Role In Hepatocellular Carcinoma Metastasis Research Articles

Gene Expression Reprogramming by Citrate Supplementation Reduces HepG2 Cell Migration and Invasion.

Citrate, which is obtained from oxaloacetate and acetyl-CoA by citrate synthase in mitochondria, plays a key role in both normal and cancer cell metabolism. In this work, we investigated the effect of 10 mM extracellular citrate supplementation on HepG2 cells. Gene expression reprogramming was evaluated by whole transcriptome analysis using gene set enrichment analysis (GSEA). The transcriptomic data were validated through analyzing changes in the mRNA levels of selected genes by qRT-PCR. Citrate-treated cells exhibited the statistically significant dysregulation of 3551 genes; 851 genes were upregulated and 822 genes were downregulated. GSEA identified 40 pathways affected by differentially expressed mRNAs. The most affected biological processes were related to lipid and RNA metabolism. Several genes of the cytochrome P450 family were upregulated in treated cells compared to controls, including the CYP3A5 gene, a tumor suppressor in hepatocellular carcinoma (HCC) that plays an important protective role in HCC metastasis. The citrate-induced dysregulation of cytochromes could both improve the effectiveness of chemotherapeutics used in combination and reduce the aggressiveness of tumors by diminishing cell migration and invasion.

GDF15: Immunomodulatory Role in Hepatocellular Carcinoma Pathogenesis and Therapeutic Implications.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths globally and the sixth most common cancer worldwide. Evidence shows that growth differentiation factor 15 (GDF15) contributes to hepatocarcinogenesis through various mechanisms. This paper reviews the latest insights into the role of GDF15 in the development of HCC, its role in the immune microenvironment of HCC, and its molecular mechanisms in metabolic dysfunction associated steatohepatitis (MASH) and metabolic associated fatty liver disease (MAFLD)-related HCC. Additionally, as a serum biomarker for HCC, diagnostic and prognostic value of GDF15 for HCC is summarized. The article elaborates on the immunological effects of GDF15, elucidating its effects on hepatic stellate cells (HSCs), liver fibrosis, as well as its role in HCC metastasis and tumor angiogenesis, and its interactions with anticancer drugs. Based on the impact of GDF15 on the immune response in HCC, future research should identify its signaling pathways, affected immune cells, and tumor microenvironment interactions. Clinical studies correlating GDF15 levels with patient outcomes can aid personalized treatment. Additionally, exploring GDF15-targeted therapies with immunotherapies could improve anti-tumor responses and patient outcomes.

Unveiling the Impact of Hemodynamics on Endothelial Inflammation-Mediated Hepatocellular Carcinoma Metastasis Using a Biomimetic Vascular Flow Model.

Hepatocellular carcinoma (HCC) hematogenous dissemination is a leading cause of HCC-related deaths. The inflammatory facilitates this process by promoting the adhesion and invasion of tumor cells in the circulatory system. But the contribution of hemodynamics to this process remains poorly understood due to the lack of a suitable vascular flow model for investigation. This study develops a vascular flow model to examine the impact of hemodynamics on endothelial inflammation-mediated HCC metastasis. This work finds the increasing shear stress will reduce the recruitment of HCC cells by disturbing adhesion forces between endothelium and HCC cells. However, this reduction will be restored by the inflammation. When applying high FSS (4-6dyn cm-2) to the inflammatory endothelium, there will be a 4.8-fold increase in HCC cell adhesions compared to normal condition. Nevertheless, the increase fold of cell adhesions is inapparent, around 1.5-fold, with low and medium FSS. This effect can be attributed to the FSS-induced upregulation of ICAM-1 and VCAM-1 of the inflammatory endothelium, which serve to strengthen cell binding forces. These findings indicate that hemodynamics plays a key role in HCC metastasis during endothelial inflammation by regulating the expression of adhesion-related factors.

Exosomal miR-374c-5p derived from mesenchymal stem cells suppresses epithelial-mesenchymal transition of hepatocellular carcinoma via the LIMK1-Wnt/β-catenin axis.

