Hepatocellular Carcinoma Migration Research Articles

Histone methyltransferase SETDB1 promotes cells proliferation and migration by interacting withTiam1 in hepatocellular carcinoma

BackgroundSETDB1 is a histone H3K9 methyltransferase, which plays a significant role in the occurrence and progression of tumors. Previous studies have confirmed that T-lymphom invasion and metastasis gene (Tiam1) is a protein associated with the metastasis of hepatocellular carcinoma (HCC); however, we have not yet been successful in elucidating the specific mechanism of HCC.MethodsYeast two-hybrid test was conducted to screen proteins that interacted with Tiam1 gene. Glutathione-S-transferase (GST) pull-down and crosslinking-immunoprecipitation (CLIP) assays were performed to determine whether SETDB1 can interact with Tiam1 gene. A series of related experiments were performed to explore role of SETDB1 on cell proliferation, migration, and invasion in HCC. Recovery experiment was performed to investigate the effect of Tiam1 knockdown on cell proliferation and migration, which was caused by SETDB1 overexpression in HCC cells. The expression of SETDB1 was frequently upregulated in HCC tissues and positively correlated with Tiam1.ResultsGST pull-down and CLIP assays were performed to elucidate the interaction between SETDB1 and Tiam1. Cell proliferation, migration, and epithelial mesenchymal transformation (EMT) in HCC cells was promoted with the overexpression of SETDB1. Following the knockdown of Tiam1 gene, the effect of SETDB1 on cell proliferation and migration was reversed in HCC cells. The expression of SETDB1 was frequently up-regulated in HCC tissues, and it was positively correlated with Tiam1 gene.ConclusionsOurs is the first study to prove that SETDB1 promotes the proliferation and migration of cells by forming SETDB1-Tiam1 compounds. We found that SETDB1-Tiam1 compounds were involved in a novel pathway, which regulated epigenetic modification of gene expression in HCC samples.

Cholesterol inhibits hepatocellular carcinoma invasion and metastasis by promoting CD44 localization in lipid rafts

Cholesterol plays a vital role in modulating the action of membrane proteins critical to cellular function. The effect of serum cholesterol on the prognosis of hepatocellular carcinoma (HCC) patients remains uncertain. Here, we report that high levels of cholesterol predict good survival and low disease recurrence after surgery. Cholesterol could significantly suppress migration and invasion of HCC cells and restrain metastasis of HCC in mice. High levels of cholesterol promoted CD44 translocation into lipid rafts and attenuated CD44-Ezrin binding, which are crucial for cell migration and cancer metastasis. The suppressive effect of cholesterol on HCC metastasis was abolished by the downregulation of CD44 or its palmitoylation inhibitor, which blocked CD44 localization in lipid rafts. Furthermore, pharmacologically promoting CD44 retention inside lipid rafts obviously attenuated HCC migration and invasion, providing a potential therapeutic strategy to prolong the survival of HCC patients.

CircSMAD2 inhibits the epithelial-mesenchymal transition by targeting miR-629 in hepatocellular carcinoma.

BackgroundCircular RNAs (circRNAs) are a class of widely distributed non-coding RNAs, which drew little attention for decades. Recent studies show that circRNAs are involved in cancer progression.MethodsThe circSMAD2 expression in HCC and adjacent non-tumor tissues was measured by quantitative real-time polymerase chain reaction, and the biological function of circSMAD2 was explored by proliferation, apoptosis, migration, invasion, and Western blot assays. Next, the dual-luciferase reporter assay was performed to identify the target miRNA of circSMAD2. Finally, circSMAD2 and its target miRNA were co-transfected in HCC cells to investigate their relationship to HCC progression.ResultsIn this study, we found that circRNA SMAD2 (circSMAD2) expression was downregulated in hepatocellular carcinoma (HCC) tissues (P = 0.014) compared to the adjacent non-tumor tissues and markedly associated with the differentiation degree of the HCC tissues (P < 0.001). The in vitro experiments showed that overexpressed circSMAD2 inhibited the migration, invasion, and epithelial–mesenchymal transition (EMT) in HCC cells. Bioinformatics predicted that miR-629 is a potential target of circSMAD2, and the dual-luciferase reporter assay verified that miR-629 directly bound circSMAD2. In addition, we found that overexpression of circSMAD2 suppressed the expression of miR-629 in HCC cells, whereas knockdown of circSMAD2 upregulated the expression of miR-629. Furthermore, co-transfection of miR-629 mimics with circSMAD2 reversed the circSMAD2 effects of inhibiting the migration, invasion, and EMT of HCC cells.ConclusionAltogether, our data support that circSMAD2 inhibits the migration, invasion, and EMT of HCC cells by targeting miR-629.

