Mounting evidences indicate that circular RNAs (circRNAs) have a vital role in human diseases, especially cancers. More recently, circHIPK3, a particularly abundant circRNA, was proposed to be involved in tumorigenesis. However, its role in colorectal cancer (CRC) has not been explored. In this study, we found circHIPK3 was significantly upregulated in CRC tissues and cell lines, at least in part, due to c-Myb overexpression and positively correlated with metastasis and advanced clinical stage. Moreover, Cox multivariate survival analysis showed that high-level expression of circHIPK3 was an independent prognostic factor of poor overall survival (OS) in CRC (hazard ratio [HR] = 2.75, 95% confidence interval [CI] 1.74–6.51, p = 0.009). Functionally, knockdown of circHIPK3 markedly inhibited CRC cells proliferation, migration, invasion, and induced apoptosis in vitro and suppressed CRC growth and metastasis in vivo. Mechanistically, by using biotinylated-circHIPK3 probe to perform RNA pull-down assay in CRC cells, we identified miR-7 was the only one microRNA that was abundantly pulled down by circHIPK3 in both HCT116 and HT29 cells and these interactions were also confirmed by biotinylated miR-7 pull-down and dual-luciferase reporter assays. Overexpression of miR-7 mimicked the effect of circHIPK3 knockdown on CRC cells proliferation, migration, invasion, and apoptosis. Furthermore, ectopic expression of circHIPK3 effectively reversed miR-7-induced attenuation of malignant phenotypes of CRC cells by increasing the expression levels of miR-7 targeting proto-oncogenes (FAK, IGF1R, EGFR, YY1). Remarkably, the combination of circHIPK3 silencing and miR-7 overexpression gave a better effect on tumor suppression both in vitro and in vivo than did circHIPK3 knockdown or miR-7 overexpression alone. Taken together, our data indicate that circHIPK3 may have considerable potential as a prognostic biomarker in CRC, and support the notion that therapeutic targeting of the c-Myb/circHIPK3/miR-7 axis may be a promising treatment approach for CRC patients.

IMPORTANCE Although the benefit of reducing blood pressure for primary and secondary prevention of stroke has been established, the effect of antihypertensive treatment in patients with acute ischemic stroke is uncertain.OBJECTIVE To evaluate whether immediate blood pressure reduction in patients with acute ischemic stroke would reduce death and major disability at 14 days or hospital discharge. DESIGN, SETTING, AND PARTICIPANTS The China Antihypertensive Trial in Acute IschemicStroke, a single-blind, blinded end-points randomized clinical trial, conducted among 4071 patients with nonthrombolysed ischemic stroke within 48 hours of onset and elevated systolic blood pressure. Patients were recruited from 26 hospitals across China between August 2009 and May 2013.INTERVENTIONS Patients (n = 2038) were randomly assigned to receive antihypertensive treatment (aimed at lowering systolic blood pressure by 10% to 25% within the first 24 hours after randomization, achieving blood pressure less than 140/90 mm Hg within 7 days, and maintaining this level during hospitalization) or to discontinue all antihypertensive medications (control) during hospitalization (n = 2033). MAIN OUTCOMES AND MEASURESPrimary outcome was a combination of death and major disability (modified Rankin Scale score Ն3) at 14 days or hospital discharge.RESULTS Mean systolic blood pressure was reduced from 166.7 mm Hg to 144.7 mm Hg (−12.7%) within 24 hours in the antihypertensive treatment group and from 165.6 mm Hg to 152.9 mm Hg (−7.2%) in the control group within 24 hours after randomization (difference, −5.5% [95% CI, −4.9 to −6.1%]; absolute difference, −9.1 mm Hg [95% CI, −10.2 to −8.1]; P < .001). Mean systolic blood pressure was 137.3 mm Hg in the antihypertensive treatment group and 146.5 mm Hg in the control group at day 7 after randomization (difference, −9.3 mm Hg [95% CI, −10.1 to −8.4]; P < .001). The primary outcome did not differ between treatment groups (683 events [antihypertensive treatment] vs 681 events [control]; odds ratio, 1.00 [95% CI, 0.88 to 1.14]; P = .98) at 14 days or hospital discharge. The secondary composite outcome of death and major disability at 3-month posttreatment follow-up did not differ between treatment groups (500 events [antihypertensive treatment] vs 502 events [control]; odds ratio, 0.99 [95% CI, 0.86 to 1.15]; P = .93).CONCLUSION AND RELEVANCE Among patients with acute ischemic stroke, blood pressure reduction with antihypertensive medications, compared with the absence of hypertensive medication, did not reduce the likelihood of death and major disability at 14 days or hospital discharge.

