LncRNA HOXD-AS1 functions as a ceRNA to promote hepatocellular carcinoma metastasis in zebrafish xenograft models

Abstract Background: A few studies have shown that long noncoding RNA (lncRNA) HOXD cluster antisense RNA 1 (HOXD-AS1) plays an important role in hepatocellular carcinoma (HCC) metastasis as a competing endogenous RNA (ceRNA), but there is little in vivo evidence. This study aims to explore the zebrafish HCC xenograft as an in vivo metastasis model to verify the ceRNA network of HOXD-AS1. Methods: The quantitative reverse transcription PCR (qRT-PCR) assay was used to assess the expression level of HOXD-AS1 in HCC cell lines. Knockdown of HOXD-AS1 or miR-130a-3p was performed by transfecting small interfering RNA (siRNA) or microRNA (miRNA) inhibitor, respectively. The proliferation and invasion of HCC cells in vitro were analyzed by CCK-8 and transwell assays. The growth and metastasis of HCC cells in vivo were assessed by zebrafish xenograft models.Results: We verified that HOXD-AS1 was overexpressed in all tested HCC cell lines than the normal hepatic cells. Silence of HOXD-AS1 suppressed cell proliferation and invasion in Hep3B and Huh7 HCC cell lines in vitro. In zebrafish xenograft models, knockdown of HOXD-AS1 also reduced the growth and metastasis of the two HCC cells. Moreover, downregulation of miR-130a-3p not only increased the HCC metastasis, but also rescued the metastasis which inhibited by silence of HOXD-AS1 in vitro and in vivo.Conclusions: Our study demonstrates the metastasis role of the HOXD-AS1/miR-130a-3p ceRNA network in HCC cells in vitro and in vivo, and these findings suggest that zebrafish xenograft model could be used for ceRNA mechanism verification in tumor metastasis.