SPON2 Promotes M1-like Macrophage Recruitment and Inhibits Hepatocellular Carcinoma Metastasis by Distinct Integrin–Rho GTPase–Hippo Pathways

Tumor-associated macrophages (TAM) represent key regulators of the complex interplay between cancer and the immune microenvironment. Matricellular protein SPON2 is essential for recruiting lymphocytes and initiating immune responses. Recent studies have shown that SPON2 has complicated roles in cell migration and tumor progression. Here we report that, in the tumor microenvironment of hepatocellular carcinoma (HCC), SPON2 not only promotes infiltration of M1-like macrophages but also inhibits tumor metastasis. SPON2-α4β1 integrin signaling activated RhoA and Rac1, increased F-actin reorganization, and promoted M1-like macrophage recruitment. F-Actin accumulation also activated the Hippo pathway by suppressing LATS1 phosphorylation, promoting YAP nuclear translocation, and initiating downstream gene expression. However, SPON2-α5β1 integrin signaling inactivated RhoA and prevented F-actin assembly, thereby inhibiting HCC cell migration; the Hippo pathway was not noticeably involved in SPON2-mediated HCC cell migration. In HCC patients, SPON2 levels correlated positively with prognosis. Overall, our findings provide evidence that SPON2 is a critical factor in mediating the immune response against tumor cell growth and migration in HCC.Significance: Matricellular protein SPON2 acts as an HCC suppressor and utilizes distinct signaling events to perform dual functions in HCC microenvironment.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/9/2305/F1.large.jpg Cancer Res; 78(9); 2305-17. ©2018 AACR.

The long noncoding RNA NEAT1 contributes to hepatocellular carcinoma development by sponging miR-485 and enhancing the expression of the STAT3.

Accumulating evidence has supported the significance of lncRNAs in tumorigenesis. Recently, some studies indicate the oncogenic role of lncRNA Nuclear Enriched Abundant Transcript 1 (NEAT1) in hepatocellular carcinoma (HCC). In our present study, we focused on the biological mechanisms through which NEAT1 can regulate HCC development. We found that NEAT1 was greatly upregulated in human HCC cell lines including Huh7, Hep3B, HepG2, Bel-7404, and SK-Hep1 cells compared to the normal human liver cell line LO2. In addition, we observed that miR-485 was significantly downregulated in HCC cells. It was implied that miR-485 was increased by sh-NEAT1 and miR-485 can modulate NEAT1 expression negatively. Meanwhile, NEAT1inhibiton can repress HCC growth, migration, and invasion capacity in HepG2 and Hep3B cells. Through performing bioinformatic analysis, dual-luciferase reporter test, RNA-binding protein immunoprecipitation, and RNA pull-down assay, miR-485 was confirmed as a interacting target of NEAT1. Additionally, STAT3 was recognized as a direct target of miR-485 and miR-485 mimics can inhibit STAT3 expression. It was demonstrated that NEAT1 can increase STAT3 levels while miR-485 mimics can repress STAT3. Moreover, we found that sh-STAT3 was able to restrain HCC cell migration and invasion process. NEAT1 can act as a competing endogenous lncRNA (ceRNA) to regulated STAT3 by sponging miR-485 in HCC. Taken these together, NEAT1 can be used as an important biomarker in HCC diagnosis and treatment.

