AGAP2-AS1 serves as an oncogenic lncRNA and prognostic biomarker in glioblastoma multiforme

Long noncoding RNA (lncRNA) AGAP2 antisense RNA 1 (AGAP2-AS1) has been suggested to function as an oncogenic lncRNA in lung cancer, breast cancer, and anaplastic glioma. However, the expression pattern and molecular mechanism of AGAP2-AS1 in glioblastoma multiforme (GBM) remains unknown. The purpose of this study is to present more evidence about the clinical and biological function of AGAP2-AS1 in GBM. In our results, we found AGAP2-AS1 expression was increased in GBM compared with adjacent normal brain tissues or low-grade glioma tissues, and there was no significantly different between low-grade glioma tissues and normal tissues. Kaplan-Meier survival analysis indicated patients with GBM having high-expression of AGAP2-AS1 had shorter overall survival time than those with low expression of AGAP2-AS1. The loss-of-function studies showed that downregulation of AGAP2-AS1 depressed cell proliferation, migration, and invasion, and promoted cell apoptosis in GBM. In summary, AGAP2-AS1 is a prognostic biomarker for patients with GBM, and functions as an oncogenic lncRNA to modulate GBM cell proliferation, apoptosis, migration, and invasion, which suggests that AGAP2-AS1 is potential therapeutic target for GBM.     

TRB3 interacts with ERK and JNK and contributes to the proliferation,apoptosis, and migration of lung adenocarcinoma cells

Tribbles homolog 3 (TRB3) has been accounted for regulation of a few cell processes through interaction with other significant proteins. The molecular mechanisms underlying TRB3 in tumorigenesis in lung adenocarcinoma have not been entirely elucidated. The present study is aimed at determining the function and fundamental mechanisms of TRB3 in lung adenocarcinoma progression. TRB3 was highly expressed in A549 and H1299 cells and lung adenocarcinoma tissues compared with human bronchial epithelial cells (HBEpC) and adjacent normal lung tissues. Hypoxia significantly upregulated the expression of TRB3 protein in A549 and H1299 cells in a time-dependent way. Gene expression profiling interactive analysis data analysis indicated that patients with lung adenocarcinoma with excessive expression of TRB3 mRNA had fundamentally shorter survival time. TRB3 knockdown in A549 cells can inhibit cell proliferation and migration, and promote cell apoptosis. TRB3 knockdown reduced the expression of p-ERK and p-JNK, but did not affect the expression of p-P38 MAPK. TRB3 overexpression enhances the malignant transformation abilities of HBEpC such as cell proliferation, migration and colony formation, which could be reversed by U0126 and SP600125. TRB3 overexpression promotes the phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) but was not affected by U0126 and SP600125. The results of coimmunoprecipitation experiments indicated that TRB3 binds directly to ERK and JNK. This study suggests that TRB3 has a potentially carcinogenic role in lung adenocarcinoma by binding to ERK and JNK and promoting the phosphorylation of ERK and JNK. TRB3 can be a possible therapeutic focus for lung adenocarcinoma.     

An upstream open reading frame regulates vasculogenic mimicry of glioma via ZNRD1-AS1/miR-499a-5p/ELF1/EMI1 pathway

Increasing evidence has suggested that gliomas can supply blood through vasculogenic mimicry. In this study, the expression and function of ZNRD1-AS1-144aa-uORF (144aa-uORF) and some non-coding RNAs in gliomas were assessed. Real-time quantitative PCR or Western blot was used to discover the expression of 144aa-uORF, ZNRD1-AS1, miR-499a-5p, ELF1 and EMI1 in gliomas. In addition, RIP and RNA pull-down assays were applied to explore the interrelationship between 144aa-uORF and ZNRD1-AS1. The role of the 144aa-uORF\ZNRD1-AS1\miR-499a-5p\ELF1\EMI1 axis in vasculogenic mimicry formation of gliomas was analysed. This study illustrates the reduced expression of the 144aa-uORF in glioma tissues and cells. Up-regulation of 144aa-uORF inhibits proliferation, migration, invasion and vasculogenic mimicry formation within glioma cells. The up-regulated 144aa-uORF can increase the degradation of ZNRD1-AS1 through the nonsense-mediated RNA decay (NMD) pathway. Knockdown of ZNRD1-AS1 inhibits vasculogenic mimicry in glioma cells by modulating miR-499a-5p. At the same time, miR-499a-5p is down-regulated and has a tumour-suppressive effect in gliomas. In addition, ZNRD1-AS1 serves as a competitive endogenous RNA (ceRNA) and regulates the expression of ELF1 by binding to miR-499a-5p. Notably, ELF1 binds to the promoter region of EMI1 and up-regulates EMI1 expression, while simultaneously promoting vasculogenic mimicry in glioma cells. This study suggests that the 144aa-uORF\ZNRD1-AS1\miR-499a-5p\ELF1\EMI1 axis takes key part in regulating the formation of vasculogenic mimicry in gliomas and may provide a potential target for glioma treatment.     

