative ability and increasing cell apoptosis. FOSL1 knockdown mitigated M5-induced NLRP3 inflammasome activation and it-mediated inflammatory cytokine (IL-6, IL-8 and CCL17) expression. TRAF3 expression was increased in psoriasis patients and M5-treated HaCaT cells. FOSL1 transcriptionally activating TRAF3 in HaCaT cells. TRAF3 overexpression reversed the suppressive effects of FOSL1 silencing on M5-induced hyperproliferation and NLRP3-mediated inflammation. FOSL1 knockdown attenuated M5-induced NF-κB signaling activation by reducing TRAF3. Activation of NF-κB signaling reversed the effects of FOSL1 knockdown on hyperproliferation and inflammation in M5-treated cells. FOSL1 silencing prevented M5-induced hyperproliferation and NLRP3-mediated inflammation of keratinocytes by inhibiting TRAF3-mediated NF-κB activity, indicating FOSL1 might act as a therapeutic target of psoriasis.

miR-3,178 contributes to the therapeutic action of baicalein against hepatocellular carcinoma cells via modulating HDAC10

Hepatocellular carcinoma (HCC) is the most common type of hepatic malignancies with high mortality and poor prognosis. Baicalein, one of the major and bioactive flavonoids isolated from Scutellaria baicalensis Georgi, which is reported to have anti-proliferation effect in varying cancers, including HCC, whose underlying molecular mechanism is still largely unknown. In this study, we found that baicalein significantly inhibited proliferation and colony formation, blocked cell cycle, and promoted apoptosis in HCC cells MHCC-97H and SMMC-7721 in vitro and reduced tumor volume and weight in vivo. Increased microRNA (miR)-3,178 levels and decreased histone deacetylase 10 (HDAC10) expression were found in cells treated with baicalein and in patients' HCC tissues. HDAC10 was identified as a target gene of miR-3,178 by luciferase activity and western blot. Both baicalein treatment and overexpression of miR-3,178 could downregulate HDAC10 protein expression and inactivated AKT, MDM2/p53/Bcl2/Bax and FoxO3α/p27/CDK2/Cyclin E1 signal pathways. Not only that, knockdown of miR-3,178 could partly abolish the effects of baicalein and the restoration of HDAC10 could abated miR-3,178-mediated role in HCC cells. Collectively, baicalein inhibits cell viability, blocks cell cycle, and induces apoptosis in HCC cells by regulating the miR-3,178/HDAC10 pathway. This finding indicated that baicalein might be promising for treatment of HCC.

Micro RNAs as potential biomarkers in tuberculosis: A systematic review

Tuberculosis (TB) remains a major infectious disease across the globe. With increasing TB infections and a rise in multi-drug resistance, rapid diagnostic modalities are required to achieve TB control. Radiological investigations and microbiological tests (microscopic examination, cartridge-based nucleic acid amplification tests, and cultures) are most commonly used to diagnose TB. Histopathological/cytopathological examinations are also required for an accurate diagnosis in many patients. The causative agent, Mycobacterium tuberculosis (Mtb), is known to circumvent the host's immune system. Circulating microRNAs (miRNAs) play a crucial role in biological pathways and can be used as a potential biomarker to detect tuberculosis. miRNAs are small non-coding RNAs and negatively regulate gene expression during post-transcriptional regulation. The differential expression of miRNAs in multiple clinical samples in tuberculosis patients may be helpful as potential disease biomarkers. This review summarizes the literature on miRNAs in various clinical samples as biomarkers for TB diagnosis.

