Ya Peng

miR-106a-5p Inhibits the Proliferation and Migration of Astrocytoma Cells and Promotes Apoptosis by Targeting FASTK

Astrocytomas are common malignant intracranial tumors that comprise the majority of adult primary central nervous system tumors. MicroRNAs (miRNAs) are small, non-coding RNAs (20–24 nucleotides) that post-transcriptionally modulate gene expression by negatively regulating the stability or translational efficiency of their target mRNAs. In our previous studies, we found that the downregulation of miR-106a-5p in astrocytomas is associated with poor prognosis. However, its specific gene target(s) and underlying functional mechanism(s) in astrocytomas remain unclear. In this study, we used mRNA microarray experiments to measure global mRNA expression in the presence of increased or decreased miR-106a-5p levels. We then performed bioinformatics analysis based on multiple target prediction algorithms to obtain candidate target genes that were further validated by computational predictions, western blot analysis, quantitative real-time PCR, and the luciferase reporter assay. Fas-activated serine/threonine kinase (FASTK) was identified as a direct target of miR-106a-5p. In human astrocytomas, miR-106a-5p is downregulated and negatively associated with clinical staging, whereas FASTK is upregulated and positively associated with advanced clinical stages, at both the protein and mRNA levels. Furthermore, Kaplan-Meier analysis revealed that the reduced expression of miR-106a-5p or the increased expression of FASTK is significantly associated with poor survival outcome. These results further supported the finding that FASTK is a direct target gene of miR-106a-5p. Next, we explored the function of miR-106a-5p and FASTK during astrocytoma progression. Through gain-of-function and loss-of-function studies, we demonstrated that miR-106a-5p can significantly inhibit cell proliferation and migration and can promote cell apoptosis in vitro. The knockdown of FASTK induced similar effects on astrocytoma cells as those induced by the overexpression of miR-106a-5p. These observations suggest that miR-106a-5p functions as a tumor suppressor during the development of astrocytomas by targeting FASTK.

A microRNA expression signature predicts meningioma recurrence

The aberrant expression of microRNAs (miRNAs) is associated with a variety of diseases, including cancer. In our study, we examined the miRNA expression profile of meningiomas, which is a common type of benign intracranial tumor derived from the protective meninges membranes that surround the brain and spinal cord. To define a typical human meningioma miRNA profile, the expression of 200 miRNAs in a training sample set were screened using quantitative reverse transcription polymerase chain reaction analysis, and then significantly altered miRNAs were validated in a secondary independent sample set. Kaplan–Meier and univariate/multivariate Cox proportional hazard regression analyses were performed to assess whether miRNA expression could predict the recurrence of meningioma after tumor resection. After a two‐phase selection and validation process, 14 miRNAs were found to exhibit significantly different expression profiles in meningioma samples compared to normal adjacent tissue (NAT) samples. Unsupervised clustering analysis indicated that the 14‐miRNA profile differed between tumor and NAT samples. Downregulation of miR‐29c‐3p and miR‐219‐5p were found to be associated with advanced clinical stages of meningioma. Kaplan–Meier analysis showed that high expression of miR‐190a and low expression of miR‐29c‐3p and miR‐219‐5p correlated significantly with higher recurrence rates in meningioma patients. Cox proportional hazard regression analysis revealed that miR‐190a expression level is an important prognostic predictor that is independent of other clinicopathological factors. Our results suggest that the use of miRNA profiling has significant potential as an effective diagnostic and prognostic marker in defining the expression signature of meningiomas and in predicting postsurgical outcomes.

Long non-coding RNA in glioma: signaling pathways

Glioma is regarded as the most prevalent malignant carcinoma of the central nervous system. Thus, the development of new therapeutic strategies targeting glioma is of significant clinical importance. Long non-coding RNAs (lncRNAs) are functional RNA molecules without a protein-coding function and are reportedly involved in the initiation and progression of glioma. Dysregulation of lncRNAs in glioma is due to activation of several signaling pathways, such as the BRD4-HOTAIR-β-catenin/PDCD4, p53-Hif-H19/IGF2 and CRNDE/mTOR pathways. Furthermore, microRNAs (miRNAs) such as miR-675 also interact with lncRNAs in glioma. Thus, exploring the mechanisms by which lncRNA control processes will be instrumental for devising new effective therapies against glioma.

Predictors of Outcome and Hemorrhage in Patients Undergoing Endovascular Therapy with Solitaire Stent for Acute Ischemic Stroke.