Metastasis is a leading cause to treatment failure in hepatocellular carcinoma (HCC) patients. Exosomes act as pivotal mediators in communication between different cells and exert effects on recipient cells by delivering bioactive cargoes, such as microRNAs (miRNAs). MiRNAs function in multiple steps of HCC development, including metastasis. MiR-374c-5p was previously identified as a tumor suppressor in some malignancies, while the current knowledge of its role in HCC metastasis is still limited. Herein, miR-374c-5p was found to be downregulated in HCC cell lines and clinical samples, and positively related with favorable prognosis in HCC patients. MiR-374c-5p transferred by exosomes derived from bone marrow mesenchymal stem cell (BMSC) suppressed migration, invasion and proliferation of HCC cells. LIMK1 was verified as downstream target gene of miR-374c-5p. Knockdown of LIMK1 reduced invasion, migration and proliferation of HCC cells, whereas overexpression functioned oppositely. The miR-374c-5p/LIMK1 axis suppressed epithelial-mesenchymal transition (EMT) by inactivating Wnt/β-catenin pathway. In addition, miR-374c-5p was downregulated and LIMK1 upregulated in TGF-β1 induced EMT. This EMT model could be reversed by LIMK1 silencing or miR-374c-5p overexpression. These results suggest that exo-miR-374c-5p suppresses EMT via targeting LIMK1-Wnt/β-catenin axis and the axis is involved in TGF-β1 induced metastasis of HCC, thereby identifying miR-374c-5p as a potential target for HCC treatment.

LncRNA-EWSAT1 promotes hepatocellular carcinoma metastasis via activation of the Src-YAP signaling axis.

Regardless of the improvements in diagnostic and therapeutic methods, the clinical outcomes of hepatocellular carcinoma (HCC) patients remain poor. Although accumulating evidence indicates that lncRNAs (long noncoding RNAs) are essential within the control of tumorigenesis and the metastasis of cancer, the underlying mechanisms remain largely unknown. This work explored the pattern of expression and functional significance of a newly found lncRNA, Ewing sarcoma-associated transcript 1 (EWSAT1), in HCC metastasis. The results indicated that EWSAT1 was upregulated significantly in HCC relative to that in normal tissues and was correlated with an aggressive phenotype and low patient survival. Functional experiments demonstrated that EWSAT1 could promote proliferation and HCC cell metastasis both in vitro and in vivo. Mechanistically, EWSAT1 binds directly to Yes-associated protein (YAP), promotes Sarcoma gene (Src)-induced phosphorylation of YAP, facilitates nuclear translocation of YAP, and consequently, activates the transcription of Hippo-YAP signaling target genes involved in cancer evolution. This study found that EWSAT1 plays a crucial role in HCC metastasis and that it has the potential to be a prognosis biomarker and a target for therapeutics.

Cytochrome B5 type A alleviates HCC metastasis via regulating STOML2 related autophagy and promoting sensitivity to ruxolitinib

The incidence of hepatocellular carcinoma (HCC) is increasing in the world. However, its role and underlying molecular mechanism in HCC progression remain unclear. We found that CYB5A plays a key role in HCC metastasis by inhibiting the JAK1/STAT3 pathway through binding to STOML2. CYB5A combined with STOML2 can predict the outcome of patients. To demonstrate the effect of CYB5A on JAK1 inhibitor function, we applied Ruxolitinib in metastatic tumors with high CYB5A expression and found that it slowed disease progression and prolonged survival in mice. To the best of our knowledge, this study is the first to report the Ruxolitinib effect on the metastatic ability of HCC cells in vivo and in vitro.

27-Hydroxycholesterol promotes metastasis by SULT2A1-dependent alteration in hepatocellular carcinoma.

Oxysterol metabolism plays an important role in the initiation and development of various tumors. However, little is known that the metabolic alternation can promote the metastasis of hepatocellular carcinoma (HCC). In this study, we identify the sulfotransferase family 2A member 1 (SULT2A1) to 27‐hydroxycholesterol (27‐OHC) metabolic axis as playing a critical role in HCC metastasis. The level of 27‐OHC closely corresponded with HCC metastasis instead of proliferation in vitro and in vivo. Also, the expression of SULT2A1 is extremely downregulated in human HCC tissues and is correlated with poor prognosis and tumor metastasis. Gain‐ and loss‐of‐function studies reveal that SULT2A1 suppresses the metastasis of HCC by regulating the level of 27‐OHC. Further mechanistic studies indicated that SULT2A1‐dependent alternation of 27‐OHC activates the nuclear factor‐κB signaling pathway and promotes HCC metastasis by enhancing Twist1 expression and epithelial–mesenchymal transition. In conclusion, our findings indicate the relationship between the metabolism of 27‐OHC and the metastasis of HCC. Moreover, SULT2A1 could act as a potential prognostic biomarker and a therapeutic target for preventing HCC metastasis.

