Promotes Hepatocellular Carcinoma Metastasis Research Articles

The Crosstalk Between Cancer Cells and Neutrophils Enhances Hepatocellular Carcinoma Metastasis via Neutrophil Extracellular Traps-Associated Cathepsin G Component: A Potential Therapeutic Target.

BackgroundEmerging evidences have highlighted the roles of neutrophils, as the major host microenvironment component, in the development of hepatocellular carcinoma (HCC). Neutrophils extracellular traps (NETs) produced in the infection can strengthen the behavior of cancer metastasis. Here, we investigated the roles of NETs in HCC metastasis and further explore the underlying mechanism of how NETs interact with cancer.MethodsThe neutrophils were isolated from whole blood of HCC patients and used to evaluate the formation of NETs. NET markers were detected in tissue samples, plasma and cell climbing slice. Mouse models were used to evaluate the roles of NETs in HCC metastasis in vivo, and the corresponding mechanisms were explored using in vivo and in vitro assays.ResultsAn increase in the release of NETs in patients with HCC, particularly those with portal vein tumor thrombosis (PVTT). The presence of NETs in HCC tumor tissues closely correlated with a poor prognosis. Functionally, the invasion ability of HCC cells was enhanced by co-culture with HCC neutrophils, through NETs formation, while the neutrophils from a healthy donor (HD) exhibited the inhibition of the invasion ability. Furthermore, we observed an enhanced ability of forming NETs in neutrophils from HCC patients in vitro, especially patients with PVTT or extra-hepatic metastasis. An in-vivo animal study demonstrated that neutrophils of HCC facilitated the metastatic behavior towards the lung. The further mechanistic investigation unveiled that HCC cells-derived cytokine IL-8 triggered NETs formation in an NADPH oxidase-dependent manner, and NETs-associated cathepsin G (cG) promoted HCC metastasis in vitro as well as vivo. Clinically, the expression of the cG protein in tumor tissues displayed a close correlation with the disease prognosis of HCC patients.ConclusionOur findings implicated that the induction of NETs by HCC cells is a critical metastasis-supporting cancer–host interaction and that NETs may serve as an immune-based potential therapeutic target against HCC progression.

Can primary hepatocellular carcinoma histomorphology predict extrahepatic metastasis?

Studies comparing the histomorphologic features and phenotypic heterogeneity between primary and its corresponding metastatic hepatocellular carcinoma (HCC) are lacking. The aim of this study was to assess and compare the histomorphologic features and heterogeneity between primary and metastatic HCC. A total of 39 cases with both primary and metastatic tissues were identified from pathology archives (2000-2019). The common sites of metastasis included lung (28.21%), abdominal cavity (25.64%), lymph nodes (20.51%), bone (17.95%), soft tissue (15.38%), and adrenal gland (10.26%). Both the primary and metastatic tumors showed heterogeneity in intratumoral histologic patterns (87.18% and 76.92%, respectively). The most common histologic pattern was solid in both primary (61.54%) and metastases (56.41%), followed by macrotrabecular in primary (17.95%) and metastases (10.26%). Among HCC-subtypes, macrotrabecular-massive HCC was the most common subtype in both primary and metastases (28.21% each). Primary tumors in noncirrhotic livers were more likely to have larger size and microvascular invasion than those in cirrhotic livers. The histomorphology (histologic pattern, subtype, and grade) between the primary and metastases was discordant in about 50% cases (48.72%, 48.72%, and 51.28%, respectively). Our findings exhibit significant intratumoral heterogeneity and histomorphologic discordance between primary and metastatic HCCs. The solid and macrotrabecular histologic patternsand the macrotrabecular-massive subtype were the most common histomorphologic features seen in primary tumors associated with metastasis. Further studies to identify and explore different pathways that promote HCC metastasis and to compare the differences between primary and metastatic tumors on a larger cohort are needed to better understand the pathogenesis of metastasis.

