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Iron dyshomeostasis is associated with hepatocellular carcinoma (HCC) development. However, the role of iron in HCC metastasis is unknown. This study aimed to elucidate the underlying mechanisms of iron’s enhancement activity on HCC metastasis. In addition to the HCC cell lines and clinical samples in vitro, iron deficient (ID) mouse models were generated using iron-free diet and transferrin receptor protein knock out, followed by administration of HCC tumors through either orthotopic or ectopic route. Clinical metastatic HCC samples showed significant ID status, accompanied by overexpression of sphingosine-1-phosphate transporter spinster homologue 2 (SPNS2). Mechanistically, ID increased SPNS2 expression, leading to HCC metastasis in both cell cultures and mouse models. ID not only altered the anti-tumor immunity, which was indicated by phenotypes of lymphatic subsets in the liver and lung of tumor-bearing mice, but also promoted HCC metastasis in a cancer cell autonomous manner through the SPNS2. Since germline knockout of globe SPNS2 showed significantly reduced HCC metastasis, we further developed hepatic-targeting recombinant adeno-associated virus vectors to knockdown SPNS2 expression and to inhibit iron-regulated HCC metastasis. Our observation indicates the role of iron in HCC pulmonary metastasis and suggests SPNS2 as a potential therapeutic target for the prevention of HCC pulmonary metastasis.

Patients with hepatocellular carcinoma (HCC) have poor long-term survival following curative resection because of the high rate of tumor early recurrence. Little is known about the trajectory of genomic evolution from primary to early-recurrent HCC. In this study, we performed whole-genome sequencing (WGS) on 40 pairs of primary and early-recurrent hepatitis B virus (HBV)-related HCC tumors from patients who received curative resection, and from four patients whose primary and recurrent tumor were extensively sampled. We identified two recurrence patterns: de novo recurrence (18/40), which developed genetically independently of the primary tumor and carried different HCC drivers, and ancestral recurrence (22/40), which was clonally related to the primary tumor and progressed more rapidly than de novo recurrence. We found that the recurrence location was predictive of the recurrence pattern: distant recurrence tended to display the de novo pattern, whereas local recurrence tended to display the ancestral pattern. We then uncovered the evolutionary trajectories based on the subclonal architecture, driver-gene mutations, and mutational processes observed in the primary and recurrent tumors. Multi-region WGS demonstrated spatiotemporal heterogeneity and polyclonal, monophyletic dissemination in HCC ancestral recurrence. In addition, we identified recurrence-specific mutations and copy-number gains in BCL9, leading to WNT/β-catenin signaling activation and an immune-excluded tumor microenvironment, which suggests that BCL9 might serve as a new therapeutic target for recurrent HCC. Collectively, our results allow us to view with unprecedented clarity the genomic evolution during HBV-related HCC early recurrence, providing an important molecular foundation for enhanced understanding of HCC with implications for personalized therapy to improve patient survival.

Sarcomatoid hepatocellular carcinoma (sHCC) is a rare type of liver malignancy. Currently, the tumor immune features of sHCC are poorly understood. We recruited 31 patients with resected sHCC for whom tissue samples and complete clinicopathologic and follow-up data were available. To understand the immune infiltration of sHCC, immunohistochemical staining was performed on the resected sHCC samples to compare the expressions of programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), B7-H3, indoleamine 2,3-dioxygenase (IDO), lymphocyte-activation gene 3 (LAG-3), CD8, FOXP3, and CD68 in tumor and peritumoral tissues. Kaplan-Meier and Cox regression analyses were used to assess the predictive value of immune markers. Sarcomatoid components were characterized with significantly higher expression of PD-L1 and B7-H3 in tumor cells than in conventional HCC components, as well as in peritumoral tissue. Additionally, sarcomatoid components had a higher density of FOXP3+ and LAG-3+ cells and a lower density of CD8+ cells than conventional HCC components or peritumoral tissue. Higher expression of PD-L1 in tumor cells significantly correlated with higher densities of CD8+, PD-1+, and LAG-3+ cells. Increased tumor PD-L1 expression and decreased CD8+ T-cell density were associated with poor overall survival (OS) and disease-free survival (DFS) in patients of sHCC. These findings suggest further characterization on relative mechanism of sHCC immune infiltration may identify therapeutic targets for immunotherapy.

Background & aims Intrahepatic cholangiocarcinoma (ICC) is aggressive and has high rates of relapse, conferring poor long-term survival after curative resection. Little is known about the genomic evolution that occurs during ICC relapse. Approach & results We conducted whole-exome sequencing (WES) of 30 paired primary and relapsed tumors from 10 patients with ICC who received curative resection. We sought to identify frequently altered genes, infer tumor subclonal architectures, and track genomic evolution from primary to relapsed tumors. We examined functional effects and the mechanism of action of SLIT2, a gene specifically mutated in relapsed tumors, on tumor growth and metastasis and the tumor microenvironment. Our results indicated that relapsed ICCs were genetically derived from intrahepatic dissemination of primary tumors. But, they acquired additional mutations while maintaining most drivers, such as TP53 and IDH1. Multiregion sequencing suggested polyclonal seeding of ICC dissemination. Four of 10 relapsed ICCs acquired SLIT2 mutations that were not present in the corresponding primary tumors. Validation in an expanded sample revealed SLIT2 mutations in 2.3% (1/44) of primary ICCs and 29.5% (13/44) of relapsed ICCs. Biofunctional investigations revealed that inactivating mutation of SLIT2 resulted in activation of PI3K-Akt signaling in ICC cells, directly enhanced neutrophil chemotaxis, mediated tumor-associated neutrophil infiltration, and contributed to ICC growth and metastasis. Conclusions We characterized genomic evolution during ICC relapse and identified SLIT2 as a driver of tumor dissemination and tumor-associated neutrophil infiltration.