The role of non-coding RNA in the diagnosis and treatment of Helicobacter pylori-related gastric cancer, with a focus on inflammation and immune response

Helicobacter pylori (H. pylori) is one of the globally recognized causative factors of gastric cancer (GC). Currently, no definite therapy and drugs for H. pylori-related GC have been widely acknowledged although H. pylori infection could be eradicated in early stage. Inflammation and immune response are spontaneous essential stages during H. pylori infection. H pylori may mediate immune escape by affecting inflammation and immune response, leading to gastric carcinogenesis. As an important component of transcriptome, non-coding RNAs (ncRNAs) have been proven to play crucial roles in the genesis and development of H. pylori-induced GC. This review briefly described the effects of ncRNAs on H. pylori-related GC from the perspective of inflammation and immune response, as well as their association with inflammatory reaction and immune microenvironment. We aim to explore the potential of ncRNAs as markers for the early diagnosis, prognosis, and treatment of H. pylori-related GC. The ncRNAs involved in H. pylori-related GC may all hold promise as novel therapeutic targets for immunotherapy.

Recent advances of miRNAs in the development and clinical application of gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors. The mechanism of how GC develops is vague, and therapies are inefficient. The function of microRNAs (miRNAs) in tumorigenesis has attracted the attention from many scientists. During the development of GC, miRNAs function in the regulation of different phenotypes, such as proliferation, apoptosis, invasion and metastasis, drug sensitivity and resistance, and stem-cell-like properties. MiRNAs were evaluated for use in diagnostic and prognostic predictions and exhibited considerable accuracy. Although many problems exist for the application of therapy, current studies showed the antitumor effects of miRNAs. This paper reviews recent advances in miRNA mechanisms in the development of GC and the potential use of miRNAs in the diagnosis and treatment of GC.

Function of Non-coding RNA in Helicobacter pylori-Infected Gastric Cancer

Gastric cancer is a common malignant tumor of the digestive system. Its occurrence and development are the result of a combination of genetic, environmental, and microbial factors. Helicobacter pylori infection is a chronic infection that is closely related to the occurrence of gastric tumorigenesis. Non-coding RNA has been demonstrated to play a very important role in the organism, exerting a prominent role in the carcinogenesis, proliferation, apoptosis, invasion, metastasis, and chemoresistance of tumor progression. H. pylori infection affects the expression of non-coding RNA at multiple levels such as genetic polymorphisms and signaling pathways, thereby promoting or inhibiting tumor progression or chemoresistance. This paper mainly introduces the relationship between H. pylori-infected gastric cancer and non-coding RNA, providing a new perspective for gastric cancer treatment.

Mechanisms of the Epithelial-Mesenchymal Transition and Tumor Microenvironment in Helicobacter pylori-Induced Gastric Cancer

Helicobacter pylori (H. pylori) is one of the most common human pathogens, affecting half of the world’s population. Approximately 20% of the infected patients develop gastric ulcers or neoplastic changes in the gastric stroma. An infection also leads to the progression of epithelial–mesenchymal transition within gastric tissue, increasing the probability of gastric cancer development. This paper aims to review the role of H. pylori and its virulence factors in epithelial–mesenchymal transition associated with malignant transformation within the gastric stroma. The reviewed factors included: CagA (cytotoxin-associated gene A) along with induction of cancer stem-cell properties and interaction with YAP (Yes-associated protein pathway), tumor necrosis factor α-inducing protein, Lpp20 lipoprotein, Afadin protein, penicillin-binding protein 1A, microRNA-29a-3p, programmed cell death protein 4, lysosomal-associated protein transmembrane 4β, cancer-associated fibroblasts, heparin-binding epidermal growth factor (HB-EGF), matrix metalloproteinase-7 (MMP-7), and cancer stem cells (CSCs). The review summarizes the most recent findings, providing insight into potential molecular targets and new treatment strategies for gastric cancer.

