CircUGGT2 downregulation by METTL14-dependent m6A modification suppresses gastric cancer progression and cisplatin resistance through interaction with miR-186-3p/MAP3K9 axis.

Chemoresistance is a major therapeutic challenge in advanced gastric cancer (GC). N6-methyladenosine (m6A) RNA modification has been shown to play fundamental roles in cancer progression. However, the underlying mechanisms by which m6A modification of circRNAs contributes to GC and chemoresistance remain unknown. We found that hsa_circ_0030632 (circUGGT2) was a predominant m6A target of METTL14, and METTL14 knockdown (KD) reduced circUGGT2 m6A levels but increased its mRNA levels. The expression of circUGGT2 was markedly increased in cisplatin (DDP)-resistant GC cells. CircUGGT2 KD impaired cell growth, metastasis and DDP-resistance in vitro and in vivo, but circUGGT2 overexpression prompted these effects. Furthermore, circUGGT2 was validated to sponge miR-186-3p and upregulate MAP3K9 and could abolish METTL14-caused miR-186-3p upregulation and MAP3K9 downregulation in GC cells. circUGGT2 negatively correlated with miR-186-3p expression and harbored a poor prognosis in patients with GC. Our findings unveil that METTL14-dependent m6A modification of circUGGT2 inhibits GC progression and DDP resistance by regulating miR-186-3p/MAP3K9 axis.

METTL14-mediated m6A modification of circORC5 suppresses gastric cancer progression by regulating miR-30c-2-3p/AKT1S1 axis.

BACKGROUND: N6-methyladenosine (m6A) RNA methylation and circular RNAs (circRNAs) have been shown to act vital roles in multiple malignancies including gastric cancer (GC). However, there is little knowledge about how m6A modification of circRNAs contributes to GC progression. METHODS: The association of METTL14 expression with the clinicopathological characteristics and prognosis in patients with GC was assessed by Western blot, Immunohistochemistry and public datasets. In vitro and vivo function experiments were conducted to investigate the role of METTL14 in GC. Furthermore, m6A-circRNA epitranscriptomic microarray was utilized to identify METTL14-mediated m6A modification of circRNAs, which were validated by methylated RNA immunoprecipitation (Me-RIP), RT-qPCR and rescue experiments in GC cells. The sponge of circORC5 with miR-30c-2-3p was confirmed by luciferase gene report and RNA immunoprecipitation assays. The expression, localization and prognosis of circORC5 in GC were evaluated by fluorescence in situ hybridization. The effects of METTL14 and (or) circORC5 on miR-30c-2-3p-mediated AKT1S1 and EIF4B were estimated by RT-qPCR and Western blot analyses. RESULTS: We found that METTL14 was downregulated in GC tissue samples and its low expression acted as a prognostic factor of poor survival in patients with GC. Ectopic expression of METTL14 markedly repressed growth and invasion of GC cells in vitro and in vivo, whereas knockdown of METTL14 harbored the opposite effects. Mechanically, m6A-circRNA epitranscriptomic microarray and Me-RIP identified circORC5 as the downstream target of METTL14. Silencing of METTL14 reduced the m6A level of circORC5, but increased circORC5 expression. Moreover, circORC5 could sponge miR-30c-2-3p, and reverse METTL14-caused upregulation of miR-30c-2-3p and downregulation of AKT1S1 and EIF4B. In addition, circORC5 possessed a negative correlation with miR-30c-2-3p and indicated a poor survival in GC. CONCLUSION: Our findings demonstrate that METTL14-mediated m6A modification of circORC5 suppresses gastric cancer progression by regulating miR-30c-2-3p/AKT1S1 axis.

Alterations in the saliva microbiome in patients with gastritis and small bowel inflammation.

