Genome-wide mRNA-miRNA profiling uncovers a role of the microRNA miR-29b-1-5p/PHLPP1 signalling pathway in Helicobacter pylori-driven matrix metalloproteinase production in gastric epithelial cells

AMPK activation reduces cancer cell aggressiveness via inhibition of monoamine oxidase A (MAO-A) expression/activity

AIM

AMPK can be considered as an important target molecule for cancer for its unique ability to directly recognize cellular energy status. The main aim of this study is to explore the role of different AMPK activators in managing cancer cell aggressiveness and to understand the mechanistic details behind the process.

MAIN METHODS

First, we explored the AMPK expression pattern and its significance in different subtypes of lung cancer by accessing the TCGA data sets for LUNG, LUAD and LUSC patients and then established the correlation between AMPK expression pattern and overall survival of lung cancer patients using Kaplan-Meire plot. We further carried out several cell-based assays by employing different wet lab techniques including RT-PCR, Western Blot, proliferation, migration and invasion assays to fulfil the aim of the study.

KEY FINDINGS

SIGNIFICANCE: This study identifies the importance of AMPK activators as a repurposing agent for combating lung and colon cancer cell aggressiveness. It also suggests SRT-1720 as a potent repurposing agent for cancer treatment especially in NSCLC patients where a point mutation is present in LKB1.

The regulation roles of miRNAs in Helicobacter pylori infection

Helicobacter pylori is a kind of Gram-negative bacteria that parasitizes on human gastric mucosa. Helicobacter pylori infection is very common in human beings, which often causes gastrointestinal diseases, including chronic gastritis, duodenal ulcer and gastric cancer. MicroRNAs are a group of endogenous non-coding single stranded RNAs, which play an important role in cell proliferation, differentiation, autophagy, apoptosis and inflammation. In recent years, relevant studies have found that the expression of microRNA is changed after Helicobacter pylori infection, and then regulate the biological process of host cells. This paper reviews the regulation role of microRNAs on cell biological behavior through different signal pathways after Helicobacter pylori infection.

Uncovering the role of microRNA671-5p/CDCA7L/monoamine oxidase-A signaling in Helicobacter pylori mediated apoptosis in gastric epithelial cells

Helicobacter pylori is a gram-negative microaerophilic bacterium and is associated with gastrointestinal diseases ranging from peptic ulcer and gastritis to gastric cancer and mucosa-associated lymphoid tissue lymphoma. In our laboratory, the transcriptomes and miRnomes of AGS cells infected with H. pylori have been profiled, and an miRNA-mRNA network has been constructed. MicroRNA 671-5p is upregulated during H. pylori infection of AGS cells or of mice. In this study, the role of miR-671-5p during infection has been investigated. It has been validated that miR-671-5p targets the transcriptional repressor CDCA7L, which is downregulated during infection (in vitro and in vivo) concomitant with miR-671-5p upregulation. Further, it has been established that the expression of monoamine oxidase A (MAO-A) is repressed by CDCA7L, and that MAO-A triggers the generation of reactive oxygen species (ROS). Consequently, miR-671-5p/CDCA7L signaling is linked to the generation of ROS during H. pylori infection. Finally, it has been demonstrated that ROS-mediated caspase 3 activation and apoptosis that occurs during H. pylori infection, is dependent on the miR-671-5p/CDCA7L/MAO-A axis. Based on the above reports, it is suggested that targeting miR-671-5p could offer a means of regulating the course and consequences of H. pylori infection.

Current and future perspectives for Helicobacter pylori treatment and management: From antibiotics to probiotics

Helicobacter pylori (H. pylori) is a Gram-negative anaerobic bacterium that colonizes the human stomach and is the leading cause of gastric diseases such as chronic gastritis and peptic ulcers, as well as the most definite and controllable risk factor for the development of gastric cancer. Currently, the regimen for H. pylori eradication has changed from triple to quadruple, the course of treatment has been extended, and the type and dose of antibiotics have been adjusted, with limited improvement in efficacy but gradually increasing side effects and repeated treatment failures in an increasing number of patients. In recent years, probiotics have become one of the most important tools for supporting intestinal health and immunity. Numerous in vitro studies, animal studies, and clinical observations have demonstrated that probiotics have the advantage of reducing side effects and increasing eradication rates in adjuvant anti-H. pylori therapy and are a valuable supplement to conventional therapy. However, many different types of probiotics are used as adjuncts against H. pylori, in various combinations, with different doses and timing, and the quality of clinical studies varies, making it difficult to standardize the results. In this paper, we focus on the risk, status, prevention, control, and treatment of H. pylori infection and review international consensus guidelines. We also summarize the available scientific evidence on using Limosilactobacillus reuteri (L. reuteri) as a critical probiotic for H. pylori treatment and discuss its clinical research and application from an evidence-based perspective.