Transcriptome hallmarks in Helicobacter pylori infection influence gastric cancer and MALT lymphoma

Aim: Altered long noncoding RNA (lncRNA) and mRNA is vital in the progression from Helicobacter pylori (H. pylori, HP) infection to gastric cancer (GC) and mucosa-associated lymphoid tissue (MALT) lymphoma. Materials & methods: Five independent Gene Expression Omnibus datasets (GSE5081, GSE84433, GSE15459, GSE66229 and GSE25638) were included in our study. Results: Differentially expressed lncRNAs and mRNAs in both H. pylori-positive gastritis and GC tissues were identified. Using two GC cohorts, the H. pylori-related mRNA DYNC1I1 and MMP7 were independent predictors of overall survival. Moreover, the expressions of lncRNA GHRLOS and 44 mRNAs were significantly changed in gastric MALT lymphoma patients. Conclusion: The lncRNA/mRNA response to H. pylori infection in gastritis and GC influence the outcome of GC and progression of MALT lymphoma.

MiR-32-5p aggravates intestinal epithelial cell injury in pediatric enteritis induced by Helicobacter pylori

BACKGROUND

Pediatric enteritis is one of the infectious diseases in the digestive system that causes a variety of digestive problems, including diarrhea, vomiting, and bellyache in children. Clinically, Helicobacter pylori (H. pylori) infection is one of the common factors to cause pediatric enteritis. It has been demonstrated that aberrant expression of microRNAs (miRNAs) is found in gastrointestinal diseases caused by H. pylori, and we discovered a significant increase of miR-32-5p in H. pylori-related pediatric enteritis. However, the exact role of miR-32-5p in it is still unknown.

AIM

To investigate the role of aberrant miR-32-5p in pediatric enteritis induced by H. pylori.

METHODS

MiR-32-5p expression was detected by quantitative real time-polymerase chain reaction. The biological role of miR-32-5p in H. pylori-treated intestinal epithelial cells was evaluated by Cell Counting Kit-8 assay and flow cytometry. The potential target of miR-32-5p was predicted with TargetScanHuman and verified by luciferase assay. The downstream mechanism of miR-32-5p was explored by using molecular biology methods.

RESULTS

We found that miR-32-5p was overexpressed in serum of H. pylori-induced pediatric enteritis. Further investigation revealed that H. pylori infection promoted the death of intestinal epithelial cells, and increased miR-32-5p expression. Moreover, miR-32-5p mimic further facilitated apoptosis and inflammatory cytokine secretion of intestinal epithelial cells. Further exploration revealed that SMAD family member 6 (SMAD6) was the direct target of miR-32-5p, and SMAD6 overexpression partially rescued cell damage induced by H. pylori. The following experiments showed that miR-32-5p/SMAD6 participated in the apoptosis of intestinal epithelial cells induced by transforming growth factor-β-activated kinase 1 (TAK1)-p38 activation under H. pylori infection.

CONCLUSION

Our work uncovered the crucial role of aberrant expression of miR-32-5p in H. pylori–related pediatric enteritis, and suggested that the TAK1-p38 pathway is involved in it.

miR-29b-3p promotes progression of MDA-MB-231 triple-negative breast cancer cells through downregulating TRAF3

BACKGROUND

Breast cancer is the second common malignant cancer among females worldwide. Accumulating studies have indicated that deregulation of miRNA expression in breast cancer will contribute to tumorigenesis and form different cancer subtypes. However, the reported studies on miR-29b-3p-regulated breast cancer are limited so far. Herein, we investigated the role and mechanism of miR-29b-3p in the triple negative breast cancer cell line MDA-MB-231.

METHODS

The relative miR-29b-3p expression in different breast cancer cell lines were determined by qRT-PCR. CCK8 and colony formation assay were used to determine the influence of miR-29b-3p on cell proliferation. Migration assay and invasion assay were performed for cell migration and invasion respectively. To study the cell integrity immunofluorescence was performed. TUNEL assay, flow cytometry assay, hoechst staining and western blot were conducted to determine the influence of miR-29b-3p inhibitor on cell apoptosis. TRAF3 was found to be the target gene of miR-29b-3p using bioinformatics predictions. Dual-luciferase assay was performed to determine the relative luciferase activity in NC, miR-29b-3p mimic, miR-29b-3p inhibitor with TRAF3 3'-UTR wt or TRAF3 3'-UTR mt reporter plasmids. The proteins expression of NF-κB signaling pathway in MDA-MB-231 after transfection with NC, miR-29b-3p mimic, miR-29b-3p inhibitor were determined by western blot.

