Xiaowu Huang

CXCR2/CXCL5 axis contributes to epithelial–mesenchymal transition of HCC cells through activating PI3K/Akt/GSK-3β/Snail signaling

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.

Tumor-Associated Neutrophils Recruit Macrophages and T-Regulatory Cells to Promote Progression of Hepatocellular Carcinoma and Resistance to Sorafenib

BACKGROUND & AIMSnNeutrophils 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.nnnMETHODSnWe 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 inxa02010.nnnRESULTSnCCL2 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.nnnCONCLUSIONSnTANs recruit macrophages and Treg cells to HCCs to promote their growth, progression, and resistance to sorafenib.

Circulating microRNAs as a Fingerprint for Liver Cirrhosis

Background Sensitive and specific detection of liver cirrhosis is an urgent need for optimal individualized management of disease activity. Substantial studies have identified circulation miRNAs as biomarkers for diverse diseases including chronic liver diseases. In this study, we investigated the plasma miRNA signature to serve as a potential diagnostic biomarker for silent liver cirrhosis. Methods A genome-wide miRNA microarray was first performed in 80 plasma specimens. Six candidate miRNAs were selected and then trained in CHB-related cirrhosis and controls by qPCR. A classifier, miR-106b and miR-181b, was validated finally in two independent cohorts including CHB-related silent cirrhosis and controls, as well as non−CHB-related cirrhosis and controls as validation sets, respectively. Results A profile of 2 miRNAs (miR-106b and miR-181b) was identified as liver cirrhosis biomarkers irrespective of etiology. The classifier constructed by the two miRNAs provided a high diagnostic accuracy for cirrhosis (AUCu200a=u200a0.882 for CHB-related cirrhosis in the training set, 0.774 for CHB-related silent cirrhosis in one validation set, and 0.915 for non−CHB-related cirrhosis in another validation set). Conclusion Our study demonstrated that the combined detection of miR-106b and miR-181b has a considerable clinical value to diagnose patients with liver cirrhosis, especially those at early stage.

Galectin-1 induces hepatocellular carcinoma EMT and sorafenib resistance by activating FAK/PI3K/AKT signaling

Galectin-1 (Gal-1) is involved in several pathological activities associated with tumor progression and chemoresistance, however, the role and molecular mechanism of Gal-1 activity in hepatocellular carcinoma (HCC) epithelial–mesenchymal transition (EMT) and sorafenib resistance remain enigmatic. In the present study, forced Gal-1 expression promoted HCC progression and sorafenib resistance. Gal-1 elevated αvβ3-integrin expression, leading to AKT activation. Moreover, Gal-1 overexpression induced HCC cell EMT via PI3K/AKT cascade activation. Clinically, our data revealed that Gal-1 overexpression is correlated with poor HCC survival outcomes and sorafenib response. These data suggest that Gal-1 may be a potential therapeutic target for HCC and a biomarker for predicting response to sorafenib treatment.

miR‐28‐5p‐IL‐34‐Macrophage Feedback Loop Modulates Hepatocellular Carcinoma Metastasis

MicroRNAs (miRNAs) play a critical role in regulation of tumor metastasis. However, the role of these molecules in hepatocellular carcinoma (HCC) 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 down‐regulated in HCCs. This down‐regulation 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 (TAM) infiltration. Moreover, we found that TAMs induced by miR‐28‐5p‐IL‐34 signaling inhibit miR‐28‐5p expression on HCC cells by transforming growth factor beta 1, 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 and time to recurrence. Conclusion: A 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. (Hepatology 2016;63:1560‐1575)

Ubiquitin C-terminal Hydrolase 37, a novel predictor for hepatocellular carcinoma recurrence, promotes cell migration and invasion via interacting and deubiquitinating PRP19

Ubiquitin C-terminal hydrolase 37 (UCH37) plays a crucial role in numerous biological processes and is also involved in oncogenesis. In this study, clinicopathologic data showed that UCH37 was over-expressed in hepatocellular carcinoma (HCC) cancerous tissues and was a significant predictor for time to recurrence (TTR). In vitro, we discovered that UCH37 could promote cell migration and invasion. Subsequently, we utilized Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) to identify differentially expressed proteins in UCH37 over-expressing cells compared with the control cells, and found that PRP19, an essential RNA splicing factor, was up-regulated. The relationship between UCH37, PRP19 and the capability of cell migration and invasion was further confirmed. Collectively, this study demonstrated that UCH37 could promote cell migration and invasion in HCC cell lines through interacting and deubiquitinating PRP19, and suggested that UCH37 could be a novel predictor for HCC recurrence after curative resection.

Detecting Circulating Tumor DNA in Hepatocellular Carcinoma Patients Using Droplet Digital PCR Is Feasible and Reflects Intratumoral Heterogeneity.