Heparanase induces necroptosis of microvascular endothelial cells to promote the metastasis of hepatocellular carcinoma

Heparanase (HPSE) is a kind of multifunctional extracellular hydrolase, and related to metastasis of hepatocellular carcinoma (HCC). Endothelial necroptosis promotes the metastasis of cancer cells. It is not clear whether HPSE could mediate necroptosis of microvascular endothelial cells (MVECs) to promote HCC metastasis. Here we found HPSE expression was up-regulated in HCC tissues and its over-expression was correlated with multiple tumor foci, microvascular invasion, and poor outcome of HCC patients. Non-contact co-culture experiments showed high-expressed HPSE in HCC cells mediated the necroptosis of human umbilical vein endothelial cells (HUVECs) and elevated the expression levels of syndecan-1 (SDC-1) and tumor necrosis factor-α (TNF-α) in vitro. As a result of necroptosis, trans-endothelial migration (TEM) of HCC cells was increased. Conversely, both HPSE and SDC-1 knockdowns reversed necroptosis and decreased TNF-α expression level, while HPSE over-expression increased SDC-1 and TNF-α expression and aggravated necroptosis. Animal experiments found that the nude mice, intraperitoneally injected with HPSE high expressing HCC cells, had obvious necroptosis of MVECs and high intrahepatic metastasis rate, which could be relieved by inhibitor of necroptosis. Morever, HPSE elevated the expression levels of p38 mitogen-activated protein kinase (p38 MAPK) rather than nuclear factor kappa B in vitro. Our data suggest that HPSE induces necroptosis of MVECs to promote the metastasis of HCC by activating HPSE/SDC-1/TNF-α axis and p38 MAPK pathway.

STOML2 potentiates metastasis of hepatocellular carcinoma by promoting PINK1-mediated mitophagy and regulates sensitivity to lenvatinib

BackgroundDysregulation of both mitochondrial biogenesis and mitophagy is critical to sustain oncogenic signaling pathways. However, the mechanism of mitophagy in promoting hepatocellular carcinoma (HCC) progression remains poorly understood. In this study, we investigated the clinical significance and biological involvement of mitochondrial inner membrane protein STOML2 in HCC.MethodsSTOML2 was identified by gene expression profiles of HCC tissues and was measured in tissue microarray and cell lines. Gain/loss-of-function experiment was applied to study the biological function of STOML2 in HCC. Flow cytometry, Western blotting, laser confocal microscopy, transmission electron microscopy, and co-immunoprecipitation were used to detect and analyze mitophagy. ChIP and luciferase reporter assay were conducted to evaluate the relationship between STOML2 and HIF-1α. The sensitivity to lenvatinib was assessed in HCC both in vitro and in vivo.ResultsIncreased expression of STOML2 was found in HCC compared with paired peritumoral tissues. It was more significant in HCC with metastasis and correlated with worse overall survival and higher probability of recurrence after hepatectomy. Upregulation of STOML2 accelerated HCC cells colony formation, migration and invasion. Mechanically, TCGA dataset-based analysis showed enrichment of autophagy-related pathways in STOML2 highly-expressed HCC. Next, STOML2 was demonstrated to interact and stabilize PINK1 under cellular stress, amplify PINK1-Parkin-mediated mitophagy and then promote HCC growth and metastasis. Most interestingly, HIF-1α was upregulated and transcriptionally increased STOML2 expression in HCC cells under the treatment of lenvatinib. Furthermore, higher sensitivity to lenvatinib was found in HCC cells when STOML2 was downregulated. Combination therapy with lenvatinib and mitophagy inhibitor hydroxychloroquine obtained best efficacy.ConclusionsOur findings suggested that STOML2 could amplify mitophagy through interacting and stabilizing PINK1, which promote HCC metastasis and modulate the response of HCC to lenvatinib. Combinations of pharmacologic inhibitors that concurrently block both angiogenesis and mitophagy may serve as an effective treatment for HCC.

