ABSTRACT
Long noncoding RNAs (lncRNAs) have been reported to play pivotal roles in a variety of cancers. However, lncRNAs involved in hepatocellular carcinoma (HCC) initiation and progression remain largely unclear. In this study, we identified an lncRNA gradually increased during hepatocarcinogenesis (lncRNA-GIHCG) using publicly available microarray data. Our results further revealed that GIHCG is upregulated in HCC tissues in comparison with adjacent non-tumor tissues. High GIHCG expression is correlated with large tumor size, microvascular invasion, advanced BCLC stage, and poor survival of HCC patients. Functional experiments showed that GIHCG promotes HCC cells proliferation, migration, and invasion in vitro, and promotes xenografts growth and metastasis in vivo. Mechanistically, we demonstrated that GIHCG physically associates with EZH2 and the promoter of miR-200b/a/429, recruits EZH2 and DNMT1 to the miR-200b/a/429 promoter regions, upregulates histone H3K27 trimethylation and DNA methylation levels on the miR-200b/a/429 promoter, and dramatically silences miR-200b/a/429 expression. Furthermore, the biological functions of GIHCG on HCC are dependent on the silencing of miR-200b/a/429. Collectively, our results demonstrated the roles and functional mechanisms of GIHCG in HCC, and indicated GIHCG may act as a prognostic biomarker and potential therapeutic target for HCC. KEY MESSAGE: lncRNA-GIHCG is upregulated in HCC and associated with poor survival of patients. GIHCG significantly promotes tumor growth and metastasis of HCC. GIHCG physically associates with EZH2. GIHCG upregulates H3K27me3 and DNA methylation levels on the miR-200b/a/429 promoter. GIHCG epigenetically silences miR-200b/a/429 expression.
Subject(s)
Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Epigenesis, Genetic , Gene Expression Regulation, Neoplastic , Liver Neoplasms/genetics , MicroRNAs/genetics , RNA, Long Noncoding/genetics , Animals , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , DNA (Cytosine-5-)-Methyltransferase 1/metabolism , Disease Progression , Down-Regulation/genetics , Enhancer of Zeste Homolog 2 Protein/metabolism , Female , Gene Silencing , Humans , Liver Neoplasms/pathology , Male , Mice, Inbred BALB C , Mice, Nude , MicroRNAs/metabolism , Middle Aged , Neoplasm Metastasis , Promoter Regions, Genetic , Protein Binding , RNA, Long Noncoding/metabolism , Survival AnalysisABSTRACT
Patients with hepatocellular carcinoma (HCC) experience poor prognosis and low survival rates. In this study, we explored the molecular mechanism of microRNA-147 (miR-147) in regulating human HCC. We firstly used quantitative RT-PCR (qRT-PCR) to compare the expression levels of miR-147 between 7 HCC and two normal liver cell lines, as well as 10 paired primary HCC tissues and their adjacent non-carcinoma tissues. We found miR-147 was down-regulated in both HCC cell lines and primary HCCs tissues. HCC cell lines HepG2 and HuH7 were transfected with lentiviral vector of miR-147 mimics. We found overexpressing miR-147 significantly inhibited HCC in vitro proliferation and migration, increased 5-FU chemosensitivity, and reduced in vivo tumorigenicity. Luciferase, qRT-PCR and western blot assays showed that HOXC6 was the downstream target of miR-147, and both gene and protein levels of HOXC6 were down-regulated by miR-147 in HCC cells. SiRNA mediated HOXC6 knockdown inhibited in vitro proliferation and migration, and increased 5-FU chemosensitivity in HCC. On the other hand, HOXC6 overexpression reversed the inhibitory effect of miR-147 on HCC in vitro proliferation. Therefore, our results suggest that miR-147 can modulates HCC development through the regulation on HOXC6.
ABSTRACT
OBJECTIVE: To study the clinical value of total hemihepatic vascular exclusion (THHVE) in liver resection for patients with hepatocellular carcinoma (HCC) and impaired liver function. METHODS: The data of 70 patients who underwent liver resection for HCC with impaired liver function between January 2009 and October 2011 were analyzed retrospectively. THHVE was applied in 38 patients (THHVE group), Pringle maneuver in 25 patients (Pringle group) and no vascular occlusion in 7 patients. In the THHVE group, 36 patients were male, 2 were female, average age was (54 ± 9) years. And in Pringle group, 23 patients were male, 2 were female, average age was (53 ± 10) years. Total intraoperative blood loss, blood transfusion rate, clamping time, postoperative complication rate, postoperative hospital stay and postoperative liver function were compared between the THHVE and Pringle group. RESULTS: Total blood loss ((317 ± 186) ml vs. (506 ± 274) ml, t = -3.025, P = 0.004) and transfusion rate (10.5% vs. 32.0%, χ(2) = 4.509, P = 0.034) were significantly lower in the THHVE group than in the Pringle group. Although the clamping time was longer ((21 ± 5) minutes vs. (17 ± 5) minutes, t = 3.209, P = 0.002), the total bilirubin levels on postoperative day 3 and 7 and ALT levels on postoperative day 1, 3, 7 were significantly lower in the THHVE group than in the Pringle group, and the pre-albumin level on postoperative day 7 was higher in the THHVE group than in the Pringle group. Total complication rate (26.3% vs. 52.0%, χ(2) = 4.291, P = 0.038) and major complication rate (7.9% vs. 28.0%, χ(2) = 4.565, P = 0.033) were lower in the THHVE group than in the Pringle group. And postoperative hospital stay duration was shorter in the THHVE group than in the Pringle group ((14.0 ± 2.6) d vs. (16.4 ± 4.0) d, t = -2.625, P = 0.012). CONCLUSIONS: THHVE is a safe and effective technique in liver resection for patients with HCC and impaired liver function. It is associated with less blood loss, lower transfusion requirements, better postoperative liver function recovery, lower postoperative complication rate and shorter postoperative hospital stay.