RESULTS

The miR-29b-3p expression was significantly increased in MDA-MB-231 compare with MCF-10A. miR-29b-3p inhibitor reduced the cell viability of MDA-MB-231 and inhibited cell migration and invasion. Cell cytoskeleton integrity destroyed after miR-29b-3p inhibitor treatment. Furthermore, we identified the mechanism and found miR-29b-3p targets the TRAF3 and activates NF-κB signaling pathway.

CONCLUSIONS

From the above studies, our results indicated that miR-29b-3p acts as a promoter for the development of MDA-MB-231.

Role of abnormal microRNA expression in Helicobacter pylori associated gastric cancer

Epidemiological studies have shown that Helicobacter pylori (HP) infection is a risk factor for gastric cancer (GC). HP infection may induce the release of pro-inflammatory mediators, and abnormally increase the level of reactive oxygen species (ROS), nitric oxide (NO), and cytokines in mucosal epithelial cells of the stomach. However, the specific mechanism underlying the pathogenesis of HP-associated GC is still poorly understood. Recent studies have revealed that abnormal microRNA expression may affect the proliferation, differentiation, and apoptosis of mucosal epithelial cells of the stomach to further influence GC occurrence, development, and metastasis. Herein, we summarize the role of abnormal microRNAs in the regulation of HP-associated GC progression. Abnormal microRNA expression in HP-positive GC may be a biomarker for GC diagnosis, occurrence, and development as well as its targeted treatment and prognosis.

hsa-miR-3177-5p and hsa-miR-3178 Inhibit 5-HT1A Expression by Binding the 3'-UTR Region in vitro

Abnormal expression of the 5-HT1A receptor, which is encoded by the HTR1A gene, leads to susceptibilities to neuropsychiatric disorders such as depression, anxiety, and schizophrenia. miRNAs regulate gene expression by recognizing the 3'-UTR region of mRNA. This study evaluated the miRNAs that might identify and subsequently determine the regulatory mechanism of HTR1A gene. Using the HEK-293, U87, SK-N-SH and SH-SY5Y cell lines, we determined the functional sequence of the 3'-UTR region of the HTR1A gene and predicted miRNA binding. Dual luciferase reporter assay and Western Blot were used to confirm the effect of miRNA mimics and inhibitors on endogenous 5-HT1A receptors. In all cell lines, gene expression of the -17 bp to +443 bp fragment containing the complete sequence of the 3'-UTR region was significantly decreased, although mRNA quantification was not different. The +375 bp to +443 bp sequence, which exhibited the most significant change in relative chemiluminescence intensity, was recognized by hsa-miR-3177-5p and hsa-miR-3178. In HEK-293 and U87 cells, hsa-miR-3177-5p significantly inhibited the 5-HT1A receptor expression, while a hsa-miR-3178 inhibitor up-regulated HTR1A gene expression in SK-N-SH and SH-SY5Y cells. By constructing the pmirGLO-vector with the mutated HTR1A gene, we further confirmed that hsa-miR-3177-5p recognized the HTR1A gene tgtacaca at +377 bp to +384 bp, and the +392 bp to +399 bp fragment cgcgccca was identified by hsa-miR-3178. hsa-miR-3177-5p and hsa-miR-3178 had significant inhibitory effects on expression of the HTR1A gene and 5-HT1A receptor and may directly participate in the development of neuropsychiatric diseases.

Comprehensive Analysis of Aberrantly Expressed ceRNA network in gastric cancer with and without H.pylori infection

Objective: This study mainly focused on revealing ceRNA network in gastric cancer (GC) with Hp infection after comparing with GC without Hp infection and exploring the biological function and prognostic relevance of related molecules.

