Long noncoding RNA (lncRNA) have critical roles in various pathophysiological processes, and are frequently dysregulated in many diseases, particularly in cancer. The lncRNA glypican 3 antisense transcript 1 (GPC3-AS1) has been reported to be a potential biomarker for hepatocellular carcinoma (HCC) screening. However, the exact biological functions of GPC3-AS1 in HCC, and its roles and regulation mechanisms regarding GPC3 are still unknown. In this study, we observed a significant upregulation of GPC3-AS1 in HCC. Increased expression of GPC3-AS1 was associated with α-fetoprotein, tumor size, microvascular invasion, encapsulation, Barcelona Clinic Liver Cancer stage, and worse prognosis of HCC patients. Furthermore, we found that GPC3-AS1 physically associated with P300/CBP-associated factor and recruited it to the GPC3 gene body region, consequently inducing an increase in euchromatic histone marks and activating GPC3 transcription. GPC3-AS1 expression was strongly correlated with GPC3 in HCC tissues. Gain-of-function and loss-of-function analyses showed that GPC3-AS1 overexpression enhanced HCC cell proliferation and migration in vitro and xenograft tumor growth in vivo. GPC3-AS1 knockdown inhibited HCC cell proliferation and migration. Moreover, the effects of GPC3-AS1 on HCC cell proliferation and migration were dependent on the upregulation of GPC3. Collectively, our studies indicate that GPC3-AS1 significantly promotes HCC progression via epigenetically activating GPC3, and identifies GPC3-AS1 as a potential therapeutic target for HCC.
Keywords: GPC3; epigenetics; hepatocellular carcinoma; long noncoding RNA; progression.
© 2016 Federation of European Biochemical Societies.