Our previous study demonstrated that heterogeneous nuclear ribonucleoprotein AB (HNRNPAB) is a key gene that facilitates metastasis of hepatocellular carcinoma (HCC). However, the molecular mechanisms behind this relationship are not fully understood. In our study, we utilized long-noncoding RNA (lncRNA) microarrays to identify a HNRNPAB-regulated lncRNA named lnc-ELF209. Our findings from chromatin immunoprecipitation assays indicate that HNRNPAB represses lnc-ELF209 transcription by directly binding to its promoter region. We also analyzed clinical samples from HCC patients and cell lines with quantitative real-time polymerase chain reactions, RNA in situ hybridization and immunohistochemistry, and found that there is a negative relationship between HNRNPAB and lnc-ELF209 expression. Up/downregulation assays and rescue assays indicate that lnc-ELF209 inhibits cell migration, invasion and epithelial-mesenchymal transition regulated by HNRNPAB. This suggests a new regulatory mechanism for HNRNPAB-promoted HCC progression. RNA pull-down and LC-MS/MS were used to determine triosephosphate isomerase, heat shock protein 90-beta and vimentin may be involved in the tumor-suppressed function of lnc-ELF209. Furthermore, we found lnc-ELF209 could stabilize TPI protein expression. We also found that lnc-ELF209 overexpression in HCCLM3 cell resulted in a lower rate of lung metastatic, which suggested a less aggressive HCC phenotype. Collectively, these findings offer new insights into the regulatory mechanisms that underlie HNRNPAB cancer-promoting activities and demonstrate that lnc-ELF209 is a HNRNPAB-regulated lncRNA that may play an important role in the inhibition of HCC progression.

Although circular RNAs (circRNA) are known to modulate tumor initiation and progression, their role in hepatocellular carcinoma (HCC) metastasis remains poorly understood. Here, three metastasis-associated circRNAs identified in a previous circRNA-sequencing study were screened and validated in two HCC cohorts. CircRPN2 was downregulated in highly metastatic HCC cell lines and HCC tissues with metastasis. Patients with HCC with lower circRPN2 levels displayed shorter overall survival and higher rates of cumulative recurrence. Mechanistic studies in vitro and in vivo revealed that circRPN2 binds to enolase 1 (ENO1) and accelerates its degradation to promote glycolytic reprogramming through the AKT/mTOR pathway, thereby inhibiting HCC metastasis. CircRPN2 also acted as a competing endogenous RNA for miR-183–5p, which increases forkhead box protein O1 (FOXO1) expression to suppress glucose metabolism and tumor progression. In clinical samples, circRPN2 expression negatively correlated with ENO1 and positively correlated with FOXO1, and expression of circRPN2, either alone or in combination with ENO1 and FOXO1, was a novel indicator of HCC prognosis. These data support a model wherein circRPN2 inhibits HCC aerobic glycolysis and metastasis via acceleration of ENO1 degradation and regulation of the miR-183–5p/FOXO1 axis, suggesting that circRPN2 represents a possible therapeutic target in HCC. Significance: The circRNA circRPN2 is a potential prognostic biomarker and therapeutic target in hepatocellular carcinoma that suppresses aerobic glycolysis and metastasis.

