l-norleucine on high glucose-induced insulin sensitivity and mitochondrial function in skeletal muscle cells.

l-norleucine, an isomer of leucine, stimulates the anabolic process of insulin. However, it is not known if and how it improves insulin sensitivity and insulin resistance. This experiment describes the generation of an insulin resistance model using high glucose-induced cells and the administration of 1.0 mmol/L l-norleucine for 48 h, to observe the effects on metabolism and gene expression in skeletal muscle cells. The results showed that l-norleucine significantly increased mitochondrial ATP content, decreased the amount of reactive oxygen species (ROS) and promoted the expression of mitochondrial generation-related genes TFAM, AMPK, PGC-1α in cells under high glucose treatment; at the same time, l-norleucine also increased glucose uptake, suggesting that l-norleucine increased insulin sensitivity and improved insulin resistance. This study suggesting that l-norleucine improves insulin resistance by ameliorating oxidative stress damage of mitochondria, improving mitochondrial function, and improving insulin sensitivity in skeletal muscle cell caused by high glucose, rather than by altering mitochondrial efficiency.

Prognostic values of YTHDF1 regulated negatively by mir-3436 in Glioma.

M6A methylation is likely to be closely associated with the occurrence and development of tumours. In this study, we demonstrated that the transcription levels of the m6A RNA methylation regulators are closely related to the prognosis of glioma. Univariate Cox analysis was performed on the expression levels of methylation regulators and selected three hub genes in glioma. Next, we systematically compared the expression of these m6A RNA methylation regulators in gliomas with different clinicopathological features. The overall survival (OS) curve of the hub genes was initially established based on TCGA database information. YTHDF1 was selected from the hub genes following survival and prognosis analysis. A nomogram was developed to predict the survival probability. We further performed cell function and in vivo xenograft tumour experiments to further verify its role in tumour progression. Next, based on the miRanda and miRDB databases, we predicted one microRNA, hsa-mir-346, that might regulate and bind to 3'UTR of YTHDF1, which was confirmed by our fluorescent enzyme reporter gene experiment. In summary, m6A RNA methylation regulators play a potential role in the progression of gliomas. YTHDF1 may have an essential function in glioma diagnosis, treatment and prognosis.

Retracted Article: Long noncoding RNA PTPRG-AS1 regulates growth of glioma cells by sponging miR-185-5p.

Previous studies have found that long noncoding RNA (lncRNA) protein tyrosine phosphatase, receptor type, G, antisense (PTPRG-AS1) was upregulated in glioma cells. Our study aimed to explore the detailed molecular mechanisms of PTPRG-AS1 involved in glioma progression. qRT-PCR assay was performed to measure the expressions of PTPRG-AS1 and microRNA-185-5p (miR-185-5p). Cell viability, migration, invasion, and apoptosis were determined by CCK-8 assay, colony formation assay, transwell assay, and flow cytometry assay. Autophagy was evaluated using GFP-LC3 puncta analysis and western blot. Luciferase reporter and RIP assays were employed to explore the association between PTPRG-AS1 and miR-185-5p. Our data showed PTPRG-AS1 was upregulated in glioma cells and tissues. Besides, high expression of PTPRG-AS1 was positively associated with a low survival rate. Upregulation of PTPRG-AS1 promoted proliferation, migration, invasion, colony formations, and autophagy, and inhibited cell apoptosis in U373-MG cells. By contrast, PTPRG-AS1 downregulation had the inverse effect in SHG44 cells. PTPRG-AS1 negatively regulated the expression of miR-185-5p in U373-MG and SHG44 cells and the expression of miR-185-5p was decreased in glioma tissues and cells. In addition, miR-185-5p overexpression suppressed proliferation, metastasis, colony formations, and autophagy, while inducing cell apoptosis in SHG44 cells. As expected, miR-185-5p depletion exhibited the inverse effect in U373-MG cells. Enhanced expression of miR-185-5p attenuated the effect of PTPRG-AS1 upregulation on U373-MG cells, while silencing of miR-185-5p undermined the effect of downregulation of PTPRG-AS1 on SHG44 cells. Our data disclosed that LncRNA PTPRG-AS1 was upregulated in glioma cells and tissues. PTPRG-AS1 regulated glioma proliferation, invasion, migration, apoptosis and autophagy by sponging miR-185-5p in vitro. A new signaling pathway PTPRG-AS1/miR-185-5p was first observed in glioma.