The oral microbiome is an important part of the human microbiome. Accumulating data have shown that oral microbiome alterations are closely related to multiple human diseases. However, salivary microbiota distributions remain unclear in patients with gastritis and small bowel inflammation. Magnetically guided capsule endoscopy (MGCE) is a noninvasive diagnostic tool for patients with gastritis and small bowel inflammation. Herein, we analysed the alterations in saliva microbiota in the normal, small intestinal inflammation and chronic gastritis groups through 16S rRNA gene amplicon sequencing. We found that the abundance of Lactobacillaceae was dramatically higher in chronic gastritis group than healthy individuals (p = 0.001). The levels of Porphyromonas and Faecalibaculum in gastritis samples were increased (p = 0.028; p = 0.006), and the enrichments of Faecalibaculum and Kosakonia in small intestine inflammation samples were elevated (p < 0.001; p = 0.002) compared to those in normal individuals. Our findings clarify the saliva microbiota components and their importance of specific bacteria in gastritis and small bowel inflammation.

Mucosal microbiome dysbiosis associated with duodenum bulb inflammation.

BACKGROUND: There is high morbidity in clinical patients with duodenum bulb inflammation. Mucosa-associated microbiota, which are closely related to inflammatory processes, may have a pathogenic role, but the duodenum bulb microbial signature is poorly studied. OBJECTIVE: This study aimed to characterize microbial changes associated with duodenum bulb inflammation. METHODS: Mucosal biopsy is commonly used to assess microbial communities associated with the intestinal mucosa. Sixteen patients (8 with duodenum bulb inflammation and 8 controls) underwent gastroscopy, and duodenal bulb biopsies were obtained. Diagnoses were based on both endoscopic and histological findings. To determine microbiota composition and diversity, 454 pyrosequencing of bacterial 16S rRNA and multiple bioinformatics analyses were performed. OTU-level alpha diversity indices, such as the Chao1 richness estimator, abundance-based coverage estimator (ACE) metric, Shannon diversity index, and Simpson index, were calculated using the OTU table in QIIME. RESULTS: More OTUs were identified in the normal samples (781) than in the inflammatory samples (553). Metastats analysis identified 19 phyla and 97 genera that were significantly different between the two groups, and the beta diversity was significantly different between the two groups (unweighted UniFrac: P = 0.001; weighted UniFrac: P = 0.001). For all individuals, composition analyses showed that the most abundant phyla in the duodenal bulb samples were Fusobacteria, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria. The phylogenetic diversity of the microbiota in the duodenal bulbs of healthy volunteers was higher than that in volunteers with inflammation. Dominant microbes differed between the DN samples and DI samples. The most frequently represented genera in the DN samples were Cetobacterium, Aeromonadaceae, and Clostridium (accounting for 58.4%, 8.5%, and 4.8% of the total, respectively), and the dominant genera in the DI samples were Cetobacterium, Cupriavidus, and Helicobacter (accounting for 43.6%, 13.1%, 4.5% of the total, respectively). Significant differences in the microbiota were observed between those exhibiting an inflammatory state and the controls. CONCLUSIONS: These results confirm that the dominant species in duodenum bulbs differ between healthy subjects and patients with inflammation and that mucosal microbiome dysbiosis is involved in the development of duodenum bulb inflammation.

Novel insights into the interplay between m6A modification and noncoding RNAs in cancer.

N6-methyladenosine (m6A) is one of the most common RNA modifications in eukaryotes, mainly in messenger RNA (mRNA). Increasing evidence shows that m6A methylation modification acts an essential role in various physiological and pathological bioprocesses. Noncoding RNAs (ncRNAs), including miRNAs, lncRNAs and circRNAs, are known to participate in regulating cell differentiation, angiogenesis, immune response, inflammatory response and carcinogenesis. m6A regulators, such as METTL3, ALKBH5 and IGF2BP1 have been reported to execute a m6A-dependent modification of ncRNAs involved in carcinogenesis. Meanwhile, ncRNAs can target or modulate m6A regulators to influence cancer development. In this review, we provide an insight into the interplay between m6A modification and ncRNAs in cancer.

Correction to: CircDLST promotes the tumorigenesis and metastasis of gastric cancer by sponging miR-502-5p and activating the NRAS/MEK1/ERK1/2 signaling.

An amendment to this paper has been published and can be accessed via the original article.

Mild changes in the mucosal microbiome during terminal ileum inflammation.