CBX6 Promotes HCC Metastasis Via Transcription Factors Snail/Zeb1-Mediated EMT Mechanism.

PurposeHepatocellular carcinoma (HCC) is the most common malignant tumor worldwide with high morbidity and mortality rates. We aimed to examine the expression of chromobox 6 (CBX6) in HCC and analyze its correlation with clinicopathological features of HCC patients. Moreover, the role of CBX6 in the HCC cell proliferation, invasion and metastasis and the potential mechanism underlying HCC metastasis were also investigated.MethodsWe used quantitative polymerase chain reaction (qRT-PCR) and Western blot to evaluate the expression levels of CBX6 in HCC cell lines. Furthermore, the expression of CBX6 in HCC and the adjacent non-tumor tissues was assessed by immunohistochemistry (IHC). Cell proliferation was evaluated using MTT assay, cell migration and invasion were measured using wound healing and transwell assays. Finally, we detected the expression of target proteins in HCC cell lines transfected with CBX6 overexpression plasmid or CBX6 shRNA plasmid by Western blot.ResultsWe found that the expression of CBX6 was increased in 280 cases of HCC tissues compared that in adjacent non-tumor tissues. HCC patients with high CBX6 expression had a higher tendency to have high growth rate, strong invasion ability, high clinical stage and poor tumor differentiation. Functional study demonstrated that the upregulation of CBX6 promotes proliferation, migration and invasion of HCC cells while silencing CBX6 in HCC cells significantly inhibited cell proliferation, migration and invasion. Furthermore, CBX6 could accelerate the EMT process in HCC cells by upregulating the expression of snail and zeb1.ConclusionCBX6 played an important role in the process of tumorigenesis and progression in HCC and enhanced the invasion and metastasis ability of HCC cells through regulating transcription factors snail/zeb1-mediated EMT mechanism, which indicated that the protein could serve as a novel therapeutic target for the treatment of HCC.

PDSS2-Del2, a new variant of PDSS2, promotes tumor cell metastasis and angiogenesis in hepatocellular carcinoma via activating NF-κB.

Hepatocellular carcinoma (HCC) is among the leading causes of cancer-related mortality worldwide. Our previous study identified a novel alternative splicing variant of prenyl diphosphate synthase subunit 2 (PDSS2) in HCC characterized by a deletion of exon 2, named PDSS2-Del2, which is devoid of the tumor-suppressive function of full-length PDSS2 (PDSS2-FL). To better understand the clinical significance of PDSS2-Del2, we performed a BaseScope™ assay on an HCC tissue microarray and found that positive staining for PDSS2-Del2 predicted a worse overall survival in patients with HCC (P=0.02). PDSS2-Del2 levels correlated significantly with microvessel counts in HCC tumor tissues. Importantly, PDSS2-Del2 overexpression functionally promoted HCC metastasis, as demonstrated by in vitro and in vivo migration assays. In vivo assays also demonstrated that PDSS2-Del2 increased angiogenesis in xenografts. Furthermore, we discovered that elevated PDSS2-Del2 expression in HCC tumor cells decreased fumarate levels and activated the canonical nuclear factor-κB pathway. The epithelial-to-mesenchymal transition (EMT) and WNT/β-catenin signaling pathways were also activated by overexpression. Dimethyl fumarate (DMF), a fumaric acid ester, effectively reduced the metastasis induced by PDSS2-Del2 as observed with in vivo spleen-liver metastasis animal experiments. DMF is a prescribed oral therapy for multiple sclerosis and it might be a potential treatment for metastasis of patients with HCC. Early clinical trials are needed to validate its potential in this context.

SIX4 promotes hepatocellular carcinoma metastasis through upregulating YAP1 and c-MET.

