Long noncoding RNA FOXD2-AS1 promotes glioma malignancy and tumorigenesis via targeting miR-185-5p/CCND2 axis.

Glioma is the most aggressive malignant tumor in the adult central nervous system. Abnormal long noncoding RNA (lncRNA) FOXD2-AS1 expression was associated with tumor development. However, the possible role of FOXD2-AS1 in the progression of glioma is not known. In the present study, we used in vitro and in vivo assays to investigate the effect of abnormal expression of FOXD2-AS1 on glioma progression and to explore the mechanisms. FOXD2-AS1 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of FOXD2-AS1 was correlated with poor prognosis of glioma. Downregulation of FOXD2-AS1 decreased cell proliferation, migration, invasion, stemness, and epithelial-mesenchymal transition (EMT) in glioma cells and inhibited tumor growth in transplanted tumor. We also revealed that FOXD2-AS1 was mainly located in cytoplasm and microRNA (miR)-185-5p both targeted FOXD2-AS1 and CCND2 messenger RNA (mRNA) 3'-untranslated region (3'-UTR). miR-185-5p was downregulated in glioma tissue, cells, and sphere subpopulation. Downregulation of miR-185-5p was closely correlated with poor prognosis of glioma patients. In addition, miR-185-5p mimics decreased cell proliferation, migration, invasion, stemness, and EMT in glioma cells. CCND2 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of CCND2 was closely correlated with poor prognosis of glioma patients. CCND2 knockdown decreased cell proliferation, migration, invasion, and EMT in glioma cells. In glioma tissues, CCND2 expression was negatively associated with miR-185-5p, but positively correlated with FOXD2-AS1. FOXD2-AS1 knockdown and miR-185-5p mimics decreased CCND2 expression. Inhibition of miR-185-5p suppressed FOXD2-AS1 knockdown-induced decrease of CCND2 expression. Overexpression of CCND2 suppressed FOXD2-AS1 knockdown-induced inhibition of glioma malignancy. Taken together, our findings highlight the FOXD2-AS1/miR-185-5p/CCND2 axis in the glioma development.

MiR-129-5p inhibits glioma cell progression in vitro and in vivo by targeting TGIF2.

This study purposed to explore the correlation between miR-129-5p and TGIF2 and their impacts on glioma cell progression. Differentially expressed miRNA was screened through microarray analysis. MiR-129-5p expression levels in glioma tissues and cells were measured by qRT-PCR. CCK-8 assay, flow cytometer, transwell assay and wound-healing assay were employed to detect cell proliferation, apoptosis and cycle, invasiveness and migration, respectively. Dual-luciferase reporting assay was performed to confirm the targeted relationship between miR-129-5p and TGIF2. The effects of TGIF2 expression on cell biological functions were also investigated using the indicated methods. Tumour xenograft was applied to explore the impact of miR-129-5p on tumorigenesis in vivo. MiR-129-5p expression was down-regulated in both glioma tissues and glioma cells, while TGIF2 expression was aberrantly higher than normal level. Dual-luciferase reporter assay validated the targeting relation between miR-129-5p and TGIF2. Overexpression of miR-129-5p or down-regulation of TGIF2 inhibited the proliferation, invasion and migration capacity of glioma cells U87 and U251, and meanwhile blocked the cell cycle as well as induced cell apoptosis. MiR-129-5p overexpression repressed the tumour development in vivo. MiR-129-5p and TGIF2 had opposite biological functions in glioma cells. MiR-129-5p could inhibit glioma cell progression by targeting TGIF2, shining light for the development of target treatment for glioma.

Opposite in vivo effects of agents that stimulate or inhibit the glutamate/cysteine exchanger system xc- on the inhibition of hippocampal LTP by Aß.

Aggregated amyloid ß-protein (Aß) is pathognomonic of Alzheimer's disease and certain assemblies of Aß are synaptotoxic. Excess glutamate or diminished glutathione reserve are both implicated in mediating or modulating Aß-induced disruption of synaptic plasticity. The system xc- antiporter promotes Na+ -independent exchange of cystine with glutamate thereby providing a major source of extracellular glutamate and intracellular glutathione concentrations. Here we probed the ability of two drugs with opposite effects on system xc-, the inhibitor sulfasalazine and facilitator N-acetylcysteine, to modulate the ability of Aß1-42 to inhibit long-term potentiation (LTP) in the CA1 area of the anaesthetized rat. Whereas acute systemic treatment with sulfasalazine lowered the threshold for Aß to interfere with synaptic plasticity, N-acetylcysteine prevented the inhibition of LTP by Aß alone or in combination with sulfasalazine. Moreover acute N-acetylcysteine also prevented the inhibition of LTP by TNFα, a putative mediator of Aß actions, and repeated systemic N-acetylcysteine treatment for 7 days reversed the delayed deleterious effect of Aß on LTP. Since both of these drugs are widely used clinically, further evaluation of their potential beneficial and deleterious actions in early Alzheimer's disease seems warranted. © 2016 Wiley Periodicals, Inc.