KIAA1217 Promotes Epithelial-Mesenchymal Transition and Hepatocellular Carcinoma Metastasis by Interacting with and Activating STAT3.

The survival and prognosis of hepatocellular carcinoma (HCC) are poor, mainly due to metastasis. Therefore, insights into the molecular mechanisms underlying HCC invasion and metastasis are urgently needed to develop a more effective antimetastatic therapy. Here, we report that KIAA1217, a functionally unknown macromolecular protein, plays a crucial role in HCC metastasis. KIAA1217 expression was frequently upregulated in HCC cell lines and tissues, and high KIAA1217 expression was closely associated with shorter survival of patients with HCC. Overexpression and knockdown experiments revealed that KIAA1217 significantly promoted cell migration and invasion by inducing epithelial-mesenchymal transition (EMT) in vitro. Consistently, HCC cells overexpressing KIAA1217 exhibited markedly enhanced lung metastasis in vivo. Mechanistically, KIAA1217 enhanced EMT and accordingly promoted HCC metastasis by interacting with and activating JAK1/2 and STAT3. Interestingly, KIAA1217-activated p-STAT3 was retained in the cytoplasm instead of translocating into the nucleus, where p-STAT3 subsequently activated the Notch and Wnt/β-catenin pathways to facilitate EMT induction and HCC metastasis. Collectively, KIAA1217 may function as an adaptor protein or scaffold protein in the cytoplasm and coordinate multiple pathways to promote EMT-induced HCC metastasis, indicating its potential as a therapeutic target for curbing HCC metastasis.

Ribosomal Protein L23 Drives the Metastasis of Hepatocellular Carcinoma via Upregulating MMP9.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths globally. Tumor metastasis is one of the major causes of high mortality of HCC. Identifying underlying key factors contributing to invasion and metastasis is critical to understand the molecular mechanisms of HCC metastasis. Here, we identified RNA binding protein L23 (RPL23) as a tumor metastasis driver in HCC. RPL23 was significantly upregulated in HCC tissues compared to adjacent normal tissues, and closely related to poor clinical outcomes in HCC patients. RPL23 depletion inhibited HCC cell proliferation, migration and invasion, and distant metastasis. Mechanistically, RPL23 directly associated with 3’UTR of MMP9, therefore positively regulated MMP9 expression. In conclusion, we identified that RPL23 might play an important role in HCC metastasis in an MMP9-dependent manner and be a potential therapeutic target for HCC tumorigenesis and metastasis.

B-Cell Receptor-Associated Protein 31 Promotes Metastasis via AKT/β-Catenin/Snail Pathway in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the most lethal cancer worldwide, characterized with high heterogeneity and inclination to metastasize. Emerging evidence suggests that BAP31 gets involved in cancer progression with different kinds. It still remains unknown whether and how BAP31 plays a role in HCC metastasis. Epithelial–mesenchymal transition (EMT) has been a common feature in tumor micro-environment, whose inducer TGF-β increased BAP31 expression in this research. Elevated expression of BAP31 was positively correlated with tumor size, vascular invasion and poor prognosis in human HCC. Ectopic expression of BAP31 promoted cell migration and invasion while BAP31 knockdown markedly attenuated metastatic potential in HCC cells and mice orthotopic xenografts. BAP31 induced EMT process, and enhanced the expression level of EMT-related factor Snail and decreased contents and membrane distribution of E-cadherin. BAP31 also activated AKT/β-catenin pathway, which mediated its promotional effects on HCC metastasis. AKT inhibitor further counteracted the activated AKT/β-catenin/Snail upon BAP31 over-expression. Moreover, silencing Snail in BAP31-overexpressed cells impaired enhanced migratory and invasive abilities of HCC cells. In HCC tissues, BAP31 expression was positively associated with Snail. In conclusion, BAP31 promotes HCC metastasis by activating AKT/β-catenin/Snail pathway. Thus, our study implicates BAP31 as potential prognostic biomarker, and provides valuable information for HCC prognosis and treatment.

