Long noncoding RNA BLACAT1 is overexpressed in hepatocellular carcinoma and its downregulation suppressed cancer cell development through endogenously competing against hsa-miR-485-5p.

In this work, we explored the expression and mechanistic role of long noncoding RNA (lncRNA), bladder cancer associated transcript 1 (BLACAT1) in human hepatocellular carcinoma (HCC). BLACAT1 expression in bothin vitro HCC cell lines and in vivo human HCC clinical samples were assessed by qRT-PCR. In HeG2 and MHCC97 L cells, BLACAT1 downregulation was induced by lentiviral infection to evaluate its functions in regulating HCC cancer cell proliferation and invasion in vitro, and xenograft in vivo. A BLACAT1 endogenously competing candidate, human microRNA-485-5p (has-miR-485-5p) was assessed in dual-luciferase assay and qRT-PCR in HCC cells. Furthermore, has-miR-485-5p was inhibited in BLACAT1-downregulated HeG2 and MHCC97 L cells to evaluate the correlation of has-miR-485-5p in BLACAT1-associated functional regulation in HCC cells. BLACAT1was found to be overexpressed in both HCC cells and human HCC tumors. In HeG2 and MHCC97 L cells, lentivirus-induced BLACAT1 downregulation inhibited cancer cellin vitro proliferation and invasion, and in vivo xenograft growth. Has-miR-485-5p was confirmed to be bound by BLACAT1 and its expression in HCC cells inversely regulated by BLACAT1. Then, has-miR-485-5p downregulation reversed the inhibitory effects of BLACAT1 downregulation on HCC cancer cell in vitro functions. BLACAT1 is aberrantly upregulated in HCC and its inhibition had tumor suppressing effects in human HCC, possibly through endogenously competing against has-miR-485-5p. The BLACAT1/ has-miR-485-5p regulatory axis may be a molecular target for future HCC therapy.

Peng Y ，Leng W ，Duan S ，Hong M ... -  《-》

LncRNA SNHG7 accelerates the proliferation, migration and invasion of hepatocellular carcinoma cells via regulating miR-122-5p and RPL4.

Long noncoding RNAs (lncRNAs) play vital roles in the development and progression of hepatocellular carcinoma (HCC). The recent study finds a strong correlation between lncRNA small nucleolar RNA host gene 7 (SNHG7) and HCC metastasis. However, the molecular mechanism by which SNHG7 regulates HCC progression has not been investigated. In this study, we found that SNHG7 was highly expressed in HCC tissues compared to non-tumor tissues. Data from public databases consistently indicated the up-regulated expression of SNHG7 in HCC. Furthermore, the levels of SNHG7 were up-regulated in four HCC cell lines (Huh7, Hep3B, HCCLM3, MHCC97 H) compared with LO2 cells. Interestingly, the elevated expression of SNHG7 was closely correlated with advanced tumor stages, high tumor grades, vascular invasion and poor prognosis of HCC. Knockdown of SNHG7 markedly inhibited cell proliferation, migration and invasion in HCCLM3 and MHCC97H cells, and prominently suppressed the growth and metastasis of HCCLM3 cells in vivo. Mechanistically, SNHG7 silencing increased the level of miR-122-5p in HCC cells. Luciferase reporter assay revealed the direct interaction between SNHG7 and miR-122-5p. Moreover, SNHG7 knockdown decreased the levels of ribosomal protein L4 (RPL4) mRNA and protein in HCC cells. Accordingly, the stability of RPL4 mRNA was reduced by SNHG7 silencing. More importantly, either miR-122-5p knockdown or RPL4 restoration partially reversed SNHG7 silencing-induced tumor suppressive effects on HCC cells. In conclusion, we demonstrated that SNHG7 expression was up-regulated in HCC. SNHG7 contributed to HCC progression by regulating miR-122-5p and RPL4. Therefore, SNHG7 might be a potential biomarker and therapeutic target for HCC.

Yang X ，Sun L ，Wang L ，Yao B ，Mo H ，Yang W ... -  《-》

Long non-coding RNA NEAT1 promotes hepatocellular carcinoma cell proliferation through the regulation of miR-129-5p-VCP-IκB.