MicroRNA-383 expression regulates proliferation, migration, invasion, and apoptosis in human glioma cells.

This study aims to evaluate microRNA-383 (miR-383) expression level in glioma cells and its influences on proliferation, migration, invasion, apoptosis, and cell cycle in glioma cells. miR-383 expression levels were determined by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Thirty BALB/c-nu mice were randomly assigned into three groups: U87-miR-383 group, vector-control group, and blank group. Tumorigenicity experiment was conducted to confirm the function of miR-383. U251 and U87 glioma cells were divided into three groups: non-transfected control cells (NT group), glioma cells transfected with miR-383 (miR-383 group), and glioma cells transfected with negative sequence (NC group). Transfection efficiency was measured by qRT-PCR. Cell counting kit-8 (CCK-8) assay was used to detect cell proliferation. Cell migration and invasion were examined by utilizing a Transwell chamber. Cell cycle and apoptosis were analyzed by flow cytometry. The qRT-PCR results revealed that miR-383 expression was down-regulated in human glioma cells, and was negatively related to the pathological grading of glioma. The rates of tumor growth in vector-control group and blank group were significantly faster than that in U87-miR-383 group, and the average tumor volume and weight in vector-control group and blank group were increased as compared with U87-miR-383 group. Additionally, miR-383 levels in miR-383 group were higher than those in NT group and NC group. CCK-8 assay indicated lower cell viability in miR-383 group as compared with NT group and NC group. Flow cytometry implied that the percentages of cells in miR-383 group reduced, while the cell apoptosis rate enhanced compared with NT group and NC group. In conclusion, our findings suggest that miR-383 expression is down-regulated in glioma cells, inhibiting cell proliferation, migration, and invasion, affecting the cell cycle, and inducing cell apoptosis.

[Expression and clinical significance of ING4 and HIF-1 alpha in brain astrocytoma].

OBJECTIVE: To study the mRNA expression level of growth inhibition factor 4 (ING4) and hypoxia inducing factor 1 alpha (HIF-1 alpha), and their relationship with tumor malignant degree or the pathology classification in human brain astrocytoma. METHODS: The mRNA expression levels of ING4 and HIF-1 alpha were detected by RT-PCR method in 45 cases of grade I-IV human brain astrocytoma and 11 cases of control brain tissues from January 2009 to June 2010 in the Second Affiliated Hospital of Zhengzhou University, and their correlation was also analyzed. RESULTS: In the non-tumor brain tissue, the expression level of ING4 mRNA was 1.19 ± 0.22, while they were 0.91 ± 0.19, 0.74 ± 0.28, 0.54 ± 0.33 and 0.22 ± 0.19 in I-IV grade astrocytoma, respectively. Compared with the non-tumor control, the mRNA expression level of ING4 gene decreased significantly in the astrocytoma (P<0.05). And the expression of ING4 gradually reduced with the increase of the pathological classification of the astrocytoma.In the non-tumor brain tissue, the expression level of HIF-1 alpha mRNA was 0.26 ± 0.16, and they were 0.34 ± 0.19, 0.50 ± 0.23, 0.96 ± 0.15 and 1.04 ± 0.15 in I-IV grade astrocytoma, respectively.For HIF-1 alpha gene, the mRNA expression level increased significantly in the astrocytoma. Meanwhile, the expression gradually increased with the increase of the pathological classification of the astrocytoma (P<0.05). The mRNA expression showed a negative correlation between ING4 and HIF-1 alpha with the increase of the tumor malignant degree. CONCLUSION: The ING4 and HIF-1 alpha genes play a role in the tumorigenesis and development of human brain astrocytoma, and closely associate with the malignant degree of astrocytoma.

