The prognostic molecular markers in hepatocellular carcinoma

Proteomics in HepG2 hepatocarcinoma cells with stably silenced expression of PRDX1

Peroxiredoxin 1 (PRDX1) is a member of the peroxiredoxin family. Aberrant expression of PRDX1 has been described in various cancers. We investigated the significance of this up-regulation in non-challenged hepatocellularcarcinoma (HCC) cells by establishing a HepG2 cell line stably expressing a Prdx1 shRNA. Prdx1 silencing reversed, at least partially, the tumoural phenotype of HepG2 cells, resulting in morphological changes, delayed cell growth, down-regulation of transcripts for AFP, osteopontin and β-catenin and decreased γ-glutamyl transpeptidase activity, and oppositely up-regulation of transcripts for E-cadherin and proapoptotic proteins (BAX, CASP3) and increased alkaline phosphatase and CASP3 activities. Proteomic profiling identified 16 spots differentially expressed in Prdx1-silenced cells. Most of the variations involved the down-regulation of proteins with pivotal roles in cell proliferation and differentiation, in agreement with the observed phenotypic changes. We also investigated the effect of Prdx1 silencing on thiol protein oxidation. Proteins prone to reversible cysteine oxidation play major physiological functions. Notably, the down-regulation and altered redox status of key enzymes of carbohydrate and amino acid metabolism suggested a disturbance of the Warburg effect and glutamine utilization, two major pathways in the proliferation of tumour cells. Overall, these observations suggest that PRDX1 acts as a pro-cancer protein in HCC HepG2 cells.

Overexpression of Romo1 promotes production of reactive oxygen species and invasiveness of hepatic tumor cells

BACKGROUND & AIMS

Chronic oxidative stress from reactive oxygen species (ROS) produced by the mitochondria promotes hepatocarcinogenesis and tumor progression. However, the exact mechanism by which mitochondrial ROS contributes to tumor cell invasion is not known. We investigated the role of ROS modulator 1 (Romo1) in hepatocellular carcinoma (HCC) development and tumor cell invasiveness.

METHODS

We performed real-time, semi-quantitative, reverse transcriptase polymerase chain reaction; invasion and luciferase assays; and immunofluorescence and immunohistochemical analyses. The formation of pulmonary metastatic nodules after tumor cell injection was tested in severe combined immunodeficient mice. We analyzed Romo1 expression in HCC cell lines and tissues (n = 95).

RESULTS

Expression of Romo1 was increased in HCC cells, compared with normal human lung fibroblast cells. Exogenous expression of Romo1 in HCC cells increased their invasive activity, compared with control cells. Knockdown of Romo1 in Hep3B and Huh-7 HCC cells reduced their invasive activity in response to stimulation with 12-O-tetradecanoylphorbol-13-acetate. Levels of Romo1 were increased compared with normal liver tissues in 63 of 95 HCC samples from patients. In HCC samples from patients, there was an inverse correlation between Romo1 overexpression and patient survival times. Increased levels of Romo1 also correlated with vascular invasion by the tumors, reduced differentiation, and larger tumor size.

CONCLUSIONS

Romo1 is a biomarker of HCC progression that might be used in diagnosis. Reagents that inhibit activity of Romo1 and suppress mitochondrial ROS production, rather than eliminate up-regulated intracellular ROS, might be developed as cancer therapies.

Micronutrient Synergy in the Fight against Hepatocellular Carcinoma

The incidence of hepatocellular carcinoma (HCC), once thought to be a rare tumor in North America, has rapidly increased in recent years in the United States. Current treatment modalities to halt the progression of this disease are only marginally effective. The mainstay treatment is liver transplantation, which is often confronted with donor shortage. Invasion, metastasis and recurrence contribute to the high mortality rate of this disease. Matrix metalloproteinases (MMPs) that degrade the extracellular matrix (ECM) have been associated with the progression, invasion and metastasis of the disease. We have developed strategies to strengthen the ECM collagen and inhibit MMPs through micronutrients such as lysine, proline and ascorbic acid. Addition of epigallocatechin gallate or green tea extract to these micronutrients synergistically enhanced anti-carcinogenic activity in HepG2 cells. Addition of certain other micronutrients, such as N-acetylcysteine, selenium, copper and zinc (NM) synergistically enhanced the anticancer activity of the mixture in a model of hepatocellular carcinoma using HepG2 cells. In vitro studies using HepG2 demonstrated that NM was very effective in inhibiting cell proliferation (by MTT assay), MMPs secretion (by gelatinase zymography), cell invasion (through Matrigel) and induction of apoptosis (by live green caspase). In addition, NM was shown to down-regulate urokinase plasminogen activator (by fibrin zymography) and up-regulate tissue inhibitors of metalloproteinases (by reverse zymography) in another HCC cell line, SK-Hep-1. MMP-2 and MMP-9 activities were further modulated by phorbol 12-myristate 13-acetate (PMA) induction and inhibited by NM. In previous studies, NM inhibited Sk-Hep-1 xenografts in nude mice and also inhibited hepatic metastasis of B16FO melanoma cells. Our results suggest that NM is an excellent candidate for therapeutic use in the treatment HCC by inhibiting critical parameters in cancer development and progression, such as proliferation, invasion and metastasis, and by inducing apoptosis.

