An exosomal circRNA signature in the diagnosis and prognostification of cholangiocarcinoma: circRNA microarray analysis for 10 human bile samples

We have completed the Arraystar Human circRNA Array V2 analysis of 10 bile exosome samples (5 cholangiocarcinoma-induced biliary obstruction vs. 5 benign biliary obstruction). Total RNA from each sample was quantified using the NanoDrop ND-1000. The sample preparation and microarray hybridization were performed based on the Arraystar’s standard protocols. Briefly, total RNAs were digested with Rnase R (Epicentre, Inc.) to remove linear RNAs and enrich circular RNAs. Then, the enriched circular RNAs were amplified and transcribed into fluorescent cRNA utilizing a random priming method (Arraystar Super RNA Labeling Kit; Arraystar). The labeled cRNAs were hybridized onto the Arraystar Human circRNA Array V2 (8x15K, Arraystar). After having washed the slides, the arrays were scanned by the Agilent Scanner G2505C. Agilent Feature Extraction software (version 11.0.1.1) was used to analyze acquired array images. Quantile normalization and subsequent data processing were performed using the R software limma package. Differentially expressed circRNAs with statistical significance between two groups were identified through Volcano Plot filtering. Differentially expressed circRNAs between two samples were identified through Fold Change filtering. Hierarchical Clustering was performed to show the distinguishable circRNAs expression pattern among samples. Exosomal circRNA from 10 human bile samples (5 cholangiocarcinoma vs. 5 bile duct stones) were analysed using circRNA microarry. contributor: KangChen Services