A decade's studies on metastasis of hepatocellular carcinoma

Characterisation of a novel cell line (CSQT-2) with high metastatic activity derived from portal vein tumour thrombus of hepatocellular carcinoma

BACKGROUND

Portal vein tumour thrombus (PVTT) is highly associated with the progression and metastasis of hepatocellular carcinoma (HCC). However, there are no appropriate cell models of PVTT with which to study the biological and physiological characteristics of PVTT.

METHODS

Primary cell culture was performed by the use of a successive xenograft line called PVTT-#1, which was obtained from a 60-year-old male HCC patient accompanied by PVTT.

RESULTS

A successive cell line named CSQT-2 was established. The cell line showed aggressive phenotypes in terms of cell growth, survival, migration, xenograft and metastasis. Moreover, an orthotopic transplantation assay showed that PVTT can be generated in nude mice when CSQT-2 cells were inoculated in the liver and that it shows a typical migratory tendency in the vascular branches of portal vein. Moreover, the established CSQT-2 cells also showed varied expression of tumour-initiating cell (TIC) markers such as CD133, CD90 and EpCAM.

CONCLUSION

Establishment of CSQT-2 may provide a suitable model with which to investigate the molecular mechanisms of PVTT-related HCC.

Expression and prognostic significance of osteopontin and caspase-3 in hepatocellular carcinoma patients after curative resection

Osteopontin (OPN) plays an important role in the development, invasion, and metastasis of malignancies. Recently, several studies have reported that OPN enhances chemoresistance in small-cell lung cancer and breast cancer by blocking caspase-9 and caspase-3-dependent cell apoptosis. The aim of this study was to assess the value of OPN and caspase-3 for predicting tumor recurrence after curative resection in hepatocellular carcinoma (HCC) patients. We found that OPN expression increased concordantly with increasing metastatic potential in human HCC cell lines, whereas caspase-3 expression declined. In a tumor tissue microarray immunohistochemical analysis, we found that patients with higher levels of OPN and lower levels of caspase-3 had a significantly poorer prognosis than patients with lower OPN and higher caspase-3 levels. The combination of OPN and caspase-3 expression thus served as an effective prognosticator. These findings suggest that OPN alone or in combination with caspase-3 may act as an independent indicator for HCC patients after curative resection.

Small molecule antagonists of Tcf4/beta-catenin complex inhibit the growth of HCC cells in vitro and in vivo

Hepatocellular carcinoma (HCC) is the 5th most common cancer worldwide. It is intrinsically resistant toward standard chemotherapy, making it imperative to develop novel selective chemotherapeutic agents. The Wnt/beta-catenin pathway plays critical roles in development and oncogenesis, and is dysregulated in HCC. Our study aims to evaluate the activity of 3 small molecule antagonists of the Tcf4/beta-catenin complex (PKF118-310, PKF115-584 and CGP049090) on HCC cell lines in vitro and in vivo. All 3 chemicals displayed dose-dependent cytotoxicity in vitro against all 3 HCC cell lines (HepG2, Hep40 and Huh7), but were at least 10 times less cytotoxic to normal hepatocytes (from 3 donors) by using ATP assay. In HepG2 and Huh7 cells, treatment with the antagonists decreased Tcf4/beta-catenin binding capability and transcriptional activity, associated with downregulation of the endogenous Tcf4/ beta-catenin target genes c-Myc, cyclin D1 and survivin. In HepG2 and Huh7 cells, treatment with the antagonists induced apoptosis and cell cycle arrest at the G1/S phase. All antagonists suppressed in vivo tumor growth in a HepG2 xenograft model, associated with apoptosis and reduced c-Myc, cyclin D1 and survivin expressions. Our results suggest that these 3 antagonists of the Tcf4/beta-catenin complex are potential chemotherapeutic agents which may offer a pathway specific option for the clinical management of HCC.

Knockdown of FoxM1 by siRNA interference decreases cell proliferation, induces cell cycle arrest and inhibits cell invasion in MHCC-97H cells in vitro

AIM

To investigate the effects of small interfering RNA (siRNA) knockdown of forkhead box M1 (FoxM1) on the proliferation and invasion capacities of human hepatocellular carcinoma MHCC-97H cells in vitro.

METHODS

The expression levels of FoxM1 in human hepatocellular carcinoma samples, adjacent non-hepatocellular carcinoma liver samples and MHCC-97 cell lines were detected by RT-PCR and Western blotting. FoxM1 siRNA was transfected into MHCC-97H cells with Lipofectamine 2000. Cell growth was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell cycle analysis was performed by flow cytometry. Protein expression levels were evaluated by Western blotting. Anchorage-independent growth and the invasive potency of MHCC-97H cells were measured by soft agar colony formation and a transwell cell invasion assay, respectively.

RESULTS

FoxM1 was over-expressed in hepatocellular carcinoma samples compared to adjacent non-hepatocellular carcinoma liver samples. FoxM1 siRNA was successfully transfected into MHCC-97H cells, resulting in the significant inhibition of FoxM1 mRNA and protein expression. Down-regulation of FoxM1 inhibited cell proliferation, caused cell cycle arrest, and decreased invasion of MHCC-97H cells. Compared with control and mock groups, the FoxM1 siRNA transfected cells showed decreased protein expressions of cyclin B1 and cyclin D1, whereas p27 protein expression was increased. Down-regulation of FoxM1 reduced the expression of matrix metalloproteinase-2 (MMP-2) and urokinase plasminogen activator (uPA).

CONCLUSION

FoxM1 is functionally involved in hepatocellular carcinoma cell proliferation and invasion and is a potential target for hepatocellular carcinoma therapy.

Coronin-1C is a novel biomarker for hepatocellular carcinoma invasive progression identified by proteomics analysis and clinical validation

Background

To better search for potential markers for hepatocellular carcinoma (HCC) invasion and metastasis, proteomic approach was applied to identify potential metastasis biomarkers associated with HCC.

Methods

Membrane proteins were extracted from MHCC97L and HCCLM9 cells, with a similar genetic background and remarkably different metastasis potential, and compared by SDS-PAGE and identified by ESI-MS/MS. The results were further validated by western blot analysis, immunohistochemistry (IHC) of tumor tissues from HCCLM9- and MHCC97L-nude mice, and clinical specimens.

Results

Membrane proteins were extracted from MHCC97L and HCCLM9 cell and compared by SDS-PAGE analyses. A total of 14 differentially expressed proteins were identified by ESI-MS/MS. Coronin-1C, a promising candidate, was found to be overexpressed in HCCLM9 cells as compared with MHCC97L cells, and validated by western blot and IHC from both nude mice tumor tissues and clinical specimens. Coronin-1C level showed an abrupt upsurge when pulmonary metastasis occurred. Increasing coronin-1C expression was found in liver cancer tissues of HCCLM9-nude mice with spontaneous pulmonary metastasis. IHC study on human HCC specimens revealed that more patients in the higher coronin-1C group had overt larger tumor and more advanced stage.

Conclusions

Coronin-1C could be a candidate biomarker to predict HCC invasive behavior.

Galectin-1 and its involvement in hepatocellular carcinoma aggressiveness

Hepatocellular carcinoma is one of the most common cancers worldwide. Despite several efforts to elucidate hepatocellular carcinoma molecular pathogenesis, it is still not fully understood. To acquire further insights into the molecular mechanisms of hepatocellular carcinoma, we performed a systematic functional genomic approach on human HuH-7 and JHH-6 cells. The subsequent analysis of the differentially expressed genes in human specimens revealed a molecular signature of 11 genes from which we selected the LGALS1 gene, which was overexpressed in hepatocellular carcinoma. The expression analysis in humans of Galectin-1 (Gal-1), the protein encoded by LGALS1, showed a Gal-1 preferential accumulation in the stromal tissue around hepatocellular carcinoma tumors. Moreover, a significant association between increased expression of Gal-1 in hepatocellular carcinoma and the presence of metastasis was observed. Interestingly, Gal-1 overexpression resulted in an increase of cell migration and invasion. In conclusion, this study provides a portfolio of targets useful for future investigations into molecular marker-discovery studies on a large number of patients and functional assays. In addition, our data provide evidence that Gal-1 plays a role in hepatocellular carcinoma cell migration and invasion, and we suggest that further studies should be conducted to fully establish the role of Gal-1 in hepatocellular carcinoma pathogenesis and evaluate Gal-1 as a potential molecular therapeutic target.