MicroRNA-145-5p Inhibits Migration, Invasion, and Metastasis in Hepatocellular Carcinoma by Inhibiting ARF6.

PurposeHepatocellular carcinoma (HCC) has the fourth highest rate of mortality among the different types of cancer worldwide. This study aimed to investigate the functions of microRNA-145-5p and AFR6 on migration, invasion and metastasis in HCC.MethodsA total of 150 pairs of tumor and their matched adjacent nontumor liver tissues were collected from HCC patients. Expressions of microRNA-145-5p and AFR6 were measured by real-time PCR in HCC tissues and in HCC cell lines. The correlations between microRNA-145-5p and HCC prognosis were investigated. The proliferation, migration, invasion, cell cycle progression, and apoptosis of HCCLM3 cells were evaluated with CCK8, wound healing, transwell, and flow cytometric experiments.ResultsThe expression of miR-145-5p was confirmed to be downregulated not only in HCC tissues but also in several HCC cell lines compared with normal controls. A low expression level of miR-145-5p was notably associated with poor prognosis in patients with HCC and certain characteristics of metastatic tumors. In vitro, miR-145-5p negatively regulated cell proliferation, migration, and invasion and induced apoptosis in HCCLM3 cells. Subsequent experiments further verified that ARF6 is a novel target of miR-145-5p and is significantly overexpressed in HCC tissues. Overexpression of ARF6 circumvented the effects of miR-145-5p in HCCLM3 cells.ConclusionmiR-145-5p may play a pivotal role in HCC metastasis via regulating ARF6, and these findings may both provide further insights into the key factors of HCC metastasis and prove to be useful in the development of novel treatment options for HCC.

Identification of a Novel Metastasis-Related miRNAs-Based Signature for Predicting the Prognosis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common internal malignancies worldwide and is associated with a poor prognosis. Abnormal expression of miRNAs is believed to play a role in the recurrent metastasis of HCC. However, limited studies on the role of miRNAs in HCC metastasis have been carried out. Therefore, this study is aimed at exploring the potential value of metastasis-related miRNAs (MRMs) in HCC. We retrieved MRMs were from the Human Cancer Metastasis Database. Differential miRNAs were identified for tumor samples of HCC patients and normal samples based on the TCGA database. Further, univariate and multivariate Cox regression analyses were used to screen MRMs known to be independent prognostic factors in HCC. These MRMs were then used to build a prognostic signature. All patients were classified into high-risk and low-risk groups based on the median of the signature scores. Moreover, GO and KEGG pathway enrichment analyses were performed to predict the function of these MRMs. Finally, a nomogram was constructed to predict the OS of patients at 1, 2, and 3 years. In our study, a total of seven prognostic MRMs (miR-140-3p, miR-9-5p, miR-942-5p, miR-324-3p, miR-29c-5p, miR-551a, and miR-149-5p) were identified and used for constructing the prognostic signature based on the training cohort. Patients in the low-risk HCC group showed better overall survival (OS) than those in the high-risk group. The results were validated using the validation cohort. In summary, the findings of this study provide evidence that MRMs-based prognostic signature is an independent biomarker in the prognosis of HCC patients.