Patients with inflammation in the terminal ileum have high morbidity. In genetically susceptible hosts, chronic intestinal inflammation targeting the resident intestinal microbiota develops, but the microbial signature of the terminal ileum is poorly studied. To improve understanding of the mechanisms underlying the high prevalence of terminal ileum inflammation, we used 16S rRNA sequencing to analyse the mucosa-associated microbiota of the terminal ileum under intestinal homeostasis and inflammation conditions. Mucosal biopsy is the most commonly used sampling technique for assessing microbial communities associated with the intestinal mucosa. Thirty patients (15 with terminal ileum inflammation and 15 controls) underwent colonoscopy and biopsies were taken from the terminal ileum. Diagnosis depended on a combination of endoscopic and histological factors. To determine the composition and diversity of the microbiota, the 16S rRNA was analysed, and a variety of bioinformatics analyses were performed. Among the patients, composition analysis showed that the most abundant phyla identified in the terminal ileum samples were Fusobacteria, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria. At the phylum level, the relative proportion of Bacteroidetes was lower in patients with inflammation than in control patients. In addition, there was an increase in the abundance of the phyla Proteobacteria and Lentisphaerae in patients with inflammation. The abundances of the dominant microbes in the terminal ileum were not significantly different between patients in an inflammatory state and controls. These results confirm that partial dysbiosis of the intestinal mucosa-associated microbiota composition is associated with terminal ileum inflammation.

Taraxacum officinale extract ameliorates dextran sodium sulphate-induced colitis by regulating fatty acid degradation and microbial dysbiosis.

Numerous data show that taraxacum officinale extract (TOE) exerts protective effects on inflammatory diseases. However, the underlying mechanisms by which TOE affects dextran sulphate sodium (DSS)-induced colitis remain unclear. After DSS-induced colitis were treated with different concentrations of TOE for 8 days, the bodyweight, disease activity index (DAI), colon lengths and pathological scoring were assessed, and histopathological examination was confirmed by HE staining. Furthermore, a transcriptome sequencing was performed by using the colon tissues between TOE and DSS groups, and the differentially expressed genes were conducted for the Kyoto Encyclopaedia of Genes and Genomes (KEGG) and gene set enrichment analysis (GSEA) and were validated by qRT-PCR and immunohistochemistry analysis. In addition, a 16S rDNA sequencing was carried out to distinguish the differential gut microbiota by using the mouse faecal samples between TOE and DSS groups. We found that TOE attenuated the clinical symptoms, lowered the inflammatory scoring and inhibited the secretion of proinflammatory factors TNF-α, IL-1ß and IL-6 in DSS-induced colitis. KEGG and GSEA analysis demonstrated that fatty acid degradation and cytokine-receptor signalling were predominantly enriched in TOE-treated colitis as compared with the DSS group. Further investigations revealed that TOE increased the expression levels of Adh5, Aldh3a2 and Acox3, but decreased those of CCL20, CCR6 and CXCL1/5 in DSS-induced colitis, where TOE also induced the enrichment of S24-7 and adlercreutzia, but decreased the amount of anaerostipes, enterococcus, enterobacteriaceae and peptostreptococcaceae. In conclusion, TOE ameliorated DSS-induced colitis by regulating fatty acid degradation and microbial dysbiosis.

The role of m6A RNA methylation in human cancer.

N6-methyladenosine (m6A) is identified as the most common, abundant and conserved internal transcriptional modification, especially within eukaryotic messenger RNAs (mRNAs). M6A modification is installed by the m6A methyltransferases (METTL3/14, WTAP, RBM15/15B and KIAA1429, termed as "writers"), reverted by the demethylases (FTO and ALKBH5, termed as "erasers") and recognized by m6A binding proteins (YTHDF1/2/3, IGF2BP1 and HNRNPA2B1, termed as "readers"). Acumulating evidence shows that, m6A RNA methylation has an outsize effect on RNA production/metabolism and participates in the pathogenesis of multiple diseases including cancers. Until now, the molecular mechanisms underlying m6A RNA methylation in various tumors have not been comprehensively clarified. In this review, we mainly summarize the recent advances in biological function of m6A modifications in human cancer and discuss the potential therapeutic strategies.

