Screening of differentially expressed circular RNAs in intrahepatic cholangiocarcinoma based on microarray technique and potential mechanism of circRNA_000585 / 临床肝胆病杂志

ABSTRACT

Objective To screen out and validate the abnormally expressed circular RNAs (circRNAs) in intrahepatic cholangiocarcinoma (iCCA) by comparing the circRNA microarray results of iCCA tissue and adjacent tissue, and to investigate their potential mechanism in iCCA. Methods Tumor tissue specimens were collected from three patients with iCCA who were admitted from July to December, 2019, and microarray hybridization was used to measure the differential expression of circRNAs between iCCA tissue and adjacent tissue. A total of 15 patients with iCCA who were treated during the same period of time were enrolled, and quantitative real-time PCR was used for validation of differentially expressed circRNAs. A bioinformatics analysis was performed to identify the downstream molecules of differentially expressed circRNAs, and quantitative real-time PCR was used for validation of potential molecules. The paired samples t -test was used for comparison of continuous data between groups, and the chi-square test or the Fisher's exact test was used for comparison of categorical data between groups. Results With 1.5-fold as the cut-off value for differential expression, there were 171 upregulated circRNAs and 104 downregulated circRNAs in iCCA tissue compared with the adjacent tissue. With 3-fold as the cut-off value for differential expression, there were 10 upregulated circRNAs (circRNA_002172, circRNA_002144, circRNA_001588, circRNA_000166, circRNA_000585, circRNA_000167, circRNA_402608, circRNA_006853, circRNA_001589, and circRNA_008882) and 3 downregulated circRNAs (circRNA_406083, circRNA_104940, and circRNA_006349) compared with the adjacent tissue. Pathologically confirmed iCCA tissue samples and adjacent tissue samples were collected from 15 patients, and quantitative real-time PCR was used for the validation of differentially expressed circRNAs; the results showed that circRNA_000585 was significantly upregulated in iCCA tissue ( t =3.607, P =0.003). Further bioinformatics analysis showed that circRNA_000585/miR-615-5p/AMOT/YAP might be the potential pathway involved in the pathogenesis of iCCA, and quantitative real-time PCR showed that for this pathway, miR-615-5p was significantly downregulated in iCCA ( t =5.724, P < 0.001) and AMOT and YAP were significantly upregulated in iCCA ( t =2.664 and 2.986, P =0.019 and 0.009 8). Conclusion Abnormal expression of various circRNAs is observed in iCCA, among which circRNA_000585 is significantly upregulated in iCCA and may play an important role in the pathogenesis of iCCA via the circRNA_000585/miR-615-5p/AMOT/YAP pathway.