Chromatin remodeling factor ARID2 suppresses hepatocellular carcinoma metastasis via DNMT1-Snail axis

Recurrence and metastasis remain the major obstacles to successful treatment of hepatocellular carcinoma (HCC). Chromatin remodeling factor ARID2 is commonly mutated in HCC, indicating its important role in cancer development. However, its role in HCC metastasis is largely elusive. In this study, we find that ARID2 expression is significantly decreased in metastatic HCC tissues, showing negative correlation with pathological grade, organ metastasis and positive association with survival of HCC patients. ARID2 inhibits migration and invasion of HCC cells in vitro and metastasis in vivo. Moreover, ARID2 knockout promotes pulmonary metastasis in different HCC mouse models. Mechanistic study reveals that ARID2 represses epithelial-mesenchymal transition (EMT) of HCC cells by recruiting DNMT1 to Snail promoter, which increases promoter methylation and inhibits Snail transcription. In addition, we discover that ARID2 mutants with disrupted C2H2 domain lose the metastasis suppressor function, exhibiting a positive association with HCC metastasis and poor prognosis. In conclusion, our study reveals the metastasis suppressor role as well as the underlying mechanism of ARID2 in HCC and provides a potential therapeutic target for ARID2-deficient HCC.

Fibroblast Growth Factor 19-Mediated Up-regulation of SYR-Related High-Mobility Group Box 18 Promotes Hepatocellular Carcinoma Metastasis by Transactivating Fibroblast Growth Factor Receptor 4 and Fms-Related Tyrosine Kinase 4.

The poor prognosis of patients with hepatocellular carcinoma (HCC) is mainly attributed to its high rate of metastasis and recurrence. However, the molecular mechanisms underlying HCC metastasis need to be elucidated. The SRY-related high-mobility group box (SOX) family proteins, which are a group of highly conserved transcription factors, play important roles in cancer initiation and progression. Here, we report on a role of SOX18, a member of the SOX family, in promoting HCC invasion and metastasis. The elevated expression of SOX18 was positively correlated with poor tumor differentiation, higher tumor-node-metastasis (TNM) stage, and poor prognosis. Overexpression of SOX18 promoted HCC metastasis by up-regulating metastasis-related genes, including fibroblast growth factor receptor 4 (FGFR4) and fms-related tyrosine kinase 4 (FLT4). Knockdown of both FGFR4 and FLT4 significantly decreased SOX18-mediated HCC invasion and metastasis, whereas the stable overexpression of FGFR4 and FLT4 reversed the decrease in cell invasion and metastasis that was induced by inhibition of SOX18. Fibroblast growth factor 19 (FGF19), which is the ligand of FGFR4, up-regulated SOX18 expression. A mechanistic investigation indicated that the up-regulation of SOX18 that was mediated by the FGF19-FGFR4 pathway relied on the phosphorylated (p)-fibroblast growth factor receptor substrate 2/p-glycogen synthase kinase 3 beta/β-catenin pathway. SOX18 knockdown significantly reduced FGF19-enhanced HCC invasion and metastasis. Furthermore, BLU9931, a specific FGFR4 inhibitor, significantly reduced SOX18-mediated HCC invasion and metastasis. In human HCC tissues, SOX18 expression was positively correlated with FGF19, FGFR4, and FLT4 expression, and patients that coexpressed FGF19/SOX18, SOX18/FGFR4, or SOX18/FLT4 had the worst prognosis. We defined a FGF19-SOX18-FGFR4 positive feedback loop that played a pivotal role in HCC metastasis, and targeting this pathway may be a promising therapeutic option for the clinical management of HCC.

SETD3 is regulated by a couple of microRNAs and plays opposing roles in proliferation and metastasis of hepatocellular carcinoma.

A previous study reported that histone methyltransferase SETD3 is up-regulated in tumor tissues of hepatocellular carcinoma (HCC) and is associated with the growth of HCC. However, the clinical significance and the effect of SETD3 on HCC metastasis remain unclear. In the present study, both the protein and mRNA expression levels of SETD3 were measured in a larger cohort of HCC patients. The results showed that the protein level of SETD3 in HCC tissues was significantly higher than that in non-tumorous tissues, which was inconsistent with the mRNA expression level of SETD3. The high protein level of SETD3 in HCC tissues was significantly associated with male gender, poor pathological differentiation, liver cirrhosis and unfavorable prognosis of HCC patients. Subsequently, we demonstrated that SETD3 could be regulated at post-transcriptional step by a couple of miRNAs (miR-16, miR-195 and miR-497). Additionally, in vitro and in vivo experiments revealed that SETD3 played opposing roles in proliferation and metastasis of HCC: promoting proliferation but inhibiting metastasis. Mechanistic experiments revealed that doublecortin-like kinase 1 (DCLK1) was a downstream target of SETD3. SETD3 could increase the DNA methylation level of DCLK1 promoter to inhibit the transcription of DCLK1. Further study revealed that DCLK1/PI3K/matrix metalloproteinase (MMP) 2 (MMP-2) was an important pathway that mediated the effect of SETD3 on HCC metastasis. In conclusion, the present study revealed that SETD3 is associated with tumorigenesis and is a promising biomarker for predicting the prognosis of HCC patients after surgical resection. In addition, SETD3 plays inhibitory role in HCC metastasis partly through DCLK1/PI3K/MMP-2 pathway.