Metastasis is the main reason for high mortality in hepatocellular carcinoma (HCC) patients and the molecular mechanism remains unclear. Therefore, it is important to elucidate the mechanism underlying HCC metastasis. Here, we report a novel role of SIX homeobox 4 (SIX4), one of the SIX gene family, in promoting HCC metastasis. The elevated expression of SIX4 was positively correlated with loss of tumor encapsulation, microvascular invasion, higher TNM stage, and poor prognosis in human HCC. SIX4 expression was an independent and significant risk factor for the recurrence and survival in HCC patients. Upregulation of SIX4 promoted HCC invasion and metastasis, whereas downregulation of SIX4 decreased HCC invasion and metastasis. SIX4 transactivated Yes1 associated transcriptional regulator (YAP1) and MET proto-oncogene, receptor tyrosine kinase (MET) expression through directly binding to their promoters. Knockdown of YAP1 and c-MET inhibited SIX4-medicated HCC metastasis, while the stable overexpression of YAP1 and c-MET reversed the decreased metastasis induced by SIX4 knockdown. Hepatocyte growth factor (HGF), the specific ligand of c-MET, upregulated SIX4 expression through ERK/NF-κB pathway. Knockdown of SIX4 significantly decreased HGF-enhanced HCC metastasis. In human HCC tissues, SIX4 expression was positively correlated with nuclear YAP1, c-MET and HGF expression. Patients with positive coexpression of SIX4/ nuclear YAP1, SIX4/c-MET or HGF/SIX4 had the poorest prognosis. Moreover, the combination treatment of YAP1 inhibitor Verteporfin and c-MET inhibitor Capmatinib significantly suppressed SIX4-mediated HCC metastasis. In conclusion, SIX4 is a prognostic biomarker in HCC patients and targeting the HGF-SIX4-c-MET positive feedback loop may provide a promising strategy for the treatment of SIX4-driven HCC metastasis.

PTPRε Acts as a Metastatic Promoter in Hepatocellular Carcinoma by Facilitating Recruitment of SMAD3 to TGF-β Receptor 1.

Transforming growth factor beta (TGF-β) suppresses early stages of tumorigenesis, but contributes to the migration and metastasis of cancer cells. However, the role of TGF-β signaling in invasive prometastatic hepatocellular carcinoma (HCC) is poorly understood. In this study, we investigated the roles of canonical TGF-β/mothers against decapentaplegic homolog 3 (SMAD3) signaling and identified downstream effectors on HCC migration and metastasis. By using in vitro trans-well migration and invasion assays and in vivo metastasis models, we demonstrated that SMAD3 and protein tyrosine phosphatase receptor epsilon (PTPRε) promote migration, invasion, and metastasis of HCC cells in vitro and in vivo. Further mechanistic studies revealed that, following TGF-β stimulation, SMAD3 binds directly to PTPRε promoters to activate its expression. PTPRε interacts with TGFBR1/SMAD3 and facilitates recruitment of SMAD3 to TGFBR1, resulting in a sustained SMAD3 activation status. The tyrosine phosphatase activity of PTPRε is important for binding with TGFBR1, recruitment and activation of SMAD3, and its prometastatic role in vitro. A positive correlation between pSMAD3/SMAD3 and PTPRε expression was determined in HCC samples, and high expression of SMAD3 or PTPRε was associated with poor prognosis of patients with HCC. PTPRε positive feedback regulates TGF-β/SMAD3 signaling to promote HCC metastasis.

Depletion of VPS35 attenuates metastasis of hepatocellular carcinoma by restraining the Wnt/PCP signaling pathway

Vesicle Protein Sorting 35 (VPS35) is a novel oncogene that promotes tumor growth through the PI3K/AKT signaling in hepatocellular carcinoma (HCC). However, the role of VPS35 in HCC metastasis and the underlying mechanisms remain largely unclear. In this study, we observed that overexpression of VPS35 enhanced hepatoma cell invasion and metastasis by inducing epithelial–mesenchymal transition (EMT)-related gene expression. Conversely, knockout of VPS35 significantly inhibited hepatoma cell migration and invasion. Furthermore, depletion of VPS35 decreased the lung metastasis of HCC in nude mice. By transcriptome analysis, we determined that VPS35 promoted HCC metastasis by activating the Wnt/non-canonical planar cell polarity (PCP) pathway. Mechanistically, VPS35 activated the PCP pathway by regulating membrane sorting and trafficking of Frizzled-2 (FZD2) and ROR1 in hepatoma cells. Collectively, our results indicate that VPS35 promotes HCC metastasis via enhancing the Wnt/PCP signaling, thus providing a potential prognostic marker and therapeutic target for HCC.