The role of miR-99b in mediating hepatocellular carcinoma invasion and migration.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults with a high rate of malignancy. The potent invasion and migration of HCC mainly impact the prognosis and recurrence of the disease. Our previous study found that miR-99b was highly expressed in HCC, and its expression was associated with vascular invasion. It was speculated that miR-99b may play a role in HCC invasion and migration, while the specific mechanism remains unclear. qRT-PCR was applied to detect expressions of miR-99b and KAI1 genes in L02, HepG2, and MHCC97H cells. HepG2 cells were transfected with miR-99b inhibitor, miR-99b mimic, and NC. Flow cytometry was used to test cell cycle and apoptosis. Dual-luciferase reporter gene assay was adopted to validate the target gene of miR-99b. Wound healing assay was used to detect cell migration. Transwell assay was performed to detect cell invasion. Western blot was performed to detect KAI1, E-cadherin, and N-cadherin expressions. Immunofluorescence assay was adopted to test Vimentin expression. The level of miR-99b was reduced in L02 while up-regulated in MHCC97H. By contrast, the expression of KAI1 was increased in L02 but declined in MHCC97H. The transfection of miR-99b mimic inhibited HepG2 apoptosis and accelerated cell cycle. MiR-99b suppressed KAI gene expression through targeting its 3'-UTR. MiR-99b mimic or si-KAI1 transfection promoted cell invasion and migration, while their simultaneous action significantly enhanced cell invasion and migration. The overexpression of miR-99b or knockdown of KAI1 significantly weakened HepG2 cell adhesion, reduced E-cadherin expression, upregulated N-cadherin and Vimentin, and promoted cell epithelial-mesenchymal transition (EMT). MiR-99b contributes to promoting function in HCC migration and invasion through inhibiting KAI1 expression.

Long noncoding RNA MINCR regulates cellular proliferation, migration, and invasion in hepatocellular carcinoma

PurposeAccumulating evidence indicates that long noncoding RNAs (lncRNAs) are aberrantly expressed in many cancer types, including hepatocellular carcinoma (HCC). lncRNA MYC-induced long non-coding RNA (MINCR) were revealed to be markedly up-regulated in gallbladder cancer and Burkitt lymphoma cells. However, the biological role and function of MINCR in HCC progression are still unknown. MethodsThe expression of MINCR in HCC tissues and cell lines was determined using quantitative real-time polymerase chain reaction assays. The effects of MINCR in HCC cell proliferation, migration, and invasion were determined using cell-counting kit 8 (CCK8) assay, wound healing assay, and Transwell assays in vitro. ResultsMINCR expression was up-regulated in HCC tissues and cell lines as compared with that in the negative control. The decreased expression of MINCR in vitro markedly inhibited HCC cell proliferation, migration, and invasion. Our results showed that MINCR is important in HCC development and may act as a therapeutic target that regulates HCC cellular proliferation, migration, and invasion, which are involved in HCC tumorigenesis. ConclusionsTo the best of our know ledge, MINCR in HCC has not been studied. Our findings showed that this study is the first to reveal that MINCR may act as a therapeutic target in HCC. The in-depth exploration of the molecular mechanism is required to illuminate the molecular mechanisms of MINCR in HCC development.

Therapeutic role of meloxicam targeting secretory clusterin-mediated invasion in hepatocellular carcinoma cells.

Recurrence and metastasis are the two leading causes of poor prognosis in patients with hepatocellular carcinoma (HCC). Secreted clusterin (sCLU) is a stress-induced chaperone that is overexpressed in HCC. However, the precise molecular mechanisms of sCLU in HCC invasion and migration are largely unknown. In the present study, it was indicated that downregulation of sCLU significantly alleviated invasiveness whereas overexpression of sCLU notably enhanced the number of invasive cells via mediating the expression level of MMP-2 and E-cadherin in Bel-7402 and SMMC-7721 cells. Furthermore, as an important mediator of invasiveness, sCLU may be responsible for proliferation and invasion suppression induced by meloxicam (a selective inhibitor of cyclooxygenase-2) in HCC cells. The combination of meloxicam and CLU shRNA significantly decreased invasion in HCC cells in vitro. Furthermore, it was observed that overexpression of sCLU significantly potentiated expression of p-AKT and MMP-2. However, downregulation of sCLU by CLU shRNA alleviated the extent of p-AKT. These results suggest the targeting of sCLU may be a novel therapeutic strategy against invasion and migration in HCC.

