Long Non-Coding RNA AGAP2-AS1/miR-628-5p/PTN Axis Modulates Proliferation, Migration, Invasion, and Apoptosis of Glioma Cells

Identification of therapeutic targets and prognostic biomarkers in cholangiocarcinoma via WGCNA

Background

Cholangiocarcinoma (CCA) is a highly aggressive malignant tumor for which limited treatment methods and prognostic signatures are available. This study aims to identify potential therapeutic targets and prognostic biomarkers for CCA.

Methods

Based on differentially expressed genes (DEGs) identified from The Cancer Genome Atlas (TCGA) data, our study identified key gene modules correlated with CCA patient survival by weighted gene coexpression network analysis (WGCNA). Cox regression analysis identified survival-related genes in the key gene modules. The biological properties of the survival-related genes were evaluated by CCK-8 and transwell assays. Then, these genes were used to construct a prognostic signature that was internally and externally validated. Additionally, by combining clinical characteristics with the gene-based prognostic signature, a nomogram for survival prediction was built.

Results

WGCNA divided the 1531 DEGs into four gene modules, and the yellow gene module was significantly associated with overall survival (OS) and histologic neoplasm grade. Our study identified the lncRNA AGAP2-AS1 and a novel gene, GOLGA7B, that are closely related to survival. GOLGA7B downregulation promoted the invasion, migration and proliferation of CCA cells, but AGAP2-AS1 had the opposite effect. AGAP2-AS1 and GOLGA7B were integrated into a gene-based prognostic signature, and both internal and external validation studies confirmed that this two-gene prognostic signature and nomogram could accurately predict CCA patient prognosis.

Conclusion

AGAP2-AS1 and GOLGA7B are potential therapeutic targets and prognostic biomarkers for CCA.

Construction of a circRNA-miRNA-mRNA Regulated Pathway Involved in EGFR-TKI Lung Adenocarcinoma Resistance

Objectives: Epidermal growth factor receptor-tyrosine kinase inhibitors are widely used for lung epidermal growth factor receptor-positive lung adenocarcinomas, but acquired resistance is inevitable. Although non-coding RNAs, such as circular RNA and microRNA, are known to play vital roles in epidermal growth factor receptor-tyrosine kinase inhibitor resistance, comprehensive analysis is lacking. Thus, this study aimed to explore the circular RNA-microRNA-messenger RNA regulatory network involved in epidermal growth factor receptor-tyrosine kinase inhibitor resistance. Methods: To identify differentially expressed genes between the epidermal growth factor receptor-tyrosine kinase inhibitor sensitive cell line PC9 and resistant cell line PC9/ epidermal growth factor receptor-tyrosine kinase inhibitor resistance(PC9/ER), circular RNA, microRNA and messenger RNA microarrays were performed. Candidates were then identified to construct a circular RNA-microRNA-messenger RNA network using bioinformatics. Additionally, Gene Oncology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were conducted to evaluate the network messenger RNA, setting up a protein-protein interaction network for hub-gene identification. Afterwards, RNA immunoprecipitation was performed to enrich microRNA, and quantitative real-time PCR was used to estimated gene expression levels. Results: In total, 603, 377, and 1863 differentially expressed circular RNA, microRNA, messenger RNAs, respectively, were identified using microarray analysis, constructing a circular RNA-microRNA-messenger RNA network containing 18 circular RNAs, 17 microRNAs and 175 messenger RNAs. Moreover, Gene Oncology and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that the most enriched biological process terms and pathways were related to epidermal growth factor receptor-tyrosine kinase inhibitor resistance, including Wnt and Hippo signaling pathways. Based on the competing endogenous RNA and protein-protein interaction network, circ-0007312 was showed to interact with miR-764 and both circ-0003748 and circ-0001398 were shown to interact with miR-628; both these microRNAs targeted MAPK1. Furthermore, circ-0007312, circ-0003748, circ-0001398, and MAPK1 were up-regulated, whereas miR-764 and miR-628 were downregulated in PC9/ER cells as compared to parental PC9 cells. We also found that circ-0007312 and miR-764 were positively expressed in plasma. Conclusions: Our original study associated with mechanism of target therapy in lung cancer provided a systematic and comprehensive regulation of circular RNA, microRNA and messenger RNA in epidermal growth factor receptor-tyrosine kinase inhibitor resistance. It was found that circ-0007312- miR-764-MAPK1, circ-0003748-miR-628-MAPK1, and circ-0001398-miR-628-MAPK1 axis may play key roles in epidermal growth factor receptor-tyrosine kinase inhibitor resistance.

