Long noncoding RNA LINC00324 exerts protumorigenic effects on liver cancer stem cells by upregulating fas ligand via PU box binding protein

Hepatocellular carcinoma (HCC) represents a major cause of cancer death, but the molecular mechanism for its development has not yet been well characterized. Long noncoding RNAs (lncRNAs) are involved in a wide range of biological processes via their roles as oncogenes or tumor suppressor genes. The present study aimed to elucidate the role of LINC00324 in HCC through its interaction with Fas ligand (FasL). Initially, microarray-based gene expression profiling of HCC was employed to identify differentially expressed genes. Next, the expression of LINC00324 in HCC tissues and liver cancer stem cell (LCSC) lines was examined using RT-qPCR. Then, the interaction among LINC00324, PU box binding protein (PU.1) and FasL was identified with RIP, ChIP and dual-luciferase reporter gene assays. The effect of LINC00324 on viability, proliferation, migration, invasion, and apoptosis as well as the tumorigenesis of transfected cells was examined with gain- and loss-of-function experiments. LINC00324 and FasL were highly expressed in HCC. LINC00324 regulated FasL expression via interaction with PU.1. Silencing of LINC00324 or FasL suppressed expression of stemness-related genes, cell viability, proliferation, migration, invasion, self-renewal, and tumorigenesis, but enhanced cell apoptosis. Taken together, LINC00324 promotes the expression of FasL through the recruitment of PU.1, which ultimately maintains the biological properties of LCSCs, thus, highlighting LINC00324 as a promising therapeutic candidate for HCC.