Circular RNA AKT3 governs malignant behaviors of esophageal cancer cells by sponging miR-17-5p.

BACKGROUND: Recent studies have demonstrated that circular RNA AKT3 (circAKT3) plays a crucial role in regulating the malignant phenotypes of tumor cells. However, the potential effects of circAKT3 on esophageal cancer have not been investigated. AIM: To illuminate the role of circAKT3 in malignant behaviors of esophageal cancer cells and its underlying mechanism. METHODS: Clinical samples were collected to detect the expression of circAKT3. The role of circAKT3 in proliferation, migration, invasion, and apoptosis of esophageal cancer cells was evaluated using Cell Counting Kit-8, wound healing assays, Transwell assays, and fluorescence analysis, respectively. The target of circAKT3 was screened and identified using an online database and luciferase reporter assay. A xenograft nude mouse model was established to investigate the role of circAKT3 in vivo. RESULTS: In vitro assays showed that proliferative, migratory, and invasive capacities of esophageal cancer cells were significantly enhanced by circAKT3 overexpression. Furthermore, miR-17-5p was screened as the target of circAKT3, and miR-17-5p antagonized the effects of circAKT3 on esophageal cancer cells. Moreover, we identified RHOC and STAT3 as the direct target molecules of miR-17-5p, and circAKT3 facilitated expression of RHOC and STAT3 by inhibiting miR-17-5p. In vivo assays showed circAKT3 knockdown inhibited growth of esophageal cancer. CONCLUSION: CircAKT3 contributed to the malignant behaviors of esophageal cancer in vitro and in vivo by sponging miR-17-5p thus providing a potential target for treatment of esophageal cancer.

EIF4E regulates STEAP1 expression in peritoneal metastasis.

Gastric cancer is the most prominent form of malignancy in China, and the high mortality associated with it is mostly due to peritoneal metastasis. We have previously elucidated that the RNA-binding protein poly r(C) binding protein 1 (PCBP1) and miR-3978 function as repressors of peritoneal metastasis, partially by downregulation of six-transmembrane epithelial antigen of the prostate 1 (STEAP1). We now show that STEAP1 is regulated at the level of cap-dependent translation initiation by phosphorylated eIF4E. Chemically inhibiting phosphorylation of eIF4E or genetic ablation of phosphorylated eIF4E inhibit translational upregulation of STEAP1 in the peritoneal metastasis mimicking cell line MKN45 in comparison to the normal mesothelial cell line HMrSV5. Thus phosphorylation of eIF4E is required for peritoneal metastasis of gastric cancer via translational control of STEAP1. Chemical inhibitors targeting phosphorylation of eIF4E or its interaction with the translation initiation complex thus might prove effective in treating patients with peritoneal metastasis.

Peer support interventions for breast cancer patients: a systematic review.

PURPOSE: Due to the clear efficacy of peer support as a means of improving emotional well-being and healthy behaviors in a highly cost-effective manner, this program is widely used. Controversy remains, however, with regard to its efficacy in breast cancer patients. Given the heterogeneity of peer support interventions, this review aimed to categorize, assess, and synthesize the existing evidence from randomized controlled trials (RCTs) to clarify the effects of different types of peer support on breast cancer patients. METHODS: We searched Pubmed, EMBase, CENTRAL, CINAHL, PsychINFO, Chinese National Knowledge Infrastructure (CNKI) and Wanfang Data for English and Chinese language RCTs. The Cochrane Collaboration 'risk of bias' tool for systematic reviews was used to assess the methodological quality of each RCT. RESULTS: Of the 1494 studies screened, 15 studies met eligibility criteria for inclusion, comprising 1695 breast cancer patients. Overall, there were more positive effects than invalid or negative effects across peer interventions, with notable exceptions: unmoderated and unstructured group peer support interventions as well as Internet-based models without peer training had no effect or adverse effects on proximal and distal outcomes. However, adding other peer roles to the peer support structure or using one-on-one models could significantly improve the patients' negative emotions. Peer education showed promising effects on stress management, quality of life, and healthy behaviors. CONCLUSIONS: This systematic review found that different types of peer support have different effects on outcomes for breast cancer patients. Web-based group peer support without peer training must be avoided or used with caution in the future. Peer education is recommended for breast cancer patient support models, given its excellent results and cost-effectiveness.

