LINC00221 silencing prevents the progression of hepatocellular carcinoma through let-7a-5p-targeted inhibition of MMP11

BACKGROUND: Microarray profiles of hepatocellular carcinoma (HCC) identified that long intergenic noncoding RNA 00221 (LINC00221) was upregulated. Herein, we aimed to identify the functional significance and underlying mechanisms of LINC00221 in HCC. METHODS AND RESULTS: Human HCC samples had increased expression of LINC00221. Effects of LINC00221 on HCC cellular functions were analyzed using gain- and loss-function approaches. LINC00221 knockdown repressed HCC cell growth, migration, and invasion and enhanced their apoptosis. This anti-tumor effect was validated in vivo. Online prediction showed the potential binding relationship between LINC00221 and let-7a-5p, as well as that between let-7a-5p and matrix metalloproteinase 11 (MMP11). The results of luciferase, RNA immunoprecipitation, and RNA pull-down assays identified that LINC00221 interacted with let-7a-5p to increase expression of MMP11. Furthermore, we demonstrated that LINC00221 silencing increased let-7a-5p and inhibited MMP11 expression, thereby delaying the progression of HCC in vitro. CONCLUSIONS: Silencing of LINC00221 could prevent HCC progression via upregulating let-7a-5p and downregulating MMP11. As such, LINC00221 inhibition presents a promising antitumor strategy for the treatment of HCC.