LncRNA FABP5P3/miR-589-5p/ZMYND19 axis contributes to hepatocellular carcinoma cell proliferation, migration and invasion

Hepatocellular carcinoma (HCC) contributes to cancer-related deaths greatly every year in the world. However, there is still no radical method for HCC treatment. Here we screened out a lncRNA FABP5P3 that was up-regulated in HCC tissues. Patients with higher FABP5P3 expression displayed poorer survival rate. FABP5P3 depletion in HCC cell lines and sample cells remarkably inhibited the abilities of proliferation, migration and invasion. In mechanism, we showed that FABP5P3 bond to miR-589-5p which served as a tumor suppressor. MiR-589-5p targeted directly the mRNA of ZMYND19 whose function has not been defined in HCC. FABP5P3 promoted HCC development and progression by sponging miR-589-5p and up-regulating ZMYND19 expression. In sum, we showed that FABP5P3/miR-589-5p/ZMYND19 axis regulates cell proliferation and migration in HCC, which may serve as a new target for HCC treatment.

CADM2, as a new target of miR-10b, promotes tumor metastasis through FAK/AKT pathway in hepatocellular carcinoma

BackgroundCell adhesion molecules (CADMs) comprise of a protein family whose functions include maintenance of cell polarity and tumor suppression. Hypo-expression of CADM2 gene expression has been observed in several cancers including hepatocellular carcinoma (HCC). However, the role and mechanisms of CADM2 in HCC remain unclear.MethodsThe expression of CADM2 and miRNA-10b (miR-10b) in HCC tissues and cell lines were detected using real-time PCR and Western blotting. Immunofluorescence was used to detect Epithelial-mesenchymal transition (EMT) progression in HCC cell lines. Dual-luciferase reporter assay was used to determine miR-10b binding to CADM2 3’UTR. Wound healing assay and Transwell assay were performed to examine the migration and invasion of HCC cells.ResultsWe report the effect of CADM2 as a tumor suppressor in HCC. Firstly, we confirmed that CADM2 expression was significantly down regulated in HCC tissues compared to normal tissues according to TCGA data analysis and fresh HCC sample detection. Secondly, overexpression of CADM2 could inhibit EMT process, migratory and invasion ability of HCC cells. Furthermore, the results indicated that CADM2 is a direct target of miR-10b in HCC cells and miR-10b/CADM2 modulates EMT process and migration ability via focal adhesion kinase (FAK) /AKT signaling pathway in HCC.ConclusionsOur study demonstrates that miR-10b-CADM2-FAK/AKT axis plays an important role in HCC metastasis, which might be a novel potential therapeutic option for HCC treatment.

C-C chemokine receptor type 1 mediates osteopontin-promoted metastasis in hepatocellular carcinoma.

In the hepatocellular carcinoma (HCC) microenvironment, chemokine receptors play a critical role in tumorigenesis and metastasis. Our previous studies have found that osteopontin (OPN) is a promoter for HCC metastasis. However, the role of chemokine receptors in OPN‐induced HCC metastasis remains unclear. In this study, we demonstrate that OPN is dramatically elevated in HCC tissues with metastasis and that high expression of OPN correlates with poorer overall survival and higher recurrence rate. OPN upregulates chemokine receptor expression, migration, invasion and pulmonary metastasis in HCC. We find that C‐C chemokine receptor type 1 (CCR1) and C‐X‐C chemokine receptor type 6 (CXCR6) are the most upregulated chemokine receptors induced by OPN. CCR1 knockdown results in reduction of migration, invasion and pulmonary metastasis induced by OPN in vitro and in vivo, whereas CXCR6 knockdown does not reverse OPN‐promoted migration and invasion. Moreover, OPN upregulates the expression of CCR1 through activating phosphoinositide 3‐kinase (PI3K)/AKT and hypoxia‐inducible factor 1α (HIF‐1α) in HCC cells. Furthermore, blockade of OPN‐CCR1 axis with CCR1 antagonist significantly restrains the promoting effects of OPN on HCC progression and metastasis. In human HCC tissues, OPN expression shows significantly positive correlation with CCR1 expression, and the patients with high levels of both OPN and CCR1 have the most dismal prognosis. Collectively, our results indicate that the OPN‐CCR1 axis in HCC is important for accelerating tumor metastasis and that CCR1 is a potential therapeutic target for controlling metastasis in HCC patients with high OPN.