Background Endovascular mechanical thrombectomy is emerging as a promising therapeutic approach for acute ischemic stroke and show some advantages. However, the data of predicting clinical outcome after thrombectomy with Solitaire retriever were limited. We attempt to identify prognostic factors of clinical outcome in patients with acute ischemic stroke undergoing thrombectomy with Solitaire retriever. Methods We conducted a retrospective analysis of consecutive acute ischemic strokes cases treated between December 2010 and December2013 where the Solitaire stent retriever was used for acute ischemic stroke. We assessed the effect of selected demographic characteristics, clinical factors on poor outcome at 3 months (modified Rankin score 3–6), mortality at 3 months, and hemorrhage within 24 h (symptomatic and asymptomatic). Clinical, imaging and logistic variables were analyzed. A multivariate logistic regression analysis was used to identify variables influencing clinical outcome, based on discharge NIHSS score change and mRS at 3 months. Results Eighty nine consecutive patients with acute ischemic stroke underwent mechanical thrombectomy. Multivariate analysis revealed that admission NIHSS score, Serum glucose and endovascular procedure duration were independently associated with clinical outcome. Sex, NIHSS score at admission, diabetes and time of operation were associated with sICH in 1 day. NIHSS score ≥20 (OR 9.38; 95% CI 2.41–36.50), onset to reperfusion >5 hours (OR 5.23; 95% CI1.34,20.41) and symptomatic intracranial hemorrhage (OR 10.19; 95% CI1.80,57.83) were potential predictive factors of mortality at 3 months. Conclusion Multiple pre- and intra-procedural factors can be used to predict clinical outcome, symptomatic intracranial hemorrhage and mortality in acute ischemic stroke patients undergoing endovascular therapy. This knowledge is helpful for patients selection for endovascular mechanical thrombectomy.

Upregulation of the long non-coding RNA SNHG1 predicts poor prognosis, promotes cell proliferation and invasion, and reduces apoptosis in glioma

Long non-coding RNAs (lncRNAs), which are non-coding RNAs with a length above 200 nucleotides, have emerged as novel and important gene expression modulators in carcinogenesis. Recent evidence indicates that the lncRNA small nucleolar RNA host gene 1 (SNHG1) functions as an oncogene in several types of human cancers. However, its function in the development of glioma remains unknown. The aim of this research was to investigate the clinical aspects and biological mechanisms of SNHG1 in glioma. SNHG1 expression was measured in glioma tissues and cell lines by quantitative real-time PCR (qRT-PCR). The association between SNHG1 expression in tissues and clinicopathological characteristics and prognosis in glioma patients was also explored. Gain-of-function and loss-of-function studies using SNHG1 cDNA and siRNA, respectively, were used to investigate the role of SNHG1 in cell proliferation, invasion and apoptosis in glioma. SNHG1 was highly expressed in glioma tissues, and its upregulation was closely related to old age. Kaplan-Meier analysis showed that high expression of SNHG1 was significantly associated with poor overall survival (OS). Functionally, ectopic expression of SNHG1 enhanced cell proliferation and cell invasion and reduced cell apoptosis in vitro, while SNHG1 knockdown reversed these effects. Taken together, our findings indicate that SNHG1 functions as an oncogene in glioma and may serve as a novel therapeutic target in future treatments.

A serum 6-miRNA panel as a novel non-invasive biomarker for meningioma

Circulating microRNAs (miRNAs) hold great promise as novel clinically blood-based biomarkers for cancer diagnosis and prognosis. However, little is known about their impact in meningioma. The TLDA assay was performed as an initial survey to determine the serum miRNA expression profile in two pooled samples from 20 pre-operative meningiomas and 20 matched healthy controls. Selected candidate miRNAs were subsequently validated individually in another 210 patients and 210 healthy controls from two independent cohorts by qRT-PCR. The serum levels of miR-106a-5p, miR-219-5p, miR-375, and miR-409-3p were significantly increased, whereas the serum levels of miR-197 and miR-224 were markedly decreased. The area under the ROC curve (AUC) for the six combined miRNAs was 0.778. The 4 increased miRNAs were significantly decreased, while the 2 decreased miRNAs were significantly increased after tumor removal. Furthermore, the expression levels of miR-224 were associated with sex, and the expression levels of miR-219-5p were positively associated with the clinical stages of meningioma. Finally, the high expression of miR-409-3p and low expression of miR-224 were significantly correlated with higher recurrence rates. The present study revealed that the panel of 6 serum miRNA may have the potential to be used clinically as an auxiliary tool for meningioma patients.

Evodiamine activates cellular apoptosis through suppressing PI3K/AKT and activating MAPK in glioma

Background Glioblastoma multiforme (GBM) is the most malignant primary tumor of the central nervous system and is associated with a very poor prognosis. No further improvements in outcomes have been reported since radiotherapy-temozolomide therapy was introduced. Therefore, developing new agents to treat GBM is important. Aim This study aimed to evaluate the anti-tumor effect of evodiamine (Evo) on GBM cells, and to determine the underlying mechanisms involved. Results According to MTT assay results, Evo significantly inhibited the cell proliferation in a time- and dose-dependent manner. Fluorescence microscopy and flow cytometry analyses revealed that Evo induced cell apoptosis in a concentration-dependent manner. Moreover, Evo induced reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) disruption. Finally, Evo induced apoptosis in cancer cells by suppressing PI3K/AKT signaling and inducing MAPK phosphorylation (p38 and JNK, but not ERK) to regulate apoptotic proteins (Bax, Bcl-2, Cytochrome c, Caspase-3, and PARP). Conclusion In summary, Evo inhibits cell proliferation by inducing cellular apoptosis via suppressing PI3K/AKT and activating MAPK in GBM; these results indicate that Evo may be regarded as a new approach for GBM treatment.