Down-regulation of ABCE1 inhibits temozolomide resistance in glioma through the PI3K/Akt/NF-κB signaling pathway.

The ATP binding cassette (ABC) E1 (ABCE1), a member of the ABC family, was originally described as the RNase L inhibitor. Through forming a heterodimer with RNase L, ABCE1 participates in the negative regulation of the 2-5A/RNase L system and thus mediates a wide range of biological functions. Recent evidence has shown the new roles of ABCE1 in tumorigenesis. However, there have been no investigations on the specific effect of ABCE1 on glioma. In the present study, we examined the expression pattern and possible role of ABCE1 in glioma. Our study demonstrated that ABCE1 was up-regulated in glioma tissues and cell lines. Down-regulation of ABCE1 inhibited temozolomide (TMZ) resistance of glioma cells in vitro and in vivo In addition, we found that the PI3K/Akt/NF-κB pathway was involved in ABCE1-mediated chemoresistance of glioma cells. Taken together, our study suggested ABCE1 as a promising target for glioma chemotherapy.

MicroRNA-10a inhibits A30P α-synuclein aggregation and toxicity by targeting proapoptotic protein BCL2L11.

Parkinson's disease (PD) is the second most common neurodegenerative disorder around the world, and is characterized by progressive loss of nigrostriatal dopaminergic neurons. Certain microRNAs (miRNAs) are aberrantly expressed in the post-mortem brain tissues of patients with PD and in vivo PD model mice. However, the role of brain-enriched miRNA (miR)-10a in PD has not been studied. To investigate the regulatory role of miR-10a on α-synuclein (α-syn) in the pathology of PD, the present study aimed to examine whether upregulation of miR-10a attenuated A30P α-syn mutant aggregation and cellular toxicity. miRNA expression analysis by reverse transcription-quantitative polymerase chain reaction demonstrated that miR-10a expression was decreased in the midbrain of A30P α-syn transgenic mice and in SH-SY5Y human neuroblastoma cells transfected with A30P α-syn. In addition, miR-10a mimics were used to upregulate miR-10a expression. It was revealed that the upregulation of miR-10a suppressed α-syn intracellular accumulation and toxicity in α-syn-overexpressing SH-SY5Y cells. In addition, miR-10a overexpression resulted in a reversal of the A30P α-syn-induced upregulation of proapoptotic protein Bcl-2-associated X protein and cleaved caspase-3 expression and downregulation of antiapoptotic protein B-cell lymphoma-2 (BCL2) expression. A luciferase reporter assay demonstrated that BCL2-like 11 (BCL2L11), an apoptosis inducer, was a novel target gene of miR-10a. A30P α-syn aggregation and toxicity were alleviated by knocking down endogenous BCL2L11 in SH-SY5Y cells using a small interfering RNA specific for BCL2L11. In conclusion, these results demonstrate that miR-10a may serve a functional role in α-syn-induced neuronal pathology by inhibiting expression of BCL2L11 and that upregulation of miR-10a expression may be a useful therapeutic strategy for the treatment of PD.

Regulation of HOXA11-AS/miR-214-3p/EZH2 axis on the growth, migration and invasion of glioma cells.

BACKGROUND: Glioma is one of the most common and aggressive malignant tumors in central nervous system. Recently, long non-coding RNA (lncRNA) HOXA11-AS has been reported to be an oncogenic gene in multiple cancers. However, the molecular mechanisms of HOXA11-AS involved in cancer progression of human glioma remain unknown. MATERIALS AND METHODS: The expression levels of HOXA11-AS in 45 paired primary glioma tissues and cell lines were examined by quantitative real-time PCR, and the correlation between HOXA11-AS expression and clinicopathologic characteristics of patients with glioma were analyzed. HOXA11-AS was knockdown in glioma cells by transfection with HOXA11-AS siRNA, and cell proliferation, migration and invasion were detected. The tumor growth of xenografts with HOXA11-AS knockdown glioma cells was also analyzed. RESULTS: The expression levels of HOXA11-AS were significantly up-regulated in glioma tissues and cell lines compared with that in adjacent normal brain tissues and normal human astrocytes (NHA). High expression of HOXA11-AS was correlated with shorter overall survival in patients with glioma. Knockdown of HOXA11-AS inhibited glioma cell proliferation, migration and invasion in vitro, and tumor growth in vivo. In addition, we demonstrated that HOXA11-AS functioned as a competing endogenous RNA (ceRNA) for miR-214-3p, which in turn positively regulated the expression of its direct target EZH2. CONCLUSIONS: We demonstrated that HOXA11-AS acted as an oncogenic lncRNA that promoted cell growth and metastasis of glioma through regulating miR-214-3p/EZH2 axis. These results suggested HOXA11-AS may serve as an efficient marker and a potential therapeutic target for glioma.