Nanozeolite-driven approach for enrichment of secretory proteins in human hepatocellular carcinoma cells

Given the importance of secreted proteins as a source for early detection and diagnosis of disease, secreted proteins have been arousing considerable attention. However, the analysis of secreted proteins represents a challenge for current proteomic techniques. One of the difficulties in secretomic study is to concentrate proteins from large volume of growth media, particularly, the low abundant and low molecular weight proteins (molecular weight <30 kDa). Herein, we describe a novel strategy for harvesting secretory proteins. In this approach, proteins secreted from the human hepatocellular carcinoma cell line were enriched by zeolite LTL nanocrystals, followed by 1-D SDS-PAGE for protein fractionation and then by LC-ESI-MS/MS for protein identification. In total, 1474 unique proteins were confidently identified, including 505 low molecular weight proteins, and covered a broad range of pI and molecular weight. Furthermore, this study not only offered an efficient and powerful method for the enrichment of secretory proteins but also allowed in-depth study of secretome of hepatocellular carcinoma cells. The reported work is expected to represent one of the most comprehensive secretomic analyses so far.

Induction of apoptosis and cell cycle arrest in human HCC MHCC97H cells with Chrysanthemum indicum extract

AIM: To investigate the effects of Chrysanthemum indicum extract (CIE) on inhibition of proliferation and on apoptosis, and the underlying mechanisms, in a human hepatocellular carcinoma (HCC) MHCC97H cell line.

METHODS: Viable rat hepatocytes and human endothelial ECV304 cells were examined by trypan blue exclusion and MTT assay, respectively, as normal controls. The proliferation of MHCC97H cells was determined by MTT assay. The cellular morphology of MHCC97H cells was observed by phase contrast microscopy. Flow cytometry was performed to analyze cell apoptosis with annexin V/propidium iodide (PI), mitochondrial membrane potential with rhodamine 123 and cell cycle with PI in MHCC97H cells. Apoptotic proteins such as cytochrome C, caspase-9, caspase-3 and cell cycle proteins, including P21 and CDK4, were measured by Western blotting.

RESULTS: CIE inhibited proliferation of MHCC97H cells in a time- and dose-dependent manner without cytotoxicity in rat hepatocytes and human endothelial cells. CIE induced apoptosis of MHCC97H cells in a concentration-dependent manner, as determined by flow cytometry. The apoptosis was accompanied by a decrease in mitochondrial membrane potential, release of cytochrome C and activation of caspase-9 and caspase-3. CIE arrested the cell cycle in the S phase by increasing P21 and decreasing CDK4 protein expression.

CONCLUSION: CIE exerted a significant apoptotic effect through a mitochondrial pathway and arrested the cell cycle by regulation of cell cycle-related proteins in MHCC97H cells without an effect on normal cells. The cancer-specific selectivity shown in this study suggests that the plant extract could be a promising novel treatment for human cancer.

CD24 is a novel predictor for poor prognosis of hepatocellular carcinoma after surgery

PURPOSE

To investigate the role of CD24 in tumor invasion and prognostic significance in hepatocellular carcinoma (HCC).

EXPERIMENTAL DESIGN

CD24 expression was measured in stepwise metastatic HCC cell lines, tumor, peritumoral tissues, and normal liver tissues by quantitative real-time PCR and Western blot. The role of CD24 in HCC was investigated by CD24 depletion using small interfering RNA. Tumor tissue microarrays of 314 HCC patients who underwent resection between 1997 and 2000 were used to detect expression of CD24, beta-catenin, and proliferating cell nuclear antigen. Prognostic significance was assessed using Kaplan-Meier survival estimates and log-rank tests.

RESULTS

CD24 was overexpressed in the highly metastatic HCC cell line and in tumor tissues of patients with recurrent HCC. Depletion of CD24 caused a notable decrease in cell proliferation, migration, and invasiveness in vitro. Univariate and multivariate analyses revealed that CD24 was a significant predictor for overall survival and relapse-free survival. CD24 expression was correlated with poor prognosis independent of alpha-fetoprotein, tumor-node-metastasis stage, and Edmondson stage. High CD24 expression was significantly associated with cytoplasmic and nuclear accumulation of beta-catenin (P = 0.023), high tumor proliferative status (P = 0.018), and diffused intrahepatic recurrence and distant metastasis (P = 0.026). Adjuvant transcatheter arterial chemoembolization after surgery reduced the rate of early recurrence (

CONCLUSIONS

Overexpression of CD24 in HCC was associated with high invasiveness and metastatic potential, high tumor proliferation status, and activation of the Wnt/beta-catenin pathway. CD24 may be a novel predictor for poor prognosis of HCC patients after surgery.

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MESH Headings

• Biomarkers, Tumor/genetics
• Biomarkers, Tumor/metabolism
• CD24 Antigen/genetics
• CD24 Antigen/metabolism
• Carcinoma, Hepatocellular/metabolism
• Carcinoma, Hepatocellular/pathology
• Cell Line, Tumor
• Cell Movement/physiology
• Gene Silencing/physiology
• Humans
• Kaplan-Meier Estimate
• Liver Neoplasms/metabolism
• Liver Neoplasms/pathology
• Multivariate Analysis
• Prognosis
• Proliferating Cell Nuclear Antigen/metabolism
• RNA, Small Interfering/metabolism
• Tissue Array Analysis
• alpha-Fetoproteins/metabolism
• beta Catenin/metabolism

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Affiliation(s)

Xin-Rong Yang Liver Cancer Institute, Zhong Shan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis & Cancer Invasion, Chinese Ministry of Education, Shanghai, People's Republic of China
Yang Xu
Bin Yu
Jian Zhou
Jia-Chu Li
Shuang-Jian Qiu
Ying-Hong Shi
Xiao-Ying Wang
Zhi Dai
Guo-Ming Shi
Bin Wu
Li-Ming Wu
Guo-Huan Yang
Bo-Heng Zhang
Wen-Xin Qin
Jia Fan

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Value of the model for end-stage liver disease for predicting survival in hepatocellular carcinoma patients treated with transarterial chemoembolization

OBJECTIVE

The aim of this study was to evaluate the prognostic value of the model for end-stage liver disease (MELD) and its modified forms, and to compare these scoring systems with other staging systems for hepatocellular carcinoma (HCC) patients treated with transarterial chemoembolization (TACE).

MATERIAL AND METHODS

A total of 325 patients who underwent TACE for the initial treatment of HCC between January 2000 and May 2007 were enrolled in the study. Before TACE was carried out, MELD, MELD-Na, Child-Pugh score, Okuda stage, CLIP score, JIS score, BCLC stage, and UICC stage were checked. After one month, delta MELD and delta MELD-Na were calculated.

RESULTS

Mean MELD/MELD-Na/delta MELD/delta MELD-Na scores were 7.5+/-3.7, 8.0+/-4.7, -0.2+/-3.5 and 0.04+/-4.5, respectively. MELD (p=0.009) and MELD-Na (p=0.017) significantly correlated with survival, but delta MELD and delta MELD-Na did not (p >0.05). The Child-Pugh score and other staging systems correlated significantly with survival (p <0.05). The AUROC values for 3, 12, and 36 months' survival were 0.633, 0.545, and 0.615 for MELD; 0.655, 0.555, and 0.612 for MELD-Na; 0.639, 0.616, and 0.691 for Child-Pugh score; 0.714, 0.662, and 0.717 for the Okuda score; 0.837, 0.86, and 0.792 for the CLIP score; 0.859, 0.814, and 0.808 for the JIS score; 0.846, 0.833, and 0.749 for BCLC stage; and 0.878, 0.812, and 0.735 for UICC stage, respectively.

CONCLUSIONS

MELD and MELD-Na showed good correlations with survival, especially for patients with early-stage disease. However, these were not superior to those of other staging systems or Child-Pugh score. These parameters should only be used as supportive data.

Elevated expression of DKK1 is associated with cytoplasmic/nuclear beta-catenin accumulation and poor prognosis in hepatocellular carcinomas

BACKGROUND/AIMS

To assess the value of Dickkopf-1 (DKK1) for predicting clinical outcome of human hepatocellular carcinoma (HCC) in patients with HCC.