CircDLST promotes the tumorigenesis and metastasis of gastric cancer by sponging miR-502-5p and activating the NRAS/MEK1/ERK1/2 signaling.

BACKGROUND: Accumulating evidence shows that, the dysregulation of circular RNAs (circRNAs) is associated with the progression of multiple malignancies. But, the underlying mechanisms by which has_circ_0032627 (circDLST) contributed to gastric cancer (GC) remain undocumented. METHODS: The expression and cellular localization of circDLST and its association with clinicopathological characteristics and prognosis in patients with GC was analysed by using fluorescence in situ hybridization. Gain- and loss-of-function experiments as well as a subcutaneous xenograft tumor model and a liver metastasis model from orthotopic implantation of GC tissues were conducted to assess the role of circDLST in GC cells. CircDLST specific binding with miR-502-5p was confirmed by dual luciferase gene report, RNA immunoprecipitation (RIP) assays and RIP-miRNA expression profiling. qRT-PCR and Western blot analysis was used to detect the effects of circDLST on miR-502-5p-mediated NRAS/MEK1/ERK1/2 signaling in GC cells. RESULTS: The expression levels of circDLST were dramatically elevated in GC tissues as compared with the adjacent normal tissues, and acted as an independent prognostic factor of poor survival in patients with GC. Knockdown of circDLST inhibited the cell viability, colony formation, DNA synthesis, cell invasion and liver metastasis in vitro and in vivo, whereas overexpression of circDLST had the opposite effects. Furthermore, circDLST was co-localized with miR-502-5p in the cytoplasm of GC cells, and acted as a sponge of miR-502-3p in GC cells, which abrogated the tumor promoting effects of circDLST by inactivating the NRAS/MEK1/ERK1/2 signaling in GC cells. CONCLUSION: CircDLST promotes the tumorigenesis and metastasis of GC cells by sponging miR-502-5p to activate the NRAS/MEK1/ERK1/2 signaling.

Correction to: Circular RNA YAP1 inhibits the proliferation and invasion of gastric cancer cells by regulating the miR-367-5p/p27 Kip1 axis.

After the publication of this work [1], a spelling error was found: the ID of the circRNA, termed circYAP1, in the original publication was misspelled as "has_circ_0002320".

Circular RNA YAP1 inhibits the proliferation and invasion of gastric cancer cells by regulating the miR-367-5p/p27 Kip1 axis.

BACKGROUND: Circular RNAs (circRNAs) are a new type of non-coding RNAs and their functions in gastric cancer (GC) remain unclear. Recent studies have revealed that circRNAs play an important role in cancer development and certain types of pathological responses, acting as microRNA (miRNA) sponges to regulate gene expression. METHODS: CircNet was used to screen potential circRNAs and validated circYAP1 expression levels in 17 GC tissues by quantitative real-time PCR (qRT-PCR) and another 80 paired GC tissues by FISH. CircYAP1 overexpression and knockdown experiments were conducted to assess the effects of circYAP1 in vitro and in vivo, and its molecular mechanism was demonstrated by RNA in vivo precipitation assays, western blotting, luciferase assay and rescue experiments. RESULTS: CircYAP1 expression level was significantly lower in GC tissues than the adjacent normal tissues, and GC patients with circYAP1 low expression had shorter survival times as compared with those with circYAP1 high expression. Functionally, circYAP1 overexpression inhibited cell growth and invasion in vitro and in vivo, but its knockdown reversed these effects. Further analysis showed that circYAP1 sponged miR-367-5p to inhibit p27 Kip1 expression and GC progression. CONCLUSION: Our findings demonstrate that circYAP1 functions as a tumor suppressor in GC cells by targeting the miR-367-5p/p27 Kip1 axis and may provide a prognostic indicator of survival in GC patients.

CircSLC3A2 functions as an oncogenic factor in hepatocellular carcinoma by sponging miR-490-3p and regulating PPM1F expression.

