Objective To investigate the gut microbiota differences of obese children compared with the control healthy cohort to result in further understanding of the mechanism of obesity development. Methods We evaluated the 16S rRNA gene, the enterotypes, and quantity of the gut microbiota among obese children and the control cohort and learned the differences of the gut microbiota during the process of weight reduction in obese children. Results In the present study, we learned that the gut microbiota composition was significantly different between obese children and the healthy cohort. Next we found that functional changes, including the phosphotransferase system, ATP-binding cassette transporters, flagellar assembly, and bacterial chemotaxis were overrepresented, while glycan biosynthesis and metabolism were underrepresented in case samples. Moreover, we learned that the amount of Bifidobacterium and Lactobacillus increased among the obese children during the process of weight reduction. Conclusion Our results might enrich the research between gut microbiota and obesity and further provide a clinical basis for therapy for obesity. We recommend that Bifidobacterium and Lactobacillus might be used as indicators of healthy conditions among obese children, as well as a kind of prebiotic and probiotic supplement in the diet to be an auxiliary treatment for obesity.

Background Circular RNAs (circRNAs) have been considered to mediate occurrence and development of human cancers, generally acting as microRNA (miRNA) sponges to regulate downstream genes expression. However, the aberrant expression profile and dysfunction of circRNAs in human bladder cancer remain to be investigated. The present study aims to elucidate the potential role and molecular mechanism of circACVR2A in regulating the proliferation and metastasis of bladder cancer. Methods circACVR2A (hsa_circ_0001073) was identified by RNA-sequencing and validated by quantitative real-time polymerase chain reaction and agarose gel electrophoresis. The role of circACVR2A in bladder cancer was assessed both in vitro and in vivo. Biotin-coupled probe pull down assay, biotin-coupled microRNA capture, dual-luciferase reporter assay, and fluorescence in situ hybridization were conducted to evaluate the interaction between circACVR2A and microRNAs. Results The expression of circACVR2A was lower in bladder cancer tissues and cell lines. The down-regulation of circACVR2A was positively correlated with aggressive clinicopathological characteristics, and circACVR2A served as an independent risk factor for overall survival in bladder cancer patients after cystectomy. Our in vivo and in vitro data indicated that circACVR2A suppressed the proliferation, migration and invasion of bladder cancer cells. Mechanistically, we found that circACVR2A could directly interact with miR-626 and act as a miRNA sponge to regulate EYA4 expression. Conclusions circACVR2A functions as a tumor suppressor to inhibit bladder cancer cell proliferation and metastasis through miR-626/EYA4 axis, suggesting that circACVR2A is a potential prognostic biomarker and therapeutic target for bladder cancer. Electronic supplementary material The online version of this article (10.1186/s12943-019-1025-z) contains supplementary material, which is available to authorized users.

Background Circular RNAs (circRNAs) represent a subclass of regulatory RNAs that have been shown to have significant regulatory roles in cancer progression. However, the biological functions of circRNAs in bladder cancer (BCa) are largely unknown. Methods Cell invasion models were established, and invasion-related circRNAs were detected by qPCR. Using above method, circ-ZKSCAN1 was picked out for further study. Circ-ZKSCAN1 expression and survival analyses were performed through qPCR. The survival curves were generated by the Kaplan-Meier method, and the log-rank test was used to assess the significance. Cell proliferation, migration and invasion were examined to investigate the function of circ-ZKSCAN1. Tumorigenesis in nude mice was assessed to determine the effect of circ-ZKSCAN1 in bladder cancer. Biotin-coupled probe pull-down assays, FISH and luciferase reporter assays were conducted to confirm the relationship between circ-ZKSCAN1 and microRNA. RNA-seq revealed different molecular changes in downstream genes. Results Here, we found that circ-ZKSCAN1 was downregulated in BCa tissues and cell lines. Circ-ZKSCAN1 levels were associated with survival, tumor grade, pathological T stage and tumor recurrence. Overexpressed circ-ZKSCAN1 inhibits cell proliferation, migration, invasion and metastasis in vitro and in vivo. Mechanistically, we demonstrated that circ-ZKSCAN1 upregulated p21 expression by sponging miR-1178-3p, which suppressed the aggressive biological behaviors in bladder cancer. Conclusions These results reveal that Circ-ZKSCAN1 acts as a tumor suppressor via a novel circ-ZKSCAN1/miR-1178-3p/p21 axis, which have the important role in the proliferation, migration and invasion ablitities of BCa cells and provide a novel perspective on circRNAs in BCa progression.