Blocking hsa_circ_0006168 suppresses cell proliferation and motility of human glioblastoma cells by regulating hsa_circ_0006168/miR-628-5p/IGF1R ceRNA axis

BACKGROUND

hsa_circ_0006168 is an oncogenic circular RNA in esophageal cancer. However, its role remains unclarified in tumor progression of gliomas, especially in glioblastoma (GBM).

METHODS

Cell counting kit-8 assay, transwell assays, western blotting, and xenograft experiment, as well as colony formation assay and flow cytometry were performed to measure cell proliferation and motility. Expression of hsa_circ_0006168, microRNA (miR)-628-3p, insulin‑like growth factor 1 receptor (IGF1R), and Ras/extracellular signal regulated kinases (Erk)-related proteins were determined by quantitative real-time polymerase chain reaction and western blotting. The physical interaction was confirmed by dual-luciferase reporter assay and RNA pull-down assay.

RESULTS

hsa_circ_0006168 and IGF1R were upregulated, and miR-628-5p was downregulated in human GBM tissues and cells. Functionally, blocking hsa_circ_0006168 and overexpressing miR-628-5p suppressed cell proliferation, migration, invasion, and expression of Vimentin and Snail (mesenchymal markers) in A172 and LN229 cells, accompanied with increased E-cadherin (epithelial marker), decreased colony formation, and promoted apoptosis rate. Silencing miR-628-5p counteracted the suppression of hsa_circ_0006168 deficiency on these behaviors, and restoring IGF1R blocked miR-628-5p-mediated inhibition as well. More importantly, hsa_circ_0006168 knockdown could delay xenograft tumor growth in vivo and lower Ras and phosphorylated Erk1/2 expression in vitro and in vivo. Mechanically, hsa_circ_0006168 targeted and sponged miR-628-5p, and IFG1R was a novel target for miR-628-5p. Inhibiting miR-628-5p could abrogate in vitro role of hsa_circ_0006168 knockdown, and similarly IGF1R upregulation counteracted miR-628-5p role.

CONCLUSION

Silencing hsa_circ_0006168 might suppress GBM proliferation and motility via serving as competitive endogenous RNA for miR-628-5p and regulating IGF1R/Ras/Erk pathway.

Oncogenic roles and mechanisms of lncRNA AGAP2-AS1 in human solid tumors

Cancer remains the second leading life-threatening disease worldwide. Increasing evidence indicates that long non-coding RNAs (lncRNAs) play an important role in multiple physiological and pathological processes, including gene amplification, mutation, rearrangement, and overexpression regulations. In this review, we comprehensively summarize the current knowledge of lncRNA AGAP2-AS1 from a cancer perspective. As a member of the lncRNA family, lncRNA AGAP2-AS1 is upregulated in solid tumor malignancies, functions as an oncogene, and plays a key role in tumorigenesis and tumor progression. AGAP2-AS1 expression is significantly increased in clinical cancer tissue samples, cell lines, and in vivo, and is closely related to an unfavorable prognosis in several cancers. Upregulated lncRNA AGAP2-AS1 binds with microRNAs (miRNAs) and promotes activation of downstream genes. This aberrant regulation induces carcinogenesis and tumorigenesis. Here we provide a comprehensive overview of AGAP2-AS1 in cancer progression that leads to an improved understanding of the effects of AGAP2-AS1 on early detection and therapeutic approaches. This information is essential for the future development of lncRNA AGAP2-AS1 as a potential therapy against these devastating cancers.