lncRNA FLVCR1-AS1 regulates cell proliferation, migration and invasion by sponging miR-485-5p in human cholangiocarcinoma

Long non-coding RNA (lncRNA) FLVCR1 antisense RNA 1 (FLVCR1-AS1) serves a crucial role in many types of cancer; however, to the best of our knowledge, the biological effect of FLVCR1-AS1 in cholangiocarcinoma (CCA) remains unclear. The present study aimed to elucidate the involvement of FLVCR1-AS1 in the regulation of human CCA cell growth, migration and invasion, as well as the mechanisms underlying its effect. The expression levels of FLVCR1-AS1 in CCA tumor tissues, adjacent normal tissues, CCA cell lines and a cholangiocyte cell line were determined by reverse transcription-quantitative polymerase chain reaction. A significantly higher expression level of FLVCR1-AS1 was identified in CCA tumor tissues and the CCA cell lines HuCCT1 and CCLP1 compared with the normal controls. Short hairpin RNA targeting FLVCR1-AS1 (shFLVCR1-AS1) and a control plasmid (shNC) were transfected into CCA cell lines. Cell proliferation, colony formation, migration and invasion of CCA cells transfected with shFLVCR1-AS1 were significantly suppressed compared with the shNC groups. The expression levels of migration and invasion-associated proteins, including Twist, matrix metalloproteinase (MMP)-2 and MMP-9, were also significantly suppressed by shFLVCR1-AS1-treatment. Furthermore, FLVCR1-AS1 knockdown inhibited tumor growth in a xenograft model. Mechanistically, FLVCR1-AS1 was demonstrated to sponge microRNA-485-5p (miR-485-5p) in human CCA. The expression of miR-458-5p was significantly decreased in CCA tissue compared with normal tissue, and Pearson's correlation analysis revealed that FLVCR1-AS1 expression was negatively correlated with miR-485-5p expression in CCA tissues. These results suggested that lncRNA FLVCR1-AS1 may be used as a novel therapeutic target and a potential diagnostic marker for CCA.