Clues for Improving the Pathophysiology Knowledge for Endometriosis Using Plasma Micro-RNA Expression

The pathophysiology of endometriosis remains poorly understood. The aim of the present study was to investigate functions and pathways associated with the various miRNAs differentially expressed in patients with endometriosis. Plasma samples of the 200 patients from the prospective "ENDO-miRNA" study were analyzed and all known human miRNAs were sequenced. For each miRNA, sensitivity, specificity, and ROC AUC values were calculated for the diagnosis of endometriosis. miRNAs with an AUC ≥ 0.6 were selected for further analysis. A comprehensive review of recent articles from the PubMed, Clinical Trials.gov, Cochrane Library, and Web of Science databases was performed to identify functions and pathways associated with the selected miRNAs. In total, 2633 miRNAs were found in the patients with endometriosis. Among the 57 miRNAs with an AUC ≥ 0.6: 20 had never been reported before; one (miR-124-3p) had previously been observed in endometriosis; and the remaining 36 had been reported in benign and malignant disorders. miR-124-3p is involved in ectopic endometrial cell proliferation and invasion and plays a role in the following pathways: mTOR, STAT3, PI3K/Akt, NF-κB, ERK, PLGF-ROS, FGF2-FGFR, MAPK, GSK3B/β-catenin. Most of the remaining 36 miRNAs are involved in carcinogenesis through cell proliferation, apoptosis, and invasion. The three main pathways involved are Wnt/β-catenin, PI3K/Akt, and NF-KB. Our results provide evidence of the relation between the miRNA profiles of patients with endometriosis and various signaling pathways implicated in its pathophysiology.

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.

Nuclear Factor κB Signaling and Its Related Non-coding RNAs in Cancer Therapy

Nuclear factor κB (NF-κB) acts as a nuclear factor that is composed of five main subunits. It is a pluripotent and crucial dimer transcription factor that has a close relationship with many serious illnesses, especially its influences on cell proliferation, inflammation, and cancer initiation and progression. NF-κB acts as part of the signaling pathway and determines its effect on the expression of several other genes, such as epidermal growth factor receptor (EGFR), p53, signal transducer and activator of transcription 3 (STAT3), and non-coding RNA (ncRNA). Continuous activation of the NF-κB signaling pathway has been seen in many cancer types. While the NF-κB signaling pathway is tightly regulated in physiological settings, quite frequently it is constitutively activated in cancer, and the molecular biology mechanism underlying the deregulated activation of NF-κB signaling remains unclear. In this review, we discuss the regulatory role and possible clinical significance of ncRNA (microRNA [miRNA] and long non-coding RNA [lncRNA]) in NF-κB signaling in cancer, including in the conversion of inflammation to carcinogenesis. Non-coding RNA plays an essential and complex role in the NF-κB signaling pathway. NF-κB activation can also induce the ncRNA status. Targeting NF-κB signaling by ncRNA is becoming a promising strategy of drug development and cancer treatment.

Review: Pathogenesis of Helicobacter pylori infection

In this review, we shall focus on the last year progression understanding the pathogenesis of Helicobacter pylori infection in the light of recent data related to adaptation of H pylori to the harsh acidic environment in the stomach, colonization of gastric mucosa via interaction with mucin 5 (MUC5AC) and other host cell receptors, the ability to form biofilm, interference with the host metabolic pathways, and induction of neuroimmune cross-talk as well as downregulation of gastric barrier homeostasis and its consequences for the disease development. The role of the membrane vesicles of these bacteria has been emphasized as an important source of virulence factors. Furthermore, we shall describe molecular and functional studies on new aspects of VacA and CagA virulence, including the role of urease in the upregulation of VacA toxicity, an epithelial-mesenchymal transition mediated by CagA, and the role of interaction of HopQ adhesin with carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) in CagA translocation into the host cells by the type IV secretion system (T4SS). The role of molecular mimicry between a common sequence (ATVLA) of H pylori heat shock protein (Hsp) B and human Hsp60 in the induction of potentially autoreactive antibodies is discussed. All these new data illustrate further progress in understanding H pylori pathogenicity and facilitate the search for new therapeutic targets as well as development of immunoprophylaxis methods based on new chimeric UreB and HpA proteins.

