Abstract:Background and Aims After hepatocellular carcinoma, intrahepatic cholangiocarcinoma (ICC) is the second most common malignant tumor of the liver, with an insidious onset, high malignant level, and a unfavorable prognosis. Although aberrant circRNA expression is linked to the onset and progression of several malignant tumors, the association between circRNA and ICC is rarely investigated. As a result, this study was conducted as a preliminary test to examine circRNA's differential expression in ICC and its biological function.Methods By using high-throughput circRNA chip technology, five specimens of ICC patients confirmed by pathology in Fujian Provincial Hospital were used to screen out differentially expressed circRNA in ICC and corresponding adjacent tissues, and the circRNA with the most obvious change was selected from 500-1500 bp in length and verified by qRT-PCR. The circRNA was then overexpressed in HCCC-9810 and RBE cell lines using lentivirus, and the impact of the circRNA on the biological function of ICC cells was investigated using CCK-8, scratch, Transwell, and flow cytometry.Results Compared with normal tissues adjacent to cancer, there are 76 differentially expressed circRNAs in ICC, including 63 upregulated and 13 downregulated circRNAs. The downregulated hsa_circ_0089153 had a highest fold-change (FC=103.214). The results of qRT-PCR were consistent with those of gene chip. After hsa_circ_0089153 overexpression, the proliferation activity of ICC cells significantly increased [HCCC-9810: over-expression group (114.816±5.138) vs. no-load group (100.000±4.897), RBE: over-expression group (117.235±7.079) vs. no-load group (100.000±14.896) (all P<0.05)]. The apoptosis rate significantly decreased [HCCC-9810: over-expression group (11.277±0.243) vs. no-load group (16.673±0.660) (all P<0.05)]. The migrated and invasive ability significantly increased [HCCC-9810: over-expression group (9.070±1.090) vs. no-load group (6.206±1.197), RBE: over-expression group (6.197±0.687) vs. no-load group (4.198±1.170) (all P<0.05) and HCCC-9810: over-expression group (0.370±0.026) vs. no-load group (0.274±0.014), RBE: over-expression group(0.297±0.016) vs. no-load group (0.250±0.019) (all P<0.05)].Conclusion There are a number of aberrantly expressed circRNAs in ICC, among which hsa_circ_0089153 has a noteworthy low expression. However, unlike most circumstances, overexpression of hsa_circ_0089153 can promote the malignant biological behavior of ICC cells. So, the biological role of hsa_circ_0089153 in ICC and the associated regulatory network still need to be further clarified.