METHODS

Expression of DKK1 and beta-catenin was investigated in HCC cell lines using qRT-PCR, Western blotting and immunofluorescence. Tissue microarrays representing 314 HCC patients were used to determine the expression patterns of DKK1 and beta-catenin by immunohistochemistry, and prognostic significance was assessed by using Kaplan-Meier survival estimates and log-rank tests.

RESULTS

The expression level of DKK1 was associated with the staining pattern of beta-catenin in HCC cell lines, and DKK1 overexpression correlated with beta-catenin cytoplasmic/nuclear accumulation in clinical HCC samples (P=0.011, correlation coefficient=0.144). High DKK1 expression predicted unfavorable prognosis in HCC patients, especially in early stage patients and those with normal AFP levels. In multivariate analyses, DKK1 was an independent predictor for overall survival (OS) (P=0.002) and disease-free survival (DFS) (P=0.002) of HCC patients. Furthermore, the HCC patients with high DKK1 expression and cytoplasmic/nuclear beta-catenin accumulation had very poor prognosis.

CONCLUSIONS

Elevated expression of DKK1 is a critical event in patients with HCC that indicates poor clinical outcome. DKK1, alone or combined with beta-catenin, is a novel prognostic predictor for HCC patients.

High expressions of vascular endothelial growth factor and platelet-derived endothelial cell growth factor predict poor prognosis in alpha-fetoprotein-negative hepatocellular carcinoma patients after curative resection

PURPOSE

To evaluate the prognosis value of vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) in alpha-fetoprotein (AFP)-negative hepatocellular carcinoma (HCC) patients after curative resection.

METHODS

Tumor tissue microarrays (TMAs) were used to detect the expressions of VEGF and PD-ECGF in consecutive 162 AFP-negative HCC patients undergoing curative resection between 1997 and 2000 in our institute. Clinicopathologic data for these patients were evaluated. The prognostic significance was assessed using Kaplan-Meier survival estimates and log-rank tests. Multivariate study with Cox's proportional hazard model was used to evaluate the prognosis-related aspects.

RESULTS

The positive rates of VEGF and PD-ECGF in tumor tissues were 59.9% (97/162) and 62.3% (101/162), respectively. Univariate analysis showed that VEGF and PD-ECGF were prognostic factors for relapse-free survival (P = 0.034 and P = 0.033, respectively). Multivariate analyses demonstrated that the co-index (VEGF/PD-ECGF) was an independent prognostic factor for overall survival and relapse-free survival (P = 0.002 and P = 0.000, respectively).

CONCLUSION

The co-index of VEGF and PD-ECGF is a promising independent predictor for recurrence and survival of AFP-negative HCC patients after curative resection.

Herbal extract "Songyou Yin" inhibits tumor growth and prolongs survival in nude mice bearing human hepatocellular carcinoma xenograft with high metastatic potential

PURPOSE

Chinese herbs have become a focus of interest in cancer treatment. This study evaluates the effect of the herbal compound extract "Songyou Yin" (containing Salvia miltiorrhiza Bge.-danshen and other four herbs) on hepatocellular carcinoma (HCC).

METHODS

Human HCC cell line MHCC97H with high-metastatic potential was employed for in vitro study. In vivo study was conducted in nude mice bearing HCC orthotopic xenograft with MHCC97H.

RESULTS

In vitro, "Songyou Yin" caused dramatic attenuation of tumor proliferation by induction of apoptosis that was associated with caspase-3 activation, and inhibit invasiveness of MHCC97H via reducing matrix metalloproteinase-2 (MMP2) activity. In vivo, "Songyou Yin" minimized cancer-related body weight loss of mice bearing tumors without distinct toxicity, and inhibited tumor growth with stepwise increased dosage of "Songyou Yin" and accorded with the expression of proliferating cell nuclear antigen. Moreover, "Songyou Yin" inhibited tumor growth was associated with an increased TUNEL-positive apoptosis as well as a decreased microvessel density and vascular endothelial growth factor (VEGF) abundance, and inhibited tumor invasion via down-regulation of MMP2. The lung metastatic extent was decreased (p < 0.01, compared with control). The life span of nude mice bearing xenografts was 75.0 +/- 3.9 days in "Songyou Yin" group, whereas it was 52.0 +/- 2.3 days in the control (p < 0.001).

CONCLUSIONS

Nontoxic herbal compound extract "Songyou Yin" inhibited tumor growth and prolonged survival, via inducing apoptosis and down-regulation of MMP2 and VEGF, which indicated its potential use in patients with advanced HCC.

Protein expression profiling of vascular endothelial growth factor and its receptors identifies subclasses of hepatocellular carcinoma and predicts survival

PURPOSE

To examine expression profile and prognostic significance of vascular endothelial growth factor (VEGF) and its receptors in hepatocellular carcinoma (HCC) and peritumoral tissue.

METHODS

Expression of VEGF-A, VEGF-C, and VEGF receptor 1(VEGFR-1), VEGFR-2, and VEGFR-3 in tumor and peritumoral liver tissue was studied by immunohistochemistry in a tissue microarray from 107 patients with HCC. Unsupervised hierarchical cluster analyses were conducted to identify relevant clusters.

RESULTS

Staining of VEGF-A, VEGF-C, VEGFR-2, and VEGFR-3 was mostly found on the tumor cells and peritumoral hepatocytes, but VEGFR-1 was mostly expressed in stromal cells. In most of the cases, the expression of VEGF-A, VEGFR-1, VEGFR-2, and VEGFR-3 in was higher in peritumoral liver tissue, while VEGF-C expression was higher in tumor. Unsupervised hierarchical clustering analysis identified four prognostically different clusters, of which cluster A was classified into the "poor prognosis group," and the other three clusters were classified into the "good prognosis group" (P = 0.047). Further analysis with a set of seven markers reproduced the same four cluster groups with significantly different recurrence free probability (RFP) (P = 0.018), and the low RFP group was associated with more intrahepatic satellite lesions. Multivariate analysis showed that classification defined by seven biomarkers was of prognostic significance (P = 0.000).

CONCLUSIONS

Expression of VEGF and its receptors was higher in peritumoral tissue than in tumor in HCC. Seven biomarkers predicted patients' RFP, which consisted of tumoral expression of VEGF-A, VEGFR-1, and VEGF-C as well as peritumoral expression of VEGF-A, VEGFR-1, VEGFR-2, and VEGFR-3.

Identification of side population cells in human hepatocellular carcinoma cell lines with stepwise metastatic potentials

PURPOSE

To identify the side population (SP) cells from four hepatocellular carcinoma (HCC) cell lines with stepwise metastatic potentials.

METHODS

SP cells were sorted from HCCLM3, MHCC97-H, MHCC97-L and Hep3B by flow cytometry, and then analyzed by differentiation study, clonogenic assay, chemoresistance study and tumorigenicity assay in vivo. The expression of ABCG(2) in SP cells was detected by immunocytochemistry, western blotting and real-time quantitative PCR, respectively.

RESULTS

There was significant difference in SP proportion among HCCLM3, MHCC97-H, MHCC97-L and Hep3B (28.7 +/- 1.6%, 14.5 +/- 0.6%, 4.2 +/- 0.4%, 0.9 +/- 0.1%, respectively, P < 0.01). All the SP cells showed similar characteristics of self-renewal, high clonogenicity, remarkable chemo-resistance and high expression of ABCG(2). As low as 2,000 SP cells could initiate tumors in non-obese diabetic/severe combined immunodeficiency mice successfully.

CONCLUSIONS

SP cells purified from HCC cell lines harbors cancer stem cell-like properties, and may be related to the metastatic potentials and therapeutic-resistance of HCC.

Osteopontin combined with CD44, a novel prognostic biomarker for patients with hepatocellular carcinoma undergoing curative resection

BACKGROUND

Osteopontin (OPN) plays important roles in tumor progression and metastasis through binding to CD44 and integrin. The goal of this study was to elucidate the prognostic significance of OPN and CD44 in hepatocellular carcinoma patients.

METHODS

Tumor tissue microarray was used to detect the expression levels of OPN and CD44 in 302 hepatocellular carcinoma patients undergoing curative resection between 1997 and 2000 at our institute. Clinicopathologic data for these patients were investigated. The prognostic effects of OPN and CD44 were evaluated using the Kaplan-Meier method and compared using the log-rank test. The Spearman rank test and Fisher's exact test were applied to demonstrate correlations.

