Genomic and transcriptomic characteristics of 12 novel primary cell lines derived from three patients with cholangiocarcinoma.

Cholangiocarcinoma (CCA) is an aggressive bile duct malignancy with poor prognosis. To improve our understanding of the biological characteristics of CCA and develop effective therapies, appropriate preclinical models are required. Here, we established and characterized 12 novel patient-derived primary cancer cell (PDPC) models using multi-region sampling. At the genomic level of PDPCs, we observed not only commonly mutated genes, such as TP53, JAK3, and KMT2C, consistent with the reports in CCA, but also specific mutation patterns in each cell line. In addition, specific expression patterns with distinct biological functions and pathways involved were also observed in the PDPCs at the transcriptomic level. Furthermore, the drug-sensitivity results revealed that the PDPCs exhibited different responses to the six commonly used compounds. Our findings indicate that the established PDPCs can serve as novel in vitro reliable models to provide a crucial molecular basis for improving the understanding of tumorigenesis and its treatment.

Mechanistic insights into the allosteric inactivation mechanism of ZAP-70 induced by the hot spot W165C mutation.

Zeta chain-associated protein kinase 70 (ZAP-70) is a non-receptor tyrosine kinase that interacts with the activated T-cell receptor to transduce downstream signals, and thus plays an important role in the adaptive immune system. The biphosphorylated immunotyrosine-based activation motifs (ITAM-Y2P) binds to the N-SH2 and C-SH2 domains of ZAP-70 to promote the activation of ZAP-70. The present study explores molecular mechanisms of allosteric inactivation of ZAP-70 induced by the hot spot W165C mutation through atomically detailed molecular dynamics simulation approaches. We report microsecond-length simulations of two states of the tandem SH2 domains of ZAP-70 in complex with the ITAM-Y2P motif, including the wild-type and W165C mutant. Extensive analysis of local flexibility and dynamical correlated motions show that W165C mutation changes coupled motions of protein domains and community networks. The binding affinities of the ITAM-Y2P motif to the wild-type and W165C mutant of ZAP-70 are predicted using binding free energy calculations. The results suggest that the driving force to decrease the binding affinity in the W165C mutant derives from the difference in the protein-protein electrostatic interactions. Moreover, the per-residue free energy decomposition unravels that the contributions from residues in the phosphorylated Tyr315 (pY315) binding site, in particular pY315 of ITAM-Y2P, and Arg43, Tyr240 of ZAP-70, are the key determinants for the loss of binding affinity. This study may insights into our understanding of the pathological mechanism of ZAP-70.Communicated by Ramaswamy H. Sarma.

Surgical treatment of hilar cholangiocarcinoma: retrospective analysis.

BACKGROUND: Achieving a better prognosis for patients and reducing the risk of complications are primary considerations in surgical decisions for hilar cholangiocarcinoma. METHODS: A retrospective analysis of the authors' clinical practice outcomes in the surgical management of patients with hilar cholangiocarcinoma following the planned-hepatectomy surgical treatment programme between 2009 and 2018. RESULTS: Some 473 patients were included, of whom 127 (26.8 per cent) underwent bile duct tumour resection alone, 44 (9.3 per cent) underwent bile duct tumour resection combined with restrictive hepatectomy, and 302 (63.8 per cent) underwent bile duct tumour resection combined with extensive hepatectomy. R0 resection was achieved in 82.2 per cent and the postoperative complication rate was similar between the different operations. The 5-year survival rates after surgery were 37.0, 37.3, and 28.4 per cent in the bile duct tumour resection alone, restrictive hepatectomy, and extensive hepatectomy groups respectively, with no statistically significant differences. As TNM staging progressed, the 1-5-year cumulative survival rate for the patients in the three groups showed a significant downward trend. CONCLUSION: In the setting of a high-volume centre, a planned-hepatectomy surgical treatment programme helps to strike a better balance between achieving radical tumour resection for hilar cholangiocarcinoma and reasonable control of the extent of surgical damage.

