Zhi-Wei Quan

Long non-coding RNA CCAT1 promotes gallbladder cancer development via negative modulation of miRNA-218-5p

Protein-coding genes account for only ~2% of the human genome, whereas the vast majority of transcripts are non-coding RNAs (ncRNAs) including long ncRNAs (lncRNAs). A growing volume of literature has proposed that lncRNAs are important factors in cancer. Colon cancer-associated transcript-1 (CCAT1), an lncRNA, which was first identified in colon cancer, was previously shown to promote tumor development and be a negative prognostic factor in gastric cancer. However, the mechanism through which CCAT1 exerts its oncogenic activity remains largely unknown. Recently, a novel regulatory mechanism has been proposed in which RNAs can cross-talk with each other via competing shared for microRNAs (miRNAs). The proposed competitive endogenous RNAs could mediate the bioavailability of miRNAs on their targets, thus imposing another level of posttranscriptional regulation. In this study, we demonstrated that CCAT1 was upregulated in gallbladder cancer (GBC) tissues. CCAT1 silencing downregulated, whereas CCAT1 overexpression enhanced the expression of miRNA-218-5p target gene Bmi1 through competitively ‘spongeing’ miRNA-218-5p. Our data revealed that CCAT1 knockdown impaired the proliferation and invasiveness of GBC cells, at least in part through affecting miRNA-218-5p-mediated regulation of Bmi1. Moreover, CCAT1 transcript level was correlated with Bmi1 mRNA level in GBC tissues. Together, these results suggest that CCAT1 is a driver of malignancy, which acts in part through ‘spongeing’ miRNA-218-5p.

Long non-coding RNA Malat1 promotes gallbladder cancer development by acting as a molecular sponge to regulate miR-206

Long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (Malat1) functions as an oncogene in many types of human cancer. In this study, we show that Malat1 is overexpressed in gallbladder cancer (GBC) tissue and cells. The high Malat1 levels correlated positively with tumor size and lymphatic metastasis, and correlated negatively with overall survival. We also show that Malat1 functions as a competing endogenous RNA (ceRNA) for miR-206. Because miR-206 directly suppresses expression of ANXA2 and KRAS, which are thought to promote GBC progression, Malat1 binding of miR-206 in GBC tissue and cells has an oncogenic effect. Conversely, Malat1 knockdown inhibits proliferation and invasion by GBC cells while increasing apoptosis. In vivo, silencing Malat1 decreases tumor volume. These results suggest Malat1 could potentially serve as a therapeutic target and prognostic marker for GBC.

The lncRNA MALAT1 functions as a competing endogenous RNA to regulate MCL-1 expression by sponging miR-363-3p in gallbladder cancer.

Gallbladder carcinoma (GBC) is an aggressive neoplasm, and the treatment options for advanced GBC are limited. Recently, long non‐coding RNAs (lncRNAs) have emerged as new gene regulators and prognostic markers in several cancers. In this study, we found that metastasis‐associated lung adenocarcinoma transcript 1 (MALAT1) expression was up‐regulated in GBC tissues (P < 0.05). Luciferase reporter assays and RNA pull down assays showed that MALAT1 is a target of miR‐363‐3p. Real‐time quantitative PCR and Western blot analysis indicated that MALAT1 regulated Myeloid cell leukaemia‐1 (MCL‐1) expression as a competing endogenous RNA (ceRNA) for miR‐363‐3p in GBC cells. Furthermore, MALAT1 silencing decreased GBC cell proliferation and the S phase cell population and induced apoptosis in vitro. In vivo, tumour volumes were significantly decreased in the MALAT1 silencing group compared with those in the control group. These data demonstrated that the MALAT1/miR‐363‐3p/MCL‐1 regulatory pathway controls the progression of GBC. Inhibition of MALAT1 expression may be to a novel therapeutic strategy for gallbladder cancer.