RESULTS

Both OPN and CD44 were independent predictors for overall survival and disease-free survival. When OPN and CD44 were taken into consideration together, the predictive range was extended and the sensitivity was improved, especially for those patients with normal serum alpha-fetoprotein levels. The 8-year overall survival and disease-free survival rates in OPN+ and/or CD44+ patients were 28.2% and 25.6%, respectively, which were significantly lower than those of OPN-CD44- patients (52.1% and 51.6%, respectively).

CONCLUSIONS

OPN combined with CD44 is a promising independent predictor of tumor recurrence and survival in hepatocellular carcinoma patients.

Biological characteristics of fluorescent protein-expressing human hepatocellular carcinoma xenograft model in nude mice

OBJECTIVES

To study biological characteristics of stable red fluorescent protein (RFP)-expressing or green fluorescent protein (GFP)-expressing HCCLM3 cell lines and those of their relevant xenograft models in nude mice.

METHODS

HCCLM3, a human hepatocellular carcinoma cell line with high metastatic potential was infected with RFP or GFP full-length cDNA via lentivirus. Stable RFP-expressing or GFP-expressing HCCLM3 cells, namely HCCLM3-R and HCCLM3-G, were subcutaneously injected and two patient-like metastatic models of HCCLM3-R and HCCLM3-G in nude mice were established using surgical orthotopic implantation from subcutaneous tumor tissues. Cell proliferation, karyotype, biomarker expression, tumor growth, and metastasis of HCCLM3-R and HCCLM3-G were analyzed in vitro and in vivo.

RESULTS

RFP and GFP genes were integrated in genomic DNA of HCCLM3. HCCLM3-R and HCCLM3-G expressed red and green fluorescence, stable and intense, 300 days after 60 consecutive passages, and also positively expressed CK8+, P16+, AFP+ and negatively expressed HBsAg-. Their biomarker expression and karyotype were found to be similar to those of the parental HCCLM3, and their tumorigenesis occurred in 10 nude mice without exception after a subcutaneous injection and did the same in 20 nude mice after an orthotopic implantation. The results showed that the rate of spontaneous metastasis to the liver and lung and peritoneal seeding was 100, 100, and 90%, respectively.

CONCLUSION

Stable fluorescent protein-expressing HCCLM3-R and HCCLM3-G xenografts in nude mice could be of two useful models for studying mechanisms of hepatocellular carcinoma growth and metastasis in real time.

Bioinformatics analysis of metastasis-related proteins in hepatocellular carcinoma

AIM: To analyze the metastasis-related proteins in hepatocellular carcinoma (HCC) and discover the biomarker candidates for diagnosis and therapeutic intervention of HCC metastasis with bioinformatics tools.

METHODS: Metastasis-related proteins were determined by stable isotope labeling and MS analysis and analyzed with bioinformatics resources, including Phobius, Kyoto encyclopedia of genes and genomes (KEGG), online mendelian inheritance in man (OMIM) and human protein reference database (HPRD).

RESULTS: All the metastasis-related proteins were linked to 83 pathways in KEGG, including MAPK and p53 signal pathways. Protein-protein interaction network showed that all the metastasis-related proteins were categorized into 19 function groups, including cell cycle, apoptosis and signal transduction. OMIM analysis linked these proteins to 186 OMIM entries.

CONCLUSION: Metastasis-related proteins provide HCC cells with biological advantages in cell proliferation, migration and angiogenesis, and facilitate metastasis of HCC cells. The bird’s eye view can reveal a global characteristic of metastasis-related proteins and many differentially expressed proteins can be identified as candidates for diagnosis and treatment of HCC.

Inhibition of HBV gene expression and replication by stably expressed interferon-alpha1 via adeno-associated viral vectors

Background

Interferon‐α2 (IFNα2) is routinely used for anti‐hepatitis B virus (HBV) treatment. However, the therapeutic efficiency is unsatisfactory, particularly in East Asia. Such inefficiency might be a result of the short half‐life, relatively low local concentration and strong side‐effects of interferons. Frequent and repeated injection is also a big burden for patients. In the present study, a single dose of vector‐delivered IFNα1 was tested for its anti‐HBV effects.

Methods

Adeno‐associated viral vector (AAV‐IFNα1) was generated to deliver the IFNα1 gene into hepatocytes. IFNα1, hepatitis B surface (HBsAg) and e (HBeAg) antigens were measured by enzyme‐linked immunosorbent assay and/or western blotting. The level of viral DNA was measured by quantitative real‐time polymerase chain reaction.

Results

AAV‐IFNα1 effectively transduced HBV‐producing cells (HepAD38) and mouse hepatocytes, where IFNα1 was expressed in a stable manner. Both intracellular and extracellular HBsAg and HBeAg were significantly reduced in vitro. In the HBV‐producing mice, the concentration of IFNα1 in the liver was eight‐fold higher than that in plasma. Compared with control groups, HBeAg/HBsAg antigen levels were reduced by more than ten‐fold from day 1–5, and dropped to an undetectable level on day 9 in the AAV‐IFNα1 group. Concurrently, the level of viral DNA decreased over 30‐fold for several weeks.

Conclusions

A single dose administration of AAV‐IFNα1 viral vector displayed prolonged transgene expression and superior antiviral effects both in vitro and in vivo. Therefore, the use of AAV‐IFNα1 might be a potential alternative strategy for anti‐HBV therapy. Copyright © 2008 John Wiley & Sons, Ltd.

Expression of X-linked inhibitor-of-apoptosis protein in hepatocellular carcinoma promotes metastasis and tumor recurrence

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Despite significantly improved diagnosis and treatment in recent years, the long-term therapeutic effect is compromised by the frequent recurrence and metastasis, of which the molecular mechanisms are not fully understood. Our initial studies in established HCC cell lines with different metastatic capabilities indicated a correlation of metastasis with the resistance to apoptosis and therefore the ability to survive in stressed conditions. Subsequent investigation revealed that increased expression of X-linked inhibitor-of-apoptosis protein (XIAP) was correlated with the resistance to apoptosis and enhanced invasiveness in vitro, which could contribute to increased metastatic foci in vivo. Furthermore, we found that nearly 90% of clinical samples from advanced HCC patients expressed high levels of XIAP. Patients with XIAP-positive tumors had a significantly increased risk of relapse, which resulted from metastasis after total liver resection and orthotopic liver transplantation. Indeed, XIAP expression could be an independent prognostic factor for predicting disease-free survival rate and overall survival rate of these patients. XIAP expression was also highly correlated with advanced cases that exceeded the Milan criteria and could be a prognostic factor for disease-free survival in these patients as well.

CONCLUSION

Our studies have shown an important molecule in controlling HCC metastasis, defined a biomarker that can be used to predict HCC recurrence and patient survival after treatment, and suggest that XIAP can be a molecular target subject to intervention to reduce metastasis and recurrence.

Two pathologic types of hepatocellular carcinoma with lymph node metastasis with distinct prognosis on the basis of CK19 expression in tumor

BACKGROUND

Few studies have investigated the pathologic types and prognosis of hepatocellular carcinoma (HCC) with lymph node metastasis (LNM). The purpose was to explore pathologic types and pertinent therapy of HCC with LNM.

METHODS

An immunohistochemical study for CK19 and OV-6 was performed on tissue microarrays of HCC with LNM (n=47) and those without LNM (n=125). The clinicopathologic factors and patient survival were analyzed.

RESULTS

Immunopositivity of CK19 and OV-6 in HCC with LNM were higher than that in 125 HCC without LNM (27.7% vs 5.6%, P=.000; 29.8% vs 12.8%, P=.009); their expressions were significantly correlated in HCC with LNM (correlation coefficient: 0.637, P=.000). The CK19 expression and tumor (T) classification of American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) tumor staging system were 2 independent risk factors for developing LNM (odds ratio [OR], 5.170, 95% confidence interval [CI], 1.840-14.528, P=.002; OR, 1.879, 95% CI, 1.236-2.857, P=.003). The CK19(+) group had shorter median survival (7.7 months vs 21.7 months, P=.013); CK19 expression was the independent prognostic factor for overall survival in HCC with LNM and was correlated with proliferating cell nuclear antigen labeling index and matrix metalloproteinase-9 expression (correlation coefficient: 0.484, P=.001 and 0.459, P=.001, respectively).