AXL Overexpression in Tumor-Derived Endothelial Cells Promotes Vessel Metastasis in Patients With Hepatocellular Carcinoma.

Portal vein tumor thrombus (PVTT) is one of the most serious forms of hepatocellular carcinoma (HCC) vessel metastasis and has a poor survival rate. However, the molecular mechanism of PVTT has not yet been elucidated. In this study, the molecular mechanism of AXL expressed in tumor-derived endothelial cells (TECs) in vessel metastasis was investigated. High AXL expression was observed in TECs, but not in the tumor cells of HCC patients with PVTT and this was associated with poor overall survival (OS) and disease-free survival (DFS). AXL overexpression was positively associated with CD 31 expression both in vitro and in vivo. AXL promoted the cell proliferation, tube formation, and migration of both TECs and normal endothelial cells (NECs). High expression of AXL in TECs promoted the cell migration, but not the proliferation of HCC cells. Further studies demonstrated that AXL promoted cell migration and tube formation through activation of the PI3K/AKT/SOX2/DKK-1 axis. AXL overexpression in HUVECs promoted tumor growth and liver or vessel metastasis of HCC in xenograft nude mice, which could be counteracted by treatment with R428, an AXL inhibitor. R428 reduced tumor growth and CD 31 expression in HCC in PDX xenograft nude mice. Therefore, AXL over-expression in TECs promotes vessel metastasis of HCC, which indicates that AXL in TECs could be a potential therapeutic target in HCC patients with PVTT.

Development and Evaluation of Nomograms to Predict the Cancer-Specific Mortality and Overall Mortality of Patients with Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the most common type among primary liver cancers (PLC). With its poor prognosis and survival rate, it is necessary for HCC patients to have a long-term follow-up. We believe that there are currently no relevant reports or literature about nomograms for predicting the cancer-specific mortality of HCC patients. Therefore, the primary goal of this study was to develop and evaluate nomograms to predict cancer-specific mortality and overall mortality. Data of 45,158 cases of HCC patients were collected from the Surveillance, Epidemiology, and End Results (SEER) program database between 2004 and 2013, which were then utilized to develop the nomograms. Finally, the performance of the nomograms was evaluated by the concordance index (C-index) and the area under the time-dependent receiver operating characteristic (ROC) curve (td-AUC). The categories selected to develop a nomogram for predicting cancer-specific mortality included marriage, insurance, radiotherapy, surgery, distant metastasis, lymphatic metastasis, tumor size, grade, sex, and the American Joint Committee on Cancer (AJCC) stage; while the marriage, radiotherapy, surgery, AJCC stage, grade, race, sex, and age were selected to develop a nomogram for predicting overall mortality. The C-indices for predicted 1-, 3-, and 5-year cancer-specific mortality were 0.792, 0.776, and 0.774; the AUC values for 1-, 3-, and 5-year cancer-specific mortality were 0.830, 0.830, and 0.830. The C-indices for predicted 1-, 3-, and 5-year overall mortality were 0.770, 0.755, and 0.752; AUC values for predicted 1-, 3-, and 5-year overall mortality were 0.820, 0.820, and 0.830. The results showed that the nomograms possessed good agreement compared with the observed outcomes. It could provide clinicians with a personalized predicted risk of death information to evaluate the potential changes of the disease-specific condition so that clinicians can adjust therapy options when combined with the actual condition of the patient, which is beneficial to patients.

Impact of splenomegaly and splenectomy on prognosis in hepatocellular carcinoma with portal vein tumor thrombus treated with hepatectomy.