Short-term therapeutic effects of low-dose cytarabine plus surgical resection on elderly patients with trigeminal nerve tumor and safety observation.

OBJECTIVE: To evaluate the short-term therapeutic effects of low-dose cytarabine plus surgical resection on elderly patients with trigeminal nerve tumor and to observe the safety. METHODS: A total of 120 elderly patients with trigeminal nerve tumor were divided into a treatment group and a control group by random draw (n=60), and both groups were subjected to resection by stereotactic image-guided endoscopic nasal surgery. Afterwards, the control group was administered with high-dose cytarabine while the treatment group was given low-dose cytarabine for 14 days. RESULTS: Both groups completed treatment, but the effective rate of the treatment group (96.7%) was significantly higher than that of the control group (83.3%) (P < 0.05). The pain scores of the two groups were similar at T0, T1 and T2, but the score of the treatment group at T2 was significantly different from those at T0 and T1 (P < 0.05). During treatment, the treatment group was significantly less prone to complications such as headache, vomiting, vision impairment, nausea and local swelling than the control group (P < 0.05). During three months of follow-up, the appetite, sleep and daily living scores were significantly higher than those of the control group (P < 0.05). CONCLUSION: Stereotactic image-guided surgery was able to treat trigeminal nerve tumor well, and the effect was enhanced by low-dose cytarabine that improved postoperative outcomes and quality of life by dramatically decreasing complications.

Effect of valproic acid combined with transplantation of olfactory ensheathing cells modified by neurotrophic 3 gene on nerve protection and repair after traumatic brain injury.

BACKGROUND: Traumatic brain injury (TBI) often leads to cognitive and neurological dysfunction. Valproic acid (VPA) has a neuroprotective effect in acute central nervous system diseases; the neurotrophin 3 gene (NT-3) can maintain the survival of neurons, and olfactory ensheathing cells (OECs) can promote the growth of nerve axons. This study aimed to evaluate the restorative effect of VPA combined with NT-3 modified OECs (NT-3-OECs) on neurological function after TBI. METHODS: The neurological severity score (NSS) of rats was evaluated on the 1st, 7th, 14th, and 28th day after TBI modeling and corresponding intervention. Hematoxylin-eosin (HE) staining, p75 nerve growth factor receptor (P75), glial fibrillary acidic protein (GFAP), and neurofilament protein (NF)staining, and argyrophilic staining were used to observe the morphology of brain tissue 28 days after modeling. Moreover, TdT-mediated dUTP Nick-End Labeling (TUNEL) was used to detect the apoptosis rate of neurons. The changes in synapses and mitochondria in the injured area were observed by electron microscope. RESULTS: NT-3-OECs transplantation can increase the content of NT-3 in brain tissue, and NT-3-OECs can survive for >28 days. The NSS score of the TBI-VPA-NT-3-OECs group 28 days after cell transplantation was significantly lower than that of the other model treatment groups (P < 0.05). The morphological structure of the brain tissue was more complete, and the neurofilament fibers were neatly arranged, achieving better results than those of the other groups. The apoptosis rate of nerve cells in the TBI-VPA-NT-3-OECs group was significantly lower than in the other treatment groups (P < 0.05). Furthermore, the number of synapses in the combined intervention group was significantly higher than in the other treatment groups, and the mitochondrial structure was more complete. CONCLUSION: NT-3-OECs have good biological function, and VPA combined with NT-3-OECs transplantation can effectively improve the prognosis of TBI rats.

Coagulation factor 2 thrombin receptor promotes malignancy in glioma under SOX2 regulation.

Glioma is the most common human primary brain cancer with high mortality and unfavorable clinical outcome. Coagulation factor 2 thrombin receptor (F2R), is a key component in the thrombosis process and has been demonstrated upregulated in various cancers. However, the effect and molecular mechanisms of F2R in glioma remains unclear. In our study, we confirmed that the expression of F2R was upregulated in glioma and predicted poor prognosis. Gene Set Enrichment Analysis (GSEA) and function assays demonstrated that F2R overexpression promoted glioma cell proliferation, metastasis and epithelial-mesenchymal transition (EMT) in vitro and tumor growth in vivo. Then, we identified and validated F2R was the target gene of SRY-box 2 (SOX2) by dual luciferase reporter assay and chromatin immunoprecipitation assay. Besides, High expression of F2R in malignant glioma was associated with ß-catenint signaling pathway activation. Our findings conclude that F2R promotes glioma cell proliferation and metastasis under SOX2 and actives WNT/ß-catenin Signaling pathway, which provides novel insight to the therapeutic regimen in glioma.

lncRNA small nucleolar RNA host gene 20 predicts poor prognosis in glioma and promotes cell proliferation by silencing P21.