Long non-coding RNA H19 regulates FOXM1 expression by competitively binding endogenous miR-342-3p in gallbladder cancer

BackgroundLong non-coding RNA (lncRNA) H19 has been reported to involve in many kinds of human cancers and functions as an oncogene. Our previous study found that H19 was over-expressed in gallbladder cancer (GBC) and was shown to promote tumor development in GBC. However, the competing endogenous RNA (ceRNA) regulatory network involving H19 in GBC progression has not been fully elucidated. We aim to detect the role of H19 as a ceRNA in GBC.Methods and ResultsIn this study, the expression of H19 and miR-342-3p were analyzed in 35 GBC tissues and matched normal tissues by using quantitative polymerase chain reaction (qRT-PCR). We demonstrated H19 was overexpressed and negatively correlated with miR-342-3p in GBC. By dual-luciferase reporter assays, RNA-binding protein immunoprecipitation (RIP) and RNA pull-down assays, we verified that H19 was identified as a direct target of miR-342-3p. QRT-PCR and Western-blotting assays demonstrated that H19 silencing down-regulated, whereas over-expression enhanced the expression of miR-342-3p targeting FOXM1 through competitively ‘sponging’ miR-342-3p. Furthermore, transwell invasion assays and cell cycle assays indicated that H19 knockdown inhibited both cells invasion and proliferation, but this effects was attenuated by co-transfection of siRNA-H19 and miR-342-3p inhibitor in GBC cells. In vivo, tumor volumes were decreased significantly in H19 silenced group compared to the control group, but was attenuated by co-transfection of shRNA-H19 and miR-342-3p inhibitor, which were stablely constructed through lenti-virus vector.ConclusionOur results suggest a potential ceRNA regulatory network involving H19 regulates FOXM1 expression by competitively binding endogenous miR-342-3p in GBC. This mechanism may contribute to a better understanding of GBC pathogenesis and provides potential therapeutic strategy for GBC.

Long noncoding RNA UCA1 induced by SP1 promotes cell proliferation via recruiting EZH2 and activating AKT pathway in gastric cancer

Long noncoding RNA UCA1 has emerged as a novel regulator in cancer initiation and progression of various cancers. However, function and underlying mechanism of UCA1 in the progression of gastric cancer (GC) remain unclear. In the present study, we report that UCA1 expressed highly in GC tissues and GC cells, which was partly induced by SP1. UCA1 promoted GC cell proliferation and G1/S transition in vitro and in vivo. Moreover, UCA1 exerted its function through interacting with EZH2, promoting direct interaction with cyclin D1 promoter to activate the translation of cyclin D1. Furthermore, AKT/GSK-3B/cyclin D1 axis was activated to upregulate cyclin D1 due to overexpression of UCA1. In addition, EZH2 and phosphorylated AKT induced by UCA1 could impact each other to form a positive feedback to promote cyclin D1 expression. This study demonstrated that UCA1 as a critical regulator involved in GC proliferation and cell cycle progression by promoting cyclin D1 expression, which indicates that it may be clinically a potential therapeutic target in GC.

Long non-coding RNA TUG1 promotes cell proliferation and metastasis by negatively regulating miR-300 in gallbladder carcinoma

BACKGROUND As we all know, long non-coding RNAs (lncRNAs) have been reported to play vital roles in various human cancers. In this study, we aimed to explore the role of lncRNA TUG1 in gallbladder carcinoma (GBC) development. METHODS Total RNA was extracted from the tissues of thirty GBC patients, four GBC cell lines. We detected the expression levels of TUG1 using quantitative real-time PCR. We performed CCK8, colony formation, transwell invasion and apoptosis assays to study the effects of TUG1 on GBC cell proliferation and invasion. Western blot assay was performed to assess to the expression level of epithelial-mesenchymal transition (EMT) markers in transforming growth factor-β1 (TGF-β1) treated and TUG1 knockdown GBC cell. Lastly, dual-luciferase reporter assay and quantitative real-time PCR were performed to verify the potential target microRNAs (miRNAs) of TUG1. RESULTS TUG1 expression was significantly overexpressed in GBC tissues. Functionally, this study demonstrated that knockdown of TUG1 significantly inhibited GBC cell proliferation, metastasis. Mechanically, we found that TUG1 is upregulated by TGF-β1, and knockdown of TUG1 inhibited GBC cell EMT. Furthermore, we identified that miR-300, which has been reported as a suppressor in other types of cancer, is negatively regulated by TUG1. CONCLUSIONS LncRNA TUG1 promotes GBC cell proliferation, metastasis and EMT progression by functioning as a miRNA sponge to abrogate the endogenous effect of miR-300.

Long non-coding RNA LINC00152 promotes gallbladder cancer metastasis and epithelial-mesenchymal transition by regulating HIF-1α via miR-138.