BACKGROUND: Non-coding RNAs (ncRNAs) have been reported to participate in tumor progression by regulating gene expression. Previous studies showed that protein phosphatase Mg2+/Mn2+ dependent 1F (PPM1F) acts a dual role in cancer growth and metastasis. But, the underlying mechanisms by which ncRNAs regulate PPM1F expression in hepatocellular carcinoma (HCC) are poorly understood. METHODS: The association between PPM1F or miR-490-3p expression and clinicopathological features and prognosis in patients with HCC was analyzed by TCGA RNA-sequencing data. CircSLC3A2 was identified to bind with miR-490-3p by bioinformatic analysis, and the binding sites between miR-490-3p and PPM1F or circSLC3A2 were confirmed by dual luciferase report and RNA immunoprecipitation (RIP) assays. The localization and clinical significance of miR-490-3p and circSLC3A2 in patients with HCC were investigated by fluorescence in situ hybridization (FISH). MTT, Agar, and Transwell assays were conducted to evaluate the effects of miR-490-3p or circSLC3A2 on cell proliferation and invasive potential. RESULTS: The expression of PPM1F or miR-490-3p was associated with poor survival and tumor recurrence, and acted as an independent prognostic factor in patients with HCC. Re-expression of miR-490-3p inhibited HCC cell proliferation and invasion by targeting PPM1F, but its inhibitor reversed these effects. Moreover, circSLC3A2, predominantly localized in the cytoplasm, exhibited an oncogenic role by sponging miR-490-3p and regulating PPM1F expression, and harbored a positive correlation with poor survival in patients with HCC. CONCLUSION: CircSLC3A2 acts as an oncogenic factor in HCC by sponging miR-490-3p and regulating PPM1F expression.

Sanguinarine inhibits growth and invasion of gastric cancer cells via regulation of the DUSP4/ERK pathway.

Sanguinarine, a bioactive benzophenanthridine alkaloid extracted from plants of the Papaveraceae family, has shown antitumour effects in multiple cancer cells. But the therapeutic effects and regulatory mechanisms of sanguinatine in gastric cancer (GC) remain elusive. This study was aimed to investigate the correlation of dual-specificity phosphatase 4 (DUSP4) expression with clinicopathologic features and overall survival in patients with GC and explore the effects of sanguinarine on tumour growth and invasion in GC cells (SGC-7901 and HGC-27) and underlying molecular mechanisms. Immunohistochemical analysis showed that decreased DUSP4 expression was associated with the sex, tumour size, depth of invasion and distant metastasis in patients with GC. Functional experiments including CCK-8, Transwell and flow cytometry analysis indicated that sanguinarine or DUSP4 overexpression inhibited GC cell viability and invasive potential, and induced cell apoptosis and cycle arrest in S phase, but DUSP4 knockdown attenuated the antitumour activity of sanguinarine. Further observation demonstrated that sanguinarine up-regulated the expression of DUSP4 and Bcl-2-associated X protein (Bax), but down-regulated phosphorylated extracellular signal-regulated kinase (p-ERK), proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2 (MMP-2) and B-cell lymphoma 2 (Bcl-2) expression. Taken together, our findings indicate that sanguinarine inhibits growth and invasion of GC cells through regulation of the DUSP4/ERK pathway, suggesting that sanguinarine may have potential for use in GC treatment.

Circular RNA_LARP4 inhibits cell proliferation and invasion of gastric cancer by sponging miR-424-5p and regulating LATS1 expression.

BACKGROUND: Non-coding RNAs (ncRNAs) have been shown to regulate gene expression involved in tumor progression of multiple malignancies. Our previous studies indicated that large tumor suppressor kinase 1 (LATS1), a core part of Hippo signaling pathway, functions as a tumor suppressor in gastric cancer (GC). But, the underlying molecular mechanisms by which ncRNAs modulate LATS1 expression in GC remain undetermined. METHODS: The correlation of LATS1 and has-miR-424-5p (miR-424) expression with clinicopathological characteristics and prognosis of GC patients was analyzed by TCGA RNA-sequencing data. A novel circular RNA_LARP4 (circLARP4) was identified to sponge miR-424 by circRNA expression profile and bioinformatic analysis. The binding site between miR-424 and LATS1 or circLARP4 was verified using dual luciferase assay and RNA immunoprecipitation (RIP) assay. The expression and localization of circLARP4 in GC tissues were investigated by fluorescence in situ hybridization (FISH). MTT, colony formation, Transwell and EdU assays were performed to assess the effects of miR-424 or circLARP4 on cell proliferation and invasion. RESULTS: Increased miR-424 expression or decreased LATS1 expression was associated with pathological stage and unfavorable prognosis of GC patients. Ectopic expression of miR-424 promoted proliferation and invasion of GC cells by targeting LATS1 gene. Furthermore, circLARP4 was mainly localized in the cytoplasm and inhibited biological behaviors of GC cells by sponging miR-424. The expression of circLARP4 was downregulated in GC tissues and represented an independent prognostic factor for overall survival of GC patients. CONCLUSION: circLARP4 may act as a novel tumor suppressive factor and a potential biomarker in GC.

