Supplementary Material for: lncRNA SNHG8 Promotes the Tumorigenesis and Metastasis by Sponging miR-149-5p and Predicts Tumor Recurrence in Hepatocellular Carcinoma

Background/Aims: Long noncoding RNAs (lncRNAs) are aberrantly expressed in multiple malignant tumors involved in tumor growth and metastasis. Accumulating data show that small nucleolar RNA host gene (SNHG) 1/12/20 plays a key role in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanisms by which SNHG8 contributes to HCC remain elusive and merit exploration. Methods: The association between SNHG8 expression and the clinicopathological characteristics and prognoses in HCC patients was analysed by using qRT-PCR analysis and the data from The Cancer Genome Atlas. Cell growth and metastatic potential were determined by MTT, colony formation, Transwell assays, and the mouse xenograft tumor model and lung metastasis model. Epithelial–mesenchymal transition markers were detected by western blot analysis. The binding capacity of SNHG8 with miRNAs was evidenced by bioinformatic analysis and a luciferase reporter assay. In addition, the rescue experiments were performed based on co-transfection with sh-SNHG8 and a miR-149 inhibitor in HCC cells. Results: The expression levels of lncRNA SNHG8 were dramatically increased in HCC tissues and cell lines as compared with the adjacent normal tissues, and SNHG8 expression was an independent prognostic factor of tumor recurrence in HCC patients. Furthermore, knockdown of SNHG8 inhibited cell proliferation, invasion, and lung metastasis in vitro and in vivo, whereas overexpression of SNHG8 reversed these effects. SNHG8 acted as a sponge of miR-149 and counteracted the tumor suppressive effects of mi R-149 in HCC cells. Expression of phosphatase, Mg2+/Mn2+ dependent 1F, a target of R-149, displayed a negative correlation with miR-149 expression but a positive correlation with SNHG8 expression in HCC specimens. Conclusion: As lncRNA SNHG8 may promote HCC tumorigenesis and metastasis by sponging miR-149, it is a potential candidate marker and therapeutic target for HCC.