BACKGROUND: In multiple cancers, long non-coding RNA small nucleolar RNA host gene 20 (lncRNA SNHG20) is generally dysregulated. In the present study, both the biological role and clinicopathological value of lncRNA SNHG20 in glioma are explored. METHODS: Real-time PCR was employed to determine lncRNA SNHG20 expression in glioma patients. The prognostic role of expression of lncRNA SNHG20 was evaluated in a retrospective cohort study. In addition, the association between lncRNA SNHG20 expression and the clinicopathological features of glioma patients, such as tumor recurrence, survival status, follow-up time, WHO grade, resection extent, tumor location, Karnofsky performance scale score, cystic change, tumor size, gender and age, was discussed. By constructing and transfecting siRNAs that targeted lncRNA SNHG20 into the glioma U87 cells, the effects of lncRNA SNHG20 on the proliferation and cell cycle of U87 cells were assessed through cell counting kit-8, colony formation and cell cycle assays, respectively. In addition, Western blot and real-time PCR measured the expression levels of P21 and CCNA1 in U87 cells after being transfected with SNHG20 siRNA. RESULTS: Our results suggested the high expression of lncRNA SNHG20 in human glioma tissues compared with normal brain tissues, which was related to recurrence-free survival and poor overall survival in glioma patients. According to the existing retrospective cohort study, high lncRNA SNHG20 expression was associated with tumor size, extent of resection, WHO grade, follow-up time, survival status and recurrence. Besides, knocking down the expression of lncRNA SNHG20 could inhibit the proliferation and colony formation abilities of glioma U87 cells through cell cycle arrest. Consequently, the expression of CCNA1 was inhibited, and the expression of P21 was up-regulated in U87 cells. CONCLUSION: A high lncRNA SNHG20 expression level predicts the poor prognosis for glioma patients. Moreover, lncRNA SNHG20 can promote glioma proliferation through silencing P21 and thus lncRNA SNHG20 is an independent potential prognostic biomarker for glioma patients.

CDCA7L promotes glioma proliferation by targeting CCND1 and predicts an unfavorable prognosis.

Cell division cycle associated 7 like (CDCA7L) belongs to the JPO protein family, recently identified as a target gene of c­Myc and is frequently dysregulated in multiple cancers. However, to the best of our knowledge, no studies to date have been carried out to investigate the functions of CDCA7L in glioma. Thus, in this study, the expression level of CDCA7L and its association with the prognosis in glioma were detected through the TCGA database. The mRNA expression levels of CDCA7L in glioblastoma (GBM) tissues and normal brain tissues were detected by RT­qPCR and western blot analysis. To explore the role of CDCA7L in glioma, CDCA7L siRNA was constructed and transfected into U87 glioma cells. The expression levels of CDCA7L and cyclin D1 (CCND1) in glioma U87 cells following transfection with CDCA7L siRNA were measured by RT­qPCR and western blot analysis. CCK­8, colony formation, EdU and Transwell assays were used to measure the effects of CDCA7L on U87 cell proliferation, and flow cytometry was used to monitor the changes in the cell cycle following transfection with CDCA7L siRNA. Xenograft tumors were examined in vivo for the carcinogenic effects, as well as the mechanisms and prognostic value of CDCA7L in glioma tissues. The results revealed that CDCA7L was highly expressed in human GBM tissues, and a high expression of CDCA7L was associated with a poor prognosis of glioma patients through the TCGA database. We demonstrated that CDCA7L was highly expressed in human GBM tissues and 3 glioma cell lines. The downregulation CDCA7L expression significantly inhibited the proliferation and colony formation ability of U87 cells by blocking cell cycle progression in the G0/G1 phase. In addition, we found that the mRNA and protein levels of CCND1 were markedly decreased following transfection with CDCA7L siRNA compared with NC siRNA in vitro. The downregulation CDCA7L expression reduced the number of invading cells. Consistent with the results of the in vitro assays, the xenograft assay, immunohistochemistry (IHC) assay and western blot analysis demonstrated that, in response to CDCA7L inhibition, tumor growth was inhibited, Ki­67 and CCND1 expression levels were decreased in vivo. On the whole, the results of the current study indicate that CDCA7L is highly expressed in human glioma tissues and that a high CDCA7L expression predicts a poor prognosis of glioma patients. CDCA7L promotes glioma U87 cell growth through CCND1.