CONCLUSIONS

CK19 expression and AJCC/UICC T classification were 2 independent risk factors for developing LNM in HCC. CK19 expression was the independent prognostic factor for HCC with LNM. It is of clinical significance for treatment modalities to differentiate HCC with intrahepatic cholangiocarcinoma-like differentiation (CK19[+]) from one with a higher T classification (CK19[-]).

High Expression of Macrophage Colony-Stimulating Factor in Peritumoral Liver Tissue Is Associated With Poor Survival After Curative Resection of Hepatocellular Carcinoma

Purpose

To investigate prognostic values of the intratumoral and peritumoral expression of macrophage colony-stimulating factors (M-CSF) in hepatocellular carcinoma (HCC) patients after curative resection.

Patients and Methods

Expression of M-CSF and density of macrophages (MΦ) were assessed by immunohistochemistry in tissue microarrays containing paired tumor and peritumoral liver tissue from 105 patients who had undergone hepatectomy for histologically proven HCC. Prognostic value of these and other clinicopathologic factors was evaluated.

Results

Neither intratumoral M-CSF nor MΦ density was associated with overall survival (OS) or disease-free survival (DFS). High peritumoral M-CSF and MΦ density, which correlated with large tumor size, presence of intrahepatic metastasis, and high TNM stage, were independent prognostic factors for both OS (P = .001 and P < .001, respectively) and DFS (P = .001 and P = .003, respectively) and affected incidence of early recurrence. In a small HCC subset, peritumoral M-CSF was also correlated with both OS and DFS (P = .038 and P = .001, respectively). The combination of peritumoral M-CSF and MΦ had a better power to predict the patients' death and disease recurrence (P < .001 for both).

Conclusion

High peritumoral M-CSF and MΦ were associated with HCC progression, disease recurrence, and poor survival after hepatectomy, highlighting the importance of peritumoral tissue in the recurrence and metastasis of HCC. M-CSF and MΦ may be targets of postoperative adjuvant therapy.

Identification of SOX4 target genes using phylogenetic footprinting-based prediction from expression microarrays suggests that overexpression of SOX4 potentiates metastasis in hepatocellular carcinoma

A comprehensive microarray analysis of hepatocellular carcinoma (HCC) revealed distinct synexpression patterns during intrahepatic metastasis. Recent evidence has demonstrated that synexpression group member genes are likely to be regulated by master control gene(s). Here we investigate the functions and gene regulation of the transcription factor SOX4 in intrahepatic metastatic HCC. SOX4 is important in tumor metastasis as RNAi knockdown reduces tumor cell migration, invasion, in vivo tumorigenesis and metastasis. A multifaceted approach integrating gene profiling, binding site computation and empirical verification by chromatin immunoprecipitation and gene ablation refined the consensus SOX4 binding motif and identified 32 binding loci in 31 genes with high confidence. RNAi knockdown of two SOX4 target genes, neuropilin 1 and semaphorin 3C, drastically reduced cell migration activity in HCC cell lines suggesting that SOX4 exerts some of its action via regulation of these two downstream targets. The discovery of 31 previously unidentified targets expands our knowledge of how SOX4 modulates HCC progression and implies a range of novel SOX4 functions. This integrated approach sets a paradigm whereby a subset of member genes from a synexpression group can be regulated by one master control gene and this is exemplified by SOX4 and advanced HCC.

The inhibitory effect of p75 neurotrophin receptor on growth of human hepatocellular carcinoma cells

p75 neurotrophin receptor (p75NTR), a member of the TNF receptor superfamily, is a focus for study at present. Up to now, its role and functions in hepatocellular carcinoma were not fully elucidated. In this study, we investigated the expression of p75NTR in hepatocellular carcinoma and the impact of its alteration on tumor growth. We found that the expression of p75NTR was decreased significantly in 158 cases of hepatocellular carcinoma tissues as compared with their adjacent noncancerous counterparts, and its expression was also significantly decreased in various human hepatocellular carcinoma cell lines. Down-regulating p75NTR by specific siRNA promoted the growth of normal liver cell lines, whereas up-regulating p75NTR inhibited the growth of hepatocellular carcinoma cell lines in vitro and caused dramatic attenuation of tumor growth in vivo by induction of cell cycle arrest. Furthermore, we found that up-regulating p75NTR could down-regulate the expression of cyclin A, cyclin D1, cyclin E, cdk2, p-Rb and PCNA, but up-regulate the expression of Rb. Conversely, the results were inverse when p75NTR was down-regulated by specific siRNA. Therefore, we provided the evidence that p75NTR was a potential tumor suppressor and might be used as a therapeutic target for hepatocellular carcinoma.

Generation and modulation of hepatocellular carcinoma circulating cells: a new experimental model

BACKGROUND

To establish a new experimental model of human hepatocellular carcinoma by orthotopic implantation of tumoral cells with its subsequent removal, to generate and modulate circulating tumoral cells.

MATERIALS AND METHODS

Three human hepatoma cell lines (HepG2, PLC/PRF, and Mahlavu) were orthotopically implanted under the Glisson's capsule of the left lateral lobe of the liver in a total of 56 non-obese diabetic/severe combined immunodeficiency mice. Tumor removal was performed 30 d after injection, and a laparotomy without tumor removal was done in control mice. Generation of circulating cells was monitored by flow cytometry using fluorescein isothiocyanate-conjugated anti-HLA antibody.

RESULTS

In 26 mice implanted with Mahlavu cells, 20 developed a unique tumor allowing a resection (77%), which was technically feasible in 80% of cases. The overall perioperative mortality was 30% (3/10) after resection; no mortality was observed in the control group. The circulating tumoral cells decreased dramatically after resection of the tumor as compared with control mice.

CONCLUSION

This new model is feasible and may be an interesting useful tool to study the hepatocellular carcinoma metastatic process and is consistent with the human clinical practice.

Functional localization of metastasis suppressor genes for hepatocellular carcinoma on human chromosome 8p21.1-23.1

AIM: To further refine the region harboring the metastasis suppressor genes in the human chromosome 8p21.1-23.1, and to pave the way for finding and cloning novel metastasis suppressor genes.

METHODS: The STS primer sequences were found according to the National Center for Biotechnology Information Database (NCBI). C5F genomic DNA and A9/neo8 genomic DNA were used as negative and positive controls for chromosome 8 amplification, respectively. Genomic DNA was isolated and quantified from cultured hybrid clones. A9/C5F-1 and A9/C5F-2 microcell hybrid clones were used as metastasis-unsuppressed groups, while A9/C5F-4, A9/C5F-8 and A9/C5F-10 clones were used as metastasis-suppressed groups. STS-PCR products were separated by electrophoresis.

RESULTS: STS markers were preserved in metastasis-suppressed microcell hybrid clones (A9/C5F-4, A9/C5F-8 and A9/C5F-10), such as D8S552 (12786562-12786681), D8S1733(22576582-22576836), D8S1734 (22851217-22851336), D8S254(16652480-16652550) and D8S1973 (28681110-28681363) on human chromosome 8p21.1-23.1. In contrast, STS markers were lost in metastasis-unsuppressed clones (A9/C5F-1 and A9/C5F-2) in this region.

CONCLUSION: The metastasis suppressor genes may be located within the interval between D8S542 and D8S1973 on human chromosome 8p21.1-23.1.

Significance of CD90+ cancer stem cells in human liver cancer

This study characterized cancer stem cells (CSCs) in hepatocellular carcinoma (HCC) cell lines, tumor specimens, and blood samples. The CD90+ cells, but not the CD90(-) cells, from HCC cell lines displayed tumorigenic capacity. All the tumor specimens and 91.6% of blood samples from liver cancer patients bore the CD45(-)CD90+ population, which could generate tumor nodules in immunodeficient mice. The CD90+CD44+ cells demonstrated a more aggressive phenotype than the CD90+CD44(-) counterpart and formed metastatic lesions in the lung of immunodeficient mice. CD44 blockade prevented the formation of local and metastatic tumor nodules by the CD90+ cells. Differential gene expression profiles were identified in the CD45(-)CD90+ and CD45(-)CD90(-) cells isolated from tissue and blood samples from liver cancer patients and controls.