Roles for rat hepatocyte malignant transforming factor (HMTF) in late stage of hepatocarcinogenesis

In a previous study, to identify genes of importance for hepatocellular carcinogenesis, and especially for processes involved in malignant transformation, the authors investigated differences in gene expression between adenomas and carcinomas by DNA microarray. In the present study, the authors investigated AW434047, one of the sequences that was upregulated in carcinomas. The investigation led to the identification of a novel gene, which the authors named hepatocyte malignant transforming factor (HMTF), of unknown function whose expression was increased in hepatocellular carcinomas. Northern blot and in situ hybridization also demonstrated high levels of HMTF in rat hepatocellular carcinoma (HCC) cell lines, lymphocytes in the spleen, colon mucosal epithelia, spermatocytes, and granule cells of the hippocampus. Reduction of HMTF by RNA interference (RNAi) in N1 cells, an HCC cell line, caused suppression of cell proliferation, invasion, and migration. Suppression of proliferation appeared to be due to cell cycle arrest without increased apoptosis. Decreased HMTF expression resulted in down-regulation of STAT3, PCNA, and cyclin D1 and upregulation of p27. These results suggest that HMTF is a new marker for rat HCC and is involved in HCC cell proliferation and may also be linked to cell proliferation in the spleen, colon, brain, and testis.

Predictors of hepatocyte proliferative activity in chronic hepatitis B and C vs. steatohepatitis as assessed by the monoclonal antibody MIB1-Ki-67

BACKGROUND AND STUDY AIMS

Chronic hepatitis is characterised by increased regenerative cell proliferation, a process that makes cells more susceptible to gene mutations and development of hepatocellular carcinoma (HCC). Evaluation of the proliferative index could be a useful tool for identifying patients at risk for HCC. The current study was planned to evaluate hepatocyte proliferation in predominant causes of chronic liver disease in an attempt to investigate predictors of proliferation.

PATIENTS AND METHODS

This study included 84 patients with chronic liver diseases, and they were classified into three groups: chronic hepatitis C (50 patients), non-alcoholic steatohepatitis (NASH) (20 patients) and chronic hepatitis B (14 patients). All cases were investigated by liver function tests, polymerase chain reaction (PCR) hepatitis C virus (HCV) and hepatitis B virus (HBV), routine abdominal ultrasound and liver biopsy with detection of the proliferative index using the monoclonal antibody MIBI-Ki-67.

RESULTS

The proliferative index was significantly higher in the chronic hepatitis C group than in the chronic hepatitis B group (P value=0.007). There were significant correlations of the Ki-67 index in both zone 1 and zones 2 and 3 with alanine aminotransferase (ALT), aspartate aminotransferase (AST) and histological activity index (HAI) score. Using the multiple regression analysis on the variables affecting proliferation, it was found that predictors of zone 1 proliferation were the following variables: ALT, age, AST and aetiological factor, in that order.

CONCLUSION

HCV aetiology had significantly higher proliferation index, whereas NASH had the least. Increased HAI score is associated with higher proliferative index in either zone 1 or zones 2 and 3. Predictors of proliferation index in zone 1 were ALT, age, AST and aetiological factor.

Osteopontin enhances the expression and activity of MMP-2 via the SDF-1/CXCR4 axis in hepatocellular carcinoma cell lines

Background and Aims

Osteopontin, SDF-1α, and MMP-2 are important secreted molecules involved in the pathophysiology of human hepatocellular carcinoma (HCC). This study investigates the effect of the SDF-1α/CXCR4 axis on expression and activity of MMP-2 induced by osteopontin.

