CircRNAs are a class of endogenous RNA that regulates gene expression at the post-transcriptional or transcriptionallevel through interacting with other molecules or microRNAs. Increasing studies have demonstrated that circRNAs play a crucial role in biology processes. CircRNAs are proved as potentialbiomarkers in many diseases including cancers. However, the role of Cdr1as in Hepatocellular carcinoma (HCC) remains to be elucidated. We demonstrated that Cdr1as expression was upregulated in HCC tissues compared with the adjacent non-tumor tissues. In addtion, miR-7 expression was downregulated in HCC tissues compared with the adjacent non-tumor tissues. Moreover, the expression level of miR-7 was inversely correlated with that in HCC tissues. Knockdown of Cdr1as suppressed the HCC cell proliferation and invasion. Overexpression of miR-7 inhibited the HCC cell proliferation and invasion. Overexpression of miR-7 could suppress the direct target gene CCNE1 and PIK3CD expression. Knockdown of Cdr1as suppressed the expression of miR-7 and also inhibited the CCNE1 and PIK3CD expression. Furthermore, knockdown of Cdr1as suppressed the HCC cell proliferation and invasion through targeting miR-7. These data suggested that Cdr1as acted as an oncogene partly through targeting miR-7 in HCC.

In February 2019, following the annual taxon ratification vote, the order Bunyavirales was amended by creation of two new families, four new subfamilies, 11 new genera and 77 new species, merging of two species, and deletion of one species. This article presents the updated taxonomy of the order Bunyavirales now accepted by the International Committee on Taxonomy of Viruses (ICTV).

Tick-borne viral diseases have attracted much attention in recent years because of their increasing incidence and threat to human health. Severe fever with thrombocytopenia syndrome phlebovirus (SFTSV) and Heartland virus (HRTV) were recently identified as tick-borne phleboviruses (TBPVs) in Asia and the United States, respectively, and are associated with severe human diseases with similar clinical manifestations. In this study, we report the first identification and isolation of a novel TBPV named Guertu virus (GTV) from Dermacentor nuttalli ticks in Xinjiang Province, China, where TBPVs had not been previously discovered. Genome sequence and phylogenetic analyses showed that GTV is closely related to SFTSV and HRTV and was classified as a member of the genus Phlebovirus, family Phenuiviridae, order Bunyavirales. In vitro and in vivo investigations of the properties of GTV demonstrated that it was able to infect animal and human cell lines and can suppress type I interferon signaling, similar to SFTSV, that GTV nucleoprotein (NP) can rescue SFTSV replication by replacing SFTSV NP, and that GTV infection can cause pathological lesions in mice. Moreover, a serological survey identified antibodies against GTV from serum samples of individuals living in Guertu County, three of which contained neutralizing antibodies, suggesting that GTV can infect humans. Our findings suggested that this virus is a potential pathogen that poses a threat to animals and humans. Further studies and surveillance of GTV are recommended to be carried out in Xinjiang Province as well as in other locations.

BackgroundEmerging evidences have indicated that long noncoding RNAs (lncRNAs) play essential roles in the development and progression of cancers. Dysregulation of lncRNA MIR31HG has recently been reported in several types of cancers, and researches on the function of MIR31HG in cancers suggested that MIR31HG could act as either oncogene or tumor suppressor. But the functional involvement of MIR31HG has not been studied in hepatocellular carcinoma (HCC).MethodsIn this study, MTS assays, colony formation assay, Wound-healing assay, Transwell assy, and tumor xenografts experiments were used to identify biological effects of MIR31HG on HCC cells HCC proliferation and metastasis in vitro and in vivo. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to show the interactions of MIR31HG and miR-575. The bioinformatics methods were completed to find the target genes of miR-575. And Dual-luciferase reporter assay and Western blot analysis were further used to confirm the target gene of miR-575.ResultsWe found that overexpression of MIR31HG obviously suppressed HCC proliferation and metastasis in vitro and in vivo, whereas knockdown of MIR31HG had the opposite effects. Besides, overexpression of MIR31HG significantly decreased the expression of microRNA-575 (miR-575), which plays an oncogenic role in HCC. Moreover, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay revealed that MIR31HG exerted tumor-suppressive functions by binding directly to miR-575, and there was a reciprocal inhibition between MIR31HG and miR-575 in the same RNA-induced silencing complex (RISC). Furthermore, overexpression of MIR31HG enhanced the expression of suppression of tumorigenicity 7 like (ST7L), which was identified as a downstream target gene of miR-575. Thus, MIR31HG positively regulated ST7L expression through sponging miR-575, and acted as tumor suppressor in HCC.ConclusionsOverall, our study illuminates the role of MIR31HG as a miRNA sponge in HCC, and sheds new light on lncRNA-directed diagnostics and therapeutics in HCC.Electronic supplementary materialThe online version of this article (10.1186/s13046-018-0853-9) contains supplementary material, which is available to authorized users.