Integrated genomic analyses of lung squamous cell carcinoma for identification of a possible competitive endogenous RNA network by means of TCGA datasets

The etiology of cancer includes aberrant cellular homeostasis where a compromised RNA regulatory network is a prominent contributing factor. In particular, noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) were recently shown to play important roles in the initiation, progression, and metastasis of human cancers. Nonetheless, a mechanistic understanding of noncoding RNA functions in lung squamous cell carcinoma (LUSC) is lacking. To fill this critical gap in knowledge, we obtained mRNA, miRNA, and lncRNA expression data on patients with LUSC from the updated Cancer Genome Atlas (TCGA) database (2016). We successfully identified 3,366 mRNAs, 79 miRNAs, and 151 lncRNAs as key contributing factors of a high risk of LUSC. Furthermore, we hypothesized that the lncRNA-miRNA-mRNA regulatory axis positively correlates with LUSC and constructed a competitive endogenous RNA (ceRNA) network of LUSC by targeting interrelations with significantly aberrant expression data between miRNA and mRNA or lncRNA. Six ceRNAs (PLAU, miR-31-5p, miR-455-3p, FAM83A-AS1, MIR31HG, and MIR99AHG) significantly correlated with survival (P < 0.05). Finally, real-time quantitative PCR analysis showed that PLAU is significantly upregulated in SK-MES-1 cells compared with 16-BBE-T cells. Taken together, our findings represent new knowledge for a better understanding the ceRNA network in LUSC biology and pave the way to improved diagnosis and prognosis of LUSC.