Long non-coding RNA nuclear-enriched abundant transcript 1 (NEAT1) plays an important role in the pathogenesis and development of several types of cancer. However, the functional mechanism of NEAT1 in hepatocellular carcinoma (HCC) remains unclear. NEAT1 and microRNA (miR)-129-5p expression in HCC tissues and cell lines was quantified by means of quantitative PCR. The effects of NEAT1 expression inhibition or upregulation in HCC cell lines were analyzed in terms of cell viability and apoptosis. Biological software was used to predict the binding sites of NEAT1 and miR-129-5p. The expression of the miR-129-5p target molecules valosin-containing protein (VCP) and IκB was detected using Western blotting. The effect of NEAT1 on tumor growth was observed in mouse models of transplanted hepatoma. In the present study, it was concluded that the expression of NEAT1 was significantly increased in the HCC tissues and cell lines. Meanwhile, after downregulating NEAT1 expression in HepG2/Huh7 cell lines, the cell viability was significantly lowered, whereas the corresponding rate of apoptosis was significantly increased. Additionally, it was found that the NEAT1 and miR-129-5p expression showed a negative correlation in HCC tissues. It was further proved that there was a certain negative regulatory mechanism between NEAT1 and miR-129-5p, which was related to the expression of VCP and IκB. The mouse model experiments confirmed that the interference with NEAT1 expression inhibited tumor growth. The study concluded that the overexpression of NEAT1 inhibited the expression of miR-129-5p by regulating VCP/IκB, thereby promoting the proliferation of HCC cells. This study provides new insights into the pathogenesis of HCC, as well as identifying new target genes for diagnosis and treatment.NEW & NOTEWORTHY The results provide strong evidence that upregulated NEAT1 promotes the proliferation of cancer cells in hepatocellular carcinoma (HCC) and this regulatory mechanism depends on the microRNA (miR)-129-5p-valosin-containing protein-IκB axis. The study also indicates that NEAT1 could be a potential therapeutic target for HCC.

Fang L ，Sun J ，Pan Z ，Song Y ，Zhong L ，Zhang Y ，Liu Y ，Zheng X ，Huang P ... -  《-》

Long noncoding RNA LINC01189 is associated with HCV-hepatocellular carcinoma and regulates cancer cell proliferation and chemoresistance through hsa-miR-155-5p.

Emerging evidence has demonstrated that long noncoding RNAs (lncRNAs) may be closely associated with Hepatitis C virus (HCV) infection and the development of hepatocellular carcinoma (HCC). In this study, we investigated the expression and functions of a lncRNA, LINC01189, in HCV-associated HCC. LINC01189 expression was measured in HCC tumors, HCV-infected HCC tumors and HCV-infected HCC cells. LINC01189 was overexpressed in HCV-infected HepG2 cells to measure its function on HCV-correlated cancer proliferation. In HCC cell lines of Huh7 and Hep3B, LINC01189 was upregulated to investigate its effects on cancer cell proliferation and 5-FU chemoresistance. The competing endogenous RNA (ceRNA) target of LINC01189, human microRNA-155-5p (hsa-miR-155-5p) was probed by dual-luciferase assay and qRT-PCR. Hsa-miR-155-5p was upregulated in LINC01189-overexpessed Huh7 and Hep3B cells to investigate their epigenetic correlation on HCC development regulation. LINC01189 is downregulated in HCV-infected HCC tumors and cell lines. LINC01189 overexpression inhibited HCC cancer cell proliferation and 5-FU chemoresistance. Hsa-miR-155-5p was confirmed to be a ceRNA target of LINC01189 in HCC. Upregulating hsa-miR-155-5p reversed the LINC01189-mediated inhibition on HCC proliferation and 5-FU chemoresistance. LINC01189 downregulation is associated with HCV infection in HCC, and it has tumor-suppressing effects on HCC development through hsa-miR-155-5p.

Yao Y ，Shu F ，Wang F ，Wang X ，Guo Z ，Wang H ，Li L ，Lv H ... -  《Annals of Hepatology》

Long noncoding RNA PCAT-1 promotes invasion and metastasis via the miR-129-5p-HMGB1 signaling pathway in hepatocellular carcinoma.

The long non-coding RNA (lncRNA) prostate cancer-associated transcript 1(PCAT-1) has been shown to be dysregulated and exert vital roles in tumorigenesis and progression of various malignancies. However, the precise molecular mechanism in the metastasis and invasion of HCC remain unclear. The expression levels of PCAT1 derived from human HCC tissues and cell lines were analyzed through quantitative real-time PCR. QRT-PCR was also applied to detect the expression of HMGB1 and miR-129-5p. Wound healing assay and transwell assays were performed to analyze cell migration and invasion ability. The mRNA levels and protein expression of HMGB1 were detected by western-blotting analysis and immunohistochemistry, respectively. Luciferase assays were used to investigate binding seeds beteen miRNA-129-5p and other transcripts, such as PCAT-1, HMGB1. In this study, our founding demonstrated that PCAT-1 was not only aberrantly upregulated in HCC tissues and cell lines, but also associated with TNM stage, metastasis and Histological grade. In vitro, downregulation of PCAT-1 could reduce the invasion and migration of HCC cells. Moreover, our results showed that PCAT-1 could act as an endogenous RNA by directly binding to miR-129-5p. In addition, Luciferase reporter assay and western blotting analyses showed that PCAT-1 repressed inhibitory effect of miR-129-5p and reverse high mobility group box 1 (HMGB1) expression, a target gene of miR-129-5p. PCAT-1 functions as competing endogenous RNA (ceRNA) to provide a better understanding for HCC metastasis, and serves as a potential diagnostic and therapeutic target via PCAT-1/miR-129-5p/HMGB1 regulatory crosstalk for the deadly disease.

Zhang D ，Cao J ，Zhong Q ，Zeng L ，Cai C ，Lei L ，Zhang W ，Liu F ... -  《-》