Methods: The RNA expression profile data of GC patients with or without Hp infection were extracted from TCGA GDC data portal, including 20 GC cases with Hp infection and 168 GC cases without Hp infection. Differentially expressed lncRNAs, miRNAs and mRNAs were unveiled by package edgeR of R, and lncRNA-miRNA-mRNA ceRNA network was constructed by integrating the miRNA target information and the expression data of lncRNAs, miRNAs and mRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of aberrantly expressed mRNAs were performed to identify the related biological functions and pathologic pathways, and protein-protein interaction (PPI) network was constructed by STRING database. The overall survival (OS) of aberrantly expression lncRNAs and miRNAs were analyzed by package survival of R. A total of 30 gastric cancer tissues were used to validate the bioinformatics analysis results by real-time PCR.

Results: Among the 32 differentially expressed miRNAs, 27 differentially expressed lncRNAs and 257 differentially expressed mRNAs were identified by comparing GC patients with and without Hp infection. Totally 10 miRNA, 11 lncRNA, 219 mRNA were included to build ceRNA network. GO and KEGG analysis revealed that differentially expressed mRNAs involved in the ceRNA network were mainly involved in extracellular exosomes, structural molecular activities, proteolysis and P13K-Akt signaling pathways. And PPI analysis obtained six hub genes of NTS, APOC3, OTX2, KRT13, CALCA, GNG4. Survival analysis showed that four lncRNAs (LINC01254, LINC01287, LINC01524, U95743.1) and four miRNAs (miR-302a, miR-302b, miR-1286, miR-378g) were associated with overall survival of GC with Hp infection. The real-time PCR results showed that, the levels of LINCO1254, LINCO1287, LINCO1524, U95743.1 were significantly higher in Hp positive GC patients than Hp negative patients (P=0.02, 0.048, 0.04, 0.036, respectively).

Conclusion: Using TCGA database for data mining, we have successfully constructed a ceRNA regulatory network of GC with Hp infection, consisting of 10 lncRNAs, 11 miRNAs and 219 mRNAs. These findings might provide critical clues for the regulatory role of ceRNA network in the development of GC with Hp infection.

Regulation of TLR signaling pathways by microRNAs: implications in inflammatory diseases

The control of the immune response during the development of some diseases is crucial for the maintenance or restoration of homeostasis. Several mechanisms can initiate inflammation, one of which is the activation of toll-like receptors (TLRs), necessary to initiate the immune response to eliminate an infection. However, inappropriate activation can compromise immunological homeostasis, leading to pathologies such as autoimmune diseases, chronic inflammation, and even cancer. Regulatory mechanisms that intervene in the initiation or modulation of inflammation include microRNAs (miRNAs), which have emerged as key post-transcriptional regulators of proteins involved in distinct cellular processes, such as regulation of the immune response. The focus of this review is on the diverse roles of miRNAs in the regulation of TLR-signaling pathways by targeting multiple molecules, including TLRs, the signaling proteins and cytokines induced by TLRs. It will also address the relationships of these molecules with some diseases that involve inflammation such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), cancer, as well as bacterial or viral infections.

Genetic Alterations of TRAF Proteins in Human Cancers

The tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) family of cytoplasmic adaptor proteins regulate the signal transduction pathways of a variety of receptors, including the TNF-R superfamily, Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and cytokine receptors. TRAF-dependent signaling pathways participate in a diverse array of important cellular processes, including the survival, proliferation, differentiation, and activation of different cell types. Many of these TRAF-dependent signaling pathways have been implicated in cancer pathogenesis. Here we analyze the current evidence of genetic alterations of TRAF molecules available from The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutations in Cancer (COSMIC) as well as the published literature, including copy number variations and mutation landscape of TRAFs in various human cancers. Such analyses reveal that both gain- and loss-of-function genetic alterations of different TRAF proteins are commonly present in a number of human cancers. These include pancreatic cancer, meningioma, breast cancer, prostate cancer, lung cancer, liver cancer, head and neck cancer, stomach cancer, colon cancer, bladder cancer, uterine cancer, melanoma, sarcoma, and B cell malignancies, among others. Furthermore, we summarize the key in vivo and in vitro evidence that demonstrates the causal roles of genetic alterations of TRAF proteins in tumorigenesis within different cell types and organs. Taken together, the information presented in this review provides a rationale for the development of therapeutic strategies to manipulate TRAF proteins or TRAF-dependent signaling pathways in different human cancers by precision medicine.