Elevated G6PD expression contributes to migration and invasion of hepatocellular carcinoma cells by inducing epithelial-mesenchymal transition.

Altered metabolism is one of the hallmarks of cancer cells. Pentose phosphate pathway (PPP) is a fundamental component of cellular metabolism. Glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the PPP, is elevated in many cancers and contributes to tumor growth by producing ribose-5-phosphate and NADPH through PPP. However, the role of G6PD in hepatocellular carcinoma (HCC) metastasis and the clinical significance of G6PD in HCC progression and prognosis have not been well determined. In this study, by investigating tissue samples from HCC patients and HCC cell lines, we found that elevated G6PD expression is significantly associated with HCC metastasis and poor prognosis of HCCs, and that knockdown of G6PD inhibits in vitro proliferation, migration and invasion of HCC cell lines. Further studies reveal that G6PD contributes to HCC migration and invasion of hepatocellular carcinoma cells by inducing epithelial-mesenchymal transition through activation of signal transducer and activator of transcription 3 (STAT3) pathway. Our findings suggest that targeting G6PD could open up possibilities for metastasis intervention and improve the patients' outcomes for HCC.

M2-polarized tumor-associated macrophages facilitated migration and epithelial-mesenchymal transition of HCC cells via the TLR4/STAT3 signaling pathway

BackgroundM2-polarized macrophages are tumor-associated-macrophages (TAMs), which are important contents of tumor-infiltrating immune cells. Toll-like receptor 4 (TLR4) is a molecular biomarker of tumor aggressiveness and poor prognosis. Toll-like receptors (TLRs) have important roles in the immune system and M2-polarized macrophages. However, the effects of TLR4 on M2-polarized macrophages in hepatocellular carcinoma (HCC) are unknown. Here, TLR4 expressed on HCC cells mediates the pro-tumor effects and mechanisms of M2-polarized macrophages.MethodsTHP-1 cells were induced to differentiate into M2-like macrophages through treatments with IL-4, IL-13, and phorbol myristate acetate (PMA). We used the HCC cell lines SMMC-7721 and MHCC97-H cultured in conditioned medium from M2-like macrophages (M2-CM) to investigate the migration potential of HCC cells and epithelial-mesenchymal transition (EMT)-associated molecular genetics. Signaling pathways that mediated M2-CM-promoted HCC migration were detected using western blotting.ResultsHCC cells cultured with M2-CM displayed a fibroblast-like morphology, an increased metastatic capability, and expression of EMT markers. TLR4 expression was markedly increased in M2-CM-treated HCC cells. TLR4 overexpression promoted HCC cell migration, and a TLR4-neutralizing antibody markedly inhibited HCC EMT in cells cultured with M2-CM. Furthermore, the TLR4/(signal transducer and activator of transcription 3 (STAT3) signaling pathway contributed to the effects of M2-CM on HCC cells.ConclusionsTaken together, M2-polarized macrophages facilitated the migration and EMT of HCC cells via the TLR4/STAT3 signaling pathway, suggesting that TLR4 may be a novel therapeutic target. These results improve our understanding of M2-polarized macrophages.

