MiRNA Synergistic Network Construction and Enrichment Analysis for Common Target Genes in Small-cell Lung Cancer

Background: Small-cell lung cancer (also known as SCLC) is an aggressive form and untreated patientsgenerally die within about 3 months. To obtain further insight into mechanism underlying malignancy with thiscancer, an miRNA synergistic regulatory network was constructed and analyzed in the present study.
Method: AmiRNA microarray dataset was downloaded from the NCBI GEO database (GSE27435). A total of 546 miRNAswere identified to be expressed in SCLC cells. Then a miRNA synergistic network was constructed, and theincluded miRNAs mapped to the network. Topology analysis was also performed to analyze the properties of thesynergistic network. Consequently, we could identified constitutive modules. Further, common target genes ofeach module were identified with CFinder. Finally, enrichment analysis was performed for target genes.
Results:In this study, a miRNA synergistic network with 464 miRNAs and 2981 edges was constructed. According to thetopology analysis, the topological properties between the networks constructed by LC related miRNAs and LCunrelated miRNAs were significantly different. Moreover, a module cilque0 could be identified in our networkusing CFinder. The module included three miRNAs (hsa-let-7c, hsa-let-7b and hsa-let-7d). In addition, severalgenes were found which were predicted to be common targets of cilque0. The enrichment analysis demonstratedthat these target genes were enriched in MAPK signaling pathways.
Conclusions: Although limitations exist inthe current data, the results uncovered here are important for understanding the key roles of miRNAs in SCLC.However, further validation is required since our results were based on microarray data derived from a smallsample size.