LncRNA FLJ33360 Accelerates the Metastasis in Hepatocellular Carcinoma by Targeting MiRNA-140/MMP9 Axis

This study aims to detect expression level of long non-coding RNA (lncRNA) FLJ33360 in hepatocellular carcinoma (HCC) and its regulatory effects on accelerating malignant progression of HCC. Expression levels of FLJ33360 in 29 matched HCC tissues and paracancerous tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). After transfection of sh-FLJ33360#1 in Bel-7402 and HepG2 cells, changes in migratory and invasive capacities were evaluated by Transwell and wound healing assay. Potential miRNAs targeting FLJ33360 were verified. The correlation between expression levels of FLJ33360 and miRNA-140 in HCC tissues was determined. At last, potential influences of FLJ33360/miRNA-140 regulatory loop on HCC phenotypes were determined by rescue experiments. FLJ33360 was upregulated in HCC tissues relative to paracancerous ones. After knockdown of FLJ33360, migratory and invasive capacities in Bel-7402 and HepG2 cells were attenuated. There were five miRNA candidates predicted to bind FLJ33360, and miRNA-140 was the most differentially expressed by FLJ33360 regulation. Dual-luciferase reporter gene assay confirmed the binding between FLJ33360 and miRNA-140. Besides, their expression levels were negatively correlated in HCC tissues. Moreover, knockdown of miRNA-140 could stimulate metastatic ability in HCC. At last, rescue experiments verified the involvement of miRNA-140 in FLJ33360-regulated HCC progression. LncRNA FLJ33360 is upregulated in HCC. It accelerates the metastasis of HCC through targeting miRNA-140/MMP9 axis.