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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.

Infiltrating immune cells in the tumor microenvironment (TME) influence tumor progression and patient prognosis, making them attractive therapeutic targets for immunotherapy research. A deeper understanding of immune cell distributions in the TME in hepatocellular carcinoma (HCC) is needed to identify interactions among different immune cell types that might impact the effectiveness of potential immunotherapies. We performed multiplex immunohistochemistry using a tissue microarray of samples from 302 patients with HCC to elucidate the spatial distributions of immune cell subpopulations (CD3+ , CD4+ , CD8+ , CD66b+ , and CD68+ ) in HCC and normal liver tissues. We analyzed the associations between different immune subpopulations using Pearson's correlation. G(r) functions, K(r) functions and Euclidean distance were applied to characterize the bivariate distribution patterns among the immune cell types. Cox regression and Kaplan-Meier analysis were used to evaluate the associations between tumor infiltration by different immune cells and patient outcomes after curative surgery. We also analyzed the relationship between the spatial distribution of different immune cell subpopulations with HCC patient prognosis. We found that the immune cell spatial distribution in the HCC TME is heterogeneous. Our study provides a theoretical basis for HCC immunotherapy.

Background & Aims Early recurrence of hepatocellular carcinoma (HCC) after curative resection is common. However, the association between genetic mechanisms and early HCC recurrence, especially in Chinese patients, remains largely unknown. Methods We performed whole-genome sequencing (49 cases), whole-exome sequencing (18 cases), and deep targeted sequencing (115 cases) on 182 primary HCC samples. Focusing on WNK2, we used Sanger sequencing and qPCR to evaluate all the coding exons and copy numbers of that gene in an additional 554 HCC samples. We also explored the functional effect and mechanism of WNK2 on tumor growth and metastasis. Results We identified 5 genes (WNK2, RUNX1T1, CTNNB1, TSC1, and TP53) harboring somatic mutations that correlated with early tumor recurrence after curative resection in 182 primary HCC samples. Focusing on WNK2, the overall somatic mutation and copy number loss occurred in 5.3% (39/736) and 27.2% (200/736), respectively, of the total 736 HCC samples. Both types of variation were associated with lower WNK2 protein levels, higher rates of early tumor recurrence, and shorter overall survival. Biofunctional investigations revealed a tumor-suppressor role of WNK2: its inactivation led to ERK1/2 signaling activation in HCC cells, tumor-associated macrophage infiltration, and tumor growth and metastasis. Conclusions Our results delineate genomic events that characterize Chinese HCCs and identify WNK2 as a driver of early HCC recurrence after curative resection. Lay summary We applied next-generation sequencing and conducted an in-depth genomic analysis of hepatocellular carcinomas from a Chinese patient cohort. The results delineate the genomic events that characterize hepatocellular carcinomas in Chinese patients and identify WNK2 as a driver associated with early tumor recurrence after curative resection.

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.

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.

Background Due to the phenotypic and molecular diversity of hepatocellular carcinomas (HCC), it is still a challenge to determine patients’ prognosis. We aim to identify new prognostic markers for resected HCC patients. Methods 274 patients were retrospectively identified and samples collected from Zhongshan hospital, Fudan University. We analyzed the gene expression patterns of tumors and compared expression patterns with patient survival times. We identified a “9-gene signature” associated with survival by using the coefficient and regression formula of multivariate Cox model. This molecular signature was then validated in three patients cohorts from internal cohort (n = 69), TCGA (n = 369) and GEO dataset (n = 80). Results We identified 9-gene signature consisting of ZC2HC1A, MARCKSL1, PTGS1, CDKN2B, CLEC10A, PRDX3, PRKCH, MPEG1 and LMO2. The 9-gene signature was used, combined with clinical parameters, to fit a multivariable Cox model to the training cohort (concordance index, ci = 0.85), which was successfully validated (ci = 0.86 for internal cohort; ci = 0.78 for in silico cohort). The signature showed improved performance compared with clinical parameters alone (ci = 0.70). Furthermore, the signature predicted patient prognosis than previous gene signatures more accurately. It was also used to stratify early-stage, HBV or HCV-infected patients into low and high-risk groups, leading to significant differences in survival in training and validation (P

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.

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.

CXCL5 (epithelial neutrophil-activating peptide-78) is a member of a proangiogenic subgroup of the CXC-type chemokine family of small, secreted proteins. Recently, evidence that CXCL5 is involved in carcinogenesis and cancer progression has emerged. To investigate the role of CXCL5 in tumor growth, invasion, and prognosis of hepatocellular carcinoma (HCC), we examined CXCL5 messenger RNA (mRNA) and protein levels in HCC cell lines with various metastatic potentials and in three independent cohorts of 919 HCC patients. We found that CXCL5 expression was increased in the highly metastatic HCC cell lines and in tumor tissues from patients with recurrent HCC compared to controls. CXCL5 activated the PI3K-Akt and ERK1/2 signaling pathways in HCC cells and promoted proliferation, migration, and invasion. Furthermore, we found that CXCL5 had a direct chemoattractant effect on neutrophils in vitro. In animal studies, the up-regulation of CXCL5 in HCC cells promoted tumor growth, lung metastasis, and intratumoral neutrophil infiltration. Conversely, down-regulation of CXCL5 in HCC cells reduced tumor growth, metastasis, and intratumoral neutrophil infiltration. Immunohistochemical analysis in HCC samples showed that overexpression of CXCL5 was well correlated with intratumoral neutrophil infiltration, shorter overall survival, and tumor recurrence. Multivariate analysis revealed that CXCL5 overexpression alone, or combined with the presence of intratumoral neutrophils, was an independent prognostic indicator for overall survival and cumulative recurrence. Conclusion: CXCL5 promotes HCC cell proliferation, invasion, and intratumoral neutrophil infiltration. CXCL5 overexpression, alone or combined with intratumoral neutrophil presence, is a novel prognostic predictor, and CXCL5 is a potential therapeutic target for HCC. (HEPATOLOGY 2012;56:2242–2254)