Purpose: Circulating tumor DNA (ctDNA) is increasingly recognized as liquid biopsy to profile tumor genome. Droplet digital PCR (ddPCR) is a highly sensitive and easily operable platform for mutant detection. Here, we tried to detect ctDNA in hepatocellular carcinoma (HCC) patients using ddPCR. Methods: Studies sequencing the genome of HCCs and COSMIC (Catalogue of Somatic Mutations in Cancer) database were reviewed to identify hotspot mutations. Circulating cell-free DNAs (cfDNAs) extracted from 1 ml preoperative plasma sample were analyzed to detect circulating mutants using ddPCR. The DNAs from matched tumor and adjacent liver tissues or peripheral blood mononuclear cells (PBMCs) were sequenced to identify the origin of circulating mutants. Results: Forty-eight HCC patients were enrolled and four gene loci, TP53 (c.747G>T), CTNNB1 (c.121A>G, c.133T>C), and TERT (c.1-124C>T) were chosen as targets for ddPCR assay. Serial dilution demonstrated the detection limit of ddPCR to be 0.01%. Twenty-seven patients (56.3%, 27/48) were found to have at least one kind of circulating mutants, with the mutant allele frequency ranging from 0.33% to 23.7%. Six patients (22.2%, 6/27) also had matched mutants in tumor tissues while none of the mutants were detected in adjacent liver tissues or PBMCs in all patients, which excluded the nonneoplastic origin of these circulating mutants and qualified them as ctDNA. Conclusions: ctDNA could be readily detected in HCC patients by targeting hotspot mutations using ddPCR and might reflect intratumoral heterogeneity. ctDNA detecting may serve as a promising liquid biopsy in HCC management.

New-onset diabetes after liver transplantation and its impact on complications and patient survival.

The aim of the present study was to investigate the incidence and risk factors of new‐onset diabetes after transplantation (NODAT) in liver transplant recipients and the influence of NODAT on complications and long‐term patient survival.

BIRC6 promotes hepatocellular carcinogenesis: Interaction of BIRC6 with p53 facilitating p53 degradation

The genes that encode inhibitor of apoptosis proteins (IAPs) are frequently overexpressed in human cancers. However, the expression pattern and clinical significance of BIRC6, a member of IAPs, in hepatocellular carcinoma (HCC) remains unclear. Here we investigated the role of BIRC6 in hepatocellular carcinogenesis. We used immunoblot and immunochemical analyses to determine the levels of BIRC6 in 7 hepatoma cell lines and 160 HCC specimens. We evaluated the proognostic value of BIRC6 expression and its association with clinical parameters. A lentivirus‐mediated silencing method was used to knockdown BIRC6, and the biological consequences of BIRC6 silencing in three hepatoma cell lines were investigated in vitro and in vivo. We found that BIRC6 overexpression was significantly correlated with serum ALT level and HCC vascular invasion. Patients with positive BIRC6 expression in tumor tissue had a poor survival and a high rate of recurrence. BIRC6 knockdown remarkably suppressed cell proliferation, caused G1/S arrest and sensitized hepatoma cells to sorafenib‐induced apoptosis in hepatoma cells, which was partly reversed by RNA interference targeting p53. The mechanistic study revealed that BIRC6 interacted with p53 and facilitated its degradation. The in vivo study showed that BIRC6 knockdown inhibited xenograft tumor growth and increased the sensitivity of tumor cells to sorafenib in nude mice. Taken together, these findings demonstate that BIRC6 overexpression in HCC specimens is indicative of poor prognosis and that its interaction with p53 facilitates the degradation of p53, leading to carcinogenesis and an anti‐apoptotic status.

Clinical significance of the ubiquitin ligase UBE3C in hepatocellular carcinoma revealed by exome sequencing

Virus‐induced hepatocarcinogenesis involves a series of histological developmental processes with the stepwise acquisition of several genetic changes that are necessary for the malignant transformation of hepatocytes. Although genetic alterations are known to be involved in the pathogenesis of hepatocellular carcinoma (HCC), little is known about the contributions of specific genes to this process. To gain insight into the genetic alterations involved in the neoplastic evolution from chronic hepatitis B virus infection to dysplastic nodules (DN) to HCC, we captured and sequenced the exomes of four DNA samples: one DN sample, two HCC samples, and one control peripheral blood sample from a single HCC patient. Mutations in the UBE3C gene (encoding ubiquitin ligase E3C) were observed in both tumor tissues. Then we resequenced the UBE3C gene in a cohort of 105 HCC patients and identified mutations in 17 out of a total of 106 (16.0%) HCC patients. The subsequent experiments showed that UBE3C promoted HCC progression by regulating HCC cells epithelial‐mesenchymal transition. Clinically, a tissue microarray study of a cohort containing 323 HCC patients revealed that the overexpression of UBE3C in primary HCC tissues correlated with decreased survival (hazard ratio [HR]u2009=u20091.657, 95% confidence interval [CI]u2009=u20091.220‐2.251, Pu2009=u20090.001) and early tumor recurrence (HRu2009=u20091.653, 95% CIu2009=u20091.227‐2.228, Pu2009=u20090.001) in postoperative HCC patients. Conclusion: Our findings indicate that UBE3C is a candidate oncogene involved in tumor development and progression and therefore a potential therapeutic target in applicable HCC patients. (Hepatology 2014;59:2216–2227)