The noncoding RNA HOXD-AS1 is a critical regulator of the metastasis and apoptosis phenotype in human hepatocellular carcinoma.

BACKGROUND: Despite accumulating evidence that long noncoding RNAs (lncRNAs) are associated with cancer development in multiple types of cancer, the biological roles of many lncRNAs in human hepatocellular carcinoma (HCC) metastasis have not been well characterized. METHODS: A lncRNA+ mRNA human gene expression microarray analysis was used to identify differentially expressed lncRNAs in metastatic HCC tissues compared to non-metastatic tissue. RESULTS: We observed remarkable overexpression of HOXD-AS1 in metastatic cancer tissues. In vitro and in vivo gain- or loss-of-function studies re-affirmed that HOXD-AS1 is able to facilitate cancer metastasis and inhibit apoptosis. Moreover, we identified that HOXD-AS1 upregulated the Rho GTPase activating protein 11A (ARHGAP11A) by competitively binding to microRNA-19a (miR19a), resulting in induced metastasis. Interestingly, the regulator of G-protein signaling 3 (RGS3), a potential inhibitor of the MEK-ERK1/2 signaling axis, was also found to be downregulated by ectopic HOXD-AS1 overexpression, leading to a remarkably reduced apoptotic effect. CONCLUSIONS: The present investigation strongly indicates that HOXD-AS1 is an oncogenic lncRNA that promotes HCC metastasis and that its pro-metastatic phenotype can partially be attributed to the HOXD-AS1/miR19a/ARHGAP11A signaling axis.