Background Long noncoding RNAs (lncRNAs) are functionally associated with cancer development and progression. Although gene copy number variation (CNV) is common in hepatocellular carcinoma (HCC), it is not known how CNV in lncRNAs affects HCC progression and recurrence. We aimed to identify a CNV‐related lncRNA involved in HCC progression and recurrence and illustrate its underlying mechanisms and prognostic value. Methods We analyzed the whole genome sequencing (WGS) data of matched cancerous and noncancerous liver samples from 49 patients with HCC to identify lncRNAs with CNV. The results were validated in another cohort of 238 paired HCC and nontumor samples by TaqMan copy number assay. We preformed Kaplan‐Meier analysis and log‐rank test to identify lncRNA CNV with prognostic value. We conducted loss‐ and gain‐of‐function studies to explore the biological functions of LINC01133 in vitro and in vivo. The competing endogenous RNAs (ceRNAs) mechanism was clarified by microRNA sequencing (miR‐seq), quantitative real‐time PCR (qRT‐PCR), western blot, and dual‐luciferase reporter assays. We confirmed the binding mechanism between lncRNA and protein by RNA pull‐down, RNA immunoprecipitation, qRT‐PCR, and western blot analyses. Results Genomic copy numbers of LINC01133 were increased in HCC, which were positively related with the elevated expression of LINC01133. Increased copy number of LINC01133 predicted the poor prognosis in HCC patients. LINC01133 overexpression in HCC cells promoted proliferation and aggressive phenotypes in vitro, and facilitated tumor growth and lung metastasis in vivo, whereas LINC01133 knockdown had the opposite effects. LINC01133 sponged miR‐199a‐5p, resulting in enhanced expression of SNAI1, which induced epithelial‐to‐mesenchymal transition (EMT) in HCC cells. In addition, LINC01133 interacted with Annexin A2 (ANXA2) to activate the ANXA2/STAT3 signaling pathway. Conclusions LINC01133 promotes HCC progression by sponging miR‐199a‐5p and interacting with ANXA2. LINC01133 CNV gain is predictive of poor prognosis in patients with HCC., Genomic copy numbers of LINC01133 were increased in HCC, which were positively related with its elevated expression, and LINC01133 CNV gain predicted the poor prognosis in HCC patients. LINC01133 sponged miR‐199a‐5p, resulting in enhanced expression of SNAI1, which induced EMT in HCC cells. LINC01133 interacted with ANXA2 to activate ANXA2/STAT3 signaling pathway.

BackgroundTumor-associated neutrophils (TANs) and macrophages (TAMs) can each influence cancer growth and metastasis, but their combined effects in intrahepatic cholangiocarcinoma (ICC) remain unclear.MethodsWe explored the distributions of TANs and TAMs in patient-derived ICC samples by multiplex immunofluorescent staining and tested their separate and combined effects on ICC in vitro and in vivo. We then investigated the mechanistic basis of the effects using PCR array, western blot analysis and ELISA experiments. Finally, we validated our results in a tissue microarray composed of primary tumor tissues from 359 patients with ICC.ResultsThe spatial distributions of TANs and TAMs were correlated with each other in patient-derived ICC samples. Interaction between TANs and TAMs enhanced the proliferation and invasion abilities of ICC cells in vitro and tumor progression in a mouse xenograft model of ICC. TANs and TAMs produced higher levels of oncostatin M and interleukin-11, respectively, in co-culture than in monoculture. Both of those cytokines activated STAT3 signaling in ICC cells. Knockdown of STAT3 abolished the protumor effect of TANs and TAMs on ICC. In tumor samples from patients with ICC, increased TAN and TAM levels were correlated with elevated p-STAT3 expression. All three of those factors were independent predictors of patient outcomes.ConclusionsTANs and TAMs interact to promote ICC progression by activating STAT3.

Background: Long non-coding RNAs (lncRNAs) have been found to be functionally associated with cancer development and progression. Although copy number variations (CNVs) are common in hepatocellular carcinoma (HCC), little is known about how CNVs in lncRNAs affect HCC progression and recurrence.Methods: We analyzed the whole genome sequencing (WGS) data of matched cancerous and non-cancerous liver samples from 49 patients with HCC to identify lncRNAs with CNVs. The results were validated in another cohort of 238 paired HCC and non-tumor samples by TaqMan copy number assay. Kaplan-Meier analysis and the log-rank test were performed to determine the prognostic value of CNVs in lincRNAs. Loss- and gain-of-function studies were conducted to determine the biological functions of LINC01133 in vitro and in vivo. The competing endogenous RNAs (ceRNAs) mechanism was clarified by microRNA sequencing (miR-seq), quantitative real-time PCR (qRT-PCR), western blot, and dual-luciferase reporter analyses. The protein binding mechanism was confirmed by RNA pull-down, RNA immunoprecipitation (RIP), qRT-PCR, and western blot analyses.Results: Genomic copy number of LINC01133 was increased in HCC, which is positively related with the elevated expression of LINC01133. Increased copy number of LINC01133 predicted the poor prognosis in HCC patients. LINC01133 overexpression promoted proliferation, colony formation, migration, and invasion in vitro, and facilitated tumor growth and lung metastasis in vivo, whereas LINC01133 knockdown had the opposite effects. Mechanistically, LINC01133 acted as a sponge of miR-199a-5p, resulting in enhanced expression of SNAI1, which induced epithelial-mesenchymal transition (EMT) in HCC cells. In addition, LINC01133 interacted with Annexin A2 (ANXA2) to activate ANXA2/STAT3 signaling pathway.Conclusions: LINC01133 promotes HCC progression by sponging miR-199a-5p and interacting with ANXA2. LINC01133 CNV gain is predictive of poor prognosis in HCC patients undergoing curative resection.