Identification of local and circulating cancer stem cells in human liver cancer

Increasing evidence has revealed the importance of cancer stem cells (CSCs) in carcinogenesis. Although liver CSCs have been identified in hepatocellular carcinoma (HCC) cell lines, no data have shown the presence of these cells in human settings. The present study was designed to delineate CSCs serially from HCC cell lines, human liver cancer specimens to blood samples, using CD90 as a potential marker. The number of CD90(+) cells increased with the tumorigenicity of HCC cell lines. CD45(-)CD90(+) cells were detected in all the tumor specimens, but not in the normal, cirrhotic, and parallel nontumorous livers. In addition, CD45(-)CD90(+) cells were detectable in 90% of blood samples from liver cancer patients, but none in normal subjects or patients with cirrhosis. A significant positive correlation between the number of CD45(-)CD90(+) cells in the tumor tissues and the number of CD45(-)CD90(+) cells in the blood samples was identified. CD90(+) cells sorted from cell lines and CD45(-)CD90(+) cells from the tumor tissues and blood samples of liver cancer patients generated tumor nodules in immunodeficient mice. Serial transplantation of CD90(+) cells from tumor xenografts generated tumor nodules in a second and subsequently third batch of immunodeficient mice. Treatment of CD90(+) CSCs with anti-human CD44 antibody induced cell apoptosis in a dose-dependent manner.

CONCLUSION

Identification of CD45(-)CD90(+) CSCs in both tumor tissues and circulation suggests that CD45(-)CD90(+) could be used as a marker for human liver cancer and as a target for the diagnosis and therapy of this malignancy.

Development of a survival evaluation model for liver transplant recipients with hepatocellular carcinoma secondary to hepatitis B

AIM

To develop a model using easily obtainable, objective, verifiable preoperative parameters, to help evaluate post transplant survival probability for hepatocellular carcinoma (HCC) patients with hepatitis B.

METHODS

We retrospectively examined a cohort of 150 consecutive primary cadaveric liver transplants with HCC in our center over 6 years. Thirteen preoperative biochemical parameters and six tumor-related factors were analyzed to identify their correlation with post transplant survival using the Cox proportional-hazards regression model. The predictive power of a new model and the model for end stage liver disease was compared by the receiver operating characteristic curve.

RESULTS

In univariate analysis, the factors significantly associated with post transplant survival were serum concentrations of albumin, total bilirubin, alkaline phosphatase, alpha-fetoprotein, gamma-glutamyltransferase, aspartate aminotransferase, sodium, tumor diameter and the number of tumor nodules. Multivariate analysis showed alpha-fetoprotein, serum sodium, alkaline phosphatase and the number of tumor nodules were significantly associated with the post transplant outcome. Based on the four variables, we established a new model with a c-statistic of 0.72 which was significantly greater than 0.50 (P = 0.001), and the c-statistic of MELD was 0.59 (P = 0.146).

CONCLUSION

The new model based on four objective tumor-related parameters has the capacity to evaluate the risk of post transplant mortality for HCC patients with hepatitis B.

KAI1 gene suppresses invasion and metastasis of hepatocellular carcinoma MHCC97-H cells in vitro and in animal models

BACKGROUND

Downregulation of KAI1 gene expression has been found in many types of cancer cells and is closely related to cancer invasion and metastasis. This study was aimed at investigating the effects and possible underlying mechanisms of KAI1 gene on invasion and metastasis of human hepatocellular carcinoma (HCC).

METHODS

The invasive ability, visco-elastic properties and cell adhesion forces were analysed in different HCC cells originating from the MHCC97-H cell line transfected with either the sense or the antisense KAI1 expression plasmid. Tumuorigenicity, metastatic abilities, extracellular matrix (ECM) and intercellular adhesion molecule-1 (ICAM-1) expression were also evaluated in the nude mouse models of the xenografted and orthotopic liver cancer cells.

RESULTS

Compared with their parental cells, in the HCC cells transfected with the sense KAI1 gene, the invasive ability in vitro was significantly decreased (P<0.01); the cellular elastic coefficients K(1), K(2) and mu were significantly higher (P<0.05); the cells adhesion forces to fibronectin were significantly lower (P<0.01). The sense KAI1 gene transfection into the cancer cells also inhibited their invasion and lung metastasis in the orthotopic liver cancer nude mice. However, the opposite changes were observed in the HCC cells transfected with the antisense KAI1 gene. KAI1 gene transfection also affected ECM and ICAM-1 expression in the transplanted liver cancer.

CONCLUSION

The KAI1 gene plays an important role in the invasion and metastasis of human HCC and its upregulation in HCC cells suppresses their invasive and metastatic abilities. KAI1 gene functioned as a metastasis inhibitor by regulating the HCC cell biophysical behaviours including aggregation, adhesion, motility and visco-elastic properties.

Positive serum hepatitis B e antigen is associated with higher risk of early recurrence and poorer survival in patients after curative resection of hepatitis B-related hepatocellular carcinoma

BACKGROUND/AIMS

To study the impact of hepatitis B e antigen on tumor recurrence and patients' survival after curative resection of hepatocellular carcinoma.

METHODS

Two hundred and three patients with small hepatocellular carcinomas (3cm) who had undergone curative resection were divided into HBeAg-positive group and HBeAg-negative group. Clinicopathological factors and postoperative outcomes were compared between groups, and risk factors for survival and recurrence were studied.

RESULTS

The median follow-up time was 32.9months. Patients with negative HBeAg had higher 5-year overall survival rates (76% vs 53.9%, hazards ratio (HR): 2.363, 95% CI: 1.335-4.181, p=0.002) and 5-year disease-free survival rates (52.9% vs 37.4%, HR: 1.603, 95% CI: 1.00-2.561, p=0.046). There was no significant difference in operative morbidity and tumor factors between the two groups, but younger age, higher serum alanine aminotransferase levels, and more macronodular cirrhosis were found in the HBeAg-positive group. Multivariate analysis revealed that age >50years, HBeAg positivity and macronodular cirrhosis were independent factors for overall survival, and HBeAg positivity and multiple tumor nodules were independent factors for disease-free survival. Positive serum HBeAg was associated with a higher risk of early recurrence (within 1year).

CONCLUSIONS

HBeAg is associated with a higher risk of early recurrence and poorer survival in patients after curative resection of small HCC.

APC promoter methylation and protein expression in hepatocellular carcinoma

PURPOSE

We investigated the impact of promoter methylation on APC protein expression in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

50 patients [HCC (n=19), liver metastasis (n=19), cholangiocellular cancer (n=7), and benign liver tumors (n=5)] were studied for methylation using Methylight analysis. APC mutation was investigated by protein truncation test and direct sequencing of genomic DNA. The protein expression was evaluated by immunohistochemistry and Western blot analysis.

RESULTS

The APC promoter was hypermethylated in 81.8% of non-cancerous liver tissue samples. All HCC samples and ten patients with liver metastasis (52.6%) exhibited APC promoter methylation. The degree of methylation was significantly higher in samples from HCC compared to the non-cancerous liver tissue samples (63.1% vs. 24.98%; p=0.001). The level of APC protein expression was significantly reduced in HCC samples compared to that of the corresponding non-tumor liver tissue (p<0.05).

CONCLUSIONS

Promoter methylation of the APC gene seems to be of significance in hepatocarcinogenesis and results in reduced protein expression in HCC. Interestingly, APC promoter methylation is also present in the vast majority of non-cancerous liver tissue whose (patho)physiological function remains unresolved.

Pathophysiological role of osteopontin in hepatic inflammation, toxicity, and cancer

Osteopontin (OPN) is a highly modified integrin-binding extracellular matrix glycophosphoprotein produced by cells of the immune system, epithelial tissue, smooth muscle cells, osteoblasts, and tumor cells. Extensive research has elucidated the pivotal role of OPN in cell signaling that controls inflammation, tumor progression, and metastasis. OPN interaction with the integrin receptors expressed on inflammatory cells through its arginine-glycine-aspartate (RGD) and non-RGD motifs promote migration and adhesion of cells. In the liver, it has been reported that hepatic Kupffer cells secrete OPN facilitating macrophage infiltration into necrotic areas following carbon tetrachloride liver toxicity. Recent work has highlighted the role of OPN in inflammatory liver diseases such as alcoholic and nonalcoholic liver disease and T-cell-mediated hepatitis. The role of OPN in hepatocellular carcinoma (HCC) has also generated significant interest, especially with regards to its role as a prognostic factor. OPN therefore appears to play an important role during liver inflammation and cancer. In this review we will present data to demonstrate the key role played by OPN in mediating hepatic inflammation (neutrophils, monocytes/macrophages, and lymphocytes) and its role in HCC. Greater understanding of the pathophysiologic role of OPN in hepatic inflammation and cancer may enable development of novel inflammation and cancer treatment strategies.