BACKGROUND: Hepatocellular carcinoma (HCC) commonly occurs in patients with splenomegaly. This study aimed to investigate the impact of splenomegaly with or without splenectomy on long-term survival of HCC patients with portal vein tumor thrombus (PVTT) treated with liver resection (LR). METHODS: HCC patients with PVTT who underwent LR from 2005 to 2012 from 6 hospitals were retrospectively studied. The long-term overall survival (OS) and recurrence-free survival (RFS) were compared between patients with or without splenomegaly, and between patients who did or did not undergo splenectomy for splenomegaly. Propensity score matching (PSM) analysis was performed to match patients in a 1:1 ratio. RESULTS: Of 716 HCC patients with PVTT who underwent LR, 140 patients had splenomegaly (SM group) and 576 patients had no splenomegaly (non-SM group). The SM group was further subdivided into 49 patients who underwent splenectomy (SPT group), and 91 patients who did not received splenectomy (non-SPT group). PSM matched 140 patients in the SM group, and 49 patients in the SPT group. Splenomegaly was an independent risk factor of poor RFS and OS. The OS and RFS rates were significantly better for patients in the non-SM group than the SM group (OS: P<0.001; RFS: P<0.001), and for patients in the SPT group than the non-SPT group (OS: P<0.001; RFS: P<0.001). CONCLUSIONS: Patients who had splenomegaly had significantly worse survival in HCC patients with PVTT. Splenectomy for splenomegaly significantly improved long-term survival in these patients.

Screening and verification of long noncoding RNA promoter methylation sites in hepatocellular carcinoma.

BACKGROUND: Long noncoding ribonucleic acid (lncRNA) promoter methylation is closely related to the occurrence and development of hepatocellular carcinoma (HCC). Thus, we aim to screen and verify the lncRNA promoter methylation sites associated with overall survival (OS), vascular invasion, pathological grade, and clinical stage in HCC. METHODS: Methylation-related data including clinical characteristic, transcriptome, methylation, and messenger RNA (mRNA) expression were taken from the Cancer Genome Atlas (TCGA) database. The OS, vascular invasion, pathological grade, and clinical stage-related lncRNA promoter methylation models were developed by the least absolute shrinkage and selection operator (LASSO) algorithm based on the lncRNA promoter methylation sites screened via R software. The Kaplan-Meier analysis, the area under the receiver operating characteristic (ROC) curve (AUC), the calibration curve (C-index) were performed to evaluate the performance of these models. Finally, the methylation-specific polymerase chain reaction (MS-PCR) was performed to verify the accuracy of these models based on 146 HCC tissues from our hospital. RESULTS: A total of 10 methylation sites were included in the OS-related lncRNA promoter methylation model that could effectively divide HCC patients into high-risk and low-risk groups (P < 0.0001) via survival analysis. COX univariable and multivariable regression analysis found that the OS-related model (P < 0.001, 95% CI 1.378-2.942) and T stage (P < 0.001, 95% CI 1.490-3.418) were independent risk factors affecting OS in HCC patients. The vascular invasion-related model contained 8 methylation sites with its AUC value of 0.657; the pathological grade-related model contained 22 methylation sites with its AUC value of 0.797; the clinical stage-related model contained 13 methylation sites with its AUC of 0.724. Target genes corresponded to vascular invasion-related lncRNA promoter methylation sites were involved in many kinds of biological processes in HCC such as PI3K-Akt signaling pathway. The accuracy of the vascular invasion-related model was consistent with our bioinformatics conclusion after being verified via MS-PCR. CONCLUSION: The lncRNA promoter methylation sites are closely correlated with the process of HCC and can be utilized to improve the therapy and prognosis of HCC.

A novel molecular-clinicopathologic nomogram to improve prognosis prediction of hepatocellular carcinoma.