TGF-β1 Promotes Hepatocellular Carcinoma Invasion and Metastasis via ERK Pathway-Mediated FGFR4 Expression

Background/Aims: TGF-β1 is beneficial during early liver disease but is tumor-progressive during late stages especially for hepatocellular carcinoma (HCC). Thus, exploring the underlying mechanisms may provide information about a potentially therapeutic role of TGF-β1 in HCC. Methods: Western blot and real-time quantitative PCR were used to quantify FGFR4 expression in HCC cell lines and a normal liver cell line. After constructing the best silencing FGFR4 expression vector, migration and invasiveness of TGF-β1 in HCC was studied in vitro and in vivo. Western blot was used to study the mechanism of TGF-β1 induction on FGFR4 expression with various inhibitors. Results: HepG2 cell lines had the most FGFR4 expression, and data show that silencing FGFR4 suppressed cell proliferation, invasion and migration in HCC induced by TGF-β1 in vitro and in vivo. Moreover, TGF-β1 induced FGFR4 expression through the ERK pathway. Conclusion: Promoting FGFR4 expression via the ERK pathway, TGF-β1 contributes to HCC invasion and metastasis.

Long Non-Coding MALAT1 Functions as a Competing Endogenous RNA to Regulate Vimentin Expression by Sponging miR-30a-5p in Hepatocellular Carcinoma

Background/Aims: Hepatocellular carcinoma (HCC) has a high morbidity as well as mortality and is believed to be one of the most prevalent cancers worldwide. The long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is involved in numerous cancers, including HCC. This study aimed to explore the role of MALAT1 in HCC progression. Methods: The expression levels of MALAT1 and Vimentin in HCC tissues and relative pair-matched adjacent normal liver tissues were analyzed by RT-PCR, and immunohistochemistry. Using bioinformatics analysis and dual-luciferase assay, we examined the correlation between MALAT1 and miR-30a-5p. Dual-luciferase assay and western blotting suggested that Vimentin was a target of miR-30a-5p. A wound healing assay and transwell assays were employed to determine the effect of MALAT1 and miR-30a-5p on cell migration and invasion in HCC. Results: Our data demonstrated that the levels of MALAT1 and Vimentin were upregulated in HCC tissues and that miR-30a-5p was a direct target of MALAT1. Silenced MALAT1 and overexpressed miR-30a-5p each inhibited cell migration and invasion. Additionally, dual-luciferase assay and western blotting demonstrated that MALAT1 could competitively sponge miR-30a-5p and thereby regulate Vimentin. Conclusion: Our data suggest that MALAT1 acts as an oncogenic lncRNA that promotes HCC migration and invasion. Therefore, the MALAT1-miR-30a-5p-Vimentin axis is a potential therapeutic target and molecular biomarker in HCC.

Long-Noncoding RNA Colorectal Neoplasia Differentially Expressed Gene as a Potential Target to Upregulate the Expression of IRX5 by miR-136-5P to Promote Oncogenic Properties in Hepatocellular Carcinoma

Background/Aims: The long-noncoding RNA colorectal neoplasia differentially expressed (CRNDE) gene was first found to be activated in colorectal neoplasia. Now, it also has been found to be upregulated in many other solid tumors. Whether CRNDE affects tumorigenesis remains unknown. Methods: We conducted bioinformatics, real-time polymerase chain reaction (PCR), Western blot analysis, cell proliferation assay, colony formation assay, wound healing assay, cell migration and invasion assays, RNA immunoprecipitation, and reporter vector construction and luciferase assays. Results: CRNDE was upregulated in hepatocellular carcinoma (HCC). The overexpression of CRNDE promoted HCC cellular proliferation, migration, and invasion in intro and in vivo, and acted as an oncogene in HCC progression. Furthermore, CRNDE impaired miR-136-5P expression in a RISC manner, and a reciprocal repression feedback loop was possible between CRNDE and miR-136-5P. We found that the neighboring mRNA of CRNDE was IRX5, and IRX5 increased the tumorigenicity of HCC cells. IRX5 was a potential downstream target gene of miR-136-5P. MiR-136 regulated IRX5 by interacting with its 3’UTR. In addition, miR-136-5P was involved in the CRNDE-regulated expression of IRX5. Conclusion: CRNDE acted as a tumor oncogene by exhibiting oncogenic properties of human HCC and revealed a novel CRNDE-miR-136-5P-IRX5 regulatory network in HCC. CRNDE may be considered to be a potential target for HCC therapies based on its ability to upregulate IRX5, and it deserves further investigation.