Intratumoral balance of regulatory and cytotoxic T cells is associated with prognosis of hepatocellular carcinoma after resection

PURPOSE

To investigate the prognostic value of tumor-infiltrating lymphocytes (TILs), especially regulatory T cells (Tregs), in hepatocellular carcinoma (HCC) patients after resection.

PATIENTS AND METHODS

CD3+, CD4+, CD8+, Foxp3-positive, and granzyme B-positive TILs were assessed by immunohistochemistry in tissue microarrays containing HCC from 302 patients. Prognostic effects of low- or high-density TIL subsets were evaluated by Cox regression and Kaplan-Meier analysis using median values as cutoff.

RESULTS

CD3+, CD4+, CD8+ TILs were associated with neither overall survival (OS) nor disease-free survival (DFS). The presence of low intratumoral Tregs in combination with high intratumoral activated CD8+ cytotoxic cells (CTLs), a balance toward CTLs, was an independent prognostic factor for both improved DFS (P = .001) and OS (P < .0001). Five-year OS and DFS rates were only 24.1% and 19.8% for the group with intratumoral high Tregs and low activated CTLs, compared with 64.0% and 59.4% for the group with intratumoral low Tregs and high activated CTLs, respectively. Either intratumoral Tregs alone (P = .001) or intratumoral activated CTLs (P = .001) alone is also an independent predictor for OS. In addition, high Tregs density was associated with both absence of tumor encapsulation (P = .032) and presence of tumor vascular invasion (P = .031).

CONCLUSION

Tregs are associated with HCC invasiveness, and intratumoral balance of regulatory and cytotoxic T cells is a promising independent predictor for recurrence and survival in HCC. A combination of depletion of Tregs and concomitant stimulation of effector T cells may be an effective immunotherapy to reduce recurrence and prolong survival after surgery.

Concomitant activation of the JAK/STAT, PI3K/AKT, and ERK signaling is involved in leptin-mediated promotion of invasion and migration of hepatocellular carcinoma cells

Various epidemiologic studies have shown that obesity is associated with hepatocellular carcinoma. Leptin, the key player in the regulation of energy balance and body weight control, also acts as a growth factor on certain organs in both normal and disease states. It is plausible that leptin acts to promote hepatocellular carcinogenesis directly affecting malignant properties of liver cancer cells. However, a direct role for leptin in hepatocellular carcinoma has not been shown. In this study, we analyzed the role of leptin and the mechanism(s) underlying its action in hepatocellular carcinoma cells, which express both short and long isoforms of leptin receptors. Treatment with leptin resulted in increased proliferation of both HepG2 and Huh7 cells and involves activation of signal transducers and activators of transcription 3 (STAT3), AKT, and extracellular signal-regulated kinase (ERK) signaling pathways. Leptin-induced phosphorylation of ERK and AKT was dependent on Janus-activated kinase (JAK)/STAT activation. Intriguingly, we also found that leptin potently induces invasion of hepatocellular carcinoma cells in Matrigel invasion and electric cell-substrate impedance-sensing assays. Leptin-stimulated invasion was effectively blocked by pharmacologic inhibitors of JAK/STAT and, to a lesser extent, by ERK and phosphatidylinositol 3-kinase (PI3K) inhibition. Importantly, leptin also induced the migration of both HepG2 and Huh7 cells on fibronectin matrix. Inhibition of JAK/STAT, ERK, and PI3K activation using pharmacologic inhibitors effectively blocked leptin-induced migration of HepG2 and Huh7 cells. Taken together, these data indicate that leptin promotes hepatocellular carcinoma growth, invasiveness, and migration and implicate the JAK/STAT pathway as a critical mediator of leptin action. Our findings have potential clinical implications for hepatocellular carcinoma progression in obese patients.

A novel peptide that selectively binds highly metastatic hepatocellular carcinoma cell surface is related to invasion and metastasis

Using a phage display approach, we identified AWYPLPP peptide as a specific peptide ligand that binds to the cell surface of highly metastatic human hepatocellular carcinoma (HCC). Moreover, the peptide was able to promote in vitro invasion of highly metastatic HCC cells by activating matrix metalloproteinase-9 and in vivo lung metastasis of HCC tumors. These results indicate that AWYPLPP peptide likely recognizes a novel receptor that is selectively expressed on the cell surface of highly metastatic HCC and mediates cellular activities associated with the invasive phenotype. Identification of the receptor for the AWYPLPP peptide may provide new insights into the molecular mechanism of HCC metastasis.

Identification of metastasis candidate proteins among HCC cell lines by comparative proteome and biological function analysis of S100A4 in metastasis in vitro

Widespread metastasis of hepatocellular carcinoma (HCC) was a complex cascade of events, which is still beyond full appreciation. Screening key proteins, which play a critical role in metastasis, using high-throughput proteomics approach help discover valuable biomarkers and elucidate the mechanism of metastasis. This study was to find out some metastasis candidate proteins among HCC cell lines with various metastatic potential by comparative proteomics, and then further validate the biological function of these proteins in metastasis in vitro. The protein profiles of metastatic HCC cell lines (MHCC97H and MHCC97L) displayed obvious differences compared with nonmetastatic ones (Hep3B). Twenty-six metastasis candidate proteins, which were identified by on-line LC-ESI-MS/MS, such as S100 calcium-binding protein A4 (S100A4), annexin 1, etc., might have much application in diagnostic procedures and prognosis evaluation. S100A4, as a leading different metastasis candidate protein, which overexpressed only in the metastatic cells, was selected for further investigation. A series of assays related to invasion and metastasis in vitro, including cell motility, invasion, and matrix metalloproteinases (MMPs) secretion, were performed in MHCC97H/antisense recombinant plasmid to S100A4 (pcDNA3.1(+) AS S100A4) and the mock controls. All the data in the present study suggested that S100A4 might contribute to HCC invasion and metastasis through two paths of matrix metalloproteinase (MMP9) secretion regulation and strengthened motility and invasion properties.

A randomized controlled trial of Licartin for preventing hepatoma recurrence after liver transplantation

Orthotopic liver transplantation (OLT) is the only curative therapy of HCC with underlying cirrhosis, but due to HCC metastasis and recurrence, its benefit is limited to a small population who meet the strict selection criteria. We previously reported that Licartin ([131I] mAb HAb18G/CD147) was safe and effective in treating HCC patients, and its antigen, HAb18G/CD147, was closely related to HCC invasion and metastasis. Here, we reported a randomized controlled trial to assess the post-OLT antirecurrence efficacy of Licartin in advanced HCC patients. We randomized 60 post-OLT patients with HCC, who were at tumor stage 3/4 and outside the Milan criteria before OLT, into 2 groups. Three weeks after OLT, the treatment group received 15.4 MBq/kg of Licartin, while the control group received placebo intravenously for 3 times with an interval of 28 days. At 1-year follow-up, the recurrence rate significantly decreased by 30.4% (P = 0.0174) and the survival rate increased by 20.6% (P = 0.0289) in the treatment group, compared with those in the control group. For the control group versus the treatment group, the hazard ratio for recurrence was 3.60 (95% confidence interval [CI], 1.50-8.60) and that for death was 3.87 (95% CI, 1.23-12.21). Licartin treatment also resulted in an earlier decreased AFP level and a longer time of normal AFP level than placebo (P = 0.0016). No Licartin-related toxic effects were observed.

CONCLUSION

Licartin is a promising drug for preventing post-OLT tumor recurrence in advanced HCC patients excluded by the currently strict criteria for OLT. HAb18G/CD147 can be a good drug target.