Long non-coding RNA MALAT1 promotes proliferation and suppresses apoptosis of glioma cells through derepressing Rap1B by sponging miR-101.

Long non-coding RNAs (lncRNAs) have been recently shown to be dysregulated and closely related to several cancers. Here, we aimed to elucidate the function and the possible molecular mechanisms of lncRNA Metastasis-associated lung Adenocarcinoma transcript-1 (MALAT1) in human glioma. Quantitative real-time PCR (qRT-PCR) was used to detect the expressions of MALAT1, miR-101 and Rap1B mRNA in U251 and U87 cells. The protein level of Rap1B was examined by western blot assays. Moreover, the proliferation and apoptosis of U251 and U87 cells were determined by CCK-8 assay and flow cytometry analysis, respectively. Additionally, the targets of miR-101 were identified by target prediction and luciferase reporter assays. The results demonstrated that MALAT1 and Rap1B were upregulated, while miR-101 expression was downregulated in glioma cell lines U251 and U87. MALAT1 and Rap1B knockdown could inhibit proliferation and induce apoptosis of glioma cells. Moreover, MALAT1 promoted the Rap1B expression by sponging miR-101 in U251 and U87 cells. Furthermore, miR-101 downregulation or Rap1B overexpression reversed the proliferation inhibitory and apoptosis induction of glioma cell lines caused by MALAT1 knockdown. Taken together, MALAT1 promotes proliferation and suppresses apoptosis of glioma cells through derepressing Rap1B by sponging miR-101. The present study elucidates a novel MALAT1-miR-101-Rap1B regulatory axis in glioma, contributing to a better understanding of the glioma pathogenesis and providing a promising therapeutic target for glioma patients.

Knockdown of Ras-Related Protein 25 (Rab25) Inhibits the In Vitro Cytotoxicity and In Vivo Antitumor Activity of Human Glioblastoma Multiforme Cells.

Ras-related protein 25 (Rab25) is a member of the Rab family, and it has been reported to play an important role in tumorigenesis. However, its direct involvement in human glioblastoma multiforme (GBM) is still unclear. The aim of the current study was to investigate the potential role of Rab25 in the growth, proliferation, invasion, and migration of human GBM. Our results showed that Rab25 expression was significantly higher in human GBM cell lines compared with a normal astrocyte cell line. In vitro functional studies revealed that knockdown of Rab25 reduced cell proliferation and inhibited invasion and migration of GBM cells. In vivo experiments showed that knockdown of Rab25 attenuated the tumor growth in nude mice. Finally, knockdown of Rab25 significantly inhibited the phosphorylation levels of PI3K and AKT in GBM cells. Taken together, these findings indicate that Rab25 may act as a tumor promoter in human GBM and that approaches to target Rab25 may provide a novel strategy to treat this disease.

Forkhead Box A2 (FOXA2) Inhibits Invasion and Tumorigenesis in Glioma Cells.

The forkhead box A2 (FOXA2) is the key transcriptional factor that plays an important role in tumorigenesis. However, until now the expression pattern and role of FOXA2 in glioma have yet to be elucidated. Therefore, the aim of this study was to evaluate the expression of FOXA2 in glioma and investigate its role in glioma cells. Our data showed that FOXA2 was significantly downregulated in human glioma cell lines. Forced expression of FOXA2 suppressed the ability of glioma cells to proliferate, migrate, and invade and influenced the expression level of EMT-associated proteins. In addition, forced expression of FOXA2 attenuated tumor growth of glioma in a nude mouse xenograft model. Mechanistically, we disclosed that forced expression of FOXA2 greatly downregulated the expression of ß-catenin, cyclin D1, and c-Myc in glioma cells. Taken together, these results show that FOXA2 may play an important role in proliferation, invasion, and tumorigenesis in glioma cells. Thus, FOXA2 may be a potential therapeutic target for the treatment of glioma.