Identification and Characterization of Small-Molecule Inhibitors to Selectively Target the DFG-in over the DFG-out Conformation of the B-Raf Kinase V600E Mutant in Colorectal Cancer.

V600E is the most common mutation in the B-Raf kinase domain and the B-RafV600E mutant has been recognized as an attractive target of colorectal cancer. Here, the structural dynamics of V600E-induced conformational conversion in the B-Raf activation loop (A-loop) was characterized in detail using a computational simulation strategy. The simulations revealed that the V600E mutation would induce A-loop flipping from DFG-out to DFG-in, and the approved B-Raf inhibitor vemurafenib exhibits strong selectivity for the mutant over the wild-type kinase. The selectivity is closely associated with the kinase conformation, which can be influenced directly by the V600E mutation. The molecular structure of vemurafenib was applied to a chemical similarity search against a large library of drug/lead-like compounds, from which three hits with high structural similarity were identified, and their inhibitory activities against both the wild-type and mutant kinases were measured by in vitro kinase assay, from which two compounds were determined to possess higher selectivity for the B-RafV600E mutant than for the wild type (5.2- and 3.1-fold, respectively). They can potently inhibit the kinase mutant with IC50 = 54 and 76 nM, respectively. Structural analysis suggested that specific noncovalent interactions play a crucial role in the selectivity of B-Raf inhibitors.

Curcumin suppresses lymphatic vessel density in an in vivo human gastric cancer model.

This study aimed to assess the effects of curcumin on lymphatic vessel density (LVD) in an in vivo model of gastric cancer using the gastric cancer cell line, SGC-7901. Gastric tumor-bearing nude mice were treated with saline or 40, 80, or 160 mg kg(-1) day(-1) curcumin for 8 weeks. The results indicated that the tumor volumes were significantly lower in mice treated with 80 and 160 mg kg(-1) day(-1) curcumin as compared with that of the control group (both P < 0.001). In addition, both 80 and 160 mg kg(-1) day(-1) curcumin significantly reduced LVD (both P < 0.01). Although immunohistochemical analysis showed that curcumin did not significantly alter the expression of prospero homeobox 1 (Prox-1), podoplanin, and vascular endothelial growth factor receptor 3 (VEGFR-3), 160 mg kg(-1) day(-1) curcumin significantly decreased the expression of Prox-1, podoplanin, and VEGFR-3 levels as detected by Western blot analysis (P ≤ 0.03). Downregulation of lymphatic vessel endothelial receptor 1 (LYVE-1), Prox-1, podoplanin, and VEGFR-3 mRNA expression by curcumin was also detected (all P < 0.05). Furthermore, the apoptosis rates of tumor cells increased with curcumin in a concentration-dependent manner (all P < 0.001). Thus, curcumin may inhibit gastric cancer lymph node metastasis. Our findings provide theoretical evidence and an experimental basis for further analysis of the clinical application of curcumin in the therapy of gastric cancer.

Tetramethylpyrazine improves oxazolone-induced colitis by inhibiting the NF-κB pathway.