Long noncoding RNA miR503HG, a prognostic indicator, inhibits tumor metastasis by regulating the HNRNPA2B1/NF-κB pathway in hepatocellular carcinoma.

Long noncoding RNAs (lncRNAs) have been associated with hepatocellular carcinoma (HCC), but the underlying molecular mechanisms of their specific association with hepatocarcinogenesis have not been fully explored.Methods: miR503HG was identified by microarray and validated by real-time PCR. Survival analysis was evaluated using the Kaplan-Meier method and assessed using the log-rank test. In vitro and in vivo assays were preformed to explore the biological effects of miR503HG in HCC cells. The interaction of miR503HG with HNRNPA2B1 was identified by RNA pull-down and RNA immunoprecipitation. Expression of HNRNPA2B1 was examined by western blotting, immunofluorescence and immunohistochemical analyses, while HNRNPA2B1 ubiquitination was detected by immunoprecipitation.Results: We have identified 713 differentially expressed lncRNAs in 12 pairs of HCC tissues compared with corresponding noncancerous liver tissues. One of these lncRNAs, miR503HG, the host gene of miR503, is markedly decreased in HCC. Expression level of miR503HG is significantly associated with the time to recurrence and overall survival and is an independent risk factor for recurrence and survival. Enhanced expression of miR503HG could noticeably inhibit HCC invasion and metastasis in vitro and in vivo. Further investigation suggested that miR503HG could specifically interact with the heterogeneous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1). miR503HG promoted HNRNPA2B1 degradation via the ubiquitin-proteasome pathway, which reduced the stability of p52 and p65 mRNA, and simultaneously suppressed the NF-κB signaling pathway in HCC cells. In addition, miR503HG can function synergistically with miR503 to inhibit HCC migration.Conclusion: Our findings support a role for miR503HG in tumor recurrence risk and survival prediction in HCC patients. We demonstrate a novel mechanism by which miR503HG inhibits the NF-κB signaling pathway and exerts its metastatic tumor suppression function through modulating the ubiquitination status of HNRNPA2B1.

Hypoxia-induced up-regulation of VASP promotes invasiveness and metastasis of hepatocellular carcinoma.

Rational: Patients with hepatocellular carcinoma (HCC) have a poor prognosis mostly due to intrahepatic as well as distal metastasis. Vasodilator-stimulated phosphoprotein (VASP), a regulator of actin cytoskeleton and cell migration, is overexpressed in HCC and correlated with its malignant features and poor prognosis. Very little is known about its function in HCC.Methods: qRT-PCR, Western blot and IHC were used to detect the VASP expression in tissues and cells. Transwell and wound healing assays were used to measure the migration and invasion of HCC cells. Immunoblotting and immunofluorescence were used for detection of epithelial-to-mesenchymal transition (EMT) progression in HCC cells. A lung metastasis mouse model was used to evaluate metastasis of HCC in vivo. The putative targets of miR-204 were disclosed by public databases and a dual-luciferase reporter assay. IP was used to show the interaction between VASP and CRKL. ChIP was used to analyze the binding of HIF-1α to VASP promoter region.Results: Our data involving both gain- and loss-of-function studies revealed that VASP activated AKT and ERK signaling and promoted HCC migration and invasion in vitro and in vivo by altering the EMT phenotype and expression of MMPs. We investigated the positive correlation between VASP and an adapter protein, CRKL. VASP dynamically co-localized at the SH3N domain of CRKL and mediated its function. Mechanistically, VASP overexpression at the transcriptional level was mediated by HIF-1α through direct binding to two hypoxia response elements (HRE) in the VASP promoter region. Furthermore, we identified hypoxia-induced down-regulation of miR-204, which functioned as the regulator of VASP overexpression at the post-transcriptional level. Also, hypoxia-activated p-Smad3 dependent TGF-β signaling indirectly promoted VASP expression.Conclusion: A variety of hypoxia-induced molecular mechanisms contributed to the upregulation of VASP at transcriptional and post-transcriptional levels. These mechanisms involved CRKL, HIF-1α, miR-204, and TGF-β activating the AKT and ERK signaling to promote EMT and expression of MMPs. Taken together, our results defined VASP as an oncogene of HCC pathogenesis and metastasis with the potential to serve as a prognostic biomarker.