STEAP1 Regulates Tumorigenesis and Chemoresistance During Peritoneal Metastasis of Gastric Cancer.

In China, majority of the mortality in gastric cancer are associated with peritoneal metastasis. Since most gastric tumors are metastatic at initial diagnosis, the treatment of gastric cancer is limited to radical resection. Therefore, it is imperative to identify diagnostic and prognostic biomarkers. From 2014 to 2015, 20 patients were enrolled in the study. To search translationally upregulated genes in the context of epithelial to mesenchymal transition (EMT), polysome profiling was performed. The MTT, migration, and invasion assay were conducted to determine cell proliferation, migration, and invasion ability respectively. Experiments of gain and loss of function were performed using the overexpression plasmid, siRNA, and shRNA. Xenograft assay was established using nude mice to explore the role of targets translationally upregulated gene in vivo. Polysome profiling defined the landscape of translationally regulated gene products with differential expression between non-metastatic and metastatic cohorts. Six-transmembrane epithelial antigen of the prostate 1 (STEAP1) was found to be the most translationally upregulated gene product in either experimental groups. STEAP1 was found to be required for cell proliferation, in vitro migration and invasion, and in vivo tumorigenesis. RNAi-mediated silencing of STEAP1 potentiated chemosensitivity of the MKN45 cells to docetaxel treatment, highlighting the importance of STEAP1 as a novel biomarker in gastric cancer patients with peritoneal metastasis. STEAP1 is thus induced translationally and its expression promotes proliferation, migration, invasiveness, and tumorigenicity of gastric cancer. STEAP1 can be a potent candidate for designing of targeted therapy.

Author Correction: Expression of both poly r(C) binding protein 1 (PCBP1) and miRNA-3978 is suppressed in peritoneal gastric cancer metastasis.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Synergistically suppressive effects on colorectal cancer cells by combination of mTOR inhibitor and glycolysis inhibitor, Oxamate.

Colorectal cancer (CRC) is the third most common cancer worldwide, representing a major cancer burden. As a natural mTOR inhibitor, rapamycin has been demonstrated to regulate various cellular biological behaviors of cancer cells, including growth inhibition and induction of apoptosis in multiple types of malignant tumors. In this study, we report mTOR inhibitor treatments significantly decreased colon cancer cells glucose metabolism. The glucose uptake and lactate product of DLD-1 and LoVo cells were suppressed by rapamycin. In addition, rapamycin resistant DLD-1 cells display elevated glycolysis rate. The expressions of glycolysis enzymes, Hexokinase 2, PKM2 and LDHA are upregulated in rapamycin resistant cells. We observed promotion of cellular glycolysis by overexpressing LDHA renders colon cancer cells resistant to rapamycin and inhibition of glycolysis by knockdown LDHA sensitizes colon cancer cells to rapamycin. Importantly, we demonstrate the combination of rapamycin and glycolysis inhibitor, Oxamate showed a synergistically inhibitory effect on colon cancer cells. Our study will contribute to the development of therapeutic approaches through combination of mTOR inhibitor with glycolysis inhibitor for the treatment of colorectal cancer patients.

Expression of both poly r(C) binding protein 1 (PCBP1) and miRNA-3978 is suppressed in peritoneal gastric cancer metastasis.

The expression of legumain which has been shown overexpressed in patients with metastatic gastric cancer is positively correlated to both disease progression and outcome, and negatively correlated to microRNA (miR)-3978 expression. The RNA-binding protein, poly r(C) binding protein 1 (PCBP1) was the most downregulated protein in the metastatic tissue specimens. Quantitative real-time PCR showed that PCBP1 expression is transcriptionally downregulated in peritoneal metastasis tissues. RNA immunoprecipitation experiments showed that PCBP1 and miR-3978 are sequestered in normal peritoneal tissue, but the complex is disrupted following metastatic progression. PCBP1 expression mimicked miR-3978 expression across gastric cancer patients. Finally, replenishment of PCBP1 or miR-3978 expression in the peritoneal metastasis cell line MKN45 decreased legumain protein expression and chemosensitized the cells to treatment with docetaxel. However, replenishment of one and concomitant depletion of the other failed to induce chemosensitivity to docetaxel. Replenishment of miR-3978 also resulted in induction of PCBP1 protein expression, potentially indicating that miR-3978 expression might downregulate a negative regulator targeting PCBP1. Our current study reveals PCBP1 as an additional biomarker in peritoneal metastasis. PCBP1 and miR-3978 expression were correlated and suggests a potential interplay of differential miRNA biogenesis and RNA binding protein during metastatic progression.