Long Noncoding RNA LINC01134 Promotes Hepatocellular Carcinoma Metastasis via Activating AKT1S1 and NF-κB Signaling.

Hepatocellular carcinoma (HCC) is one of the most common malignancies with poor outcomes. The main causes of HCC-related deaths are recurrence and metastasis. Long noncoding RNAs (lncRNAs) are recently identified as critical regulators in cancers. However, the lncRNAs involved in HCC recurrence and metastasis are poorly understood. In this study, via analyzing The Cancer Genome Atlas Liver Hepatocellular Carcinoma dataset, we identified a novel lncRNA LINC01134, which is highly expressed in HCC tissues and correlated with microvascular invasion, macrovascular invasion, recurrence, and poor overall survival of HCC patients. Functional experiments revealed that ectopic expression of LINC01134 promotes HCC cell migration and invasion in vitro and HCC liver metastasis and lung metastasis in vivo. Knockdown of LINC01134 represses HCC cell migration and invasion in vitro and HCC liver metastasis and lung metastasis in vivo. Mechanistically, we found that LINC01134 directly binds the promoter of AKT1S1 and activates AKT1S1 expression. Via activating AKT1S1, LINC01134 further activates NF-κB signaling. The expression of LINC01134 is significantly positively correlated with that of AKT1S1 in HCC tissues. In line with LINC01134, AKT1S1 is also highly expressed in HCC tissues and correlated with poor survival of HCC patients. Functional rescue experiments showed that repressing AKT1S1 or NF-κB signaling abrogates the roles of LINC01134 in HCC. Taken together, these findings recognized LINC01134 as a novel oncogenic lncRNA, which indicates vascular invasion, recurrence, and poor overall survival of HCC patients. LINC01134 promotes HCC metastasis via activating AKT1S1 expression and subsequently activating NF-κB signaling. This study suggested LINC01134 as a potential prognostic biomarker and therapeutic target for HCC.

Down-Regulated CMTM2 Promotes Epithelial-Mesenchymal Transition in Hepatocellular Carcinoma.

BackgroundOur recent study identified that human chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing family member 2 (CMTM2) was deregulated in hepatocellular carcinoma (HCC) tissues and posed as a potential tumor suppressor. However, the mechanism of CMTM2 in HCC occurrence and development has not been well elaborated.Materials and MethodsThe expression of CMTM2 was knocked-down by RNA interruption in Huh-7 and SMMC7721 cells. Cell proliferation ability was detected by CCK8 test and colony formation assay. The cell invasion and migration were measured by wound healing and Transwell assay.ResultsWe found that the cell proliferation was significantly increased by interruption of CMTM2 expression, both in Huh-7 and SMMC7721 cells. Moreover, down-regulated CMTM2 could promote the invasion and migration ability of HCC cells through inducing the epithelial-mesenchymal transition (EMT) process. We further discovered that both the expression of CMTM2 and the EMT-associated marker E-cadherin were decreased in the same thirty cases of HCC tissues compared with the corresponding adjacent non-tumor tissues. Pearson correlation test showed that there was a significantly positive correlation between CMTM2 and E-cadherin in HCC tissues (P<0.05).ConclusionBased on the results of cell model and HCC tissues, our study suggests that down-regulated CMTM2 promotes HCC metastasis through inducing the EMT process.

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.

PDLIM1 Inhibits Tumor Metastasis Through Activating Hippo Signaling in Hepatocellular Carcinoma.