BACKGROUND: Emerging evidence suggests that long non-coding RNA (lncRNA) plays a crucial part in the development and progress of hepatocellular carcinoma (HCC). The objective was to develop novel molecular-clinicopathological prediction methods for overall survival (OS) and recurrence of HCC. RESULTS: An 8-lncRNA-based classifier for OS and a 14-lncRNA-based classifier for recurrence were developed by LASSO COX regression analysis, both of which had high accuracy. The tdROC of OS-nomogram and recurrence-nomogram indicates the satisfactory accuracy and predictive power. The classifiers and nomograms for predicting OS and recurrence of HCC were validated in the Test and GEO cohorts. CONCLUSIONS: These two lncRNA-based classifiers could be independent prognostic factors for OS and recurrence. The molecule-clinicopathological nomograms based on the classifiers could increase the prognostic value. METHODS: HCC lncRNA expression profiles from the cancer genome atlas (TCGA) were randomly divided into 1:1 training and test cohorts. Based on least absolute shrinkage and selection operator method (LASSO) COX regression model, lncRNA-based classifiers were established to predict OS and recurrence, respectively. OS-nomogram and recurrence-nomogram were developed by combining lncRNA-based classifiers and clinicopathological characterization to predict OS and recurrence, respectively. The prognostic value was accessed by the time-dependent receiver operating characteristic (tdROC) and the concordance index (C-index).

Screening and verification of microRNA promoter methylation sites in hepatocellular carcinoma.

The promoter methylation mode of microribonucleic acid (miRNA) plays a crucial role in the process of hepatocellular carcinoma (HCC). Therefore, the primary purpose of this study was to screen and verify the miRNA methylation sites associated with the overall survival (OS) and clinical characteristics of HCC patients. Methylation-related data were from the Cancer Genome Atlas (TCGA). R software was utilized to screen the methylation sites. The least absolute shrinkage and selection operator algorithm was utilized to develop the miRNA promoter methylation models. Then, methylation-specific polymerase chain reaction was performed with 146 HCC tissues to verify the accuracy of the vascular infiltration-related model. Additionally, we verified the functions of vascular infiltration-related miRNA by utilizing cells transfected with miR-199a-3p mimic. The model for predicting OS of HCC patients contained eight methylation sites. The Kaplan-Meier analysis suggested that the model could divide HCC patients into high- and low-risk groups (P < .0001). COX regression analysis suggested that the model (P < .001; 95% CI, 1.264-2.709) and T category (P < .001; 95% CI, 1.472-3.119) were independent risk factors for affecting OS of HCC patients. The model for predicting vascular infiltration, pathological grade, and clinical stage contained 7, 10, and 9 methylation sites respectively, with their area under the receiver operating characteristic curve (AUC) values 0.667, 0.745, and 0.725, respectively. The functional analysis suggested that miRNA methylation is involved in various biological processes such as WNT, MAPK, and mTOR signaling pathways. The accuracy of the vascular infiltration-related model was consistent with our previous bioinformatics assay. And upregulation of miR-199a-3p decreased migration and invasion abilities. The screened miRNA promoter methylation sites can be served as biomarkers for judging OS, vascular infiltration, pathology grade, and clinical stage. It can also provide new targets for improving the treatment and prognosis of HCC patients.

A novel genomic-clinicopathologic nomogram to improve prognosis prediction of hepatocellular carcinoma.

There is a lack of precise and clinical accessible model to predict the prognosis of hepatocellular carcinoma (HCC) in clinic practice currently. Here, an inclusive nomogram was developed by integrating genomic markers and clinicopathologic factors for predicting the outcome of patients with HCC. A total of 365 samples of HCC were obtained from the Cancer Genome Atlas (TCGA) database. The LASSO analysis was carried out to identify HCC-related mRNAs, and the multivariate Cox regression analysis was used to construct a genomic-clinicopathologic nomogram. As results, 9 mRNAs were finally identified as prognostic indicators, including RGCC, CDH15, XRN2, RAB3IL1, THEM4, PIF1, MANBA, FKTN and GABARAPL1, and used to establish a 9-mRNA classifier. Additionally, an inclusive nomogram was built up by combining the 9-mRNA classifier (P < 0.001) and clinicopathologic factors including age (P = 0.006) and metastasis (P < 0.001) to predict the mortality of HCC patients. Time-dependent receiver operating characteristic, index of concordance and calibration analyses indicated favorable accuracy of the model. Decision curve analysis suggested that appropriate intervention according to the established nomogram will bring net benefit when threshold probability was above 25%. The genomic-clinicopathologic model could be a reliable tool for predicting the mortality, helping determining the individualized treatment and probably improving HCC survival.

