Long Noncoding RNA (lncRNA) MT1JP Suppresses Hepatocellular Carcinoma (HCC) in vitro

INTRODUCTION: The purpose of this study was to evaluate the effects and mechanisms of the long noncoding RNA (lncRNA) MT1JP on hepatocellular carcinoma (HCC) in vitro. PATIENTS AND METHODS: Thirty pairs of tumor and adjacent normal tissues were collected from HCC patients. Tissue pathology and MT1JP expression were evaluated by hematoxylin and eosin staining and in situ hybridization (ISH), respectively. The correlation between MT1JP and HCC prognosis was investigated. MTT assays, cloning, flow cytometry, transwell assays, and wound-healing assays were used to evaluate the effects of MT1JP on HCC cell lines. RT-qPCR and Western blot were used to measure the relative mRNA and protein expression levels. RESULTS: The expression of MT1JP was downregulated in HCC tumor tissues compared with that in adjacent normal tissues, while the percent survival was significantly greater in the high MT1JP expression group than in the low MT1JP expression group (P=0.0238). In vitro, overexpression of MT1JP suppressed the proliferation, invasion, and migration, reduced colony cell number, increased cell apoptosis, and induced G1-phase cell cycle arrest in Bel-7402 and Huh-7 cells. Meanwhile, the mRNA and protein expression levels of RUNX3 and P21 were significantly upregulated, whereas those of MMP2 and MMP9 were significantly downregulated, in Bel-7402 and Huh-7 cells overexpressing MT1JP (all P<0.001). CONCLUSION: LncRNA MT1JP may function as a tumor suppressor in HCC. Overexpression of MT1JP suppressed HCC cell biological activities through the regulation of RUNX3.