Background Plasmacytoid dendritic cells (pDCs) are present in various primary and metastatic human neoplasms; however, their clinical significance in intrahepatic cholangiocarcinoma is not clear. Methods To evaluate pDCs’ distributions in and around tumors as well as their potential function and predictive value for prognosis in patients undergoing curative resection, we performed immunohistochemistry to examine the expression of pDC marker BDCA2, and CD3, CD4, CD8 and Foxp3 in intratumoral and peritumoral tissues from 359 patients with intrahepatic cholangiocarcinoma and compared with prognostic and clinicopathologic factors. Results Results showed that patients with high numbers of BDCA2+ pDCs in peritumoral tissues were more likely to have elevated levels of carbohydrate antigen 19-9 and gamma-glutamyl transferase, larger and more tumors, advanced tumor-node-metastasis staging, more vascular/bile duct invasion, and lymphatic metastasis in association with greater chance of recurrence and shorter overall survival. Peritumoral tissues with larger numbers of pDCs also showed increased Foxp3+ regulatory T cell infiltration, both of which were found to be independent factors for predicting time to recurrence and overall survival. By contrast, patient outcomes were not associated with the presence of intratumoral pDCs. Conclusions Peritumoral pDC infiltration may indicate an immune tolerogenic peritumor microenvironment and can be used to predict a poor prognosis for patients undergoing curative resection for intrahepatic cholangiocarcinoma.

Natural killer (NK) cell can inhibit tumor initiation and regulates metastatic dissemination, acting as key mediators of the innate immune response. Intrinsic factors modulating NK cells infiltration and its anticancer activity remain poorly characterized. We investigated the roles of dysregulation of micro(mi)RNAs and NK cells in progression of hepatocellular carcinoma (HCC). Methods: Small RNA sequencing were used to detect the miRNA profiles of tumor tissues from HCC patients with (n=14) or without (n=13) pulmonary metastasis and HCC cell lines with different pulmonary metastatic potentials. Chemokine expression profiling and bioinformatics were used to detect the downstream target of candidate target. In gain- and loss-of-function assays were used to investigate the role of miRNA in HCC progression. Different subsets of NK cells were isolated and used for chemotaxis and functional assays in vivo and in vitro. In situ hybridization and immunohistochemical analyses were performed to detect the expression of miRNA in tumor tissues from 242 HCC patients undergoing curative resection from 2010. Results: Three miRNAs (miR-137, miR-149-5p, and miR-561-5p) were identified to be associated with pulmonary metastasis in patients with HCC. miR-561-5p was most highly overexpressed in metastatic HCC tissues and high-metastatic-potential HCC cell lines. In gain- and loss-of-function assays in a murine model, miR-561-5p promoted tumor growth and spread to the lungs. Yet, miR-561-5p did not appear to affect cellular proliferation and migration in vitro. Bioinformatics and chemokine expression profiling identified chemokine (C-X3-C motif) ligand 1 (CX3CL1) as a potential target of miR-561-5p. Furthermore, miR-561-5p promoted tumorigenesis and metastasis via CX3CL1-dependent regulation of CX3CR1+ NK cell infiltration and function. CX3CR1+ NK cells demonstrated stronger in vivo anti-metastatic activity relative to CX3CR1- NK cells. CX3CL1 stimulated chemotactic migration and cytotoxicity in CX3CR1+ NK cells via STAT3 signaling. Blockade of CX3CL1, CX3CR1, or of pSTAT3 signaling pathways attenuated the antitumor responses. Clinical samples exhibited a negative correlation between miR-561-5p expression and levels of CX3CL1 and CX3CR1+ NK cells. High miR-561-5p abundance, low CX3CL1 levels, and low numbers of CX3CR1+ NK cells were associated with adverse prognosis. Conclusion: We delineated a miR-561-5p/CX3CL1/NK cell axis that drives HCC metastasis and demonstrated that CX3CR1+ NK cells serve as potent antitumor therapeutic effectors.

Recent studies suggested that the immune microenvironment and mutational landscape are associated with the response to immune-based therapy in several types of cancer. The roles of those factors in Chinese HCC remain largely unknown. In this study, we obtained 182 FFPE samples of HCC cohort that were previously subjected to NGS (49 WGS, 18 WES, and 115 targeted sequencing). We performed immunohistochemistry to detect CD3, CD4, CD8, CD57, Foxp3, CD68, CD66b, and PD-L1 expression in the samples. We identified diverse associations between the mutational landscape and the immune microenvironment in the HCC samples. High mutational burden and an aristolochic acid-dominated mutational signature were both correlated with elevated tumoral PD-L1 expression and CD3+ T-cell infiltration and high numbers of CD68+ TAMs and CD66b+ TANs. CD4+ and CD8+ T cells exhibited lower infiltration levels in tumors with mutations in AXIN1/CTNNB1 and in tumors with aflatoxin-dominant mutational signatures. Moreover, tumors with TP53 mutations had less CD8+ T-cell infiltration and more Foxp3+ Treg-cell infiltration than those without TP53 mutations. Kaplan–Meier survival analysis revealed that the presence of CD8+, Foxp3+, CD66b+, or CD68+ immune cells; tumoral PD-L1 expression alone; or the presence of CD8+ or Foxp3+ cells combined with TP53 mutation were predictive of recurrence and poor overall survival after curative resection. In conclusion, the association between the mutational landscape and the immune microenvironment warrants further analysis to determine its impact on patient outcomes to guide personalized immune-based therapy for Chinese patients with HCC.