Tumor metastasis is a major factor of high recurrence and mortality in hepatocellular carcinoma (HCC), but its underlying mechanism remains elusive. We report that PDZ and LIM domain protein 1 (PDLIM1) is significantly down-regulated in metastatic human HCC tissues, which predicts unfavorable prognosis, suggesting that PDLIM1 may play an important inhibitory role during HCC metastasis. Functional studies indicate that PDLIM1 knockdown induces epithelial-to-mesenchymal transition (EMT) of HCC cells, elevates their invasive capacity, and promotes metastasis in vitro and in vivo, whereas overexpression of PDLIM1 exhibits opposite phenotypes. Mechanistically, PDLIM1 competitively binds to the cytoskeleton cross-linking protein alpha-actinin 4 (ACTN4), leading to the disassociation of ACTN4 from F-actin, thus preventing F-actin overgrowth. In contrast, loss of PDLIM1 induces excessive F-actin formation, resulting in dephosphorylation of large tumor suppressor kinase 1 and activation of Yes-associated protein, thereby promoting HCC metastasis. Moreover, Asn145 (N145) of PDLIM1 is critical for its interaction with ACTN4, and N145A mutation abolishes its regulatory function in Hippo signaling and HCC metastasis. Our findings indicate that PDLIM1 suppresses HCC metastasis by modulating Hippo signaling, suggesting that PDLIM1 may be a potential prognostic marker for metastatic HCC.

LncRNA ANCR promotes hepatocellular carcinoma metastasis through upregulating HNRNPA1 expression

ABSTRACTLncRNA ANCR plays important roles in the modulation of epithelial mesenchymal transition (EMT) and tumour metastasis in many tumours. However, the role of ANCR in regulating hepatocellular carcinoma (HCC) metastasis is still not known. The current study aims to investigate the underlying mechanism for tumour oncogenesis of ANCR in HCC metastasis. HCC cell proliferation and migration/invasion were measured by MTT and Transwell assays. Xenograft model was established to determine the effect of ANCR on HCC growth and metastasis. ChIP assay was used to detect the H3 and H4 histone acetylation levels at the ANCR promoter region. RNA pull-down and RIP assay was performed to analyse the relationship between ANCR and heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1). Dual-luciferase reporter gene assay was conducted to determine the interaction between ANCR and miR-140-3p. The results indicated that ANCR was highly expressed in HCC tissues and cells, which promoted the proliferation and migration/invasion of HCC cells. In vivo experiments showed interfering ANCR suppressed the growth and metastasis of HCC. H3/H4 histone acetylation levels at the ANCR promoter region were elevated in HCC tissues and cells, and interfering histone deacetylases 3 (HDAC3) significantly up-regulated ANCR expression. ANCR could bind to HNRNPA1, and promoted the expression of HNRNPA1 through regulating its degradation. In addition, ANCR upregulated the expression of HNRNPA1 through sponging miR-140-3p. Finally, we found that ANCR promoted the EMT and invasion/migration of HCC cells through regulating HNRNPA1. In conclusion, ANCR promoted HCC metastasis by upregulating HNRNPA1, inhibiting HNRNPA1 degradation and sponging miR-140-3p.

Hsa_circ_102559 Acts as the Sponge of miR-130a-5p to Promote Hepatocellular Carcinoma Progression Through Regulation of ANXA2

Circular RNAs (circRNAs) are critical regulators in tumor initiation and development and participate in the pathological process of hepatocellular carcinoma (HCC). However, the specific role and mechanism of circRNA, hsa_circ_102559, in HCC remains elusive. First, analysis of HCC-related circRNA expression profile GSE97332 and HCC patients showed a significant upregulation of hsa_circ_102559 in HCC tissues. Upregulation of hsa_circ_102559 in HCC cells was associated with the metastatic properties. Second, hsa_circ_102559 significantly promoted HCC metastasis, while knockdown of hsa_circ_102559 reversed the promotive effects on HCC progression. Functionally, hsa_circ_102559 could target and colocalize with miR-130a-5p in the cytoplasm of HCC cells. Annexin A2 (ANXA2) was identified as a target gene of miR-130a-5p, and overexpression of ANXA2 counteracted with the suppressive effects of hsa_circ_102559 silence on HCC metastasis. Lastly, xenograft experiment was established and results indicated that knockdown of hsa_circ_102559 inhibited HCC growth and metastasis through the downregulation of ANXA2. In conclusion, hsa_circ_102559 inhibited HCC progression via sponging miR-130a-5p to reduce ANXA2 expression, suggesting that hsa_circ_102559 might be a potential biomarker or therapeutic target for HCC.