High expression of S100A12 on intratumoral stroma cells indicates poor prognosis following surgical resection of hepatocellular carcinoma.

The S100 protein family is widely involved in the pathological process of various types of cancer. However, the prognostic value of the S100 protein family member S100A12 in hepatocellular carcinoma (HCC) remains unknown. A total of 139 patients undergoing curative surgical resection for HCC from December 2005 to June 2006 were investigated. Immunohistochemistry of S100A12 tissue was performed and expression was classified according to the total positive staining area. Co-expression of S100A12 with cluster of differentiation (CD)11B, CD15 and CD68 was evaluated using immunofluorescence. Associations between S100A12 expression and preoperative clinicopathological parameters were assessed using a χ2 test or independent sample Student's t-test. Kaplan-Meier estimator survival analysis and multivariate Cox's proportional hazard regression model were used to evaluate the prognostic value of S100A12 expression. The expression of S100A12 was restricted exclusively to stroma cells, primarily to myeloid-derived immune cells, CD15-positive neutrophils and CD68-positive macrophages in particular. A total positive staining area of 1,600 µm2 was selected as the threshold between high and low S100A12 expression. There was a statistically significant association between intratumoral S100A12 expression and tumor differentiation (P=0.010). High expression of S100A12 on intratumoral stroma cells was an independent prognostic factor for the overall (P=0.002) and disease-free survival (P=0.007) rates of HCC following curative surgical resection. No significant association was identified between peritumoral S100A12 expression and HCC prognosis. The results of the present study demonstrated that high expression of S100A12 on intratumoral stroma cells is associated with poor HCC prognosis following curative resection, which may serve as a potential target for an adjuvant therapy.

CD31 regulates metastasis by inducing epithelial-mesenchymal transition in hepatocellular carcinoma via the ITGB1-FAK-Akt signaling pathway.

Platelet endothelial cell adhesion molecule-1 (PECAM-1 or CD31) is a well-known marker of endothelial cells and a key factor for adhesion and accumulation of platelets. CD31 plays roles in cell proliferation, apoptosis, migration, and cellular immunity. CD31 is also expressed on tumor cells, such as breast cancer cells and non-Hodgkin's lymphomas, and contributes to tumor cell invasion. Here, our experiments show that CD31 promotes metastasis by inducing the epithelial-mesenchymal transition in hepatocellular carcinoma by up-regulating integrin ß1 via the FAK/Akt signaling pathway.

Insufficient Radiofrequency Ablation Treated Hepatocellular Carcinoma Cells Promote Metastasis by Up-Regulation ITGB3.

Radiofrequency ablation (RFA) is one of the standards of care for early stage hepatocellular carcinoma (HCC). However, rapid progression of residual tumor after RFA has been confirmed. The aim of this study was to investigate the underlying mechanism of this phenomenon. Human HCC cell lines HCCLM3 and HepG2 were employed to establish insufficient RFA models in vivo and in vitro, respectively. The effects of insufficient RFA on metastatic potential of residual tumors were evaluated. The molecular changes after insufficient RFA were evaluated by PCR array, western blot, immunofluorescence, and immunohistochemistry. Results showed that insufficient RFA significantly promoted lung and intrahepatic residual tumor cells in vivo, and heat intervention promoted migration and invasion of hepatoma cells in vitro. PCR array revealed that the expression of integrin ß3 (ITGB3) and MMP2 were up-regulated in the residual tumors of HCCLM3 xenograft model. The up-regulation of ITGB3 was confirmed by qRT-PCR, Western blot and immunohistochemistry. Knockdown ITGB3 expression in HCCLM3 cells by shRNA significantly lowered the pro-metastatic effects of insufficient RFA. Mechanism studies indicated that ITGB3 mediated the expression of MMP2 by activing FAK/PI3K/AKT signaling pathway. The up-regulation of ITGB3 contributed to enhanced metastatic potential of residual cancer in HCCLM3 model after insufficient RFA. Targeting ITGB3 expression may further improve the clinical effects of RFA.