miR-17-92 functions as an oncogene and modulates NF-κB signaling by targeting TRAF3 in MGC-803 human gastric cancer cells

The miR-17-92 cluster plays either an oncogenic or anti-oncogenic role in cancer progression in diverse human cancers. However, the underlying mechanisms of the miR-17-92 cluster in gastric cancer have not yet been fully elucidated. In this study, the function of the miR-17-92 cluster in diverse aspects of MGC-803 gastric cancer cells was systematically elucidated. The enforced introduction of the miR-17-92 cluster into the MGC-803 cells significantly promoted cell growth due to the increased cellular proliferation and decreased cellular apoptosis, which were detected by CCK-8, cell viability and TUNEL assays. Moreover, the results of western blot analyses revealed that the activated protein kinase B (AKT), extracellular-signal-regulated kinase (ERK) and nuclear factor (NF-κB) signaling pathways were activated in these processes. Moreover, the overexpression of the miR-17-92 cluster markedly enhanced the migratory and invasive abilities of the MGC-803 cells, which was associated with the occurrence of epithelial-mesenchymal transition (EMT). Tumor necrosis factor receptor associated factor 3 (TRAF3), which negatively regulates the NF-κB signaling pathway, was identified as a direct target of miR-17-92. Furthermore, TRAF3 silencing enhanced the oncogenic functions of the miR-17-92 cluster in the MGC-803 cells, including the increased cellular proliferation, migration and invasion. Moreover, immunohistochemical staining and survival analyses of a gastric cancer tissue microarray revealed that TRAF3 functioned as a tumor suppressor in gastric cancer. Taken together, the findings of this study provide new insight into the specific biological functions of the miR-17-92 cluster in gastric cancer progression by directly targeting TRAF3.

Involvement of Aryl Hydrocarbon Receptor and Aryl Hydrocarbon Receptor Repressor in Helicobacter Pylori-related Gastric Pathogenesis

Background: Persistent Helicobacter pylori (H. pylori) infection leads to various gastric diseases. Multiple studies have demonstrated that aryl hydrocarbon receptor (AHR) plays roles in the antibacterial response and aryl hydrocarbon receptor repressor (AHRR) is downregulated in stomach cancer. However, the role of AHR or AHRR in H. pylori-related gastric diseases remains unclear. Aims: To investigate whether AHR or AHRR is involved in H. pylori-related gastric diseases. Methods: Patients with gastritis or gastric adenocarcinoma were enrolled randomly, and gastric tissue specimens were diagnosed pathologically. AHR, AHRR, and H. pylori infection status in tissues were detected by immunohistochemistry. Human gastric cells were cocultured with H. pylori. siRNAs were used to silence AHR or AHRR, and a C57bl/6 mouse model colonized by H. pylori was established. Protein expression was determined by western blotting analysis, and TNF, IL-8 and IL-1β in cell supernatants were measured by ELISA. Results: AHR and AHRR were expressed in gastritis tissues and gastric cancer tissues without H. pylori infection, and principally located in the cytoplasm and nucleus. AHR expression was significantly correlated with AHRR expression in gastric tissues without H. pylori infection (P=0.008). However, their expressions were negatively correlated with H. pylori infection status. H. pylori coculture inhibited AHR and AHRR expression in stomach mucosa in vitro and in vivo. Gastric cells produced more TNF, IL-8 and IL-1β when AHR or AHRR was silenced. Conclusions: This preliminary study indicates that AHR and AHRR may be involved in H. pylori-related gastric pathogenesis, and helps toward understanding of inflammation-initiated carcinogenesis of gastric cancer.

