miR-124-3p availability is antagonized by LncRNA-MALAT1 for Slug-induced tumor metastasis in hepatocellular carcinoma.

Background: As an oncogene, long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) can promote tumor metastasis. Hyperexpression of MALAT1 has been observed in many malignant tumors, including hepatocellular carcinoma (HCC). However, the role and mechanism of MALAT1 in HCC remain unclear.

Methods: Thirty human HCC and paracancerous tissue specimens were collected, and the human hepatoma cell lines Huh7 and HepG2 were cultured according to standard methods. MALAT1 and Snail family zinc finger (Slug) expression were measured by real-time PCR, immunohistochemistry, and western blotting. Luciferase reporter assay and RNA immunoprecipitation (RIP) assay verified the direct interaction between miR-124-3p and Slug(SNAI2) or MALAT1. Wound healing and transwell assays were performed to examine invasion and migration, and a subcutaneous tumor model was established to measure tumor progression in vivo.

Results: MALAT1 expression was upregulated in HCC tissues and positively correlated with Slug expression. MALAT1 and miR-124-3p bind directly and reversibly to each other. MALAT1 silencing inhibited cell migration and invasion. miR-124-3p inhibited HCC metastasis by targeting Slug.

Conclusions: MALAT1 regulates Slug through miR-124-3p, affecting HCC cell metastasis. Thus, the MALAT1/miR-124-3p/Slug axis plays an important role in HCC.