Colony-stimulating factor-1-induced AIF1 expression in tumor-associated macrophages enhances the progression of hepatocellular carcinoma.

M2-polarized (alternatively activated) macrophages play an important role in the progression of hepatocellular carcinoma (HCC). Allograft inflammatory factor 1 (AIF1) is overexpressed in M2-polarized macrophages. This study explored the role of AIF1 in tumor-associated macrophages in HCC. Macrophages were stimulated with colony-stimulating factor 1 (CSF1) to characterize the regulatory pathway of AIF1 in macrophages. The chromatin immunoprecipitation and luciferase reporter gene assay were conducted to examine transcription factors associated with AIF1 expression. AIF1 was down or upregulated, and the effects on tumor progression were evaluated by using in vitro and in vivo co-culture systems. A cytokine array was performed to screen the downstream functional components of AIF1. Tumor tissue from 206 patients with HCC were used to explore the clinical significance of AIF1. AIF1 induced a M2-like phenotype of macrophages. By facilitating the binding of c-Jun to the promoter of AIF1, CSF1 secreted from hepatoma cells increased AIF1 expression through the CSF1R-MEK1/2-Erk1/2-c-Jun axis. AIF1 expressed in macrophages promoted the migration of hepatoma cells in co-culture system of RAW264.7 and Hepa1-6 and tumor growth in an animal model. The cytokine array showed that CXCL16 was increased in RAW264.7 cells with overexpressed AIF1, leading to enhanced tumor cell migration. In human HCC tissue, AIF1-positive macrophages in the adjacent microenvironment was associated with microvascular invasion and advanced TNM stages and with patients' overall and disease-free survival (p = 0.002 for both). AIF1 expression in macrophages plays a pivotal role in the interaction between macrophages and hepatoma cells.

Colony-Stimulating Factor 1 Receptor Blockade Inhibits Tumor Growth by Altering the Polarization of Tumor-Associated Macrophages in Hepatocellular Carcinoma.

Colony-stimulating factor-1 (CSF-1) and its receptor, CSF-1R, regulate the differentiation and function of macrophages and play an important role in macrophage infiltration in the context of hepatocellular carcinoma. The therapeutic effects of CSF-1R blockade in hepatocellular carcinoma remain unclear. In this study, we found that CSF-1R blockade by PLX3397, a competitive inhibitor with high specificity for CSF-1R tyrosine kinase, significantly delayed tumor growth in mouse models. PLX3397 inhibited the proliferation of macrophages in vitro, but intratumoral macrophage infiltration was not decreased by PLX3397 in vivo Gene expression profiling of tumor-associated macrophages (TAM) showed that TAMs from the PLX3397-treated tumors were polarized toward an M1-like phenotype compared with those from vehicle-treated tumors. In addition, PLX3397 treatment increased CD8+ T-cell infiltration, whereas CD4+ T-cell infiltration was decreased. Further study revealed that tumor cell-derived CSF-2 protected TAMs from being depleted by PLX3397. In conclusion, CSF-1R blockade delayed tumor growth by shifting the polarization rather than the depletion of TAMs. CSF-1R blockade warrants further investigation in the treatment of hepatocellular carcinoma. Mol Cancer Ther; 16(8); 1544-54. ©2017 AACR.

Reduced expression of CD109 in tumor-associated endothelial cells promotes tumor progression by paracrine interleukin-8 in hepatocellular carcinoma.