Overexpression of CSN6 promotes the epithelial-mesenchymal transition and predicts poor prognosis in hepatocellular carcinoma

CSN6, as a critical subunit of the constitutive photomorphogenesis 9 (COP9) signalosome (CSN), has been previously reported to be increased in various cancers; however, its effect in hepatocellular carcinoma (HCC) remains unknown, which is the aim of present study, in terms of its explore the expression and role of CSN6 in HCC. QRT-PCR, Western blot and immunohistochemistry (IHC) were used to examine the expression of CSN6. Kaplan-Meier survival analysis and univariate and multivariate Cox analyses were used to investigate the clinical and prognostic significance of CSN6 expression in HCC patients. Furthermore, the biological function of CSN6 on HCC cell proliferation and migration was investigated through CCK-8, transwell migration and invasion assays. Besides, the associations between CSN6 and epithelial-mesenchymal transition (EMT) were determined. CSN6 was increased in HCC tissues, and its overexpression was found to be associated with a poor prognoses for HCC patients. Overexpression of CSN6 promoted processes of HCC cell proliferation, migration, and invasion, while these processes were inhibited when CSN6 was silenced. Additionally, CSN6 was found to promote EMT by inhibiting E-cadherin, which were significantly mitigated via upregulation of Snail as a result of MEK/ERK pathway activation. CSN6 up-regulation may play a contributory role in HCC metastasis and poor prognosis via activation of EMT, and may serve as an independent predictor for HCC prognosis.

Core fucosylated glycan-dependent inhibitory effect of QSOX1-S on invasion and metastasis of hepatocellular carcinoma

The goal of the present study was to identify glycoproteins associated with the postoperative relapse of hepatocellular carcinoma (HCC) and to investigate their potential role in HCC metastasis. A method for quantitating N-glycoproteome was used to screen for, and identify, recurrence-related N-linked glycoproteins from 100 serum samples taken from patients with early-stage HCC. The prognostic significance of candidate glycoproteins was then validated in 193 HCC tissues using immunohistochemical staining. Serum core fucosylated quiescin sulfhydryl oxidase 1 (cf-QSOX1) was identified as a leading prognostic glycoprotein that significantly correlated with HCC recurrence. Patients with high serum cf-QSOX1 levels had a significantly longer time to recurrence (TTR) as compared with those with low serum cf-QSOX1. As was seen with serum cf-QSOX1, QSOX1 in HCC tissues was further shown to be significantly associated with good patient outcome. Gain-functional and loss-functional analyses of QSOX1-S were performed in vitro and in vivo. QSOX1-S overexpression significantly increased in vitro apoptosis, but decreased the invasive capacity of HCC cells, and reduced lung metastasis in nude mice models bearing human HCC. Furthermore, overexpression of a mutant version of QSOX1-S, which had eliminated the core-fucosylated glycan at Asn-130, showed no demonstrable effect on invasion or metastasis of HCC cells. Our study suggests that serum cf-QSOX1-S and tumor QSOX1 levels are helpful for predicting recurrence in HCC patients, and its core-fucosylated glycan at Asn-130 is critical for the inhibitory effects of QSOX1-S on invasion and metastasis of HCC