STAT3 aggravates TGF-β1-induced hepatic epithelial-to-mesenchymal transition and migration

Signal transducer and activator of transcription 3 (STAT3) has been shown to affect epithelial-to-mesenchymal transition (EMT) in cancers. We investigated the underlying molecular mechanisms of STAT3 crosstalk with Snail-Smad3/transforming growth factor (TGF)-β1 signaling pathways during the EMT in hepatocellular carcinoma (HCC). STAT3 and TGF-β1 expressions are examined in liver tissues of HCC patients and rats. The effect of IL-6/ STAT3 crosstalk with Snail-Smad3/TGF-β1 on EMT, carcinogenesis, migration and invasion are tested in vitro and in vivo. Phosphorylation of STAT3 and TGF-β1 proteins are universally high and positively co-expressed in HCC tissues from human and rats. Hepatic lower p-STAT3 proteins are related to earlier tumor stages in HCC patients. AG490 (a JAK2-specific inhibitor) treatment could reduce tumor numbers and sizes depending on suppression of STAT3 signaling in HCC rats. TGF-β1 could induce EMT along with an E-cadherin decrease, while vimentin, Snail, p-Smad2/3, and p-STAT3/STAT3 increase in HepG2. SIS3 (a specific inhibitor of Smad3) could markedly inhibit Snail, Vim and p-STAT3 along with blocking phosphorylation of Smad3, but E-cadherin could be activated in HepG2. IL-6 activates STAT3 signaling and then has cascading consequences for activating Snail-Smad3/TGF-β1 and vimentin as well as migration and invasion in liver cancer cells. In contrast, AG490 has an effect that inhibits phosphorylation of STAT3, lowers Snail-p-Smad3 protein levels, decreases TGF-β1-related PAI-1 promoter activation and then reduces migration or invasion of liver cancer cells. STAT3 functions as a positive regulator to activate TGF-β1-induced EMT and metastasis of HCC. STAT3 and the Snail-Smad3/TGF-β1 signaling pathways synergistically augment EMT and migration in HCC.

FOXA1 inhibits hepatocellular carcinoma\xa0progression by suppressing PIK3R1 expression in male patients

BackgroundForkhead box A1 (FOXA1) expression is associated with various types of tumors; however, the function and underlying mechanism of FOXA1 in the development of hepatocellular carcinoma (HCC) remains obscure.MethodsHere, we investigated the role of FOXA1 in the development of HCC by applying gene function gain and loss analysis to HepG2 and Hep3B cell lines, and comparing outcomes with those of clinical HCC samples.ResultsPhosphoinositide-3-kinase regulatory subunit 1 (PIK3R1), which encodes protein PI3Kp85 (p85), was identified as a FOXA1 target gene. Analyses of the mechanism and function revealed that FOXA1 suppresses hepatocellular carcinoma cell viability and motility by inhibiting PI3K/Akt signaling through direct inhibition of PIK3R1 transcription. Moreover, in clinical samples from male HCC patients, FOXA1 expression was much lower, whereas PI3Kp85 levels were much higher in tumor than in non-tumor tissues. Elevated PI3Kp85 is an unfavorable factor in HCC.ConclusionsAs a tumor suppressor, FOXA1 targets PIK3R1 directly to inhibit PI3K/Akt signaling pathway, thus exerting a negative regulatory effect on proliferation, migration, and invasion of HCC in male patients.