Methods

The expression of CXCR4, SDF-1α, MMP-2 and their associated cellular signaling cascades, involving Akt and MAP Kinases, were determined by Western blotting. The activities of MMP-2 and MMP-9 were assayed by gel zymography. The role of the osteopontin receptors integrin α_vβ₃ and CD44v6 was evaluated using neutralizing antibodies. We also established CXCR4-deficient SMMC7721 cell lines by transfection with miRNA-CXCR4 plasmids and determined cell invasion activity in a transwell assay.

Results

In comparison with untreated cells, recombinant human osteopontin (rhOPN) up-regulated CXCR4, SDF-1α, and MMP-2 expression about 5-, 4-, and 6-fold on the protein levels through binding to integrin α_vβ₃ and CD44v6 in hepatocellular carcinoma cells (SMMC7721 and HepG2). Inhibition of the SDF-1α/CXCR4 axis down-regulated the rhOPN-induced MMP-2 expression and activity. rhOPN also activated Akt, p38 and JNK. Down-regulation of CXCR4 decreased the rhOPN-induced invasion in SMMC7721 cells.

Conclusion

These results indicate that rhOPN up-regulates MMP-2 through the SDF-1α/CXCR4 axis, mediated by binding to integrin α_vβ₃ and CD44v6 and activating the PI-3K/Akt and JNK pathways in HepG2 and SMMC7721 cells. Therefore, the osteopontin-SDF-1α/CXCR4-MMP-2 system may be a new therapeutic target for treating HCC progression.

Blood neutrophil-to-lymphocyte ratio predicts survival in patients with unresectable hepatocellular carcinoma undergoing transarterial chemoembolization

PURPOSE

To evaluate whether the neutrophil-to-lymphocyte ratio (NLR) predicts survival in patients with unresectable hepatocellular carcinoma (HCC) before and after transarterial chemoembolization treatment.

MATERIALS AND METHODS

Clinical and laboratory data for 145 consecutive patients undergoing transarterial chemoembolization for unresectable HCC during 2001-2004 were analyzed retrospectively. The NLR was recorded before and 3 days after treatment.

RESULTS

The pretreatment mean NLR was 3.3; 59 (40.7%) patients had an elevated NLR (≥ 3.3). The median survival of patients with a high NLR was 8 months (range 1-28 months) compared with 12 months (range 2-41 months) for patients with a normal NLR; a significant difference was found in overall survival (log-rank test, P = .001). The NLR was increased in 127 (87.6%) patients after transarterial chemoembolization and was decreased in 18 patients; the increase indicated better outcomes (log-rank test, P = .006). Age (≥ 49 y), high NLR, decreased NLR after treatment, large tumor (≥ 5 cm), vascular invasion, and elevated serum α-fetoprotein (AFP) level all were predictors of poor survival. Multivariate analysis showed that a high NLR (P = .041) and vascular invasion (P = .040) were independent factors for predicting worse survival.

CONCLUSIONS

A high NLR independently predicts poor survival in patients with unresectable HCC undergoing transarterial chemoembolization treatment, and an increased NLR indicates a better outcome than a decreased NLR for patients after transarterial chemoembolization.

Transplantable subcutaneous hepatoma 22a affects functional activity of resident tissue macrophages in periphery

Tumors spontaneously develop central necroses due to inadequate blood supply. Recent data indicate that dead cells and their products are immunogenic to the host. We hypothesized that macrophage tumor-dependent reactions can be mediated differentially by factors released from live or dead tumor cells. In this study, functional activity of resident peritoneal macrophages was investigated in parallel with tumor morphology during the growth of syngeneic nonimmunogenic hepatoma 22a. Morphometrical analysis of tumor necroses, mitoses and leukocyte infiltration was performed in histological sections. We found that inflammatory potential of peritoneal macrophages in tumor-bearing mice significantly varied depending on the stage of tumor growth and exhibited two peaks of activation as assessed by nitroxide and superoxide anion production, 5'-nucleotidase activity and pinocytosis. Increased inflammatory reactions were not followed by the enhancement of angiogenic potential as assessed by Vascular Endothelial Growth Factor mRNA expression. Phases of macrophage activity corresponded to the stages of tumor growth characterized by high proliferative potential. The appearance and further development of necrotic tissue inside the tumor did not coincide with changes in macrophage behavior and therefore indirectly indicated that activation of macrophages was a reaction mostly to the signals produced by live tumor cells.

The effectiveness of particle radiotherapy for hepatocellular carcinoma associated with inferior vena cava tumor thrombus

BACKGROUND

The prognosis of patients who have hepatocellular carcinoma (HCC) associated with inferior vena cava tumor thrombus (IVCTT) is very poor, and effective treatment modalities are extremely limited. The objective of this study was to determine the therapeutic efficacy of particle radiotherapy for HCC with IVCTT.

