Differential circular RNA expression profiles of invasive and non-invasive non-functioning pituitary adenomas A microarray analysis

Non-functioning pituitary adenomas (NFPAs) are the most common pituitary tumors, and some exhibit locally invasive or even clinically aggressive behavior. Circular RNAs (circRNAs) are a reinvented class of non-coding RNAs that play important roles in tumor initiation and progression. CircRNA microarray assays were performed in 4 invasive and 4 non-invasive NFPAs, and 4 typically differential expression circRNAs were selected for validation using quantitative reverse transcription-polymerase chain reaction. The diagnostic and prognostic values of tested cirRNAs were further evaluated. Bioinformatics analysis and a literature review of potential miRNAs targets involved in pituitary tumor invasion were performed. A specific circRNA expression profile was detected between invasive and non-invasive NFPAs, including 91 upregulated and 61 downregulated circRNAs in invasive tumors. The dysregulation of the 4 circRNAs has been confirmed. The expression of hsa_circRNA_102597, a downregulated circRNA, was significantly correlated with tumor diameter (P<.05) and Knosp grade (P<.01). Hsa_circRNA_102597 alone or in combined with Ki-67 index was able to accurately differentiate invasive from non-invasive NFPAs as well as predict tumor progression/recurrence. Fourteen aberrantly expressed circRNAs might be involved in the invasiveness of pituitary adenomas via seven predicted potential miRNA targets. CircRNAs are participated in pituitary tumor invasion, and may be used as novel diagnostic and prognostic biomarkers in NFPAs.