Structural variations (SVs) influence the development and progression of multiple types of cancer. The genes affected by SVs in hepatocellular carcinoma (HCC) and their contribution to tumor growth and metastasis remain unknown. In this study, through whole-genome sequencing (WGS), we identified MACROD2 as the gene most frequently affected by SVs, which were associated with low MACROD2 expression levels. Low MACROD2 expression was predictive of tumor recurrence and poor overall survival. MACROD2 expression was decreased in HCC cell lines, especially those with high metastatic potential. MACROD2 knockdown in HCC cells markedly enhanced proliferation and invasiveness in vitro and tumor progression in vivo and promoted epithelial–mesenchymal transition (EMT). By contrast, MACROD2 overexpression reversed EMT and inhibited HCC growth and metastasis. Mechanistically, MACROD2 deficiency suppressed glycogen synthase kinase-3β (GSK-3β) activity and activated β-catenin signaling, which mediated the effect of MACROD2 on HCC. In clinical HCC samples, decreased MACROD2 expression was correlated with the activation of GSK-3β/β-catenin signaling and the EMT phenotype. Overall, our results revealed that MACROD2 is frequently affected by SVs in HCC, and its deficiency promotes tumor growth and metastasis by activating GSK-3β/β-catenin signaling.

Background and aims There is growing evidence that single-stranded, circular RNA (circRNA) plays a key role in the development of certain cancers, including hepatocellular carcinoma (HCC). It is less clear, however, what role circRNA plays in HCC metastasis. Approach and results In this study, through circRNA sequencing, we identified a circRNA: circASAP1 (a circRNA derived from exons 2 and 3 of the ASAP1 gene, hsa_circ_0085616), which is associated with pulmonary metastasis after curative resection in patients with HCC. CircASAP1 was overexpressed in HCC cell lines with high metastatic potential and in metastatic HCCs. In vitro, circASAP1 promoted cell proliferation, colony formation, migration, and invasion, and in vivo, it enhanced tumor growth and pulmonary metastasis. Mechanism studies showed that circASAP1 acts as a competing endogenous RNA for microRNA 326 (miR-326) and microRNA 532-5p (miR-532-5p), both of which are tumor suppressors in HCC. We found that mitogen-activated protein kinase (MAPK) 1 and colony stimulating factor (CSF)-1 were direct common targets for microRNA 326 (miR-326) and microRNA 532-5p (miR-532-5p), which were regulated by circASAP1. CircASAP1 promotes HCC cell proliferation and invasion by regulating miR-326/miR-532-5p-MAPK1 signaling and, furthermore, mediates tumor-associated macrophage infiltration by regulating the miR-326/miR-532-5p-CSF-1 pathway. Clinical HCC samples exhibited a positive correlation between circASAP1 expression and levels of CSF-1, MAPK1, and CD68+ tumor-associated macrophages, all of which were predictive of patient outcomes. Conclusion We identified circASAP1 as a key regulator of HCC metastasis that acts on miR-326/miR-532-5p-MAPK1/CSF-1 signaling and serves as a prognostic predictor in patients with HCC.

The semaphorins were originally identified as having roles as guidance cues during neural development. Class 3 semaphorins are involved in cancer progression. However, the roles of class 3 semaphorins in hepatocellular carcinoma (HCC) are unknown. We examined the expression levels of class 3 semaphorins in HCC cell lines with different metastatic potential and in carcinoma tissue samples. The results indicated that Semaphorin 3A expression was up-regulated in metastatic cell lines and in samples from patients with tumor recurrence. Cell functional studies revealed that Semaphorin 3A promoted HCC cell proliferation, migration, and invasion. Animal studies indicated that Semaphorin 3A overexpression enhanced tumor growth and lung metastasis. Semaphorin 3A also acted as a chemoattractant involved in direct recruitment of macrophages in vitro, and facilitated tumor-associated macrophage (TAM) infiltration in vivo. Multivariate analysis revealed that Semaphorin 3A expression alone, or combined with the number of TAMs, can be an independent predictor for overall survival time and time to recurrence. Overall, the results suggested that Semaphorin 3A increased TAM infiltration and promoted HCC progression. Semaphorin 3A expression alone, or combined with the number of TAMs, is a new prognostic factor and potential target for the treatment of HCC.

Plasmacytoid dendritic cells (pDCs) are present in various primary and metastatic human neoplasms; however, their clinical significance in hepatocellular carcinoma (HCC) is unclear. In this study, we investigated the distribution, prognostic value, and potential function of pDCs in HCC patients undergoing curative resection. We performed immunohistochemical analyses of whole tumor sections from 224 patients to assess the expression of BDCA2, CD3, CD4, CD8, Foxp3, granzyme B, IL-17, and CD34. The findings were validated using tissue microarrays from another two independent cohorts totaling 841 HCC patients undergoing curative resection. Our results demonstrated that high numbers of BDCA2+ pDCs within tumors correlated with high alpha-fetoprotein levels, greater vascular invasion, advanced tumor-node-metastasis stage, shorter overall survival, and a higher recurrence rate. However, patient outcomes were not associated with pDCs in peritumoral stromal or nontumor tissues. Furthermore, an increase in intratumoral pDCs was associated with increased intratumoral infiltration of Foxp3+ regulatory T cells and IL-17-producing cells and correlated with tumor vascular density. Univariate and multivariate analyses revealed that the presence of intratumoral pDCs alone or in combination with regulatory T and/or IL-17-producing cells was an independent predictor of time to recurrence and overall survival. In conclusion, our study demonstrated that intratumoral infiltration by pDCs is a novel indicator for poor prognosis in patients with HCC, possibly through the induction of an immune tolerogenic and inflammatory tumor microenvironment comprising regulatory T and IL-17-producing cells. An assessment of the combination of these cells represents a superior predictor of patient outcome.

