Background: Long non-coding RNAs (lncRNAs) have emerged as critical regulators of tumor progression. However, the role and molecular mechanism of lncRNA XIST in gastric cancer is still unknown.Methods: Real-time PCR analysis was performed to measure the expression levels of lncRNA XIST in gastric cancer tissues and cell lines, the correlation between lncRNA XIST expression and clinicopathological characteristics and prognosis was analyzed in gastric cancer patients. The biological function of lncRNA XIST on gastric cancer cells were determined both in vitro and in vivo. The regulating relationship between lncRNA XIST and miR-101 was investigated in gastric cancer cells.Results: lncRNA XIST was significantly up-regulated in gastric cancer tissues and cell lines. Overexpression of lncRNA XIST was markedly associated with larger tumor size, lymph node invasion, distant metastasis and TNM stage in gastric cancer patients. Functionally, knockdown of lncRNA XIST exerted tumor-suppressive effects by inhibiting cell proliferation, migration and invasion in vitro and tumor growth and metastasis in vivo. Furthermore, an inverse relationship between lncRNA XIST and miR-101 was found. Polycomb group protein enhancer of zeste homolog 2 (EZH2), a direct target of miR-101, could mediated the biological effects that lncRNA XIST exerted.Conclusions: lncRNA XIST is up-regulated and is associated with aggressive tumor phenotypes and patient survival in gastric cancer, and the newly identified lncRNA XIST/miR-101/EZH2 axis could be a potential biomarkers or therapeutic targets for gastric cancer patients.

An elevated preoperative C-reactive protein/albumin (CRP/Alb) ratio has been reported to be associated with a poor prognosis for hepatocellular carcinoma. The aim of the present study was to investigate the prognostic value of the preoperative CRP/Alb ratio and compare it with other systemic inflammatory response markers in patients with gastric cancer (GC). A retrospective study was performed in 455 patients with GC undergoing curative resection. We investigated the correlations between the preoperative CRP/Alb ratio and overall survival (OS). Kaplan-Meier and Cox regression models were used to assess independent prognostic factors. The area under the curve was used to compare the prognostic value of different markers. On multivariate analysis, the CRP/Alb ratio were independently associated with OS in patients with GC (hazard ratio: 1.626; 95% confidence interval: 1.191-2.219; P = .002), along with age (P = .003), preoperative body weight loss (P = .001), tumor location (P = .008), metastatic lymph node ratio (P < .001), and seventh tumor-nodes-metastasis stage (American Joint Committee on Cancer) (P = .007). However, several other systemic inflammation-based prognostic scores (neutrophil lymphocyte ratio, platelet lymphocyte ratio and systemic immune-inflammation index, Glasgow Prognostic Score, modified Glasgow prognostic score, and high-sensitivity modified Glasgow prognostic score) were not. In addition, the CRP/Alb ratio had a higher area under the curve value (0.625) compared with several other systemic inflammation-based prognostic scores (P < .001). The preoperative CRP/Alb ratio, a system inflammation-based prognostic score, is a superior predictor of OS in patients undergoing curative resection for GC and may help to identify the high-risk patients for treatment decisions.

PI3K/Akt signaling is activated in cancers and governs tumor initiation and progression, but how Akt is activated under diverse stresses is poorly understood. Here we identify AMPK as an essential regulator for Akt activation by various stresses. Surprisingly, AMPK is also activated by growth factor EGF through Ca2+/Calmodulin-dependent kinase and is essential for EGF-mediated Akt activation and biological functions. AMPK phosphorylates Skp2 at S256 and promotes the integrity and E3 ligase activity of Skp2 SCF complex leading to K63-linked ubiquitination and activation of Akt and subsequent oncogenic processes. Importantly, AMPK-mediated Skp2 S256 phosphorylation promotes breast cancer progression in mouse tumor models, correlates with Akt and AMPK activation in breast cancer patients, and predicts poor survival outcomes. Finally, targeting AMPK-mediated Skp2 S256 phosphorylation sensitizes cells to anti-EGF receptor targeted therapy. Our study sheds light on how stress and EGF induce Akt activation and new mechanisms for AMPK-mediated oncogenesis and drug resistance.