Carnosic acid prevents dextran sulfate sodium-induced acute colitis associated with the regulation of the Keap1/Nrf2 pathway

Crohn’s disease and ulcerative colitis are inflammatory bowel diseases (IBDs) with high prevalence in humans. Carnosic acid (CA) has been reported to possess antioxidative properties; however, its role in IBDs has not been determined. In the present study, we found that CA significantly prevented the loss of body weight and shortening of colon length in acute colitis induced by dextran sodium sulfate (DSS). Pronounced infiltration of immune cells and a loss of crypt architecture and goblet cells were ameliorated by CA. CA significantly decreased the activity of MPO and infiltration of F4/80+ macrophages in the colon. DSS-induced pro-inflammatory cytokine mRNA and protein levels in the colon were also attenuated by CA. CA decreased the activation of p65 and c-Jun signalling. CA inhibited DSS-induced NLRP3 inflammasome activation by reducing caspase 1 activity. In addition, CA increased the level of Nrf2 and prevented the degradation of Nrf2 via ubiquitination by blocking the interaction between Cullin3 and Keap1, which resulted in the decrease of Nrf2 target genes. Finally, GSH levels and SOD activity were increased after CA treatment, while MDA and iNOS levels were significantly reduced. Taken together, our data showed that CA may be useful as a potential therapeutic candidate for IBDs.

Inactivation of Semicarbazide-Sensitive Amine Oxidase Stabilizes the Established Atherosclerotic Lesions via Inducing the Phenotypic Switch of Smooth Muscle Cells.

Given that the elevated serum semicarbazide-sensitive amine oxidase (SSAO) activity is associated with the severity of carotid atherosclerosis in clinic, the current study aims to investigate whether SSAO inactivation by semicarbazide is beneficial for established atherosclerotic lesions in LDLr knockout mice on a high-fat/high- cholesterol Western-type diet or after dietary lipid lowering. Despite no impact on plasma total cholesterol levels, the infiltration of circulating monocytes into peripheral tissues, and the size of atherosclerotic lesions, abrogation of SSAO activity resulted in the stabilization of established lesions as evidenced by the increased collagen contents under both conditions. Moreover, SSAO inactivation decreased Ly6Chigh monocytosis and lesion macrophage contents in hypercholesterolemic mice, while no effect was observed in mice after normalization of hypercholesterolemia by dietary lipid lowering. Strikingly, abrogation of SSAO activity significantly increased not only the absolute numbers of smooth muscle cells (SMCs), but also the percent of SMCs with a synthetic phenotype in established lesions of mice regardless of plasma cholesterol levels. Overall, our data indicate that SSAO inactivation in vivo stabilizes the established plaques mainly via inducing the switch of SMCs from a contractile to a synthetic phenotype. Targeting SSAO activity thus may represent a potential treatment for patients with atherosclerosis.

Mechanical thrombectomy by Solitaire stent for treating acute ischemic stroke: A prospective cohort study

BACKGROUND Acute ischemic stroke (AIS) is a worldwide serious health problem. Intravenous (IV) thrombolysis with recombinant tissue plasminogen activator (rt-PA) is the standard treatment; however, only a small number of patients benefit from it due to the strict application restrictions. Recently, more and more evidence prove mechanical thrombectomy is an effective and safe therapy of AIS. PATIENTS AND METHODS From December 2010 to March 2015, 83 patients who underwent mechanical thrombectomy were collected as a sample pool. All patients met the following criteria: National Institutes of Health Stroke Scale (NIHSS) score ≥10, treatment performed within 6 h from the onset of symptoms, no large hypodensity on CT or multimodal MRI, and angiography revealed occlusion of a major cerebral artery. Recanalization rates were assessed immediately post-procedure by follow-up angiography according to the thrombolysis in cerebral infarction score criteria. Assessment of the modified Rankin Scale was performed 90 days after treatment. RESULTS The mean age of patients was 63.3 years, and NIHSS scores 19.12 ± 4.60 at presentation. The vessel occlusions occurred in the middle cerebral artery (68.7%), distal internal carotid artery (7.2%), internal carotid artery with tandem middle cerebral artery occlusion (14.5%), basilar artery (2.4%), and vertebral artery (7.2%). Successful recanalization (TICI 3/2b) was achieved in 56 of 83 patients (67.5%). At 90-day follow-up, good clinical outcome (mRS ≤ 2) was achieved in 33 of 83 patients (39.8%), while 20 patients died (24.1%). CONCLUSIONS This study revealed mechanical thrombectomy with Solitaire stent device was an effective and safe therapy, which achieved a high rate of angiographic recanalization and independent outcome accompanied by a low mortality rate.