Increasing numbers of evidences have demonstrated that microRNAs (miRNAs) are implicated in metastasis and progression of hepatocellular carcinoma (HCC). However, their detailed expression levels and actual functions in HCCs have not been fully clarified yet. Results from our recent study revealed that some miRNAs were particularly related to metastasis of HCCs. As one of these newly found miRNAs, miR-501-3p showed to highly involve into metastatic process of HCCs. Here we reported that the expression of miR-501-3p was decreased in both metastatic HCC cell lines and tissue samples from HCC patients with recurrence and metastasis. Downregulation of miR-501-3p correlated with tumor progression and poor prognosis in the HCC patients. Results of functional analyses revealed that overexpression of miR-501-3p in HCCLM3 cancer cells inhibited their proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT), while miR-501-3p loss in PLC/PRF/5 cancer cells facilitated all these cellular activities. In addition, Lin-7 homolog A (LIN7A) was directly targeted by miR-501-3p to mediate the suppression effects on metastasis in HCC cells. miR-501-3p suppresses metastasis and progression of HCCs through targeting LIN7A. This finding suggests that miR-501-3p could be used as a potential prognostic predictor as well as a potential therapeutic tool for HCC therapies.

Upregulation of CXCR2 in tumor cells has been documented in several types of cancer. As one of its ligands, CXCL5 is associated with neutrophil infiltration and poor prognosis in hepatocellular carcinoma (HCC). However, little is known about the role of the CXCR2/CXCL5 axis in the invasion and metastasis of HCC cells. In this study, we examined CXCR2 expression in human HCC cell lines and in three independent cohorts of HCC patients. The molecular effects of high expression levels of CXCR2 and CXCL5 in HCC cells were determined using qRT-PCR, western blot analysis, immunofluorescence, matrigel invasion assay, and xenograft mouse models. We found that high levels of CXCR2 correlated with progression and poor prognosis in human HCC. CXCR2/CXCL5 together promoted cell spreading by inducing the epithelial-mesenchymal transition (EMT) through activation of the PI3K/Akt/GSK-3β/Snail signaling pathway. In clinical HCC samples, high expression of both CXCR2 and CXCL5 showed a significant correlation with the activation of PI3K/Akt/GSK-3β/Snail signaling and EMT phenotype. In conclusion, our data showed that the CXCR2/CXCL5 axis contributes to EMT of HCC cells through activating PI3K/Akt/GSK-3β/Snail signaling, and it may serve as a potential therapeutic target.

Calpain small subunit 1 (Capn4) has been identified as a major gene that promotes metastasis of hepatocellular carcinoma (HCC). However, the mechanism by which Capn4 promotes progression of HCC is not understood. In this study, we found that Capn4 expression was increased in highly metastatic HCC cell lines and in tumour tissue from HCC patients compared to healthy patient tissue. Over-expression of Capn4 in HCC cells enhanced tumour cell growth in vitro and increased invasiveness, tumourigenicity and lung metastasis in vivo. Protein microarray analyses showed that expression of multiple proteins was regulated by Capn4. Interestingly, Capn4 was found to physically associate with FAK and promoted hyperactivity of the FAK-Src signalling pathway via increased phosphorylation of specific tyrosine residues of FAK, Src and p130Cas. Knock-down of Capn4 expression suppressed the malignant behaviour of HCC cells and inhibited the FAK-Src signalling pathway. Furthermore, Capn4-mediated invasion and metastasis of HCC cells required up-regulation of matrix metalloproteinase-2 (MMP2) through activation of this signalling pathway. Our clinical data revealed that Capn4 expression correlated well with the levels of phospho-FAK, and over-expression of both Capn4 and phospho-FAK correlates with the poorest survival outcomes in HCC. In conclusion, our data showed that Capn4 can contribute to HCC growth and metastasis via activation of the FAK-Src signalling pathway and MMP2.