Background: Gastric cancer (GC) is one of the most common tumours in East Asia countries and is associated with Helicobacter pylori infection. H. pylori utilizes virulence factors, CagA and VacA, to up‐regulate pro‐inflammatory cytokines and activate NF‐κB signaling. Meanwhile, the PIEZO1 upregulation and cancer‐associated fibroblast (CAF) enrichment were found in GC progression. However, the mechanisms of PIEZO1 upregulation and its involvement in GC progression have not been fully elucidated.Methods: The CAF enrichment and clinical significance were investigated in animal models and primary samples. The expression of NF‐κB and PIEZO1 in GC was confirmed by immunohistochemistry staining, and expression correlation was analysed in multiple GC datasets. GSEA and Western blot analysis revealed the YAP1‐CTGF axis regulation by PIEZO1. The stimulatory effects of CTGF on CAFs were validated by the co‐culture system and animal studies. Patient‐derived organoid and peritoneal dissemination models were employed to confirm the role of the PIEZO1‐YAP1‐CTGF cascade in GC.Results: Both CAF signature and PIEZO1 were positively correlated with H. pylori infection. PIEZO1, a mechanosensor, was confirmed as a direct downstream of NF‐κB to promote the transformation from intestinal metaplasia to GC. Mechanistic studies revealed that PIEZO1 transduced the oncogenic signal from NF‐κB into YAP1 signaling, a well‐documented oncogenic pathway in GC progression. PIEZO1 expression was positively correlated with the YAP1 signature (CTGF, CYR61, and c‐Myc, etc.) in primary samples. The secreted CTGF by cancer cells stimulated the CAF infiltration to form a stiffened collagen‐enrichment microenvironment, thus activating PIEZO1 to form a positive feedback loop. Both PIEZO1 depletion by shRNA and CTGF inhibition by Procyanidin C1 enhanced the efficacy of 5‐FU in suppressing the GC cell peritoneal metastasis.Conclusion: This study elucidates a novel driving PIEZO1‐YAP1‐CTGF force, which opens a novel therapeutic avenue to block the transformation from precancerous lesions to GC. H. pylori‐NF‐κB activates the PIEZO1‐YAP1‐CTGF axis to remodel the GC microenvironment by promoting CAF infiltration. Targeting PIEZO1‐YAP1‐CTGF plus chemotherapy might serve as a potential therapeutic option to block GC progression and peritoneal metastasis.

Understanding the mechanism by which cell growth, migration, polyploidy, and tumorigenesis are regulated may provide important therapeutic strategies for cancer therapy. Here we identify the Skp2–macroH2A1 (mH2A1)–cyclin-dependent kinase 8 (CDK8) axis as a critical pathway for these processes, and deregulation of this pathway is associated with human breast cancer progression and patient survival outcome. We showed that mH2A1 is a new substrate of Skp2 SCF complex whose degradation by Skp2 promotes CDK8 gene and protein expression. Strikingly, breast tumour suppression on Skp2 deficiency can be rescued by mH2A1 knockdown or CDK8 restoration using mouse tumour models. We further show that CDK8 regulates p27 protein expression by facilitating Skp2-mediated p27 ubiquitination and degradation. Our study establishes a critical role of Skp2–mH2A1–CDK8 axis in breast cancer development and targeting this pathway offers a promising strategy for breast cancer therapy.

The association between vitamin intake and gastric cancer (GC) has been widely debated due to the relatively weak evidence. In this study, a meta-analysis of prospective and well designed observational studies were performed to explore this association. MEDLINE, Cochrane Library, and Sciencedirect were searched for studies of vitamin consumption and gastric cancer. This produced 47 relevant studies covering 1,221,392 human subjects. Random effects models were used to estimate summary relative risk (RR). Dose-response, subgroup, sensitivity, meta-regression, and publication bias analyses were conducted. The RR of gastric cancer in the group with the highest vitamin intake was compared to that of the lowest intake group. Total vitamin intake was 0.78 (95% CI, 0.71−0.83). In 9 studies that individuals were given doses at least 4 times above the tolerable upper intake (UL) vitamins, the RR was 1.20 (95% CI, 0.99−1.44). However, in 17 studies that individuals received doses below the UL, the RR was 0.76 (95% CI, 0.68−0.86). Dose-response analysis was conducted on different increments in different types of vitamins (vitamin A: 1.5 mg/day, vitamin C: 100 mg/day, vitamin E: 10 mg/day) intake with a significant reduction in the risk of gastric cancer, respectively, 29% in vitamin A, 26% in vitamin C, and 24% in vitamin E. This meta-analysis clearly demonstrated that low doses of vitamins can significantly reduce the risk of GC, especially vitamin A, vitamin C, vitamin E.