Tumor-associated endothelial cells (TEC) directly facilitate tumor progression, but little is known about the mechanisms. We investigated the function of CD109 in TEC and its clinical significance in hepatocellular carcinoma (HCC). The correlation between CD109 expressed on tumor vessels and the prognosis after surgical resection of HCC was studied. The effect of human umbilical vein endothelial cells (HUVEC) with different CD109 expression on hepatoma cell proliferation, migration, and invasion was compared in co-culture assay. Associated key factors were screened by human cytokine antibody array and validated thereafter. HUVEC with different CD109 expression were co-implanted with HCCLM3 or HepG2 cells in nude mice to investigate the effect of CD109 expression on tumor growth and metastasis. Reduced expression of CD109 on tumor vessels was associated with large tumor size, microvascular invasion, and advanced tumor stage. CD109 was an independent risk factor for disease-free survival (P = 0.001) after curative resection of HCC. CD109 knockdown in HUVEC promoted hepatoma cell proliferation, migration, and invasion. Interleukin-8 (IL-8) was a key tumor-promoting factor secreted from CD109 knockdown HUVEC. CD109 knockdown upregulated IL-8 expression through activation of TGF-ß/Akt/NF-κB pathway in HUVEC. Co-implantation with CD109 knockdown HUVEC accelerated tumor growth and metastasis in mice models. In conclusion, CD109 expression on tumor vessels is a potential prognostic marker for HCC, and its reduced expression on TEC promoted tumor progression by paracrine IL-8.

microRNA-26a suppresses recruitment of macrophages by down-regulating macrophage colony-stimulating factor expression through the PI3K/Akt pathway in hepatocellular carcinoma.

BACKGROUND: microRNAs (miRNAs) have been reported to modulate macrophage colony-stimulating factor (M-CSF) and macrophages. The aim of this study was to find whether miR-26a can suppress M-CSF expression and the recruitment of macrophages. METHODS: Hepatocellular carcinoma (HCC) cell lines with decreased or increased expression of miR-26a were established in a previous study. M-CSF expression by tumor cells was measured by enzyme-linked immunosorbent assay, and cell migration assays were used to explore the effect of HCC cell lines on macrophage recruitment in vitro. Real-time PCR measured a panel of mRNAs expressed by macrophages. Xenograft models were used to observe tumor growth. Immunohistochemistry was conducted to study the relation between miR-26a expression and M-CSF expression and macrophage recruitment in patients with HCC. RESULTS: Ectopic expression of miR-26a reduced expression of M-CSF. The conditioned medium (CM) from HepG2 cells that overexpressed miR-26a reduced the migration ability of THP-1 cells stimulated by phorbol myristate acetate (PMA) increased expression of interleukin (IL)-12b or IL-23 mRNA and decreased expression of chemokine (C-C motif) ligand (CCL)22, CCL17, and IL-10 mRNA, in comparison to the medium from the parental HepG2 cells. These effects could be interrupted by the PI3K/Akt pathway inhibitor LY294002. Ectopic expression of miR-26a in HCC cells suppressed tumor growth, M-CSF expression, and infiltration of macrophages in tumors. Similar results were also found when using HCCLM3 cells. Furthermore, the expression of miR-26a was inversely correlated with M-CSF expression and macrophage infiltration in tumor tissues from patients with HCC. CONCLUSIONS: miR-26a expression reduced M-CSF expression and recruitment of macrophages in HCC.

Robo1 promotes angiogenesis in hepatocellular carcinoma through the Rho family of guanosine triphosphatases' signaling pathway.

Robo1 is a member of the Robo immunoglobulin superfamily of proteins, and it plays an important role in angiogenesis and cancer. In this study, we investigate the role of roundabout 1 (Robo1) in tumor angiogenesis in hepatocellular carcinoma (HCC). Firstly, the relationship between Robo1 expression on tumors and patient's survival and endothelial cells in tumor blood vessels and patient's survival was studied. Secondly, Robo1 was overexpressed or knocked down in human umbilical vein endothelial cells (HUVECs). Cell proliferation, motility, and tube formation were compared in HUVEC with different Robo1 expression. Also, HUVECs with different Robo1 expression were mixed with HCCLM3 and HepG2 hepatoma cells and then implanted in a nude mouse model to examine the effects of Robo1 in endothelial cells on tumor growth and angiogenesis. Cell motility-related molecules were studied to investigate the potential mechanism how Robo1 promoted tumor angiogenesis in HCC. The disease-free survival of the patients with high Robo1 expression in tumoral endothelial cells was significantly shorter than that of those with low expression (P = 0.021). Overexpression of Robo1 in HUVECs resulted in increased proliferation, motility, and tube formation in vitro. In the implanted mixture of tumor cells and HUVECs with an increased Robo1 expression, tumor growth and microvessel density were enhanced compared with controls. Robo1 promoted cell division cycle 42 (Cdc42) expression in HUVECs, and a distorted actin cytoskeleton in HUVECs was observed when Robo1 expression was suppressed. In conclusion, Robo1 promoted angiogenesis in HCC mediated by Cdc42.

