Increasing evidence highlights the important role of XIST, a long non-coding RNA (lncRNA), in the regulation of multiple cancers. However, the underlying mechanism of XIST in human hepatocellular carcinoma (HCC) still remains to be explored. Herein, intended to investigate the functional role of XIST in HCC initiation and progression. We first detected that XIST was significantly upregulated in HCC tissues and associated with tumor size and vascular invasion. Gain- and loss-of-function of XIST further presented that XIST promoted the progression of HCC cells, including proliferation, migration, and invasion. Moreover, silencing of XIST could inhibit tumor growth in vivo. We also found that XIST could target miR-194-5p and thus decrease miR-194-5p expression. Besides that, restoring XIST could reverse the inhibitory effect of miR-194-5p on the proliferation and invasion of HCC cells. We further elucidated such rescue role might through derepressing MAPK1 expression, the target of miR-194-5p. In brief, the above results elucidate the important role of XIST in HCC tumorigenesis, suggesting that XIST might be a candidate prognostic biomarker and a novel therapeutic target for treating HCC.
BackgroundChemokines have been recognized as important modulators of angiogenesis, and they play critical roles in the development and metastasis of hepatocellular carcinoma (HCC), although their origins and latent molecular mechanisms remain elusive. The aim of this study was to investigate how activated hepatic stellate cells (a-HSCs) promote angiogenesis in HCC.MethodsA total of 22 HCC patients were enrolled randomly. We used immunohistochemistry, western blotting, and enzyme-linked immunosorbent assay (ELISA) to analyse the production of interleukin-8 (IL-8) in a-HSCs derived from HCC tissues. The angiogenic effects of IL-8 in vitro and in vivo were assessed by ELISA, real-time quantitative polymerase chain reaction, capillary tube formation assay, and chick embryo chorioallantoic membrane assay.ResultsThe present study showed that IL-8 was enriched predominantly in the tumour stroma of HCC tissues and was mainly derived from a-HSCs, rather than from hepatoma cells, in vivo and in vitro. Angiogenesis was most active at the invading edge, which was close to the a-HSCs. The angiogenic effect was dramatically attenuated by an IL-8 neutralizing antibody both in vitro and in vivo. Moreover, the IL-8 neutralizing antibody down-regulated Ser727-phosphorylated STAT3 levels in hepatoma cells treated with a-HSCs conditioned medium.ConclusionsThese findings reveal that a-HSCs within the stroma of HCC contribute to tumour angiogenesis via IL-8.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-015-0730-7) contains supplementary material, which is available to authorized users.
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