Reduced Expression of Jumonji AT-Rich Interactive Domain 2 (JARID2) in Glioma Inhibits Tumor Growth In Vitro and In Vivo.

Jumonji AT-rich interactive domain 2 (JARID2) is a member of the Jumonji family of proteins and has been proposed as an oncogene in several types of human cancer. However, the role of JARID2 in human glioma has not yet been understood. The present study was designed to determine the roles of JARID2 in the proliferation and migration in human glioma cells and the growth of glioma cells in nude mice. Our data indicate that JARID2 is upregulated in human glioma tissues and cell lines. Knockdown of JARID2 obviously inhibits the proliferation of U87MG cells and tumor growth in vivo. Furthermore, knockdown of JARID2 inhibits migration and invasion as well as the epithelial-mesenchymal transition (EMT) process in U87MG cells. Mechanistically, knockdown of JARID2 reduces the phosphorylation levels of PI3K and Akt in U87MG cells. In summary, our study is the first one in our knowledge to indicate that JARID2 plays an important role in glioma development and progression. Therefore, JARID2 may serve as a potential therapeutic target for the treatment of glioma.

Expression of TYMS in lymph node metastasis from low-grade glioma.

The aim of the present study was to investigate the expression of thymidylate synthase (TYMS) in the primary foci and metastatic lymph nodes of low-grade glioma, and to analyze the function of TYMS in the lymph node metastases from low-grade glioma. The study included 93 cases of surgically resected and pathologically confirmed low-grade glioma, form patients treated at Huaihe Hospital of Henan University (Kaifeng, China). The following clinical data was obtained from each patient: Gender, age, subjective symptoms (dizziness, headache, a feeling of pressure in the head, etc.), site of disease, tumor type, pathological stage, degree of differentiation and lymph node involvement. The surgically resected gliomas and dissected cervical lymph nodes were immunohistochemically stained, and DNA was extracted from the tumor and lymph node tissues samples for polymerase chain reaction sequencing and amplification. The expression of TYMS in the primary foci and metastatic lymph nodes of low-grade glioma was examined. Additionally, the association between pathological features and the postoperative survival rate of the patients was analyzed. The primary lesions of all 93 cases exhibited positive TYMS expression and 43/157 (27.39%) lymph nodes exhibited positive TYMS expression. Factors that significantly influenced the postoperative survival rate of the patients, included the metastasis of the cervical lymph nodes (P<0.01), the number of dissected cervical lymph nodes (P<0.01) and the degree of differentiation (P<0.05). The metastasis of the cervical lymph nodes was the only independent risk factor affecting postoperative disease-free survival. The risk of recurrence in patients with metastasis of the cervical lymph nodes was 6.3-fold higher than in those without metastasis (P<0.01). Thus, the results of the present study provide a theoretical basis for accurately predicting the prognosis of patients with low-grade malignant brain glioma, reducing the conjecture involved in selecting postoperative treatment strategies and improving therapeutic efficacy.

Gene expression profiles of entorhinal cortex in Alzheimer's disease.

The incidence of Alzheimer's disease (AD) has been increasing in the recent years but the underlying mechanisms remain uncertain. This study aimed to analyze the differentially expressed genes (DEGs) in entorhinal cortex with AD and identify featured genes related to AD. Gene expression profile GSE5281 was downloaded from Gene Expression Omnibus, including 10 AD and 13 control samples. Differentially expressed genes were identified by Student t test including 119 upregulated and 591 downregulated DEGs. Then, we obtained 14 enrichment Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways among which 11 pathways were significantly enriched (adjusted P value < .05). The KEGG pathway network which was constructed by 14 KEGG pathways showed that 6-phosphofructokinase, muscle type, phosphoglucomutase 1, aldolase A, and adolase C had high degree. Glycometabolism pathways network which was constructed by 4 glycometabolism pathways showed that adenosine triphosphate (ATP) synthase, H+transporting, mitochondrial F1 complex ATP5B, ATP5C1, ATP5D, and ATP5G1 had high degree related to ATP metabolism. These findings suggested that these genes with high degree may be the underlying potential therapeutic targets for AD.