Long noncoding RNA ZEB1-AS1 promotes the tumorigenesis of glioma cancer cells by modulating the miR-200c/141-ZEB1 axis.

Long noncoding RNA Zinc Finger E-box-binding homeobox 1 antisense 1 (ZEB1-AS1) reportedly participates in the tumorigenesis of various cancers. However, the clinical significance and biological functions of ZEB1-AS1 in glioma remain virtually unknown. Here, we show that ZEB1-AS1 expression was higher in glioma tissues and cell lines than in corresponding noncancerous samples and primary normal human astrocytes, respectively. The positive correlation of ZEB1-AS1 expression with the poor prognosis and progressive histological stages of glioma patients was clinically proven. In vitro assays revealed that silencing ZEB1-AS1 inhibited glioma cancer-cell growth and motility. Xenograft experiments confirmed that ZEB1-AS1 depletion attenuated tumor growth and metastasis. Dual-luciferase report assay showed that ZEB1-AS1 directly regulated microRNA-200c/141 (miR-200c/141) in glioma cells, which was confirmed by RNA immunoprecipitation assay. Furthermore, the inhibition of miR-200c/141 partially balanced the inhibition effects of cell proliferation and motility induced by ZEB1-AS1 depletion on U87 cells. Additionally, ZEB1-AS1 can regulate ZEB1 through miR-200c/141. Hence, ZEB1-AS1 directly regulated miR-200c/141 in glioma cells and relieved the inhibition of ZEB1 caused by miR-200c/141. Overall, this study revealed a novel regulatory mechanism between ZEB1-AS1 and the miR-200c/141-ZEB1 axis. The interaction between ZEB1-AS1 and miR-200c/141-ZEB1 axis was involved in the progression of glioma cells. Therefore, targeting this interaction was a promising strategy for glioma treatment.

Meta-analysis of the prognostic value of long non-coding RNA AFAP1-AS1 for cancer patients in China.

LncRNA actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) is often dysregulated in cancer. We performed this meta-analysis to clarify the usefulness of AFAP1-AS1 as a prognostic marker in malignant tumors. The PubMed, Medline, OVID, Cochrane Library, and Web of Science databases were searched from inception to Augest 7, 2017. Sixteen studies with a total of 1,386 patients were included in the study. The pooled hazard ratio (HR) suggested high AFAP1-AS1 expression correlated with poor overall survival (OS) (HR = 1.98, 95% confidence interval (CI): 1.71-2.28), disease-free survival (DFS) (HR = 1.54, 95% CI: 1.22-1.95), and progression-free survival (PFS) (HR = 2.17, 95% CI:1.64-2.88) in cancer patients, without obvious heterogeneity. High AFAP1-AS1 expression also correlated with larger tumor size (odds ratio (OR) = 2.04, 95% CI: 1.54-2.72), advanced tumor stage (OR=2.35, 95% CI: 1.70-3.26), poor histological grade (OR =1.39, 95% CI: 1.02-1.90), lymph node metastasis (OR = 2.71, 95% CI: 1.98-3.72) and distant metastasis (OR = 2.96, 95% CI: 2.03-4.32). Thus high AFAP1-AS1 expression is predictive of poor OS, DFS, PFS, lymph node metastasis, distant metastasis, histological grade, larger tumor size and tumor stage, which suggests high AFAP1-AS1 expression may serve as a novel biomarker of poor prognosis in cancer.

LncRNA PANDAR as a prognostic marker in Chinese cancer.

