The Expression And Function Of Long Noncoding RNA-HTSG In Hepatocellular Carcinoma

Objective:Long non-coding RNAs(lnc RNAs) regulate a variety of key biological processes in development and disease. Dysregulation of lnc RNAs is linked to various human diseases, including cancer. Using lnc RNA expression profiling, we try to find differentially expressed lnc RNAs as well as its functional role in hepatocellular carcinoma.Methods : High-throughput lnc RNA microarray was performed in 16 paired HCC and adjacent non-cancer tissues. Lnc-HTSG, a novel lnc RNA, was identified to be significantly downregulated in HCC. Using UCSC genome browser and ENCODE database, we analysed the integrated genome information of lnc-HTSG. Decreased expression of Lnc-HTSG was further validated by quantitative real-time PCR in 6paired HCC and adjacent noncancer tissues. Database analysis and Rapid amplification of c DNA ends(RACE) was used to confirm the sequence of lnc-HTSG. The full length of lnc-HTSG was obtained by overlap PCR and cloned into lentivirus vector p LVX-Ac GFP-N1. Overexpression of lnc-HTSG was determined by RT-PCR. The integrity of transcript of lnc-HTSG was further validated by RT-PCR using special primers. We employed si RNA to knockdown the expression of lnc-HTSG in HCC-LM3 cells or elevate it by lentivirus encoding lnc-HTSG in SMMU-7721 cells. Cell migration and invasion was measured by wound-healing and Matrigel transwell assay in vitro.Results: To identify lnc RNAs involved in HCC, we conducted transcriptome microarray analysis of 16 paired HCC and adjacent noncancer tissues. A panel of noncoding RNA transcripts were aberrantly expressed and we focused on anuncharacterized lnc RNA, termed lnc-HTSG. Lnc-HTSG is one of the most significantly downregulated lnc RNAs in HCC. UCSC database showed lnc-HTSG was composed of two exons and was modestly conserved. We further confirmed that lnc-HTSG was significantly decreased in HCC by RT-PCR. A total length of lnc-HTSG transcript was determined by database analysis and rapid amplification of c DNA ends(RACE) assay.The full length of lnc-HTSG was cloned, and cloned into lentivirus vector. RT-PCR confirmed the upregulation and the integrity of transcript of lnc-HTSG. Compared with the si Con control group, down-regulation of lnc-HTSG by si RNA significantly promoted the migration and invasion ability of HCC-LM3 cells. Conversely,up-regulation of lnc-HTSG inhibited the migration protential of SMMU-7721 cells compared to LV-GFP group.Conclusions: Using transcriptome microarray analysis, we identified a long noncoding RNA(lnc RNA) termed lnc-HTSG that is downregulated in HCC. Lnc-HTSG can inhibit the migration and invasion ability of HCC cells and is a novel tumor suppressor with therapeutic potentials.