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.     

Long noncoding RNA HAND2-AS1 inhibits cancer cell proliferation,migration, and invasion in esophagus squamous cell carcinoma by regulating microRNA-21

Long noncoding RNA (lncRNA) HAND2-AS1 is a well-characterized tumor suppressor in several types of malignancies, while its role in esophagus squamous cell carcinoma (ESCC) is unknown. In this study, we found that lncRNA HAND2-AS1 was downregulated, while microRNA-21 ( miRNA-21) was upregulated in tumor tissues than in adjacent healthy tissues of ESCC patients. Expression levels of lncRNA HAND2-AS1 and miRNA-21 were significantly and inversely correlated in tumor tissues but not in healthy tissues. Plasma levels of lncRNA HAND2-AS1 were lower in ESCC patients than in healthy controls, and downregulation of plasma lncRNA HAND2-AS1 distinguished early stage ESCC patients from healthy controls. lncRNA HAND2-AS1 overexpression resulted in downregulation of miRNA-21 in cells of ESCC cell lines and inhibited cell proliferation, migration, and invasion. miRNA-21 overexpression failed to affect lncRNA HAND2-AS1 expression but significantly attenuated the inhibitory effect of lncRNA HAND2-AS1 overexpression on cancer cell proliferation, migration, and invasion. Therefore, lncRNA HAND2-AS1 may inhibit cancer cell proliferation, migration, and invasion in ESCC by regulating miRNA-21.     

JNK信号通路对蜂胶抑制白血病K562细胞增殖的调控作用

目的探讨JNK信号通路对蜂胶抑制K562细胞增殖过程的调控作用。方法体外培养K562细胞,用不同浓度蜂胶、c—Jun氨基末端激酶（c—JanN—terminalkinase,JNK）特异性抑制剂SP600125对白血病K562细胞进行处理,用MTT法检测细胞增殖抑制率,流式细胞术（FCM）检测细胞凋亡率,Western印迹检测JNK下游分子c—Jun以及磷酸化c—Jan（p-c-Jun）的变化。结果蜂胶作用K562细胞后,增殖抑制率、凋亡率显著升高,具有时间和剂量依赖性,并伴随p-c-Jun蛋白水平上调;加入SP600125能下调p-c-Jun的水平,显著提高蜂胶对K562细胞的增殖抑制率和凋亡率。结论JNK信号通路参与了蜂胶抑制K562细胞增殖过程的调控。抑制JNK活性可增强蜂胶对K562细胞的增殖抑制、凋亡诱导作用。     

Transient receptor potential melastatin 2–antisense RNA is overexpresed in osteosarcoma and regulates cell proliferation and apoptosis

Accumulating evidence suggested that transient receptor potential melastatin 2–antisense RNA (TRPM2-AS) played crucial roles in the progression of human cancers. However, the role of TRPM2-AS was still unknown in osteosarcoma. The aim of this study was to explore the clinical significance of TRPM2-AS in osteosarcoma patients, and determine the role of TRPM2-AS on osteosarcoma cell proliferation and apoptosis. In our results, we identified a novel oncogenic long noncoding RNA TRPM2-AS, which was overexpressed in osteosarcoma tissues and cells, and correlated with advanced Enneking stage, large tumor size and high histological grade in osteosarcoma cases. Survival analysis indicated that osteosarcoma patients with high TRPM2-AS expression had an obviously shorter overall survival time than those with low TRPM2-AS expression. Loss-of-function studies suggested that suppression of TRPM2-AS expression inhibited osteosarcoma cell proliferation and induced cell apoptosis through upregulating cleaved caspase-3 and cleaved caspase-9 expression. In conclusion, TRPM2-AS acts as an oncogenic long noncoding RNA and predicts poor prognosis in osteosarcoma.     