miRNAs reshape immunity and inflammatory responses in bacterial infection

Pathogenic bacteria cause various infections worldwide, especially in immunocompromised and other susceptible individuals, and are also associated with high infant mortality rates in developing countries. MicroRNAs (miRNAs), small non-coding RNAs with evolutionarily conserved sequences, are expressed in various tissues and cells that play key part in various physiological and pathologic processes. Increasing evidence implies roles for miRNAs in bacterial infectious diseases by modulating inflammatory responses, cell penetration, tissue remodeling, and innate and adaptive immunity. This review highlights some recent intriguing findings, ranging from the correlation between aberrant expression of miRNAs with bacterial infection progression to their profound impact on host immune responses. Harnessing of dysregulated miRNAs in bacterial infection may be an approach to improving the diagnosis, prevention and therapy of infectious diseases.

Changes in production of tiny cellular RNAs in response to bacterial infection could guide the development of better diagnostics and therapies. MicroRNAs regulate other genes by binding to messenger RNA strands and controlling their translation into proteins. Xikun Zhou, Min Wu and colleagues of the University of North Dakota have now reviewed current knowledge about how microRNA levels shift during infection with various bacterial pathogens. These microRNAs can modulate the immune response as well as pathways that influence metabolic activity and cell survival. Increasing studies have indicated that shifts in microRNA levels in response to different infections could provide a potential bacterial ‘fingerprint’ for achieving accurate diagnosis. With deeper insight into how different microRNAs influence infection, it might one day day become possible to target these molecules with ‘antisense’ or ‘agonist’ drugs that modulate their activity.

NF-κB/miR-223-3p/ARID1A axis is involved in Helicobacter pylori CagA-induced gastric carcinogenesis and progression

Infection with Helicobacter pylori (H. pylori) and the resulting gastric inflammation is regarded as the strongest risk factor for gastric carcinogenesis and progression. NF-κB plays an important role in linking H. pylori-mediated inflammation to cancer. However, the underlying mechanisms are poorly understood. In this study, we find that H. pylori infection induces miR-223-3p expression in H. pylori CagA-dependent manner. NF-κB stimulates miR-223-3p expression via directly binding to the promoter of miR-223-3p and is required for H. pylori CagA-mediated upregulation of miR-223-3p. miR-223-3p promotes the proliferation and migration of gastric cancer cells by directly targeting ARID1A and decreasing its expression. Furthermore, miR-223-3p/ARID1A axis is involved in CagA-induced cell proliferation and migration. In the clinical setting, the level of miR-223-3p is upregulated, while ARID1A is downregulated significantly in human gastric cancer tissues compared with the corresponding noncancerous tissues. The expression level of miR-223-3p is significantly higher in H. pylori-positive gastric cancer tissues than that in H. pylori-negative tissues. Moreover, a negative correlation between miR-223-3p and ARID1A expression is found in the gastric cancer tissues. Taken together, our findings suggested NF-κB/miR-223-3p/ARID1A axis may link the process of H. pylori-induced chronic inflammation to gastric cancer, thereby providing a new insight into the mechanism underlying H. pylori-associated gastric diseases.