MiR-1203 is involved in hepatocellular carcinoma metastases and indicates a poor prognosis.

Non-coding RNAs, especially miRNAs, have been shown to be important regulators in multiple human diseases, including malignant tumors, congenital disease, and autoimmune disease. In this study, we screened the metastasis-associated miRNAs in hepatocellular carcinoma (HCC). Based on the miRNA microarray screening, miR-1203 was confirmed to be the most significant miRNA and was also highly associated with HCC metastases. Bioinformatics prediction indicated direct binding of miR-1203 in SOCS3, which was also confirmed by a dual luciferase reporter assay, resulting in suppression of SOCS3. Increased miR-1203 also promoted invasion of HCC cells through suppressing SOCS3, while no effect on cell proliferation or apoptosis was detected. Circulating expression of miR-1203 and SOCS3 might serve as a predictor of metastases and poor prognosis in HCC patients. In conclusion, miR-1203 might promote HCC metastasis by decreasing SOCS3. MiR-1203 predicts a poor outcome in HCC patients and thus might serve as a potential therapeutic target for the prevention of HCC.

Sec62 promotes early recurrence of hepatocellular carcinoma through activating integrin\u03b1/CAV1 signalling

Postsurgical recurrence within 2 years is the major cause of poor survival of hepatocellular carcinoma (HCC) patients. However, the molecular mechanism underlying HCC recurrence remains unclear. Here, we distinguish the function and mechanism of Sec62 in promoting HCC recurrence. The correlation between Sec62 and early recurrence was demonstrated in 60 HCC samples from a prospective study. HCC cells with Sec62 knockdown (Sec62KD) or overexpression (Sec62OE) were used to determine the potential of Sec62 in cell migration in vitro. Microarray analysis comparing Sec62KD or Sec62OE to their control counterparts was used to explore the mechanisms of Sec62-induced recurrence. A luciferase-labelled orthotopic nude mouse model of HCC with Sec62KD or Sec62OE was used to validate the potential of Sec62 in early HCC recurrence in vivo. We found that high expression of Sec62 was positively correlated with surgical recurrence in clinical HCC samples. Multivariate analysis revealed that Sec62 was an independent prognostic factor for early recurrence in postoperative HCC patients. Moreover, Sec62 promoted migration and invasion of HCC cells in vitro and postsurgical recurrence in vivo. Mechanically, integrinα/CAV1 signalling was identified as one of the targets of Sec62 in cell movement. Overexpression of integrin α partially rescued the Sec62 knockdown-induced inhibition of cell migration. Sec62 is a potentially prognostic factor for early recurrence in postoperative HCC patients and promotes HCC metastasis through integrinα/CAV1 signalling. Sec62 might be an attractive drug target for combating HCC postsurgical recurrence.

Deubiquitinating enzyme USP10 promotes hepatocellular carcinoma metastasis through deubiquitinating and stabilizing Smad4 protein.