Expression of heterogeneous nuclear ribonucleoprotein AB (HNRNPAB) has been reported to be dysregulated in tumors, but its specific contributions to tumor formation and progression are not fully understood. Here, we demonstrate that HNRNPAB is overexpressed in highly metastatic cells and tumor tissues from patients with hepatocellular carcinoma (HCC) with recurrence. We found that HNRNPAB overexpression promoted epithelial–mesenchymal transition (EMT) in a manner associated with HCC metastasis in vitro and in vivo. RNA interference-mediated silencing of the EMT factor SNAIL attenuated HNRNPAB-enhanced cell invasion in vitro and lung metastasis in vivo. Mechanistically, HNRNPAB acted to transactivate SNAIL1 transcription, which in turn inhibited transcription of the pivotal SNAIL target gene E-cadherin. Overexpression of HNRNPAB in HCC samples correlated with higher SNAIL levels, shorter overall survival, and higher tumor recurrence. HNRNPAB overexpression, alone or in combination with SNAIL, was found to be a significant independent risk factor for recurrence and survival after curative resection. In conclusion, our findings define HNRNPAB as an activator of EMT and metastasis in HCC that predicts poor clinical outcomes. Cancer Res; 74(10); 2750–62. ©2014 AACR.

CXCL5 is a member of the CXC-type chemokine family that may play a role in carcinogenesis and cancer progression. This study investigates the biological function and clinical significance of CXCL5 in intrahepatic cholangiocarcinoma (ICC). We demonstrated that CXCL5 was overexpressed in ICC cell lines and tumor samples compared with paired normal tissues. CXCL5 had a direct chemoattractant effect on neutrophils in vitro through PI3K-Akt and extracellular signal-regulated kinase 1/2 signaling pathways. In animal studies, CXCL5 promoted tumor growth and metastasis without altering in vitro proliferative and invasive ability of ICC cells, and this effect was mediated by the recruitment of intratumoral infiltrative neutrophils by tumor-derived CXCL5. Immunohistochemical analysis of ICC samples showed that overexpression of CXCL5 correlated strongly with intratumoral neutrophil infiltration, shorter overall survival and high tumor recurrence. Multivariate analysis revealed that CXCL5 overexpression alone, or combined with the presence of intratumoral neutrophils, was an independent prognostic indicator for ICC. In conclusion, our data showed that CXCL5 promotes ICC growth and metastasis by recruiting intratumoral neutrophils. CXCL5 alone or combined with intratumoral neutrophils is a novel prognostic predictor for ICC patients and a potential therapeutic target.

Semaphorin 3A (SEMA3A), a secretory protein, is a founding member of the semaphorin family and functions in both the biological behavior of tumor cells and the modulation of tumor-associated macrophages. However, the role of SEMA3A in hepatocellular carcinoma (HCC) is still not well established. In the present study, we investigated the expression levels of SEMA3A in 80 HCC tissues and cell lines, using RT-qPCR, western blotting and immunohistochemistry. Expression profile analysis revealed that SEMA3A was significantly overexpressed in human HCC patients and positively correlated with the metastatic potential of HCC cells. Lentiviral transfection into PLC/PRF/5 and HCCLM3 cells was performed to stably upregulate and downregulate the expression of SEMA3A in HCC cells. Cell Counting Kit-8 (CCK-8), wound-healing and invasion assays revealed that SEMA3A promoted the proliferation and migration of HCC cells in vitro. Proteome profiler antibody microarray analysis revealed that overexpression of SEMA3A in HCC cells induced a significant increase in the expression levels of gelsolin-like capping protein (CapG), galectin-3, enolase 2 and epithelial cell adhesion molecule (EpCAM). Furthermore, the upregulation of SEMA3A in HCC cells promoted tumor growth and progression in an HCC mouse model. These results indicate that SEMA3A enhances CapG, galectin-3, enolase 2 and EpCAM expression to promote HCC progression and is a potential therapeutic target for HCC.

// Er-Bao Chen 1, 2, * , Shao-Lai Zhou 1, * , Xu-Guang Pang 3, * , Dan Yin 1 , Pei-Zhen Miao 1 , Yi Yang 1 , Qing Chen 1 , Kai Zhu 1 , Dong-Mei Gao 1 , Tian-Shu Liu 4 , Xiao-Yi Wang 1 , Ying-Hong Shi 1 , Wei-Zhong Wu 1 , Jian Zhou 1, 2 , Zheng-Jun Zhou 1 and Zhi Dai 1, 2 1 Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Labolatory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, China 2 State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, China 3 Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China 4 Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai, China * These authors have contributed equally to this work Correspondence to: Zhi Dai, email: dai.zhi@zs-hospital.sh.cn Zheng-Jun Zhou, email: zhou.zhengjun@zs-hospital.sh.cn Keywords: PDEF, HCC, EMT, invasion, proliferation Received: August 25, 2016 Accepted: December 27, 2016 Published: January 31, 2017 ABSTRACT Prostate-derived E-twenty-six (ETS) factor (PDEF), an epithelium-specific ETS transcription factor, regulates carcinogenesis and tumor progression. The prognostic importance and biologic functions in hepatocellular carcinoma (HCC) have not been established. We investigated PDEF expression in 400 HCC patients using quantitative real-time polymerase chain reaction, western blot and immunohistochemistry analysis. PDEF expression was significantly lower in tumors than in peritumoral tissues. Lower PDEF levels were associated with poorer prognosis in patients. PDEF was an independent predictor of overall survival in multivariate analysis. PDEF expression was suppressed in highly metastatic HCC cell lines, and shRNA-mediated down-regulation of PDEF in low-metastatic HCC cell lines (with high PDEF) significantly increased cellular proliferative and invasive capacity in vitro and in vivo . RNA sequencing analysis indicated that PDEF may mediate transcription of several genes involved in apoptosis and the cell cycle. PDEF modulated epithelial-mesenchymal transition by up-regulating E-cadherin expression and down-regulating Slug and Vimentin expression, thereby lowering migration and invasion abilities of HCC cells. In conclusion, PDEF is associated with proliferation and invasiveness of HCC cells. It may serve as an independent predictor of prognosis in patients with HCC.