Helicobacter pylori-Induced DNA Damage Is a Potential Driver for Human Gastric Cancer AGS Cells

Helicobacter pylori is a major cause of gastric cancer. This study was aimed to explore the characteristic of DNA damage induced by H. pylori infection in gastric cancer AGS cells. After infection with H. pylori, the reactive oxygen species (ROS) levels in AGS cells were significantly higher than those in the uninfected cells. Cells with longer comet tails were detected after infection with H. pylori. The number of apurinic/apyrimidinic endonuclease 1- and phosphorylated H2AX-positive cells was significantly increased compared with the number of negative control cells. The expression of pChk1 and pChk2 was significantly upregulated by H. pylori infection. Cell growth was inhibited after H. pylori infection. All these results were dose dependent. The cell alterations were more significant upon infection with H. pylori at a multiplicity of infection (MOI) of 100:1 than at an MOI of 50:1. H. pylori infection can induce DNA single-strand breaks, DNA double-strand breaks, and cell cycle checkpoint activation after ROS generation in the gastric cancer cell line AGS, which is a potential driver for gastric cancer.

Mechanisms of Inflammasome Signaling, microRNA Induction and Resolution of Inflammation by Helicobacter pylori

Inflammasome-controlled transcription and subsequent cleavage-mediated activation of mature IL-1β and IL-18 cytokines exemplify a crucial innate immune mechanism to combat intruding pathogens. Helicobacter pylori represents a predominant persistent infection in humans, affecting approximately half of the population worldwide, and is associated with the development of chronic gastritis, peptic ulcer disease, and gastric cancer. Studies in knockout mice have demonstrated that the pro-inflammatory cytokine IL-1β plays a central role in gastric tumorigenesis. Infection by H. pylori was recently reported to stimulate the inflammasome both in cells of the mouse and human immune systems. Using mouse models and in vitro cultured cell systems, the bacterial pathogenicity factors and molecular mechanisms of inflammasome activation have been analyzed. On the one hand, it appears that H. pylori-stimulated IL-1β production is triggered by engagement of the immune receptors TLR2 and NLRP3, and caspase-1. On the other hand, microRNA hsa-miR-223-3p is induced by the bacteria, which controls the expression of NLRP3. This regulating effect by H. pylori on microRNA expression was also described for more than 60 additionally identified microRNAs, indicating a prominent role for inflammatory and other responses. Besides TLR2, TLR9 becomes activated by H. pylori DNA and further TLR10 stimulated by the bacteria induce the secretion of IL-8 and TNF, respectively. Interestingly, TLR-dependent pathways can accelerate both pro- and anti-inflammatory responses during H. pylori infection. Balancing from a pro-inflammation to anti-inflammation phenotype results in a reduction in immune attack, allowing H. pylori to persistently colonize and to survive in the gastric niche. In this chapter, we will pinpoint the role of H. pylori in TLR- and NLRP3 inflammasome-dependent signaling together with the differential functions of pro- and anti-inflammatory cytokines. Moreover, the impact of microRNAs on H. pylori-host interaction will be discussed, and its role in resolution of infection versus chronic infection, as well as in gastric disease development.

Long noncoding RNA n339260 promotes vasculogenic mimicry and cancer stem cell development in hepatocellular carcinoma

Vasculogenic mimicry (VM) refers to the unique capability of aggressive tumor cells to mimic the pattern of embryonic vasculogenic networks. Cancer stem cells (CSC) represent a subpopulation of tumor cells endowed with the capacity for self‐renewal and multilineage differentiation. Previous studies have indicated that CSC may participate in the formation of VM. With the advance of high‐resolution microarrays and massively parallel sequencing technology, long noncoding RNAs (lncRNAs) are suggested to play a critical role in tumorigenesis and, in particular, the development of human hepatocellular carcinoma (HCC). Currently, no definitive relationship between lncRNA and VM formation has been described. In the current study, we demonstrated that expression of the lncRNA, n339260, is associated with CSC phenotype in HCC, and n339260 level correlated with VM, metastasis, and shorter survival time in an animal model. Overexpression of n339260 in HepG2 cells was associated with a significant increase in CSC. Additionally, the appearance of VM and vascular endothelial (VE)‐cadherin, a molecular marker of VM, was also induced by n339260 overexpression. Using a short hairpin RNA approach, n339260 was silenced in tumor cells, and knockdown of n339260 was associated with reduced VM and CSC. The results of this study indicate that n339260 promotes VM, possibly by the development of CSC. The related molecular pathways may be used as novel therapeutic targets for the inhibition of HCC angiogenesis and metastasis.