Background and Aims: Studies have demonstrated that long non-coding RNA RUSC1-AS1 (lncRNA RUSC1-AS1) has a close relationship with the malignant biological behaviors of tumors. However, its role in hepatocellular carcinoma (HCC) is still unclear. Our previous study demonstrated that there are binding interactions between lncRNA RUSC1-AS1 and microRNA-326 (miR-326). Therefore, this study was conducted to investigate the expression of lncRNA RUSC1-AS1 in HCC, and whether it regulates the biological behaviors of HCC cells by targeting miR-326. 
Methods: The expressions of lncRNA RUSC1-AS1 and miR-326 in 41 paired specimens of HCC tissue and tumor adjacent were detected by qRT-PCR. Using lncRNA RUSC1-AS1 expression inhibition plasmid/negative control plasmid, miR-326 mimics/negative control sequences and miR-326 inhibitors/negative control sequences as tools, the changes in proliferative ability, migration and invasion abilities, and apoptosis as well as the expressions of the related proteins in HCC MHCC97-H cells after different transfection treatments were determined by MTT assay, Transwell assay, flow cytometry and western blot analysis, respectively. The targeting relationship between lncRNA RUSC1-AS1 and miR-326 was analyzed by luciferase report assay, and then validated by qRT-PCR.
Results: In HCC tissue compared with adjacent tissue, the expression level of lncRNA RUSC1-AS1 was significantly increased, and the expression level of miR-326 was significantly decreased (both P<0.05). In MHCC97-H cells after transfection with lncRNA RUSC1-AS1 expression inhibition plasmid or miR-326 mimics, the proliferative ability as well as the migration and invasion abilities were significantly reduced, while the apoptosis rate was significantly increased, and the protein expression levels of cyclin D1, MMP-2, MMP-9, Bcl-2 were significantly reduced, while the protein expression levels of P21, Bax were significantly increased (all P<0.05). In MHCC97-H cells transfected with lncRNA RUSC1-AS1 expression inhibition plasmid with simultaneous transfection of miR-326 inhibitors, the influences of the former on MHCC97-H cells were abolished (all P<0.05). The results of luciferase report assay and qRT-PCR validation showed that miR-326 was a target molecule for lncRNA RUSC1-AS1. 
Conclusion: The expression of lncRNA RUSC1-AS1 is up-regulated in HCC, and it can promote the malignant biological behaviors of HCC cells by targeting miR-326.