Aberrant expression of lncRNAs SNHG6, TRPM2-AS1, MIR4435-2HG,and hypomethylation of TRPM2-AS1 promoter in colorectal cancer

Accumulating evidence has indicated that deregulation of lncRNAs plays essential roles in colorectal cancer (CRC) carcinogenesis. The goal of this study was to analyze the expression of lncRNAs in colorectal cancer and their association with clinicopathological variables. Bioinformatics analysis of published CRC microarray data was performed to identify the important lncRNAs. The expression levels of candidate genes were assessed in the human colon cancer/normal cell lines, CRC, adenomatous colorectal polyps, and their marginal tissues by qRT-PCR. Moreover, the methylation status of the TRPM2-AS1 promoter was studied using qMSP assay. Furthermore, we investigated the molecular mechanisms of these lncRNAs in CRC progression using in silico analysis. Microarray analysis revealed that lncRNAs SNHG6, MIR4435-2HG, and TRPM2-AS1 were upregulated in CRC. These results were validated in colon cell lines. Moreover, qRT-PCR showed that the expression levels of SNHG6 and TRPM2-AS1 were upregulated in the colorectal tumor tissues compared with their paired tissues. Nonetheless, there was no significant increase in MIR4435-2HG expression in CRC samples. Furthermore, we observed a significant hypomethylation of TRPM2-AS1 promoter and its activation in CRC tissues. By in silico analysis, we found that the lncRNAs upregulation could promote proliferation and drug resistance of colorectal cancer cells via miRNAs sponging and modulation of their targets expression. In conclusion, based on our results upregulation of SNHG6 and TRPM2-AS1, and hypomethylation of TRPM2-AS1 promoter might be considered as potential diagnostic biomarkers for CRC initiation and development.     

肌肽通过调节JNK和NF-kappaB通路抑制高糖诱导的心肌细胞凋亡

高血糖症是糖尿病并发心血管疾病的重要危险因素. 高血糖诱导产生的活性氧（ROS）能够引起糖尿病心肌病.我们的前期工作已经证实,肌肽对高糖环境下细胞凋亡具有保护作用,但其机制尚未明确.为研究肌肽对高糖诱导的大鼠心肌细胞凋亡的抑制作用及相关信号机制,以高糖诱导心肌细胞H9c2为模型,采用Brdu-ELISA法检测细胞增殖过程中DNA合成情况,流式细胞术检测细胞凋亡率,免疫印迹实验检测JNK/c-Jun、NF-κB的磷酸化水平,RT-PCR检测TNF-α的mRNA表达. 实验结果显示,肌肽能够提高高糖损伤的H9c2细胞增殖能力,降低心肌细胞凋亡,抑制高糖激活的JNK、c-Jun和NF-κB磷酸化水平及TNFα的mRNA表达. 上述结果表明,肌肽拮抗高糖诱导的心肌细胞凋亡机制与抑制p-JNK /p-c-Jun、p-NF-κB水平和TNF-α表达有关.     

lncRNA RPL34-AS1 inhibits cell proliferation and invasion while promoting apoptosis by competitively binding miR-3663-3p/RGS4 in papillary thyroid cancer

Papillary thyroid cancer (PTC) accounts for 80% of all thyroid cancers and seriously impacts the quality of people's lives. Long noncoding RNAs (lncRNAs) play an important role in PTC. In previous studies, thousands of lncRNAs were screened to study their potential relationships with PTC. The aim of this study was to investigate the effect of RPL34-AS1 in PTC and to explore its potential mechanisms. Bioinformatic analyses were performed to characterize the possible function and biological features of RPL34-AS1. Apoptosis, proliferation, and invasion were detected to assess the effect of RPL34-AS1. Cell proliferation was measured using a Cell Counting Kit-8 assay. Western blot analysis was used to assess the apoptosis proteins Bax and Bcl-2. Cell invasion was measured using a Transwell assay. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was performed to examine RPL34-AS1, miR-3663-3P, and RGS4 expression. Dual-luciferase assay was performed to assess the binding of miR-3663-3P by RPL34-AS1. RIP experiment was used to verify the combination between miR-3663-3p and RGS4. We found that overexpression of RPL34-AS1 could inhibit proliferation and invasion while promoting apoptosis in PTC cell lines. Moreover, RPL34-AS1 could also competitively bind miR-3663-3p and exert its function by regulating the miR-3663-3p/RGS4 in PTC cell lines. We found a previously uncharacterized lncRNA, RPL34-AS1, and studied its function and mechanism in PTC. Our research will provide new insights into PTC and new clues for its clinical treatment.     

TRPM7 is required for ovarian cancer cell growth,migration and invasion

Our previous study demonstrated that the melastatin-related transient receptor potential channel 7 (TRPM7) was highly expressed in ovarian carcinomas and its overexpression was significantly associated with poor prognosis in ovarian cancer patients. However, the function of TRPM7 in ovarian cancer is mostly unknown. In this study, we examined the roles of TRPM7 in ovarian cancer cell proliferation, migration and invasion. We found that short hairpin RNA interference-mediated silence of TRPM7 significantly inhibited cell proliferation, colony formation, migration and invasion in multiple ovarian cancer cell lines. Mechanistic investigation revealed that silence of TRPM7 decreased phosphorylation levels of Akt, Src and p38 and increased filamentous actin and focal adhesion number in ovarian cancer cells. Thus, our results suggest that TRPM7 is required for proliferation, migration and invasion of ovarian cancer cells through regulating multiple signaling transduction pathways and the formation of focal adhesions.     