METHODS

Between June 2001 and January 2009, 16 evaluable patients who had HCC with IVCTT were treated with particle radiotherapy. They were divided into 2 groups: 6 were treated with curative intent; 10 with palliative intent. The local tumor control rates, overall survival rates, and toxicities were evaluated.

RESULTS

All tumors treated with particle radiotherapy remained controlled without local recurrence at the last follow-up. The overall survival rates for the 16 patients at 1 and 3 years were 61.1 and 36.7%, respectively. We observed a significant difference in the survival rates according to treatment policy. The median survival time was 25.4 months for patients treated with curative intent and 7.7 months for those treated with palliative intent. The one-year survival rates were 100.0 and 33.3%, respectively. No Grade 3 or higher treatment-related toxicities were observed.

CONCLUSIONS

Particle radiotherapy is thought to be potentially effective and safe for HCC with IVCTT. Considering the current lack of effective and less-invasive local therapy for HCC with IVCTT, particle radiotherapy may therefore be an attractive new therapeutic approach for this type of HCC.

Emerging roles of microRNA in the intracellular signaling networks of hepatocellular carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs of 19-23 nucleotides that negatively regulate gene expression through binding to the 3'-untranslated regions of target messenger RNAs (mRNAs). Although the miRNA family constitutes only a minor fraction of the human genome, they hold fundamental importance in diverse physiological and developmental processes due to their pleiotropic effects on the post-transcriptional regulation of many vital genes. This class of regulatory RNAs has also emerged as important players in carcinogenesis; most, if not all, cancer types have abnormal miRNA expression patterns. In hepatocellular carcinoma (HCC), miRNA dysregulation plays a key role in mediating the pathogenicity of several etiologic risk factors and, more importantly, they promote a number of cancer-inducing signaling pathways. Recent studies have also demonstrated their potential values in the clinical management of HCC patients as some miRNAs may be used as prognostic or diagnostic markers. The significance of miRNAs in liver carcinogenesis emphasizes their values as therapeutic targets, while technological advances in the delivery of miRNA has shed new possibilities for their use as novel therapeutic agents against HCC.

Decreased expression of BATF2 is associated with a poor prognosis in hepatocellular carcinoma

Human BATF2, a basic leucine zipper protein, was recently detected in several normal immortalized cell lines but not in transformed cell lines. In addition, the expression of BATF2 also slowed the growth rate of malignant tumor cells injected into athymic nude mice. In this study, to study the role of BATF2 in hepatocellular carcinoma (HCC), we examined BATF2 expression in 50 paired HCC tumorous and nontumorous tissues, as well as in five HCC cell lines. Moreover, BATF2 expression in 114 HCC patients was evaluated using immunohistochemistry, and its relationship with clinicopathological parameters and prognosis was investigated. We found that BATF2 expression was significantly reduced in most HCC tumorous tissues, when compared with nontumorous tissues, as well as in the five HCC cell lines. Consistent with these results, the immunohistochemistry revealed that decreased BATF2 expression was present in 63 of the 114 cases and was significantly correlated with age (p = 0.006), tumor size (p = 0.046) and tumor differentiation (p = 0.030). Patients with negative BATF2 expression showed a shorter survival than those with positive expression (p = 0.016). Multivariate analysis revealed that BATF2 expression was an independent predictor of overall survival (p = 0.015). All the data support the hypothesis that BATF2 plays an important role in the progression of HCC and that it may work as a candidate tumor suppressor and a prognostic marker as well as a potential target for treatment.

Inhibition of telomerase activity by HDV ribozyme in cancers

Background

Telomerase plays an important role in cell proliferation and carcinogenesis and is believed to be a good target for anti-cancer drugs. Elimination of template function of telomerase RNA may repress the telomerase activity.

Methods

A pseudo-knotted HDV ribozyme (g.RZ57) directed against the RNA component of human telomerase (hTR) was designed and synthesized. An in vitro transcription plasmid and a eukaryotic expression plasmid of ribozyme were constructed. The eukaryotic expression plasmid was induced into heptocellular carcinoma 7402 cells, colon cancer HCT116 cells and L02 hepatocytes respectively. Then we determine the cleavage activity of ribozyme against human telomerase RNA component (hTR) both in vitro and in vivo, and detect telomerase activity continuously.