Long non-coding RNA LINC00152 had been reported as an oncogene in gastric and hepatocellular cancer. In this study, we show that LINC00152 is overexpressed in gallbladder cancer (GBC) tissue samples and cell lines. The high LINC00152 levels correlated negatively with the overall survival time in GBC patients. Functionally, LINC00152 dramatically promoted cell migration, invasion and epithelial–mesenchymal transition (EMT) progression in vitro. In vivo, LINC00152 overexpression significantly promoted tumour peritoneal spreading and metastasis. Mechanistic analyses indicated that LINC00152 functions as a molecular sponge for miR-138, which directly suppresses the expression of hypoxia inducible factor-1α (HIF-1α). We revealed that miR-138 is a suppressor of GBC cell metastasis and EMT progression, and a similar phenomenon was observed in HIF-1α knockdown NOZ cells. Through binding to miR-138, LINC00152 has an oncogenic effect on GBC. Overall, our study suggested that the LINC00152/miR-138/HIF-1α pathway potentiates the progression of GBC, and LINC00152 may be a novel therapeutic target.

The microRNA miR-33a suppresses IL-6-induced tumor progression by binding Twist in gallbladder cancer

Cytokine is a key molecular link between chronic inflammation and gallbladder cancer (GBC) progression. The potential mechanism of cytokine-associated modulation of microRNAs (miRNAs) expression in GBC progression is not fully understood. In this study, we investigated the biological effects and prognostic significance of interleukin-6 (IL-6) -induced miRNAs in the development of GBC. We identify that inflammatory cytokine, IL-6 promotes proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of GBC both in vitro and in vivo. Among all the changed miRNAs in miRNA profiling, miR-33a expression was significantly decreased in IL-6 treated GBC cell lines, as well as in GBC tissues compared with case-matched normal tissues and cholecystitis tissues. In turn, miR-33a suppresses IL-6−induced tumor metastasis by directly binding Twist which was identified as an EMT marker. High expression of miR-33a suppressed xenograft tumor growth and dissemination in nude mice. The downregulation of miR-33a was closely associated with advanced clinical stage, lymph node metastasis, and poor clinical outcomes in patients with GBC. miR-33a acts as a tumor suppressor miRNA in GBC progression and may be considered for the development of potential therapeutics against GBC.

Long non-coding RNA UCA1 promotes gallbladder cancer progression by epigenetically repressing p21 and E-cadherin expression

A growing number of studies indicated that long non-coding RNAs (lncRNAs) determine some cellular processes in cancer, such as proliferation, metastasis and differentiation. Urothelial carcinoma associated 1 (UCA1), an lncRNA, had been reported for its overexpression and oncogenic effect on various human cancers. In this study, we found that UCA1 was significantly overexpressed in gallbladder cancer (GBC) and positively correlated with tumor size, lymph node metastasis, TNM stage and short survival time. Moreover, UCA1 promoted GBC cell proliferation and metastasis in vitro and tumor growth in vivo. Mechanically, we identified that UCA1 promoted GBC progression through recruiting enhancer of zeste homolog 2 (EZH2) to the promoter of p21 and E-cadherin, and epigenetically suppressing their transcript.

Higher proliferation of peritumoral endothelial cells to IL-6/sIL-6R than tumoral endothelial cells in hepatocellular carcinoma

BackgroundThis study aimed to explore the responses to the interleukin-6 (IL-6)/soluble interleukin-6 receptor (sIL-6R) complex in peritumoral endothelial cells (PECs) and tumor endothelial cells (TECs), as well as determine the signaling pathways in the angiogenesis of hepatocellular carcinoma (HCC).MethodsThe expression of IL-6, IL-6R, gp130, CD68, HIF-1α, and microvessel density (MVD) were assessed with an orthotopic xenograft model in nude mice. ECs were incubated under hypoxic conditions to detect IL-6 and gp130. The proliferation of PECs and TECs in the presence of IL-6 and sIL-6R, as well as the expression of gp130, JAK2/STAT3, PI3K/AKT in endothelial cells were measured.ResultsPeritumoral IL-6, IL-6R, gp130, CD68, and HIF-1α expression, as well as MVD, gradually increased during tumor growth. Hypoxia could directly induce IL-6 expression, but not gp130 in PECs. The co-culture of IL-6/sIL-6R induced much higher PEC proliferation and gp130 expression, as well as the elevated phosphorylation of JAK2 and STAT3, however not the phosphorylation of PI3K and AKT.ConclusionsPECs exhibited higher proliferation in response to IL-6/sIL-6R co-treatment compared with TECs in HCC via the up-regulation of gp130 /JAK2/STAT3. PEC and its associated peritumoral angiogenesis microenvironment may be a potential novel target for anti-angiogenic treatment.