Hepatocellular carcinoma (HCC) has emerged as one of the most prevalent life‐threatening cancers, and the high mortality rate is largely due to the metastasis. The sustained activation of Smad4 and transforming growth factor‐β (TGF‐β) is closely associated with advanced HCC metastasis. However, the regulatory mechanism underlying the aberrant activation of Smad4 and TGF‐β pathway remains elusive. In this study, using a functional screen of USPs siRNA library, we identified ubiquitin‐specific proteases USP10 as a deubiquitinating enzyme (DUB) that sustains the protein level of Smad4 and activates TGF‐β signaling. Further analysis showed that USP10 directly interacts with Smad4 and stabilizes it through the cleavage of its proteolytic ubiquitination, thus promoting HCC metastasis. The suppression of USP10 by either shRNAs or catalytic inhibitor Spautin‐1 significantly inhibited the migration of HCC cells, whereas the reconstitution of Smad4 was able to efficiently rescue this defect. Overall, our study not only uncovers the regulatory effect of USP10 on the protein abundance of Smad4, but also indicates that USP10 could be regarded as a potential intervention target for the metastatic HCC in Smad4‐positive patients.

MicroRNA-148b-colony-stimulating factor-1 signaling-induced tumor-associated macrophage infiltration promotes hepatocellular carcinoma metastasis

BackgroundMicroRNAs (miRNAs) are small non-coding molecules that exhibit important regulatory roles in various biological or cellular functions, including tumor metastasis. However, the detailed mechanisms of the expression and functions of miRNAs in hepatocellular carcinoma (HCC) have not yet been completely investigated. MethodsIn this study, the levels of miR-148b in HCC cells and patient specimens were determined using qPCR assays. MiR-148b-overexpressing HCC cells were used to investigate the effect of miR-148b in vitro and in vivo. The relationship between the expression of miR-148b and colony stimulating factor-1 (CSF1) in HCC patients and the infiltration of macrophages into the tumor microenvironment were assessed by immunohistochemical staining. ResultsMiR-148b expression was decreased in metastatic HCC cells. A positive association between downregulated miR-148b expression and several clinical parameters, including recurrence, metastasis, and poor prognosis, was observed in patients with HCC. The results of bio-functional experiments indicated that the biological characteristics of HCC cells were not affected by miR-148b deficiency in vitro. However, miR-148b deficiency significantly enhanced the progression and metastasis of HCC in nude mice. By analyzing the gene expression profiles, we demonstrated that CSF1 was regulated by miR-148b and that miR-148b deficiency promoted HCC growth and metastasis through CSF1/CSF1 receptor (CSF1R)-mediated tumor-associated macrophage (TAM) infiltration. These results were supported by the negative relationship between miR-148b and CSF1 expression and TAM infiltration in HCC patients. Moreover, HCC patients with low miR-148b levels and high TAM infiltration were associated with poorer prognosis. ConclusionMiR-148b-CSF1 signaling-induced TAM infiltration promotes HCC metastasis. Therefore, miR-148b plays a suppressor role in HCC and might be a potential prognostic factor and therapeutic candidate for HCC.

Metadherin-PRMT5 complex enhances the metastasis of hepatocellular carcinoma through the WNT-β-catenin signaling pathway.

Accumulating data suggest that metadherin (MTDH) may function as an oncogene. Our previous study showed that MTDH promotes hepatocellular carcinoma (HCC) metastasis via the epithelial-mesenchymal transition. In this study, we aim to further elucidate how MTDH promotes HCC metastasis. Using Co-immunoprecipitation (co-IP) and mass spectrometry, we found that MTDH can specifically bind to protein arginine methyltransferase 5 (PRMT5). Further functional assays revealed that PRMT5 overexpression promoted the proliferation and motility of HCC cells and that knockout of PRMT5 impeded the effect of MTDH. The immunohistochemistry assay/tissue microarray results showed that when MTDH was overexpressed in HCC cells, PRMT5 translocated from the nucleus to the cytoplasm, with the subsequent translocation of β-catenin from the cytoplasm to the nucleus and upregulation of the WNT–β-catenin signaling pathway. Further in vivo experiments suggested that PRMT5 and β-catenin played a pivotal role in MTDH-mediated HCC metastasis. We therefore concluded that the MTDH–PRMT5 complex promotes HCC metastasis by regulating the WNT–β-catenin signaling pathway.