Annexin A2 interacting with ELMO1 regulates HCC chemotaxis and metastasis

AimsSDF-1α induced chemotaxis plays an important role in hepatocellular carcinoma metastasis. CXCR4 stimulated by SDF-1α/CXCL12 triggers heterotrimeric G proteins activation, which regulate migration and chemotaxis of hepatocellular carcinoma cells. The pathways linking the chemokine GPCR/Gi signaling to actin polymerization for migration of cancer cells are not known. Materials and methodsThrough would healing assay, chemotaxis assay, F-actin polymerization assay, confocal assay, immunohistochemical assay, protein identification and coimmunoprecipitation assay, we detected the role and mechanisms of Annexin A2 in hepatocellular carcinoma. Key findingsIn the present study, we firstly investigated the role of Annexin A2 in HepG2 cell chemotaxis and metastasis. Immunohistochemical analysis showed that Annexin A2 was highly expressed in hepatocellular carcinoma tissues. Its expression was closely associated with lymph node and distant metastasis. Knockdown Annexin A2 impaired cancer cell chemotaxis. Co-immunoprecipitation results showed an interaction between Annexin A2 and ELMO1. CXCL12 triggers an ELMO1-dependent membrane translocation of Annexin A2. SignificanceTaken together, our results indicated an important role of Annexin A2 in hepatocellular carcinoma tissues metastasis and revealed a novel molecular mechanism of its activation.

PARP12 (ARTD12) suppresses hepatocellular carcinoma metastasis through interacting with FHL2 and regulating its stability

PARP12 is a mono-ADP-ribosyltransferase, but its function remains largely unknown. Here, we identified four-and-a-half LIM-only protein 2 (FHL2) as a functional partner of PARP12 through protein affinity purification. Although PARP12 did not mono-ADP-ribosylate FHL2 in vitro and in vivo, PARP12 deficiency decreased the protein level of FHL2 by promoting its ubiquitination and increased the expression level of transforming growth factor beta1 (TGF-β1), which is independent of PARP12 enzymatic activity. We also provided evidence that PARP12 deficiency increased the migration and invasion of hepatocellular carcinoma (HCC) cells and promoted HCC metastasis in vivo by regulating the epithelial–mesenchymal transition process. These results indicated that PARP12 is a tumor suppressor that plays an important role in HCC metastasis through the regulation of FHL2 stability and TGF-β1 expression.

Osteopontin alters DNA methylation through up-regulating DNMT1 and sensitizes CD133+/CD44+ cancer stem cells to 5 azacytidine in hepatocellular carcinoma

BackgroundIn hepatocellular carcinoma (HCC), CD133+/CD44+ cells are one subgroup with high stemness and responsible for metastatic relapse and resistance to treatment. Our previous studies have demonstrated that osteopontin (OPN) plays critical roles in HCC metastasis. We further investigated the molecular mechanism underlying the role of OPN in regulating the stemness of HCC epigenetically and explored possible targeting strategy.MethodsCD133+/CD44+ subgroup sorting from HCC cell lines and HCC tissues was used to investigate the effects of OPN knockdown on stemness. iTRAQ and MedIP-sequencing were applied to detect the protein profile and epigenetic modification of CD133+/CD44+ subgroup with or without OPN knockdown. The antitumor effects of 5 Azacytidine were examined in cultured HCC cells and patient derived xenograft (PDX) models.ResultsOPN was accumulated in CD133+/CD44+ subgroup of HCC cells. Knocking down OPN significantly inhibited the sphere formation and stemness-related genes expression, and delayed tumor initiation of CD133+/CD44+ subgroup of HCC cells. Employing MedIP-sequencing, dot blot and iTRAQ analyses of CD133+/CD44+ SCR and CD133+/CD44+ shOPN cells, we found that OPN knockdown leaded to reduction in DNA methylation with particular enrichment in CGI. Meanwhile, DNA (cytosine-5)-methyltransferase 1 (DNMT1), the main methylation maintainer, was downregulated via proteomics analysis, which mediated OPN altering DNA methylation. Furthermore, DNMT1 upregulation could partially rescue the properties of CD133+/CD44+ shOPN cells. Both in vitro and in vivo assays showed that CD133+/CD44+ cells with high OPN levels were more sensitive to DNA methylation inhibitor, 5 Azacytidine (5 Aza). The above findings were validated in HCC primary cells, a more clinically relevant model.ConclusionsOPN induces methylome reprogramming to enhance the stemness of CD133+/CD44+ subgroup and provides the therapeutic benefits to DNMT1 targeting treatment in HCC.