PURPOSE: Tetramethylpyrazine (TMP) is an effective Chinese plant-derived medicine for colitis in the clinic, but the underlying molecular mechanisms of its use remain poorly understood. The purpose of this study was to investigate the mechanisms involved in its therapeutic action. METHODS: A colitis mouse model was induced by oxazolone enema. TMP was administered at 80 mg/kg/day and sulphasalazine (SASP) was used as positive control and administered at 100 mg/kg/day for the treatment of colitis. On the fourth day after enema, mice were sacrificed. The inflammatory response was assessed by the disease activity index and histology. Colon mucosa was isolated and biochemically analyzed. In addition, in vitro studies were performed to evaluate the activity of TMP in Caco-2 cells. RESULTS: Our results showed that TMP improved the colonic inflammatory status as evidenced by histological findings, as well as SASP. These effects were associated with a decrease in nucleus translocation of NF-κB. Paired with this inhibitive activity, there was a decrease in downstream signaling, such as C-MYC, iNOS and COX-2. In vitro assays revealed that TMP inhibited NF-κB translocation and its downstream production of inflammatory factors, such as TNF-α, IL-6 and IL-8, and that ROS production that was induced by LPS in Caco-2 cells. CONCLUSION: TMP improved the colitis induced by oxazoline, and its activity was associated with inhibition of NF-κB translocation, and subsequent inhibition of pro-inflammatory factor production and oxidative stress.

Oleanolic acid induces apoptosis of MKN28 cells via AKT and JNK signaling pathways.

CONTEXT: Oleanolic acid (OA) belongs to the triterpenoid compound group existing widely in food, medicinal herbs and other plants. Its effects on gastric cancer cells and the mechanisms involved have not been investigated. OBJECTIVE: This study aimed to substantiate whether OA induces apoptosis of gastric cancer cell line (MKN28) and to elucidate the molecular mechanism involved. MATERIALS AND METHODS: Cell viability was assessed by MTT assay within the range of 0-160 µg/mL. The effects of OA (5, 10 and 20 µg/mL) on apoptosis of MKN28 cells were evaluated by flow cytometry, DNA fragmentation and mitochondrial membrane potential assays. Western blot and FQRT-PCR assays were used to investigate the mechanism of cell apoptosis induced by OA (5 and 10 µg/mL). RESULTS: OA evidently inhibited cell viability with IC50 of 44.8 and 15.9 µg/mL at 12 and 24 h, respectively. Furthermore, OA increased JNK phosphorylation, decreased AKT phosphorylation, but did not affect p38 and ERK phosphorylation in MKN28 cells. In contrast, OA also significantly enhanced the mRNA expression levels of caspase 3, caspase 9 and Apaf-1 in MKN28 cells. CONCLUSION: OA induces apoptosis of MKN28 cells via the mitochondrial pathway regulated by AKT and JNK signaling pathways.

Helicobacter Pylori-Enhanced hnRNPA2B1 Coordinates with PABPC1 to Promote Non-m6A Translation and Gastric Cancer Progression.

Helicobacter pylori (H. pylori) infection is the primary risk factor for the pathogenesis of gastric cancer (GC). N6-methyladenosine (m6A) plays pivotal roles in mRNA metabolism and hnRNPA2B1 as an m6A reader is shown to exert m6A-dependent mRNA stabilization in cancer. This study aims to explore the role of hnRNPA2B1 in H. pylori-associated GC and its novel molecular mechanism. Multiple datasets and tissue microarray are utilized for assessing hnRNPA2B1 expression in response to H. pylori infection and its clinical prognosis in patients with GC. The roles of hnRNPA2B1 are investigated through a variety of techniques including glucose metabolism analysis, m6A-epitranscriptomic microarray, Ribo-seq, polysome profiling, RIP-seq. In addition, hnRNPA2B1 interaction with poly(A) binding protein cytoplasmic 1 (PABPC1) is validated using mass spectrometry and co-IP. These results show that hnRNPA2B1 is upregulated in GC and correlated with poor prognosis. H. pylori infection induces hnRNPA2B1 upregulation through recruiting NF-κB to its promoter. Intriguingly, cytoplasm-anchored hnRNPA2B1 coordinated PABPC1 to stabilize its relationship with cap-binding eIF4F complex, which facilitated the translation of CIP2A, DLAT and GPX1 independent of m6A modification. In summary, hnRNPA2B1 facilitates the non-m6A translation of epigenetic mRNAs in GC progression by interacting with PABPC1-eIF4F complex and predicts poor prognosis for patients with GC.