BACKGROUND: LncRNA promoter of CDKN1A antisense DNA damage activated RNA (PANDAR) is reportedly dysregulated in various cancers. We performed this meta-analysis to clarify the efficacy of PANDAR as a prognostic marker in malignant tumors. METHODS: The PubMed, Medline, OVID, Cochrane Library, and Web of Science databases were searched from inception to July 3, 2017. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to explore the relationship between PANDAR expression and overall survival (OS). Odds ratios (ORs) were calculated to assess the association between PANDAR expression and pathological parameters. RESULTS: Eight original studies covering 1,132 cancer patients were included. The pooled HR suggested that high PANDAR expression correlated with poor OS (pooled HR=1.60, 95% CI: 1.09-2.33) in cancer patients. PANDAR expression was also related to lymph node metastasis (OR=3.26, 95% CI: 2.09-5.09), advanced tumor stage (OR=3.60, 95% CI: 2.39-5.44) and histological grade (OR=2.75, 95% CI: 1.73-4.38). Begg's funnel plot showed no evidence of obvious asymmetry for overall survival and lymph node metastasis. CONCLUSIONS: Thus high PANDAR expression appears predictive of poor OS, lymph node metastasis, advanced tumor stage and histological grade in multiple cancers. This suggests PANDAR expression could serve as a biomarker of poor prognosis in Chinese cancer patients.

Long non-coding RNA TUG1 as a potential prognostic biomarker in human cancers: a meta-analysis.

LncRNA taurine upregulated gene 1 (TUG1) is reportedly dysregulated in various cancers. We performed this meta-analysis to clarify the usefulness of TUG1 as a prognostic marker in malignant tumors. The PubMed, Medline, OVID, Cochrane Library, and Web of Science databases were searched from inception to Jan 11, 2017. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to explore the relationship between TUG1 expression and overall survival (OS). Odds ratios (ORs) were calculated to assess the association between TUG1 expression and pathological parameters. Thirteen original studies covering 1,274 cancer patients were included in this meta-analysis. The pooled HR suggested that high TUG1 expression correlated with poor OS (pooled HR=1.41, 95% CI: 1.01-1.98) in cancer types other than non-small cell lung cancer. TUG1 expression was also related to distant metastasis (OR=3.24, 95% CI: 1.18-8.93), large tumor size (OR=4.07, 95% CI: 1.08-15.28) and advanced tumor stage (OR=3.45, 95% CI: 2.19-5.44). Begg's funnel plot and Egger's test showed no evidence of obvious asymmetry for overall survival or tumor stage. Thus high TUG1 expression appears predictive of poor OS, distant metastasis, advanced tumor stage and large tumor size. This suggests TUG1 expression could serve as a biomarker for poor prognosis in cancers.

PQ401, an IGF-1R inhibitor, induces apoptosis and inhibits growth, proliferation and migration of glioma cells.

Growth factor signalling pathways transduce extra-cellular physiological cues to guide cells to maintain critical cellular functions, including cell proliferation, survival and metabolism. Dysregulation of certain growth factor signalling pathways has been shown as a major route to promote tumourigenesis. Glioma is a type of aggressive malignant tumour with no effective systematic therapy so far. Overexpression or hyperactivation of IGF-1R has been observed to be tightly associated with glioma progression and poor prognosis. Here, we examined the biological effects of a specific IGF-1R inhibitor, PQ401, on suppressing U87MG glioma cell growth and migration. Specifically, we observed that PQ401 not only induced cellular apoptosis in U87MG cells and subsequently reduced cell viability and proliferation but also attenuated cell mobility in vitro. More importantly, through a mouse xenograft model, we observed that administration of PQ401 on mice led to suppression of glioma tumour growth in vivo. In summary, our study suggests that PQ401 may serve as a promising leading drug for treating glioma patients with elevated IGF-1R signalling.

Inhibitory effect of DNA topoisomerase inhibitor isoliquiritigenin on the growth of glioma cells.

OBJECTIVE: To investigate the effect of isoliquiritigenin on the activity of DNA topoisomerase (TOP I) and its inhibitory effect on the growth of U87 glioma cells. METHODS: This study investigated the inhibitory effect of isoliquiritigenin on the growth of U87 glioma cells and its cytotoxicity by MTT method and determined the effect of isoliquiritigenin on TOP I activity by agarose gel electrophoresis. On this basis, we studied the interaction between isoliquiritigenin and TOP I and DNA. Finally, we further discussed the effect of isoliquiritigenin on the activity of Caspase 3, the apoptosis protein of U87 glioma cells. RESULTS: Isoliquiritigenin could inhibit the growth of U87 glioma cells (half inhibitory concentration IC50: 0.221 mM) and is of low cytotoxicity to normal cells. Agarose gel electrophoresis showed that isoliquiritigenin had significant inhibitory effect on TOP I activity. Molecular simulation results indicated that isoliquiritigenin took priority of binding to the active center of TOP I, and formed hydrogen bonds with the catalytic site Try723. Finally, Caspase 3 activity detection results suggested that isoliquiritigenin could significantly increase the activity of Caspase 3 (P < 0.05). CONCLUSION: Isoliquiritigenin had a reversible inhibitory effect on TOP I activity, reduced the rate of single strand DNA unwinding in tumor cells, and thus played an important role in inducing the apoptosis of U87 glioma cells.

