Bioinformatics Identification of ZNFs/LINC00520/miR-181d/BCL2 Axis as a Novel Network in Cisplatin-Resistant Lung Adenocarcinoma Cells

Background: Resistance to cisplatin (DDP) leads to poor prognosis in patients with Lung Adenocarcinoma (LUAD) and limits its clinical application. It has been confirmed that autophagy promotes chemoresistance and, therefore, novel strategies to reverse chemoresistance by regulating autophagy are desperately needed. Methods: The differentially expressed lncRNAs (DElncRNAs), miRNAs (DEmiRNAs), and mRNAs (DEmRNAs) between A549 and A549/DDP cell lines were identified using the limma package in R, after gene expression profiles were obtained from Gene Expression Omnibus (GEO) database. By combining Autophagy-Related Genes (ARGs) from Human Autophagy Database (HADb), the interactions lncRNA-miRNAs and the interactions miRNAs-mRNAs respectively predicted by miRcode and miRDB/Targetscan database, the autophagy-related ceRNA network was constructed. Then, extraction of ceRNA subnetwork and Cox regression analyses were performed. A prognosis-related ceRNA subnetwork was constructed, and the upstream Transcription Factors (TFs) regulating lncRNAs were predicted by the JASPAR database. Finally, the expression patterns of candidate genes were further verified by quantitative real-time polymerase chain reaction (qRT-PCR) experiments. Results: A total of 3179 DEmRNAs, 180 DEmiRNAs, and 160 DElncRNAs were identified, and 35 DEmRNAs were contained in the HADb. Based on the ceRNA hypothesis, we established a ceRNA network, including 10 autophagy-related DEmRNAs, 9 DEmiRNAs, and 14 DElncRNAs. Then, LINC00520, miR-181d, and BCL2 were identified to construct a risk score model, which was confirmed to be a well-predicting prognostic factor. Furthermore, 5 TF ZNF family members were predicted to regulate LINC00520, whereas the RT-PCR results showed that the 5 ZNFs were consistent with the bioinformatics analysis. Finally, a ZNF regulatory LINC00520/miR-181d/BCL2 ceRNA subnetwork was constructed. Conclusions: An ZNFs/LINC00520/miR-181d/BCL2 axis as a novel network in DDP-resistant LUAD has been constructed successfully, which may provide potential therapeutic targets for LUAD.

A numerical model to simulate the transient frictional viscoelastic sliding contact

Sliding motion has always been one of the major concerns when it comes to the analysis of viscoelastic contact problems.A new model simulating the transient sliding contact of smooth viscoelastic surfaces is developed in this paper.By taking the dry contact friction and the coupling between shear tractions and normal pressure into account,the effect of the early partial slip period,which is often neglected in the study of viscoelastic sliding contact problems,is investigated numerically.Compared with solutions based on the frictionless assumption,the steady-state pressure profile is found to be slightly different under the effect of the partial slip regime,including a lower peak pressure and the shift of the contacting region in the direction opposite to the sliding motion.Furthermore,the time required for the viscoelastic contact to reach its steady state is delayed owing to the partial slip period preceding the global sliding motion.