Results

HDV ribozyme showed a specific cleavage activity against the telomerase RNA in vitro. The maximum cleavage ratio reached about 70.4%. Transfection of HDV ribozyme into 7402 cells and colon cancer cells HCT116 led to growth arrest and the spontaneous apoptosis of cells, and the telomerase activity dropped to 10% of that before.

Conclussion

HDV ribozyme (g.RZ57) is an effective strategy for gene therapy.

Concanavalin A-immobilized magnetic nanoparticles for selective enrichment of glycoproteins and application to glycoproteomics in hepatocelluar carcinoma cell line

Protein glycosylation is one of the most important PTMs in biological organism. Lectins such as concanavalin A (Con A) have been widely applied to N-glycosylated protein investigation. In this study, we developed Con A-immobilized magnetic nanoparticles for selective separation of glycoproteins. At first, a facile immobilization of Con A on aminophenylboronic acid-functionalized magnetic nanoparticles was performed by forming boronic acid-sugar-Con A bond in sandwich structure using methyl alpha-D-mannopyranoside as an intermedium. The selective capture ability of Con A-modified magnetic nanoparticles for glycoproteins was tested using standard glycoproteins and cell lysate of human hepatocelluar carcinoma cell line 7703. In total 184 glycosylated sites were detected within 172 different glycopeptides corresponding to 101 glycoproteins. Also, the regeneration of the protein-immobilized nanoparticles can easily be performed taking advantage of the reversible binding mechanism between boronic acid and sugar chain. The experiment results demonstrated that Con A-modified magnetic nanoparticles by the facile and low-cost synthesis provided a convenient and efficient enrichment approach for glycoproteins, and are promising candidates for large-scale glycoproteomic research in complicated biological samples.

The role of cytokines in UbD promoter regulation and Mallory-Denk body-like aggresomes

Mallory-Denk bodies (MDBs) are found in chronic liver diseases. Previous studies showed that diethyl-1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate (DDC) induced formation of MDBs and the up regulation of UbD expression in mouse liver. UbD is a protein over expressed in hepatocellular carcinomas. It is a potential preneoplastic marker in the mouse. It is hypothesized that inflammatory cytokines play a critical role in UbD up regulation and MDB formation. TNFa and IFNg treatment of HCC cell line Hepa 1-6, induced the expression of UbD and the expression of genes coding for the immunoproteasome (LMP2, LMP7, and MECL-1 subunits). TNFa and IFNg induced the activity of the UbD promoter, using a luciferase assay. The cotreatment with TNFa and IFNg induced the activity of the UbD promoter through an Interferon Sequence Responsive Element (ISRE). In addition, long term treatment with TNFa and IFNg induced the formation of MDB-like aggresomes in Hepa 1-6 cells, which emphasizes the role of inflammation in the formation of MDBs leading to the formation of liver tumors, in the mouse. Identifying the mechanism that regulates gene expression of UbD supports the hypothesis that down regulation of UbD and the proinflammatory gene expression would prevent MDB and HCC formations. Previous studies indicate that S-adenosylmethionine or betaine prevented IFNg induced UbD and MDB formations.

Epithelial-mesenchymal transition gene signature to predict clinical outcome of hepatocellular carcinoma

Hepatocellular carcinoma is one of the most lethal cancers worldwide. More accurate stratification of patients at risk is necessary to improve its clinical management. As epithelial-mesenchymal transition is critical for the invasiveness and metastasis of human cancers, we investigated expression profiles of 12 genes related to epithelial-mesenchymal transition through a real-time polymerase chain reaction. From a univariate Cox analysis for a training cohort of 128 hepatocellular carcinoma patients, four candidate genes (E-cadherin [CDH1], inhibitor of DNA binding 2 [ID2], matrix metalloproteinase 9 [MMP9], and transcription factor 3 [TCF3]) with significant prognostic values were selected to develop a risk score of patient survival. Patients with high risk scores calculated from the four-gene signature showed significantly shorter overall survival times. Moreover, the multivariate Cox analysis revealed that four-gene signature (P = 0.0026) and tumor stage (P = 0.0023) were independent prognostic factors for overall survival. Subsequently, the four-gene signature was validated in an independent cohort of 231 patients from three institutions, in which high risk score was significantly correlated with shorter overall survival (P = 0.00011) and disease-free survival (P = 0.00038). When the risk score was entered in a multivariate Cox analysis with tumor stage only, both the risk score (P = 0.0046) and tumor stage (P = 2.6 x 10(-9)) emerged as independent prognostic factors. In conclusion, we suggest that the proposed gene signature may improve the prediction accuracy for survival of hepatocellular carcinoma patients, and complement prognostic assessment based on important clinicopathologic parameters such as tumor stage.

