Epidermal Growth Factor Receptor Mutation Mechanisms in Nonsmall Cell Lung Cancer by Transcriptome Sequencing.

Background: This study intended to investigate the mechanisms underlying the epidermal growth factor receptor (EGFR) mutations in nonsmall cell lung cancer (NSCLC). Materials and Methods: Lung cancer tissue samples were collected from 20 patients with NSCLC (6 EGFR mutation types assigned into 2 categories and 14 EGFR wild types assigned to 4 categories). The samples were subjected to transcriptome sequencing, followed by identification of the differentially expressed mRNAs (DEMs), differentially expressed lncRNAs (DELs), and differentially expressed circRNAs (DECs) between the mutation and nonmutation groups. Function analysis and microRNA (miRNA) prediction for DEMs were performed. The correlations between long noncoding RNA (lncRNA)/circular RNA (circRNA) and messenger RNA (mRNA) were analyzed. In addition, the targeting lncRNA and circRNA of miRNA were predicted. Finally, competing endogenous RNA (ceRNA) network was constructed, and survival analysis for the mRNAs involved in the network was performed. Results: In total, 323 DEMs, 284 DELs, and 224 DECs were identified between EGFR mutation and nonmutation groups. The DEMs were significantly involved in gene ontology functions related to cilium morphogenesis and assembly. ceRNA networks were constructed based on the DEMs, DELs, DECs, and predicted miRNAs. Survival analysis showed that four genes in the ceRNA network, including ABCA3, ATL2, VAMP1, and APLN, were significantly associated with prognosis. The four genes were involved in several ceRNA pathways, including RP1-191J18/circ_000373/miR-520a-5p/ABCA3, RP5-1014D13/let-7i-5p/ATL2, circ_000373/miR-1293/VAMP1, and RP1-191J18/circ_000373/miR-378a-5p/APLN. Conclusion: EGFR mutations in NSCLC may be associated with cilium dysfunction and complex ceRNA regulatory mechanisms. The key RNAs in the ceRNA network may be used as promising biomarkers for predicting EGFR mutations in NSCLC.