LncTUG1 contributes to the progression of hepatocellular carcinoma via the miR-144-3p/RRAGD axis and mTOR/S6K pathway

Abstract

AbstractHepatocellular carcinoma (HCC) is a symptomatic disease involed multi-stage program. Here, we elucidated the molecular mechanism of LncTUG1 in the regulation of HCC evolvement. And that may in all likelyhood supply a innovative latent target for HCC’s diagnoses and prognosis. LncRNA TUG1, miR-144-3p, RRAGD and mTOR signaling pathway were screened as target genes in the database, and their expression levels at the cytological level were verified utilized qRT-PCR, Western Blot and immunohistochemistry. Then, we adopted CCK-8, Transwell and flow cytometry assays to estimate cell proliferation, invasion and apoptosis. By use of luciferase reporter assay, the relationships of LncRNA TUG1, miR-144-3p and RRAGD was confirmed. In addition, the LncRNA TUG1-miR-144-3p-RRAGD-mTOR signaling pathway in HCC cells was verified adopted rescue experiment and confirmed by xenotransplantation animal experiment. LncTUG1 in HCC tissues from three databases were identified and further verified through qRT-PCR in HCC cells (Huh7, Hep3B). Knockdown the LncTUG1 could increase apoptosis and inhibite invasion and proliferation in HCC cells. Using inhibitors and activators of the mTOR/S6K pathway, LncTUG1 was confirmed to regulate HCC progression by the mTOR/S6K pathway. Luciferase reporter assay demonstrated that TUG1 negatively regulates miR-144-3p. Furthermore, miR-144-3p negativly regulates RRAGD by way of interacting with the 3′UTR of the RRAGD mRNA in HCC utilized luciferase reporter assay. In vivo, we also discovered that neoplasm weight and tumor volume reduced significantly in subcutaneous xenograft nude mouse models derived from sh-LncTUG1-expressing Huh7 cells. And the expressions of p-mTOR, p-S6K and RRAGD were decreased obviously while the miR144-3p increased in subcutaneous xenograft nude mouse models. In a word, the research suggests that LncTUG1 targets miR-144-3p while miR-144-3p binds to RRAGD mRNA, which induces mTOR/S6K pathway activation and promotes the progression of HCC.