Circ_0001367 inhibits glioma proliferation,migration and invasion by sponging miR-431 and thus regulating NRXN3

Many studies have reported that circular RNAs play a vital role in the malignant progression of human cancers. However, the role and underlying mechanism of circRNAs in the development of gliomas have not been fully clarified. In this study, we found that circ_0001367 was downregulated in glioma tissues and showed a close correlation with glioma patient survival. Functional assays demonstrated that upregulation of circ_0001367 could suppress the proliferation, migration and invasion of glioma cells in vitro and inhibit glioma growth in vivo. Furthermore, bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation assay indicated that circ_0001367 can serve as a sponge for miR-431 and that miR-431 acts as an oncogene by regulating neurexin 3 (NRXN3). In addition, rescue experiments verified that circ_0001367 could regulate both the expression and function of NRXN3 in a miR-431-dependent manner. In conclusion, circ_0001367 functions as an suppressor in glioma by targeting the miR-431/NRXN3 axis and may be a promising therapeutic target against gliomas.Subject terms: CNS cancer, Long non-coding RNAs     

Long noncoding RNA MNX1-AS1 contributes to lung cancer progression through the miR-527/BRF2 pathway

Lung cancer belongs to a leading popular and malignant cancer around the world. However, the root mechanism underlying lung cancer progression remains unclear. Recently, long noncoding RNA (lncRNA) has been identified as important for tumorigenesis. LncRNA MNX1-AS1 is proven to regulate colon adenocarcinoma, cervical cancer, glioblastoma, and ovarian cancer. Whether MNX1-AS1 participates in lung cancer needs investigation. In our research, we found that MNX1-AS1 was dramatically upregulated in lung cancer. MNX1-AS1 upregulation indicated poor prognosis in lung cancer patients. Functionally, MNX1-AS1 promoted lung cancer progression through regulating proliferation, migration, and invasion. Mechanistically, MNX1-AS1 was found to locate in the cytoplasm and interact with miR-527. Through inhibiting miR-527 availability, MNX1-AS1 facilitated BRF2 expression. Restoration of BRF2 rescued defects of proliferation, migration, and invasion caused by MNX1-AS1 knockdown. Taken together, our study found a novel signaling pathway, namely MNX1-AS1/miR-527/BRF2 axis, involved in lung cancer progression.     

Overexpression of long noncoding RNA SLC26A4-AS1 inhibits the epithelial–mesenchymal transition via the MAPK pathway in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is recognized as one of the most prevalent types of thyroid cancer with poor prognosis. Long noncoding RNA (lncRNA) has undergone an intensive study for their involvement in tumor treatment. This study intends to unravel the association of lncRNA SLC26A4-AS1 with PTC. Initially, PTC-related expression profiling data (GSE33630) was utilized to screen differentially expressed lncRNAs in PTC and the underlying mechanisms involved with the mitogen-activated protein kinase (MAPK) pathway. Moreover, PTC tumor tissues and paracancerous tissues were arranged to determine expressions of TP53, SLC26A4-AS1, and genes related to epithelial–mesenchymal transition (EMT) and the MAPK pathway. Furthermore, SLC26A4-AS1 was overexpressed or underexpressed and JNK was underexpressed through cell transfection to examine the effect of SLC26A4-AS1 on PTC via MAPK pathway. Besides, tumor formation in nude mice was used to verify the fore experiment. LncRNA SLC26A4-AS1 regulating TP53 had the potential to participate in PTC by regulating the MAPK pathway. SLC26A4-AS1 was expressed poorly in PTC. Notably, SLC26A4-AS1 elevated E-cadherin expression while it reduced that of ERK and Vimentin. In addition, the overexpression of SLC26A4-AS1 inactivated the MAPK pathway by promoting TP53 and decreased cell migration, proliferation, and invasion. In addition to all these effects, the overexpression of SLC26A4-AS1 promoted apoptosis of TPC-1 cells. Additionally, the overexpression of lncRNA SLC26A4-AS1 reduced xenograft tumor volume in nude mice. Furthermore, the effect of SLC26A4-AS1 overexpression was found to be promoted after the MAPK pathway inactivation. Taken together, the overexpression of lncRNA SLC26A4-AS1 coffered anti-oncogenic effects on PTC through the inactivation of the MAPK pathway.