Background & Aims Nearly 20% of the global cancer burden can be linked to infectious agents. Fusobacterium nucleatum promotes tumor formation by epithelial cells via unclear mechanisms. We aimed to identify microRNAs (miRNAs) induced by F nucleatum and evaluate their ability to promote colorectal carcinogenesis in mice. Methods Colorectal cancer (CRC) cell lines were incubated with F nucleatum or control reagents and analyzed in proliferation and would healing assays. HCT116, HT29, LoVo, and SW480 CRC cell lines were incubated with F nucleatum or phosphate buffer saline (PBS control) and analyzed for miRNA expression patterns and in chromatin immunoprecipitation assays. Cells were incubated with miRNAs mimics, control sequences, or small interfering (si) RNAs; expression of reporter constructs was measured in luciferase assays. CRC cells were incubated with F nucleatum or PBS and injected into BALB/C nude mice; growth of xenograft tumors was measured. C57BL APCmin/+, C57BL miR21a−/−, and C57BL mice with full-length miR21a (controls) were given F nucleatum by gavage; some mice were given azoxymethane (AOM) and dextran sodium sulfate (DSS) to induce colitis and colon tumors. Intestinal tissues were collected and tumors were counted. Serum samples from mice were analyzed for cytokine levels by ELISAs. We performed in situ hybridization analyses to detect enrichment of F nucleatum in CRC cells. F nucleatum DNA in 90 tumor and matched non-tumor tissues from patients in China were explored for the expression correlation analysis; levels in 125 tumor tissues from patients in Japan were compared with their survival times. Results F nucleatum increased proliferation and invasive activities of CRC cell lines, compared with control cells. CRC cell lines infected with F nucleatum formed larger tumors, more rapidly, in nude mice than uninfected cells. APCmin/+ mice gavaged with F nucleatum developed significantly more colorectal tumors than mice given PBS and had shorter survival times. We found several inflammatory factors to be significantly increased in serum from mice given F nucleatum (interleukin 17F [IL17F], IL21, IL22, and MIP3A). We found 50 miRNAs to be significantly upregulated and 52 miRNAs to be significantly downregulated in CRCs incubated with F nucleatum vs PBS; levels of miR21 increased by the greatest amount (more than 4-fold). Inhibitors of miR21 prevented F nucleatum from inducing cell proliferation and invasion in culture. miR21a−/− mice had a later appearance of fecal blood and diarrhea after administration of AOM and DSS, and had longer survival times, compared with control mice. The colorectum of miR21a−/− mice had fewer tumors, of smaller size, and the miR21a−/− mice survived longer than control mice. We found RASA1, which encodes a RAS GTPase, to be one of the target genes consistently downregulated in cells that overexpressed miR21 and upregulated in cells exposed to miR21 inhibitors. Infection of cells with F nucleatum increased expression of miR21 by activating TLR4 signaling to MYD88, leadi...

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Radioresistance is a major challenge during the treatment of breast cancer. A further understanding of the mechanisms of radioresistance could provide strategies to address this challenge. In our study, we compared the expression of miR- Breast cancer is the most common cancer in women worldwide. 1 Radiotherapy is an important part of the treatment in most patients receiving breast-conserving surgery and displays significant clinical benefits, such as decreasing the risk of local recurrence and reducing the risk of mortality due to breast cancer. 2 However, for certain subtypes of breast cancer (e.g., basal-like), the local and regional control remains unsatisfactory. A major reason for this failure in treatment may be due to its radioresistance. 3-5 Therefore, understanding the molecular mechanisms involved in the radioresistance of breast tumors may lead to improved clinical outcomes.Autophagy is a cellular process that involves selfdegradation and recycling of macromolecules and cellular organelles. 6,7 It is, in most circumstances, a prosurvival mechanism under stressful conditions. Autophagy has been implicated in a variety of human diseases. [7][8][9] Similar to the situation in normal cells, autophagy is also critical for tumor cells to survive stressful conditions, and thus has been implicated in tumor resistance to chemotherapy and radiotherapy. [10][11][12][13] MicroRNAs (miRNAs) regulate a variety of biological processes, including cell proliferation, differentiation and invasion. 14 Dysregulation of miRNAs has been reported to contribute to cancer, 15,16 and implicated in chemoresistance and radioresistance via modulation of autophagy. 10,13 Such findings are not surprising considering the fact that miRNAs are key regulators of autophagy. 17 The miR-200 family is involved in the self-renewal of cancer stem cells, 18 epithelial-to-mesenchymal transition (EMT) 19,20 and chemosensitivity. 21 Recent studies indicated that miR-200c, the prevailing member of the miR-200 family, 19,20,22,23 could sensitize cancer cells to radiation by targeting TBK1 and VEGF-VEGFR2, despite the unspecified relationship between miR-200c and autophagy. 24,25 The results from our study showed that miR-200c could sensitize breast cancer cells to radiation via a mechanism associated with inhibition of irradiation-induced autophagy.