MiRNA-3978 regulates peritoneal gastric cancer metastasis by targeting legumain.

Gastric cancer incidence and mortality are among the highest in China, with majority of the mortality related to peritoneal metastasis of gastric cancer. Treatment is limited to radical resection, which is impeded by incidence of metastasis at time of initial diagnosis, thus making it imperative to identify diagnostic and prognostic biomarkers. Legumain, a lysosomal cysteine endopeptidase of the asparaginyl endopeptidase family, has been shown to be overexpressed in patients with metastatic gastric cancer disease and its expression was positively correlated to both disease progression and outcome. However, the mechanism of legumain expression is currently unknown. Legumain overexpression was found to occur at the level of post transcriptional gene regulation. In situ prediction algorithms identified legumain as a putative target of miR-3978. MiR-3978 was significantly decreased in peritoneal metastatic tissue specimens and in MKN45 cells that mimic peritoneal metastasis features. Reporter assays using LGMN (encoding legumain) 3' untranslated region (UTR) showed that miR-3978 interacted with the wild-type but not miR-3978-seed mutant. Ectopic expression of miR-3978 mimic in the MKN45 cell line significantly decreased proliferation and suppressed in vitro migration and invasion. The miR-3978 mimic inhibited gastric carcinoma and metastatic progression in a mice model by regulating legumain protein expression. Inverse correlation of LGMN mRNA and miR-3978 levels in 20 gastric patients at different stages of metastatic disease confirmed the same. Cumulatively, our results indicate that loss of miR-3978 leads to increased expression of legumain, which indicates that miR-3978might be a biomarker for peritoneal metastasis in patients with gastric cancer.

Activation of the miR-34a/SIRT1/p53 Signaling Pathway Contributes to the Progress of Liver Fibrosis via Inducing Apoptosis in Hepatocytes but Not in HSCs.

Liver fibrosis results from a sustained wound healing response to chronic liver injury, and the activation of nonparenchymal hepatic stellate cells (HSCs) is the pivotal process. MicroRNA-34a (miR-34a) is the direct target gene of p53 and activates p53 through sirtuin 1 (SIRT1) simultaneously. The miR-34a/SIRT1/p53 signaling pathway thus forms a positive feedback loop wherein p53 induces miR-34a and miR-34a activates p53 by inhibiting SIRT1, playing an important role in cell proliferation and apoptosis. miR-34a expression has been found to be increased in animal models or in human patients with different liver diseases, including liver fibrosis. However, the exact role of this classical miR-34a/SIRT1/p53 signaling pathway in liver fibrosis remains unclear. In the present study, using a CCl4-induced rat liver fibrosis model, we found that the miR-34a/SIRT1/p53 signaling pathway was activated and could be inhibited by SIRT1 activator SRT1720. Further studies showed that the miR-34a/SIRT1/p53 signaling pathway was activated in hepatocytes but not in HSCs. The activation of this pathway in hepatocytes resulted in the apoptosis of hepatocytes and thus activated HSCs. Our data indicate that the miR-34a/SIRT1/p53 signaling pathway might be a promising therapeutic target for liver fibrosis.

Waterborne exposure to bisphenol F causes thyroid endocrine disruption in zebrafish larvae.