Genetic Alterations of TRAF Proteins in Human Cancers

The tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) family of cytoplasmic adaptor proteins regulate the signal transduction pathways of a variety of receptors, including the TNF-R superfamily, Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and cytokine receptors. TRAF-dependent signaling pathways participate in a diverse array of important cellular processes, including the survival, proliferation, differentiation, and activation of different cell types. Many of these TRAF-dependent signaling pathways have been implicated in cancer pathogenesis. Here we analyze the current evidence of genetic alterations of TRAF molecules available from The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutations in Cancer (COSMIC) as well as the published literature, including copy number variations and mutation landscape of TRAFs in various human cancers. Such analyses reveal that both gain- and loss-of-function genetic alterations of different TRAF proteins are commonly present in a number of human cancers. These include pancreatic cancer, meningioma, breast cancer, prostate cancer, lung cancer, liver cancer, head and neck cancer, stomach cancer, colon cancer, bladder cancer, uterine cancer, melanoma, sarcoma, and B cell malignancies, among others. Furthermore, we summarize the key in vivo and in vitro evidence that demonstrates the causal roles of genetic alterations of TRAF proteins in tumorigenesis within different cell types and organs. Taken together, the information presented in this review provides a rationale for the development of therapeutic strategies to manipulate TRAF proteins or TRAF-dependent signaling pathways in different human cancers by precision medicine.

Helicobacter: Inflammation, immunology and vaccines

Helicobacter pylori is usually acquired in early childhood and the infection persists lifelong without causing symptoms. In a small of cases, the infection leads to gastric or duodenal ulcer disease, or gastric cancer. Why disease occurs in these individuals remains unclear, however the host response is known to play a very important part. Understanding the mechanisms involved in maintaining control over the immune and inflammatory response is therefore extremely important. Vaccines against H. pylori have remained elusive but are desperately needed for the prevention of gastric carcinogenesis. This review focuses on research findings which may prove useful in the development of prognostic tests for gastric cancer development, therapeutic agents to control immunopathology, and effective vaccines.

Pathogenesis of Helicobacter pylori infection

Helicobacter pylori is responsible for the most commonly found infection in the world's population. It is the major risk factor for gastric cancer development. Numerous studies published over the last year provide new insights into the strategies employed by H. pylori to adapt to the extreme acidic conditions of the gastric environment, to establish persistent infection and to deregulate host functions, leading to gastric pathogenesis and cancer. In this review, we report recent data on the mechanisms involved in chemotaxis, on the essential role of nickel in acid resistance and gastric colonization, on the importance of adhesins and Hop proteins and on the role of CagPAI-components and CagA. Among the host functions, a special focus has been made on the escape from immune response, the ability of bacteria to induce genetic instability and modulate telomeres, the mechanism of autophagy and the deregulation of micro RNAs.

Correlation of serum levels of IL-4, IFN-γ and TNF-α with clinicopathologic features in patients with gastric cancer

AIM

To detect the serum levels of interleukin-4 (IL-4), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) in gastric cancer (GC) patients and analyze their correlation with clinicopathologic features.

METHODS

A total of 50 GC patients and 50 healthy subjects were included in this study. We detected their serum levels of IL-4, IFN-γ and TNF-α by enzyme-linked immunosorbent assay and collected their clinicopathological data. Then we analyzed the correlation between the serum levels of IL-4, IFN-γ, TNF-α and the clinicopathologic features by spearman correlation analysis.

RESULTS

Compared to healthy subjects, serum levels of IL-4 and TNF-α significantly increased (57.62 pg/mL vs 42.63 pg/mL, P < 0.05; 315.08 pg/mL vs 34.21 pg/mL, P < 0.05), but serum level of IFN-γ significantly decreased (14.95 pg/mL vs 24.92 pg/mL, P < 0.05) in GC patients. There was a positive correlation between serum level of IL-4 and the depth of tumor invasion(r = 0.571, P < 0.05), but there was a negative correlation between serum level of IFN-γ and the number of metastatic lymph nodes (r = -0.526, P < 0.05) and depth of tumor invasion (r = -0.671, P < 0.05). Serum level of TNF-α was positively correlated with tumor differentiation (r = 0.816, P < 0.05).

CONCLUSION

GC patients have altered serum levels of IL-4, IFN-γ and TNF-α, and they may be related to the occurrence and development of GC, and have certain clinical value in predicting the biological behavior of GC and in developing treatment strategies.