The hepatic transcriptome in human liver disease

The transcriptome is the mRNA transcript pool in a cell, organ or tissue with the liver transcriptome being amongst the most complex of any organ. Functional genomics methodologies are now being widely utilized to study transcriptomes including the hepatic transcriptome. This review outlines commonly used methods of transcriptome analysis, especially gene array analysis, focusing on publications utilizing these methods to understand human liver disease. Additionally, we have outlined the relationship between transcript and protein expressions as well as summarizing what is known about the variability of the transcriptome in non-diseased liver tissue. The approaches covered include gene array analysis, serial analysis of gene expression, subtractive hybridization and differential display. The discussion focuses on primate whole organ studies and in-vitro cell culture systems utilized. It is now clear that there are a vast number research opportunities for transcriptome analysis of human liver disease as we attempt to better understand both non-diseased and disease hepatic mRNA expression. We conclude that hepatic transcriptome analysis has already made significant contributions to the understanding of human liver pathobiology.

Stathmin overexpression cooperates with p53 mutation and osteopontin overexpression, and is associated with tumour progression, early recurrence, and poor prognosis in hepatocellular carcinoma

Stathmin, a major microtubule-depolymerizing protein, is involved in cell cycle progression and cell motility. This study aimed to elucidate its role in the progression, early tumour recurrence (ETR), and prognosis of hepatocellular carcinoma (HCC). Stathmin mRNA was overexpressed in 88/156 (56%) resected, unifocal, primary HCCs, while p53 mutation was present in 72 (46%) and osteopontin mRNA overexpression in 79 (51%). Stathmin mRNA expression exhibited high concordance (93%) with protein expression in 107 cases examined by immunohistochemistry. Stathmin overexpression correlated with high alpha-fetoprotein (>200 ng/ml, p = 0.02), larger tumour size (>5 cm, p = 0.012), high tumour grade (p < 0.0002), high tumour stage (stage IIIA-IV) with vascular invasion and various degrees of intrahepatic metastasis (p < 1 x 10(-8)), ETR (p = 0.003), and lower 5-year survival (p = 0.0007). Stathmin protein expression was often more intense in the peripheral regions of tumour trabeculae, tumour borders, and portal vein tumour thrombi. Stathmin overexpression correlated with p53 mutation (p = 0.017) and osteopontin overexpression (p = 1 x 10(-8)), both of which were associated with vascular invasion (both p < 0.0001) and poorer prognosis (p < 0.0004 and p = 0.0004, respectively). Regardless of the status of p53 mutation or osteopontin expression, stathmin overexpression was associated with higher vascular invasion (all p < 0.0001). Approximately 90% of HCCs harbouring stathmin overexpression with concomitant p53 mutation or osteopontin overexpression exhibited vascular invasion, and hence the lowest 5-year survival, p = 0.00018 and p = 0.0009, respectively. However, we did not find that stathmin overexpression exerted prognostic impact independent of tumour stage. In conclusion, stathmin expression correlates with metastatic potential, is an important prognostic factor for HCC, and may serve as a useful marker to predict ETR.

Mutation analysis of the 8p22 candidate tumor suppressor gene ATIP/MTUS1 in hepatocellular carcinoma

A high frequency of allelic loss affecting chromosome 8p and a minimal region of deletion at p21-22 have been previously reported in hepatocellular carcinoma (HCC), suggesting that at least one tumor suppressor gene is present in this region. In this study, we assessed whether the angiotensin II AT2 receptor interacting protein (ATIP)/mitochondrial tumor suppressor gene (MTUS1), a gene newly identified at position 8p22, may be a candidate tumor suppressor gene mutated in HCC. We searched for alterations in the 17 coding exons of ATIP/MTUS1 by means of denaturating high-performance liquid chromatography and sequencing, in 51 HCC tumors and 58 cell lines for which loss of heterozygosity status was known. Five major nucleotide substitutions were identified, all located in exons used by the ATIP3 transcript which is the only ATIP transcript variant expressed in liver. These nucleotide variations result in amino-acid substitution or deletion of conserved structural motifs (nuclear localisation signal, polyproline motif, leucine zipper) and also affect exonic splicing enhancer motifs and physiological splice sites, suggesting potential deleterious effects on ATIP3 function and/or expression.

The prognostic significance of preoperative plasma levels of osteopontin in patients with hepatocellular carcinoma

We aimed to evaluate the prognostic value of preoperative plasma osteopontin (OPN) levels in 101 patients with hepatocellular carcinoma (HCC) who underwent liver resection. Plasma OPN levels were detected by ELISA. The association of plasma OPN levels of patients with clinicopathological characteristics, tumor recurrence, and survival was analyzed. The median plasma OPN level of patients was 176.90 ng/ml (range 13.73-780.00 ng/ml), which was significantly higher than that of 24 healthy volunteers (63.74 ng/ml, range 12.20-122.32 ng/ml). Plasma OPN levels were significantly different in patients with different numbers of tumor nodules (168.18 and 217.11 ng/ml for single and multiple nodules, respectively; P = 0.002), different Edmondson's grades (201.24, 168.36, and 503.58 ng/ml for grades I, II, and III/IV, respectively; P = 0.015), and different TNM stages (168.16, 167.54, and 216.18 ng/ml for stages I, II, and III/IV, respectively; P = 0.016). Significantly higher plasma OPN levels were found in patients with a recurrence of HCC after resection, compared with those without recurrence (213.55 versus 153.70 ng/ml; P = 0.0013). A higher plasma OPN level was a leading independent prognostic factor for both overall survival (OS) and disease-free survival (DFS) in univariate and multivariate Cox models. This suggests that the preoperative plasma OPN level can be used as a predictive marker for HCC recurrence and may be helpful to assess the prognosis of patients with HCC after surgery.

Serum CYFRA 21-1 level reflects hepatocellular carcinoma metastasis: study in nude mice model and clinical patients

Our previous proteomics study on human hepatocellular carcinoma (HCC) cell strains revealed that cytokeratin 19 (CK19) was expressed in cells with high metastasis potential; we further studied serum CK19 fragment CYFRA 21-1 level in HCC patients and nude mice model of HCC metastasis. HCC cell line HCCLM3 was injected subcutaneously into 30 nude mice which were then randomized into 6 groups of 5 mice each. The murine serum CYFRA 21-1 and pulmonary metastases were determined 2, 3, 4, 5, 6, and 7 weeks after injection. Serum CYFRA 21-1 levels of 101 normal controls and 108 HCC patients were also determined. In nude mice model, CYFRA 21-1 level increased significantly when pulmonary metastases occurred. Among 108 HCC patients, 24 (22.2%) had increased serum CYFRA 21-1 level. The presence of portal vein tumor emboli was significantly higher in CYFRA 21-1 increased cases (33.3%, 6/24) than in CYFRA 21-1 normal cases (6.0%, 5/84) (x2=7.403, P < 0.01). In addition, the percentage of TNM stage III/IV tumor was significantly higher in CYFRA 21-1 increased patients (54.2%, 13/24) than in CYFRA 21-1 normal cases (21.4%, 18/84) (x2=9.776, P < 0.005). These results suggest that CK19 may play an important role in HCC metastasis.

HTPAP gene on chromosome 8p is a candidate metastasis suppressor for human hepatocellular carcinoma

Our previous studies suggested that chromosome 8p deletion is associated with metastasis of hepatocellular carcinoma (HCC), in which some novel metastasis suppressor genes might be harbored. The present study aimed to identify the metastatic suppressor gene(s). A cDNA chip was constructed with the expressed sequence tags (ESTs) from chromosome 8p and used to compare the difference of expression profiling between the MHCC97-H and MHCC97-L cell lines with different metastatic potentials and similar genetic backgrounds. In all, 10 ESTs were significantly downregulated in MHCC97-H cell line with higher metastatic potential. One full-length gene, HTPAP (phosphatidic acid phosphatase type 2 domain containing 1B), was identified at chromosome 8p12. Sequencing and bioinformatic analyses revealed that HTPAP has 826 bp and encodes a putative protein of 175 amino acids with a transmembrane segment at the NH2 terminus, two protein kinase C phosphorylation site and one tyrosine kinase phosphorylation site. Its expression level in metastatic tumor tissues was much lower than that of primary HCC tissues. Both in vitro and in vivo assays suggested that HTPAP could suppress the invasion and metastasis of HCC. These suggested that HTPAP is a novel metastatic suppressor gene for HCC. The mechanism of the effect of HTPAP on HCC metastasis is not clear yet and deserves further investigation.