Monocyte chemoattractant protein-1 (MCP-1)/CCL2 secreted by hepatic myofibroblasts promotes migration and invasion of human hepatoma cells

The aim of our study was to investigate whether myofibroblasts and the chemokine monocyte chemoattractant protein-1 (MCP-1)/CCL2 may play a role in hepatocellular carcinoma progression. We observed that hepatic myofibroblast LI90 cells express MCP-1/CCL2 mRNA and secrete this chemokine. Moreover, myofibroblast LI90 cell-conditioned medium (LI90-CM) induces human hepatoma Huh7 cell migration and invasion. These effects are strongly reduced when a MCP-1/CCL2-depleted LI90-CM was used. We showed that MCP-1/CCL2 induces Huh7 cell migration and invasion through its G-protein-coupled receptor CCR2 and, to a lesser extent, through CCR1 only at high MCP-1/CCL2 concentrations. MCP-1/CCL2's chemotactic activities rely on tyrosine phosphorylation of focal adhesion components and depend on matrix metalloproteinase (MMP)-2 and MMP-9. Furthermore, we observed that Huh7 cell migration and invasion induced by the chemokine are strongly inhibited by heparin, by beta-D-xyloside treatment of cells and by anti-syndecan-1 and -4 antibodies. Finally, we developed a 3-dimensional coculture model of myofibroblast LI90 and Huh7 cells and demonstrated that MCP-1/CCL2 and its membrane partners, CCR1 and CCR2, may be involved in the formation of mixed hepatoma-myofibroblast spheroids. In conclusion, our data show that human liver myofibroblasts act on hepatoma cells in a paracrine manner to increase their invasiveness and suggest that myofibroblast-derived MCP-1/CCL2 could be involved in the pathogenesis of hepatocellular carcinoma.

Expression of hepatocyte growth factor and basic fibroblast growth factor as prognostic indicators in gastric cancer

We have investigated the correlations among hepatocyte growth factor (HGF) mRNA expression, basic fibroblast growth factor (bFGF) mRNA expression, tumor microvessel density (MVD), and clinical pathological features of gastric cancer in Chinese patients. In situ hybridization was used to detect the expression of HGF and bFGF mRNAs, and immunohistochemistry was used to detect CD34 in 105 gastric cancer tissues and in 20 normal control tissues. The rate of HGF mRNA expression in normal gastric tissues (25%) was significantly lower than that (57.1%) in tumor tissues (P < 0.01). The rates of HGF mRNA and bFGF mRNA expression and MVD in T3-T4 stage tissues were higher than those in T1-T2 stage tissues (P < 0.01); the HGF mRNA expression rate was directly correlated with the bFGF mRNA expression rate (P < 0.05), and they were also directly correlated with MVD (P < 0.01). The mean survival time and the 5-year survival rate of patients who were positive for expression of HGF mRNA and bFGF mRNA and who had a MVD >or= 39.5/0.72 mm(2) were significantly shorter than those who did not express HGF mRNA and bFGF mRNA and who had a MVD <39.5/0.72 mm(2). Both HGF and bFGF may participate in angiogenesis in gastric cancer and may be involved in tumor invasion and metastasis. HGF and bFGF mRNA expression can be used as useful parameters to evaluate the prognosis of gastric cancer.

The characteristics and performance of a multifunctional nanoassembly system for the co-delivery of docetaxel and iSur-pDNA in a mouse hepatocellular carcinoma model

Human hepatocellular carcinoma (HCC) is one of the most causes of cancer-related death and is well known because of resistant to chemotherapeutic drug. Co-delivery of antitumor agent docetaxel and iSur-pDNA, a suppressor of metastatic and resistance-related protein survivin, was postulated to achieve synergistic/combined effect of antitumor drug and gene therapeutics. To valid this hypothesis, a folate-modified multifunctional nanoassembly (FNA) loading both docetaxel and iSur-pDNA was constructed and evaluated as a therapeutic approach for HCC. The FNAs were prepared with folate-modified lipid FA-PEG-DSPE as the target to tumor, protamine sulfate (PS) as the condenser to protect and enhance the nuclear transfer of iSur-pDNA, and DOPE-based lipid envelope as the carrier of doctaxel and PS/DNA complex to achieve their co-delivery and enhance internalization into hepatoma cells. FNAs showed the particle size about 200nm with encapsulation efficiency >90%. Blank nanoassemblies (BNAs) loading only reporter gene revealed higher transfection efficiency with neglectable cytotoxicity compared with Lipofectamine 2000, which could result from enhanced cellular uptake via ligand-receptor recognition and efficient nuclear delivery mediated by PS. Cytotoxicity of FNAs against hepatocellular carcinoma cell line BEL 7402 was much higher than either docetaxel or non-docetaxel FNAs (nFNAs) loading only iSur-pDNA, and was also superior to the combined treatment with free docetaxel and nFNAs. Better antitumor efficacy of FNAs with low systemic toxicity was also observed on mouse hepatocellular carcinoma xenograft model. These results suggested that co-delivery of docetaxel and iSur-pDNA with FNAs could be a safer and more efficient strategy for the treatment of locally advanced and metastatic HCC.

