Microarray expression profiling and bioinformatics analysis of circular RNA expression in lung squamous cell carcinoma.

Circular RNAs (circRNAs) are novel noncoding RNAs with a wide range of physiological and pathological activities. However, the expression profile and roles in lung squamous cell carcinoma (LSCC) remain largely unknown. Therefore, we investigated the expression profile of circRNAs in three LSCC and matched adjacent normal tissues using microarray. Total 216 differentially expressed circRNAs were identified, including 135 upregulated and 81 downregulated ones in LSCC tissues. Bioinformatics analysis revealed that these differentially expressed circRNAs were potentially implicated in carcinogenesis using Gene ontology (GO) and KEGG pathway analyses. By constructing miRNA-circRNA interaction network, a total of ten key circRNAs, including 6 upregulated and 4 downregulated circRNAs were further screened and then confirmed using qRT-PCR analysis in another 40 paired of LSCC tissues and adjacent normal tissues. In addition, Kaplan-Meier survival analysis demonstrated that the overall survival time of LSCC patients with high hsa_circRNA_103827 expression and low hsa_circRNA_000122 was significantly shorter (P<0.001). In conclusion, this study provides evidence that circRNAs are differentially expressed in LSCC and closely related to the carcinogenesis of LSCC. Among these, hsa_circRNA_103827 and hsa_circRNA_000122 might be served as potential prognostic biomarkers and therapeutic target for LSCC.