Long Noncoding RNA RP11-732M18.3 Promotes Glioma Angiogenesis by Upregulating VEGFA.

Gliomas are the most aggressive and common type of malignant brain tumor, with limited treatment options and a dismal prognosis. Angiogenesis, a hallmarks of cancer, is one of two critical events in the progression of gliomas. Accumulating evidence has demonstrated that in glioma dysregulated molecules like long noncoding RNAs (lncRNAs), are closely linked to tumorigenesis and prognosis. However, the effects of and mechanisms of action of lncRNAs during tumor angiogenesis are poorly understood. The effect of lncRNA RP11-732M18.3 on angiogenesis was elucidated through an intracranial orthotopic glioma model, immunohistochemistry, and an in vitro angiogenesis assay. Co-culture experiments and cell migration assays were performed to investigate the function of lncRNA RP11-732M18.3 in vitro. lncRNA RP11-732M18.3 increased CD31+ microvessel density, and overexpression of lncRNA RP11-732M18.3 resulted in poor mouse survival. lncRNA RP11-732M18.3 promoted endothelial cell migration and tube formation. Nomogram and Kaplan-Meier survival analyses indicated that higher VEGFA is correlated with a poor prognosis. Mechanistically, lncRNA RP11-732M18.3 promotes angiogenesis by increasing the nuclear level of EP300 and facilitating the transcription and secretion of VEGFA. Our study contributes to the latest understanding of glioma angiogenesis and prognosis. lncRNA RP11-732M18.3 may be a potential treatment target in glioma.

Long non­coding RNA AL355711 promotes smooth muscle cell migration through the ABCG1/MMP3 pathway.

Atherosclerosis and related cardiovascular diseases pose severe threats to human health worldwide. There is evidence to suggest that at least 50% of foam cells in atheromas are derived from vascular smooth muscle cells (VSMCs); the first step in this process involves migration to human atherosclerotic lesions. Long non­coding RNAs (lncRNAs) have been found to play significant roles in diverse biological processes. The present study aimed to investigate the role of lncRNAs in VSMCs. The expression of lncRNAs or mRNAs was detected using reverse transcription­quantitative polymerase chain reaction. The Gene Expression Omnibus datasets in the NCBI portal were searched using the key words 'Atherosclerosis AND tissue AND Homo sapiens' and the GSE12288 dataset. Gene expression in circulating leukocytes was measured to identify patients with coronary artery disease (CAD) or controls, and used to analyze the correlation coefficient and expression profiles. The protein level of ATP­binding cassette sub­family G member 1 (ABCG1) and matrix metalloproteinase (MMP)3 was determined using immunohistochemistry and western blot analysis. The analysis of mouse aortic roots was performed using Masson's and Oil Red O staining. The expression of lncRNA AL355711, ABCG1 and MMP3 was found to be higher in human atherosclerotic plaques or in patients with atherosclerotic CAD. The correlation analysis revealed that ABCG1 may be involved in the regulation between lncRNA AL355711 and MMP3 in atherosclerotic CAD. The knockdown of lncRNA AL355711 inhibited ABCG1 transcription and smooth muscle cell migration. In addition, lncRNA AL355711 was found to regulate MMP3 expression through the ABCG1 pathway. The expression of ABCG1 and MMP3 was found to be high in an animal model of atherosclerosis. The results indicated that lncRNA AL355711 promoted VSMC migration and atherosclerosis partly via the ABCG1/MMP3 pathway. On the whole, the present study demonstrates that the inhibition of lncRNA AL355711 may serve as a novel therapeutic target for atherosclerosis. lncRNA AL355711 in circulating leukocytes may be a novel biomarker for atherosclerotic CAD.

TTDA inhibited apoptosis by regulating the p53-Bax/Bcl2 axis in glioma.

The trichothiodystrophy group A protein (TTDA) functions in nucleotide excision repair and basal transcription. TTDA plays a role in cancers and serves as a prognostic and predictive factor in high-grade serous ovarian cancer; however, its role in human glioma remains unknown. Here, we found that TTDA was overexpressed in glioma tissues. In vitro experiments revealed that TTDA overexpression inhibited apoptosis of glioma cells and promoted cell growth, whereas knockdown of TTDA had the opposite effect. Increased TTDA expression significantly decreased the Bax/Bcl2 ratio and the level of cleaved-caspase3. TTDA interacted with the p53 gene at the -1959 bp and -1530 bp region and regulated its transcription, leading to inhibition of the p53-Bax/Bcl2 mitochondrial apoptosis pathway in glioma cells. These results indicate that TTDA is an upstream regulator of p53-mediated apoptosis and acts as an oncogene, suggesting its value as a potential molecular target for the diagnosis and treatment of glioma.

The binding of lncRNA RP11-732M18.3 with 14-3-3 ß/α accelerates p21 degradation and promotes glioma growth.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been identified as regulators of a number of developmental and tumorigenic processes. However, the functions of most lncRNAs in glioma remain unknown and the mechanisms governing the proliferation of tumor cells remain poorly defined. METHODS: Both in vitro and in vivo assays were performed to investigate the roles of lncRNAs in the pathophysiology of gliomas. lncRNA arrays were used to identify differentially expressed lncRNAs. Subcutaneous tumor formation and a brain orthotopic tumor model in nude mice were used to investigate the functions of lncRNAs in vivo. The in vitro functions of lncRNAs were analyzed by fluorescence-activated cell sorting, colony formation, and western blot analyses. RNA fluorescence in situ hybridization and immunoprecipitation were used to explore the underlying mechanisms. FINDINGS: Here, we describe the newly discovered noncoding RNA RP11-732M18.3, which is highly overexpressed in glioma cells and interacts with 14-3-3ß/α to promote glioma growth, acting as an oncogene. Overexpression of lncRNA RP11-732 M18.3 was associated with the proliferation of glioma cells and tumor growth in vitro and in vivo. Remarkably, lncRNA RP11-732M18.3 promoted cell proliferation and G1/S cell cycle transition. lncRNA RP11-732M18.3 is predominately localized in the cytoplasm. Mechanistically, the interaction of lncRNA RP11-732M18.3 with 14-3-3ß/α increases the degradation of the p21 protein. lncRNA RP11-732M18.3 promoted the recruitment of ubiquitin-conjugating enzyme E2 E1 to 14-3-3ß/α and the binding of 14-3-3ß/α with ubiquitin-conjugating enzyme E2 E1 (UBE2E1) promoted the degradation of p21. INTERPRETATION: Overall these data demonstrated that lncRNA RP11-732M18.3 regulates glioma growth through a newly described lncRNA-protein interaction mechanism. The inhibition of lncRNA RP11-732M18.3 could provide a novel therapeutic target for glioma treatment.