Decreased expression of Neurensin-2 correlates with poor prognosis in hepatocellular carcinoma

AIM: To investigate the expression of Neurensin-2 (NRSN2) in hepatocellular carcinoma (HCC) and its prognostic values in predicting survival.

METHODS: The expression and prognostic significance of NRSN2 in HCC was examined by performing immunohistochemical analysis using a total of 110 HCC clinical tissue samples, and Western blotting analysis to further confirm the result.

RESULTS: Decreased NRSN2 expression was shown in 70.9% cases. Loss of NRSN2 expression in HCC was significantly related to tumor size (P = 0.006). Larger tumor size was related to negative expression of NRSN2. Patients showing negative NRSN2 expression had a significantly shorter overall survival than those with positive expression (P = 0.008). Multivariate Cox regression analysis indicated that NRSN2 expression level was an independent factor of survival (P = 0.013). Western blotting analysis further confirmed decreased expression of NRSN2 in tumor tissues compared with non-tumorous tissues.

CONCLUSION: Our study indicated that NRSN2 could be a tumor suppressor gene for HCC and a candidate biomarker for long-term survival in HCC.

Is female sex a significant favorable prognostic factor in hepatocellular carcinoma?

OBJECTIVE

As sex favorably modulates the natural history of chronic liver diseases and the risk for neoplastic evolution, our study aimed to ascertain whether female hepatocellular carcinoma (HCC) patients are also characterized by better prognosis.

METHODS

The ITA.LI.CA (Italian Liver Cancer) database was used, including 1834 HCC patients (482 females, 1352 males) that were consecutively diagnosed. The following variables were considered: age, etiology, modality of diagnosis, earlier interferon treatment, bilirubin, alpha-fetoprotein levels, constitutional syndrome, portal thrombosis, metastasis, number and size of nodules, grading, Child-Pugh class, tumor-nodes-metastases and Cancer of the Liver Italian Program staging, and treatment.

RESULTS

Female HCC patients were characterized by older age (P=0.0001), higher prevalence of HCV infection (P=0.0001), diagnosis more frequently by surveillance (P=0.003), higher alpha-fetoprotein levels (P=0.0055), lower prevalence of constitutional syndrome (P=0.03), portal thrombosis (P=0.04), and metastasis (P=0.0001). HCC in females was more frequently unifocal (P=0.0001), smaller (P=0.001), well differentiated (P=0.001), and of lower Cancer of the Liver Italian Program and tumor-nodes-metastases stage (P=0.0001 and 0.0001). However, females underwent curative treatments (transplantation, resection, percutaneous ablation) in the same percentage of cases as males. Finally, females had a significantly longer survival (median 29 [95% confidence interval (CI): 24-33] vs. 24 (22-25) months, P=0.0001). The difference was sharper [median 36 (CI: 31-41] vs. 17 (CI: 15-19)] when females undergoing surveillance were compared with males diagnosed incidentally or for symptoms. The Cox model also identified sex as an independent predictor of survival. When only patients undergoing surveillance were considered, no significant difference was observed.

CONCLUSION

HCC in females has better prognosis, but this is possibly more because of higher compliance with surveillance than to real biological differences.