BackgroundRecent studies indicate that circular RNA (circRNA) plays a pivotal role in cancer progression. Here, we sought to investigate its role in breast cancer.MethodsCircANKS1B (a circRNA originated from exons 5 to 8 of the ANKS1B gene, hsa_circ_0007294) was identified by RNA-sequencing and validated by qRT-PCR and Sanger sequencing. Clinical breast cancer samples were used to evaluate the expression of circANKS1B and its associations with clinicopathological features and prognosis. Gain- and loss-of-function experiments in cell lines and mouse xenograft models were performed to support clinical findings and elucidate the function and underlying mechanisms of circANKS1B in breast cancer.ResultsCircANKS1B was significantly up-regulated in triple-negative breast cancer (TNBC) compared with non-TNBC tissues and cell lines. Increased circANKS1B expression was closely associated with lymph node metastasis and advanced clinical stage and served as an independent risk factor for overall survival of breast cancer patients. Functional studies revealed that circANKS1B promoted breast cancer invasion and metastasis both in vitro and in vivo by inducing epithelial-to-mesenchymal transition (EMT), while had no effect on breast cancer growth. Mechanistically, circANKS1B abundantly sponged miR-148a-3p and miR-152-3p to increase the expression of transcription factor USF1, which could transcriptionally up-regulate TGF-β1 expression, resulting in activating TGF-β1/Smad signaling to promote EMT. Moreover, we found that circANKS1B biogenesis in breast cancer was promoted by splicing factor ESRP1, whose expression was also regulated by USF1.ConclusionsOur data uncover an essential role of the novel circular RNA circANKS1B in the metastasis of breast cancer, which demonstrate that therapeutic targeting of circANKS1B may better prevent breast cancer metastasis.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0914-x) contains supplementary material, which is available to authorized users.

BackgroundMounting evidence demonstrates that long noncoding RNAs (lncRNAs) have critical roles during the initiation and progression of cancers. In this study, we report that the small nucleolar RNA host gene 1 (SNHG1) is involved in colorectal cancer progression.MethodsWe analyzed RNA sequencing data to explore abnormally expressed lncRNAs in colorectal cancer. The effects of SNHG1 on colorectal cancer were investigated through in vitro and in vivo assays (i.e., CCK-8 assay, colony formation assay, flow cytometry assay, EdU assay, xenograft model, immunohistochemistry, and western blot). The mechanism of SNHG1 action was explored through bioinformatics, RNA fluorescence in situ hybridization, luciferase reporter assay, RNA pull-down assay, chromatin immunoprecipitation assay and RNA immunoprecipitation assay.ResultsOur analysis revealed that SNHG1 was upregulated in human colorectal cancer tissues, and high SNHG1 expression was associated with reduced patient survival. We also found that high SNHG1 expression was partly induced by SP1. Moreover, SNHG1 knockdown significantly repressed colorectal cancer cells growth both in vitro and in vivo. Mechanistic investigations demonstrated that SNHG1 could directly interact with Polycomb Repressive Complex 2 (PRC2) and modulate the histone methylation of promoter of Kruppel like factor 2 (KLF2) and Cyclin dependent kinase inhibitor 2B (CDKN2B) in the nucleus. In the cytoplasm, SNHG1 acted as a sponge for miR-154-5p, reducing its ability to repress Cyclin D2 (CCND2) expression.ConclusionsTaken together, the results of our studies illuminate how SNHG1 formed a regulatory network to confer an oncogenic function in colorectal cancer and suggest that SNHG1 may serve as a potential target for colorectal cancer diagnosis and treatment.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0894-x) contains supplementary material, which is available to authorized users.

Background Colorectal cancer (CRC) is one of the leading causes of tumor-related death worldwide, and its main cause of death is distant metastasis. Methyltransferase-like 14(METTL14), a major RNA N6-adenosine methyltransferase, is involved in tumor progression via regulating RNA function. The goal of the study is to uncover the biological function and molecular mechanism of METTL14 in CRC. Methods Quantitative real-time PCR (qRT-PCR), western blot and immunohistochemical (IHC) assays were employed to detect METTL14 and SOX4 in CRC cell lines and tissues. The biological functions of METTL14 were demonstrated using in vitro and in vivo experiments. Chromatin immunoprecipitation (ChIP), Transcrptomic RNA sequencing (RNA-Seq), m6A-RNA immunoprecipitation sequencing (MeRIP-Seq), RNA immunoprecipitation and luciferase reporter assays were used to explore the mechanism of METTL14 action. Results METTL14 expression was significantly downregulated in CRC and decreased METTL14 was associated with poor overall survival (OS). Both the univariate and multivariate Cox regression analysis indicated that METTL14 was an independent prognostic factor in CRC. Moreover, lysine-specific histone demethylase 5C(KDM5C)-mediated demethylation of histone H3 lysine 4 tri-methylation(H3K4me3) in the promoter of METTL14 inhibited METTL14 transcription. Functionally, we verified that METTL14 inhibited CRC cells migration, invasion and metastasis through in vitro and in vivo assays, respectively. Furthermore, we identified SRY-related high-mobility-group box 4(SOX4) as a target of METTL14-mediated m6A modification. Knockdown of METTL14 markedly abolished SOX4 mRNA m6A modification and elevated SOX4 mRNA expression. We also revealed that METTL14-mediated SOX4 mRNA degradation relied on the YTHDF2-dependent pathway. Lastly, we demonstrated that METTL14 might inhibit CRC malignant process partly through SOX4-mediated EMT process and PI3K/Akt signals. Conclusions Decreased METTL14 facilitates tumor metastasis in CRC, suggesting that METTL14 might be a potential prognostic biomarker and effective therapeutic target for CRC. Graphical abstract