MicroRNAs (miRNAs) play a critical role in the regulation of tumor metastasis. The role of these molecules in hepatocellular carcinoma (HCC), however, has not been fully elucidated. In this study, we employed miRNA-sequencing and identified 22 miRNAs involved in HCC metastasis. One of these, miR-28-5p, was downregulated in HCCs. This downregulation correlated with tumor metastasis, recurrence, and poor survival. Biofunctional investigations revealed that miR-28-5p deficiency promoted tumor growth and metastasis in nude mice without altering the in vitro biological characteristics of HCC cells. Through gene expression profiles and bioinformatics analysis, we identified interleukin-34 (IL-34) as a direct target of miR-28-5p, and the effects of miR-28-5p deficiency on HCC growth and metastasis was dependent on IL-34-mediated tumor-associated macrophage (TAMs) infiltration. Moreover, we found that TAMs induced by miR-28-5p-IL-34 signaling inhibit miR-28-5p expression on HCC cells via transforming growth factor-β1 (TGF-β1), resulting in an miR-28-5p-IL-34-macrophage positive feedback loop. In clinical HCC samples, miR-28-5p levels were inversely correlated with IL-34 expression and the number of TAMs. Patients with low miR-28-5p expression, high IL-34 levels, and high numbers of TAMs had a poor prognosis with shorter overall survival (OS) and time to recurrence (TTR). Conclusion: an miR-28-5p-IL-34-macrophage feedback loop modulates HCC metastasis and serves as a novel prognostic factor as well as a therapeutic target for HCC. This article is protected by copyright. All rights reserved.

Background & Aims Neutrophils can either promote or inhibit tumor progression, depending on the tumor microenvironment, via release of cytokines. Neither the factors produced by tumor-associated neutrophils (TANs) nor their effects on tumor progression have been characterized. We investigated the roles of TANs in progression of hepatocellular carcinoma (HCC) using cell lines and immune cells isolated from patients. Methods We performed studies with HepG2, PLC/PRF/5, MHCC97H, and HCCLM3 human and Hepa1-6 and H22 mouse HCC cell lines; expression of chemokines and cytokines were knocked down with small hairpin RNAs. Cells were analyzed in chemotaxis assays and as growth as tumors in mice. HCC tissues and peripheral blood were collected from 20 patients undergoing curative resection or 20 healthy individuals (controls) in 2012 at Zhongshan Hospital in China. TANs and peripheral blood neutrophils (PBNs) were isolated and exposed to conditioned media from HCC cell lines; reverse-transcription polymerase chain reaction was used to quantify the expression of cytokines and chemokines. We collected neutrophils from another 60 patients undergoing curative resection for HCC in 2012 to measure the production of C-C motif chemokine ligand 2(CCL2) and CCL17. Patients were followed up until March 15, 2014. For immunohistochemical analyses, we collected HCC tissues and paired, adjacent, nontumor cirrhotic liver tissues from 832 HCC patients undergoing curative resection from 2006 through 2008. All patients were followed up until March 15, 2013. To study the effects of sorafenib, we collected clinical and pathology data from 46 patients who underwent curative resection in 2010. Results CCL2 and CCL17 were the cytokines most highly expressed by TANs and HCC cell-activated PBNs. Levels of CCL2 and CCL17 messenger RNAs and proteins were significantly higher in TANs than in PBNs, and increased in patients with HCC recurrence. CCL2 and CCL17 messenger RNA and proteins also increased when PBNs were exposed to conditioned media from HCC cell lines. Immunohistochemical analysis of a tissue microarray showed that CCL2+ and CCL17+ cells, which also expressed the neutrophil marker CD66b, were distributed throughout the HCC stroma, but not in tumor cells or the adjacent nontumor liver cells. The number of CCL2+ or CCL17+ TANs correlated with tumor size, microvascular invasion, tumor encapsulation, tumor differentiation, and stage. Patients whose tumors had lower levels of CCL2+ or CCL17+ cells had longer survival times than those with higher numbers of these cells. TAN-conditioned media, as well as recombinant CCL2 and CCL17, increased the migratory activity of the macrophages and T-regulatory (Treg) cells from patients or mice with HCC to a greater extent that PBN-conditioned media. Neutralizing antibodies against CCL2 and CCL17, or their receptors C-C chemokine receptor 2 and C-C chemokine receptor 4, reduced the migratory activities of macrophage and Treg cells. HCC cell lines injected into mice formed larger tumors when they were co-injected with TANs and formed more pulmonary metastases; these tumors were infiltrated by Ly6G+ cells, F4/80+ macrophages, and Foxp3+ Treg cells. In a phosphokinase array of human PBNs, levels of phosphorylated AKT and P38 increased after exposure to conditioned media from all 4 HCC cell types. Pharmacologic inhibitors of AKT and P38 inhibited secretion of CCL2 and CCL17 by these PBNs. In tumor-bearing mice, sorafenib increased the numbers of TANs and levels of CCL2 and CCL17 in tumors. HCC tissues from patients who received sorafenib before surgery contained more TANs than tissues from patients who did not receive sorafenib. In knockdown cells, HCC cell–derived CXCL5 was the strongest effector of neutrophil migration under hypoxic conditions. In mice, the combination of sorafenib and TAN depletion inhibited tumor growth and neovascularization to a greater extent than sorafenib alone. Conclusions TANs recruit macrophages and Treg cells to HCCs to promote their growth, progression, and resistance to sorafenib.

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.