Incomplete radiofrequency ablation enhances invasiveness and metastasis of residual cancer of hepatocellular carcinoma cell HCCLM3 via activating ß-catenin signaling.

BACKGROUND: Radiofrequency ablation (RFA) is one of the curative therapies for hepatocellular carcinoma (HCC), however, accelerated progression of residual HCC after incomplete RFA has been reported more frequently. The underlying molecular mechanism of this phenomenon remains to be elucidated. In this study, we used an incomplete RFA orthotopic HCC nude mouse model to study the invasive and metastatic potential of residual cancer as well as the correlated mechanism. METHODS: The incomplete RFA orthotopic nude mouse models were established using high metastatic potential HCC cell line HCCLM3 and low metastatic potential HCC cell line HepG2, respectively. The changes in cellular morphology, motility, metastasis and epithelial-mesenchymal transition (EMT), and HCC cell molecular markers after in vitro and in vivo incomplete RFA intervention were observed. RESULTS: Pulmonary and intraperitoneal metastasis were observed in an in vivo study. The underlying pro-invasive mechanism of incomplete RFA appeared to be associated with promoting EMT, including down-regulation of E-cadherin and up-regulation of N-cadherin and vimentin. These results were in accordance with the in vitro response of HCC cells to heat intervention. Further studies demonstrated that ß-catenin was a pivotal factor during this course and blocking ß-catenin reduced metastasis and EMT phenotype changes in heat-treated HCCLM3 cells in vitro. CONCLUSION: Incomplete RFA enhanced the invasive and metastatic potential of residual cancer, accompanying with EMT-like phenotype changes by activating ß-catenin signaling in HCCLM3 cells.

Arsenic trioxide induces differentiation of CD133+ hepatocellular carcinoma cells and prolongs posthepatectomy survival by targeting GLI1 expression in a mouse model.

BACKGROUND: Cancer stem cells (CSCs) play a key role in the posthepatectomy recurrence of hepatocellular carcinoma (HCC). CD133+ HCC cells exhibit liver CSC-like properties, and CSC differentiation-inducing therapy may lead these cells to lose their self-renewal ability and may induce terminal differentiation, which may in turn allow their malignant potential to be controlled. Because arsenic trioxide (As2O3) increases remission rates and prolongs survival among patients with acute promyelocytic leukemia by inducing differentiation and apoptosis of leukemic cells, we hypothesized that As2O3 might also inhibit HCC recurrence and prolong survival time after hepatectomy by inducing differentiation of HCC CSCs. METHODS: We evaluated the As2O3 induced differentiation of human HCC CSCs and its mechanism in vitro, and we investigated the effects of treatment with As2O3 on recurrence rates and median survival in a mouse xenograft model. RESULTS: We found that As2O3 induced HCC CSC differentiation by down-regulating the expression of CD133 and some stemness genes, thus inhibiting the cells' self-renewal ability and tumorigenic capacity without inhibiting their proliferation in vitro. In vivo experiments indicated that As2O3 decreased recurrence rates after radical resection and prolonged survival in a mouse model. As2O3, which shows no apparent toxicity, may induce HCC CSC differentiation by down-regulating the expression of GLI1. CONCLUSIONS: We found that As2O3 induced HCC CSC differentiation, inhibited recurrence, and prolonged survival after hepatectomy by targeting GLI1expression. Our results suggest that the clinical safety and utility of As2O3 should be further evaluated.