Purpose: Due to the high metastatic ability and poor prognosis of lung adenocarcinoma (LUAD), we identified novel non-coding RNAs, which constitute approximately 60% of human transcripts, as prognostic biomarkers and potential therapeutic targets for LUAD. Methods: In this study, we downloaded and analyzed microRNA (miRNA) datasets from The Cancer Genome Atlas (TCGA) to identify dysregulated miRNAs correlating with the overall survival (OS) of LUAD patients. miR-421, circ_0000567, and TMEM1000 expression levels were examined by quantitative real-time polymerase chain reaction (qRT-PCR) in NSCLC tissues from 73 patients and adjacent normal tissues. Cell migration and invasion were assayed using wound healing and transwell assays. miR-421 target predictions were conducted using starBase, CircInteractome, circBank, TargetScan, miRanda, MirDB, miRpath, and Gene Expression Omnibus (GEO) databases. The circular structure and stability of circ_0000567 were verified by RNase R digestion and qRT-PCR using oligo(dT) and random primers. A luciferase reporter assay was used to evaluate the relationship between miR-421, circ_0000567, and TMEM100. Results: The miRNA panel associated with OS in patients with LUAD was screened according to the hazard ratio (HR) of miRNAs from high to low. Based on the correlation between these miRNAs and OS, as well as miRNA expression levels, miR-421 was selected for further outcome analysis. High miR-421 expression was an independent risk factor for shorter OS in 73 patients collected from our department. Bioinformatic analyses, luciferase reporter assays, and functional assays showed that circ_0000567 could act as a sponge for miR-421 and prevent it from directly targeting the 3'-untranslated region of TMEM100 mRNA and further degrading it in LUAD. miR-421 expression was significantly upregulated, while circ_0000567 and TMEM100 were downregulated in tumor tissues of LUAD, compared to their counterparts in normal tissues. Gain-and loss-of-function assays showed that miR-421 promoted LUAD cell migration and invasion. Overexpression of circ_0000567 inhibited migration and invasion, whereas co-transfection of circ_0000567 and miR-421 mimics partly counteracted this effect. TMEM1000 was upregulated by enhanced circ_0000567 in LUAD cells, and the expression of TMEM1000 was inversely proportional to miR-421, whereas it was directly proportional to circ_0000567 in 73 LUAD specimens, which confirmed the competitive endogenous RNA (ceRNA) network. Conclusion: Our findings suggest that miR-421 promotes the migration and invasion of lung adenocarcinoma via circ_0000567/miR-421/TMEM100 signaling and could be a prognostic biomarker for LUAD.

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.

Purposes: Osimertinib is a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) used for patients with gefitinib (first-generation EGFR-TKI) resistance, but osimertinib resistance inevitably occurs. Therefore, it is necessary to explore the mechanisms of osimertinib resistance. Materials and Methods: We performed quantitative real-time polymerase chain reaction to detect hsa_circ_0007312 (circ7312), miR-764, and MAPK1 expressions in tissues and cells. Western blotting was used to detect protein levels in cells. Cell Counting Kit-8, apoptotic, and Transwell assays were used to explore biological functions. Luciferase assays were used to identify the interactions between circ7312 and miR-764, MAPK1 and miR-764. A xenograft experiment was performed to clarify the role of circ7312 in vivo. Public datasets were used to identify the relation between circ7312 expression and the cell half maximal inhibitory concentration value of osimertinib in 41 lung adenocarcinoma cell lines. The Student t-test, Kaplan-Meier analysis, and Pearson correlation analysis were used in data analysis. Results: We found that circ7312 knockdown increased miR-764 expression and decreased MAPK1 expression, and circ7312 regulated MAPK1 by sponging miR-764. In addition, high circ7312 expression has significant positive correlation with osimertinib IC50 values, circ7312 knockdown decreased the cell half maximal inhibitory concentration value of osimertinib and increased pyroptosis and apoptosis by sponging the miR-764/MAPK1 axis. We also found that circ7312 and MAPK1 were highly expressed in tumor tissues and related to poor prognosis. Xenograft experiments revealed that circ7312 knockdown decreased osimertinib resistance in vivo. Conclusion:We demonstrated that the inhibition of circ7312 decreased osimertinib resistance by promoting pyroptosis and apoptosis via the miR-764/MAPK1 axis, providing a novel target for osimertinib resistance therapy.

Abstract:The promotion and application of electric vehicles will contribute to the solution of several problems, such as energy shortage and environmental pollution, and the achievement of country economy and energy security. But a large-scale vehicle-to-grid system may cause adverse effects in the distribution network operation, the power network planning and such other parts. First, this paper collects the factors that influence the electric vehicle charging load and establishes the EV charging load model with a MonteCarlo method. Then, we analyze the effect that the EV charging load made on the nodal voltage deviation under different permeability based on the IEEE30 node system. At last, this research gets the conclusion that the nodal voltage deviation is closely related to EV permeability, node type and node location. This research conclusion will provide practical guidance to the charging station planning.