Ten eleven translocation (TET) enzymes convert 5-methylcytosine (5-mC) to 5-hydroxy-methylcytosine (5-hmC) and have crucial roles in biological and pathological processes by mediating DNA demethylation, however, the functional role of this epigenetic mark and the related enzymes in hepatocellular carcinoma (HCC) progression remains unknown. Here, we demonstrated that TET-family enzymes downregulation was one likely mechanism underlying 5-hmC loss in HCC. We found that miR-29a overexpression increased DNA methylation of suppressor of cytokine signaling 1 (SOCS1) promoter was associated with HCC metastasis in vitro and in vivo. Furthermore, miR-29a silenced anti-metastatic SOCS1 through direct TET-family targeting, resulting in SOCS1 promoter demethylation inhibition. Chromatin immunoprecipitation analyses confirmed that TET1 regulated SOCS1 expression through binding to the promoter region of SOCS1. Finally, miR-29a overexpression correlated with poor clinical outcomes and TET–SOCS1–matrix metalloproteinase (MMP) 9 axis silencing in HCC patients. In conclusion, our findings demonstrate that 5-hmC loss is an epigenetic hallmark of HCC, and miR-29a is an important epigenetic modifier, promoting HCC metastasis through TET–SOCS1–MMP9 axis silencing. The results offer a new strategy for epigenetic cancer therapy.

Macrophages are a major component of the leukocyte infiltrate of tumors and play a pivotal role in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanisms by which macrophages promote HCC invasion are poorly understood. The present study was undertaken to investigate the relationship between macrophages and epithelial-mesenchymal transition (EMT) of HCC. Double-staining immunohistochemistry was used to observe the association between macrophages and EMT markers in clinical HCC samples and it showed that EMT primarily occurred at the edge of the tumor nest, in which infiltrating macrophages were always observed. This indicated that CD68 which is a marker of macrophages, was correlated with EMT marker levels. In addition, after being cultured with macrophages for 24 h, the ability of HCC cells to migrate and invade increased, Snail and N-Cadherin expression was upregulated, and E-Cadherin was downregulated. An antibody array assay was applied to analyze the supernatant of these cultures and it demonstrated IL-8 increased significantly in the macrophage co-culture system. Finally, the role of macrophage-derived IL-8 in the invasion of HCC cells was assayed, and downstream signaling pathways were also investigated. We found that IL-8: i) may induce EMT and promote HCC cell migration and invasion and ii) is associated with the JAK2/STAT3/Snail signaling pathway. Taking together, these findings revealed that macrophages that have infiltrated tumors may induce epithelial-mesenchymal transition of HCC cells via the IL-8 activated JAK2/STAT3/Snail pathway. Thus, this may offer a potential target for developing new HCC therapies.

Heterogeneous ribonucleoprotein (hnRNP) A1 is a member of the A/B subfamily of ubiquitously expressed hnRNPs, which have a wide variety of functions in gene expression and signal transduction. To investigate the biological function and clinical significance of hnRNP A1 in hepatocellular carcinoma (HCC), we measured hnRNP A1 expression in four HCC cell lines and two independent cohorts of HCC patients. We found that hnRNP A1 was overexpressed in the highly metastatic HCC cell lines and in tumor tissues of patients with recurrent HCC. Knockdown of hnRNP A1 in highly metastatic HCC cells caused a significant decrease in cell invasion, while upregulation of hnRNP A1 in poorly metastatic HCC cells led to a significant increase in their invasive capacity. We found that this effect may occur through the regulation of CD44v6 expression by hnRNP A1 in HCC cells. Both quantitative reverse transcription-polymerase chain reaction (qRT-RCR) and immunohistochemistry revealed that hnRNP A1 was upregulated in HCC tissues and coincided with overexpression of CD44v6. HCC patients with high hnRNP A1 tended to have higher levels of CD44v6, shorter overall survival (OS) and higher rates of tumor recurrence. Multivariate analyses revealed that hnRNP A1 alone or in combination with CD44v6 were independent prognostic indicators for OS and time to recurrence and have potential as therapeutic targets. In conclusion, overexpression of hnRNP A1 promotes HCC invasion by regulating the level of CD44v6 and indicates a poor prognosis for HCC patients after curative resection.

e15149 Background: Macrophages are a major component of the leukocyte infiltrate of tumors and play a pivotal role in the progression of hepatocellular carcinoma (HCC). However, the molecular mecha...