While bisphenol F (BPF) has been frequently detected in various environmental compartments, limited information is available on its effect on thyroid endocrine system. In the present study, zebrafish (Danio rerio) embryos were exposed to 0.2, 2, 20, and 200 µg/L of BPF from 2 h post-fertilization (hpf) to 144 hpf. The whole-body content of thyroid hormones, thyroid-stimulating hormone (TSH), and transcription of genes belonging to the hypothalamic-pituitary-thyroid (HPT) axis were investigated. BPF exposure resulted in alterations of both T3 and T4 contents, increased the ratios of T3/T4, demonstrating thyroid endocrine disruption. Moreover, TSH content was significantly induced in a concentration-dependent manner after exposure to BPF. The increased gene transcription of dio2 might assist to degrade increased T3 contents. Treatment with BPF also significantly increased transcription of genes involved in thyroid hormone regulation (crh) and synthesis (nis and tg) as a compensatory mechanism for the decrease of T4 contents. However, the gene encoding protein involved in TH transport (ttr) was transcriptionally significantly down-regulated after exposure to BPF. Taken together, these results suggest that BPF alters the transcription of genes involved in the HPT axis as well as changes whole-body contents of thyroid hormones and TSH in zebrafish embryos/larvae, thus causing an endocrine disruption of the thyroid system.

A case of annular pancreas accompanied with intraductal papillary mucinous neoplasm-case report.

OBJECTIVES: Annular pancreas is a rare congenital anomaly characterized by pancreatic tissues wrapping completely or incompletely around the descending duodenum. In most patients with annular pancreas, onset occurs in early childhood. Adults with annular pancreas are prone to duodenal ulcers and pancreatitis. Intraductal papillary mucinous neoplasm (IPMN) is a type of papillary mucinous secretory epithelial tumor, which originates in the main pancreatic duct and/or branch duct. We report a case of annular pancreas accompanied with intraductal papillary mucinous neoplasm. METHODS: A 52-year-old male patient hospitalized due to recurrent upper abdominal pain for one and a half years was enrolled in this study. RESULTS: One case of annular pancreas accompanied with intraductal papillary mucinous neoplasm which manifested as recurrent chronic pancreatitis was found. After pancreaticoduodenectomy, the patient died from uncontrollable gastrointestinal bleeding. CONCLUSIONS: To the best of our knowledge, this is the first case in China and the second case worldwide of annular pancreas accompanied with IPMN in English literature.

Chalcones derivatives as potent Cell division cycle 25B phosphatase inhibitors.

To discover novel cell division cycle 25 (CDC25) B inhibitors and elucidate the mechanisms of inhibition in cancer cells. Nineteen 2'-hydroxy-4'-isoprenyloxychalcone derivatives (a-s) were evaluated the inhibition CDC25B activity. The enzymatic activities of the CDC25B catalytic domain were determined by monitoring the dephosphorylation of OMFP. Cell growth inhibition was detected by MTT assay. The results showed that sixteen compounds significantly inhibited cycle 25B phosphatase in vitro. Among, three compounds k, r and s had the best inhibition activity and significantly inhibited CDC25B with inhibition rates against CDC25B of 99.95%, 99.75%, and 97.77%, respectively, which is similar to the reference drugs Na3VO4 (98%). Cytotoxic activity assays showed compounds k and r are the potent against HCT116, HeLa, and A549 cells, moreover, compound k delayed the potent tumor inhibitory activity in a colo205 xenograft model in vivo.

Association between MDM2 SNP309 T>G and risk of gastric cancer: a meta-analysis.

BACKGROUND: As a negative regulator of P53, MDM2 plays an important role in carcinogenesis; a polymorphism in its promoter region. SNP309 T>G, is known to increase the expression of MDM2, thus being considered related to higher susceptibility to neoplasia. However, no agreement has been achieved regarding its effects on gastric cancer. METHODS: The present systematic meta-analysis was performed based on comprehensive literature search from Pubmed, Web of science and CBM databases. RESULTS: It was suggested from 6 independent studies that the GG genotype is associated with a significantly increased risk of gastric cancer (Recessive: OR = 1.43, 95% CI = 1.08-1.91, P = 0.013), and subgroup analysis also confirmed the relationship (English publications-recessive model: OR = 1.45, 95% CI = 1.10-1.91, P = 0.009; Studies in China-recessive model: OR = 1.58, 95% CI = 1.08-2.30, P = 0.017). No publication bias was detected. CONCLUSION: The meta-analysis indicated a significant inverse association between GG genotype carriage and elevated risk of gastric cancer. However, more studies and detailed information are needed to fully address the topic.