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Background/Aims: Recent studies have demonstrated that the manipulation of the gut microbiome represents a promising treatment for inflammatory bowel disease (IBD). We previously identified micro integral membrane protein (MIMP) as the smallest domain of surface layer protein from Lactobacillus Plantarum. However, the therapeutic relevance of MIMP in IBD remains unknown. Methods: We initially employed a dextran sodium sulphate (DSS)-induced colitis model and evaluated the effect of MIMP on the inflammation response, intestinal barrier and gut microbiota using histological examination, Fluorescein isothiocyanate-Dextran detection and pyrosequencing analysis respectively. We then established peripheral blood mononuclear cells (PBMCs) and an epithelial CaCO-2 co-culture model to investigate the regulatory role of MIMP in inflammatory cytokines. The level changes of inflammatory cytokines were detected using Enzyme-linked immunosorbent and real-time polymerase chain reaction assay. The involved regulatory mechanisms were investigated mainly using dual luciferase reporter and chromatin immunoprecipitation assay. Results: In the DSS-induced colitis model, we observed that MIMP intervention effectively improved the body weight loss, increased the colon length and decreased disease activity index. Consistently, the inflammation scores in the MIMP treatment group were significantly lower than those in the DSS treatment group. Furthermore, MIMP intervention was found to successfully neutralize DSS treatment by decreasing the expression of pro-inflammatory cytokines (IFN-γ, IL-17 and IL-23) and increasing the expression of anti-inflammatory cytokines (IL-4 and IL-10). Notably, the permeability assay demonstrated that the MIMP treatment group was remarkably lower than that in the DSS treatment group. We also showed that MIMP improved gut microbiota dysbiosis caused by DSS-induced inflammation. Additionally, in PBMCs and the CaCO-2 co-culture model, MIMP showed an obvious suppressive effect on lipopolysaccharide-induced inflammation in a time- and dose-dependent manner. Furthermore, we revealed that MIMP could modulate inflammatory cytokine expression through the toll-like receptor 4 pathway and histone acetylation. Conclusions: Our results suggested that MIMP showed a significant anti-inflammatory effect through regulating the gut barrier, microbiota and inflammatory cytokines. MIMP may have translational relevance as clinically relevant therapy for IBD patients.

Acid-sensing ion channels 1a (ASIC1a) has been reported to promote migration and invasion in liver cancer. However, the clinical significance and molecular mechanism of ASIC1a in liver cancer remain unknown. In the study, we found that ASIC1a is frequently up-regulated in liver cancer tissues. The over-expression of ASIC1a is associated with advanced clinical stage and poor prognosis. The pro-proliferative of ASIC1a is pH dependent. Knockout of ASIC1a by CRISPR/CAS9 inhibited liver cancer cell proliferation and tumorigenicity in vitro and in vivo through β-catenin degradation and LEF-TCF inactivation. Our results indicated a potential diagnostic marker and chemotherapeutic target for liver cancer.

Background Posttranscriptional modification of tumor-associated factors plays a pivotal role in breast cancer progression. However, the underlying mechanism remains unknown. M6A modifications in cancer cells are dynamic and reversible and have been found to impact tumor initiation and progression through various mechanisms. In this study, we explored the regulatory mechanism of breast cancer cell proliferation and metabolism through m6A methylation in the Hippo pathway.  Methods A combination of MeRIP-seq, RNA-seq and metabolomics-seq was utilized to reveal a map of m6A modifications in breast cancer tissues and cells. We conducted RNA pull-down assays, RIP-qPCR, MeRIP-qPCR, and RNA stability analysis to identify the relationship between m6A proteins and LATS1 in m6A regulation in breast cancer cells. The expression and biological functions of m6A proteins were confirmed in breast cancer cells in vitro and in vivo. Furthermore, we investigated the phosphorylation levels and localization of YAP/TAZ to reveal that the activity of the Hippo pathway was affected by m6A regulation of LATS1 in breast cancer cells.  Results We demonstrated that m6A regulation plays an important role in proliferation and glycolytic metabolism in breast cancer through the Hippo pathway factor, LATS1. METTL3 was identified as the m6A writer, with YTHDF2 as the reader protein of LATS1 mRNA, which plays a positive role in promoting both tumorigenesis and glycolysis in breast cancer. High levels of m6A modification were induced by METTL3 in LATS1 mRNA. YTHDF2 identified m6A sites in LATS1 mRNA and reduced its stability. Knockout of the protein expression of METTL3 or YTHDF2 increased the expression of LATS1 mRNA and suppressed breast cancer tumorigenesis by activating YAP/TAZ in the Hippo pathway. Conclusions In summary, we discovered that the METTL3-LATS1-YTHDF2 pathway plays an important role in the progression of breast cancer by activating YAP/TAZ in the Hippo pathway.

Breast cancer has become one of the most serious disease threatening mankind health in the world. Accumulating studies indicated that circRNAs played an important role in the occurrence and progression of breast cancer, however, the roles of circRNA_103809 in breast cancer progression remain unclear. Therefore, in this study, we aimed to clarify the potential role and regulatory mechanism of circRNA_103809 in the development of breast cancer. Firstly, the expression level of circRNA_103809 and microRNA-532-3p (miR-532-3p) in breast cancer tissues and normal tissues were detected with the quantitative real-time polymerase chain reaction (RT-qPCR). In addition, the cell proliferation ability, metastasis ability and related pathways were identified by Cell Counting Kit-8 (CCK-8), flow cytometry, and western blot, respectively. Furthermore, the connection between circRNA_103809 and miR-532-3p was detected by dual-luciferase reporter assay. Then, our data showed that circRNA_103809 was down-regulated in breast cancer tissues in contrast to adjacent non-tumor tissues, and the relative expression level of circRNA_103809 was closely associated with distant metastasis size, TNM stage, HER-2 status and overall survival time. In addition, our in vitro assays showed that the overexpression of circRNA_103809 could significantly inhibit epithelialmesenchymal transition (EMT) pathway, then suppress breast cancer cell proliferation and metastasis ability. Moreover, we also found that the antitumor effect induced by circRNA_103809 could be reversed with the addition of miR-532-3p mimics. Taken together, this study showed that circRNA_103809 could inhibit cell proliferation and metastasis in breast cancer by sponging miR-532-3p, and circRNA_103809 might be a prospective target of breast cancer therapy.