Probucol Protects Against Asymmetric Dimethylarginine-Induced Apoptosis in the Cultured Human Brain Microvascular Endothelial Cells.

Asymmetric dimethylarginine (ADMA) is emerging as a key contributor to endothelial dysfunction. The drug probucol was reported to have an anti-lipid peroxidation effect and improve endothelial dilation function. But little is known about the protective effect of probucol on ADMA-induced human brain microvascular endothelial cell (HBMEC) injury and its underlying mechanisms. Therefore, in this study, we investigated the effect of probucol on ADMA-induced HBMEC injury and its potential mechanisms. Results showed that probucol protected against ADMA-induced HBMEC injury in a dose-dependent manner; probucol pretreatment also significantly reduced the level of reactive oxygen species (ROS) and malondialdehyde (MDA), downregulated the expression of pro-apoptotic gene Bax and caspase-3 activity, as well as increased the brain-derived neurotrophic factor (BDNF) release and promoted anti-apoptotic gene Bcl-2 and eNOS expression in the cultured HBMECs. Furthermore, we found that ADMA significantly increased the phosphorylation of c-Jun NH2-terminal kinase (JNK) and p38, while probucol pretreatment effectively inhibited ADMA-induced JNK and p38 phosphorylation in HBMECs. In conclusion, our present results demonstrated that probucol protected against ADMA-induced HBMEC injury and suppressed oxidative stress through the JNK/p38 MAPK pathway, which was the potential underlying mechanism of HBMEC injury in ischemic cerebrovascular disease.

GSK1838705A, an IGF-1R inhibitor, inhibits glioma cell proliferation and suppresses tumor growth in vivo.

Glioma is a type of primary malignant tumor of the central nervous system in humans. At present, standard treatment involves surgical resection, followed by radiation therapy and chemotherapy. However, the prognosis is poor and the long­term survival rate remains low. An improved understanding of the molecular basis for glioma tumorigenesis is in urgently required. The pro­survival effect of the insulin­like growth factor (IGF) signaling pathway has been implicated in progression of the glioma disease state. GSK1838705A is a novel, small molecule kinase inhibitor of IGF­IR, which inhibits IGF signal transduction and downstream target activation. Its anti-proliferative activity has been demonstrated in various tumor cell lines. The present study investigated the potential use of GSK1838705A for the treatment of glioma. Human U87MG glioma cells were used to examine the inhibitory activity of GSK1838705A in cell proliferation, migration and apoptosis. The antitumor activity of GSK1838705A was assessed in a xenograft mouse model. GSK1838705A inhibited the growth and induced the apoptosis of the U87MG glioma cells in a dose­dependent manner. The GSK1838705A­treated cells exhibited reduced migratory activity in response to chemoattractants. The present study further demonstrated the antitumor activity of GSK1838705A in vivo. The administration of GSK1838705A significantly inhibited the growth of glioma tumors by inducing the apoptosis of tumor cells. These results suggested that targeting IGF signaling with GSK1838705A may be a promising therapeutic strategy for the treatment of patients with glioma.

Transient axonal glycoprotein-1 induces apoptosis-related gene expression without triggering apoptosis in U251 glioma cells.

Previous studies show that transient axonal glycoprotein-1, a ligand of amyloid precursor protein, increases the secretion of amyloid precursor protein intracellular domain and is involved in apoptosis in Alzheimer's disease. In this study, we examined the effects of transient axonal glycoprotein-1 on U251 glioma cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that transient axonal glycoprotein-1 did not inhibit the proliferation of U251 cells, but promoted cell viability. The terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed that transient axonal glycoprotein-1 did not induce U251 cell apoptosis. Real-time PCR revealed that transient axonal glycoprotein-1 substantially upregulated levels of amyloid precursor protein intracellular C-terminal domain, and p53 and epidermal growth factor receptor mRNA expression. Thus, transient axonal glycoprotein-1 increased apoptosis-related gene expression in U251 cells without inducing apoptosis. Instead, transient axonal glycoprotein-1 promoted the proliferation of these glioma cells.