Integrin alpha(v)beta(3), metalloproteinases, and sphingomyelinase-2 mediate urokinase mitogenic effect

Plasminogen activators are implicated in the pathogenesis of several diseases such as inflammatory diseases and cancer. Beside their serine-protease activity, these agents trigger signaling pathways involved in cell migration, adhesion and proliferation. We previously reported a role for the sphingolipid pathway in the mitogenic effect of plasminogen activators, but the signaling mechanisms involved in neutral sphingomyelinase-2 (NSMase-2) activation (the first step of the sphingolipid pathway) are poorly known. This study was carried out to investigate how urokinase plasminogen activator (uPA) activates NSMase-2. We report that uPA, as well as its catalytically inactive N-amino fragment ATF, triggers the sequential activation of MMP-2, NSMase-2 and ERK1/2 in ECV304 cells that are required for uPA-induced ECV304 proliferation, as assessed by the inhibitory effect of Marimastat (a MMP inhibitor), MMP-2-specific siRNA, MMP-2 defect, and NSMase-specific siRNA. Moreover, upon uPA stimulation, uPAR, MT1-MMP, MMP-2 and NSMase-2 interacted with integrin alpha(v)beta(3), evidenced by co-immunoprecipitation and immunocytochemistry experiments. Moreover, the alpha(v)beta(3) blocking antibody inhibited the uPA-triggered MMPs/uPAR/integrin alpha(v)beta(3) interaction, NSMase-2 activation, Ki67 expression and DNA synthesis in ECV304. In conclusion, uPA triggers interaction between integrin alpha(v)beta(3), uPAR and MMPs that leads to NSMase-2 and ERK1/2 activation and cell proliferation. These findings highlight a new signaling mechanism for uPA, and suggest that, upon uPA stimulation, uPAR, MMPs, integrin alpha(v)beta(3) and NSMase-2 form a signaling complex that take part in mitogenic signaling in ECV304 cells.

The regulation of non-coding RNA expression in the liver of mice fed DDC

Mallory-Denk bodies (MDBs) are found in the liver of patients with alcoholic and chronic nonalcoholic liver disease, and hepatocellular carcinoma (HCC). Diethyl 1,4-dihydro-2,4,6,-trimethyl-3,5-pyridinedicarboxylate (DDC) is used as a model to induce the formation of MDBs in mouse liver. Previous studies in this laboratory showed that DDC induced epigenetic modifications in DNA and histones. The combination of these modifications changes the phenotype of the MDB forming hepatocytes, as indicated by the marker FAT10. These epigenetic modifications are partially prevented by adding to the diet S-adenosylmethionine (SAMe) or betaine, both methyl donors. The expression of three imprinted ncRNA genes was found to change in MDB forming hepatocytes, which is the subject of this report. NcRNA expression was quantitated by real-time PCR and RNA FISH in liver sections. Microarray analysis showed that the expression of three ncRNAs was regulated by DDC: up regulation of H19, antisense Igf2r (AIR), and down regulation of GTL2 (also called MEG3). S-adenosylmethionine (SAMe) feeding prevented these changes. Betaine, another methyl group donor, prevented only H19 and AIR up regulation induced by DDC, on microarrays. The results of the SAMe and betaine groups were confirmed by real-time PCR, except for AIR expression. After 1 month of drug withdrawal, the expression of the three ncRNAs tended toward control levels of expression. Liver tumors that developed also showed up regulation of H19 and AIR. The RNA FISH approach showed that the MDB forming cells' phenotype changed the level of expression of AIR, H19 and GTL2, compared to the surrounding cells. Furthermore, over expression of H19 and AIR was demonstrated in tumors formed in mice withdrawn for 9 months. The dysregulation of ncRNA in MDB forming liver cells has been observed for the first time in drug-primed mice associated with liver preneoplastic foci and tumors.

Hepatocellular Carcinoma: Tumorigenesis and Prediction Markers

Hepatocellular carcinoma (HCC) is one of the most common malignancies. Although many advances have been made in the clinical study of HCC, the prognosis remains poor. Despite the discoveries in cancer biology in respect with physiological and pathological factors in relation to prognosis, HCC remains still a fatal disease due to late diagnosis. For improving the outcomes of patients with HCC, it is important to identify the factors predisposing to patient death. In recent years, based on cellular and molecular biology techniques, many tumor markers related to invasion, metastasis, recurrence and survival have been explored. However, routine biomarkers for the prediction of HCC evolution and prognosis are available in small number and less specific. These reviews focus on the recent advances in HCC tumorigenesis, revealing those biomarkers with prognosis significance or can be used for early detection.

Characteristic Genotypes of Vascular Endothelial Growth Factor are Susceptible to Ascites in Patients with Cirrhosis

This study was designed to investigate whether different vascular endothelial growth factor (VEGF) genotypes are associated with ascites formation in cirrhotic patients. Seventy cirrhotic patients were included in the study: 25 cirrhotic patients with ascites and 45 cirrhotic patients without ascites. Patient characteristics were investigated and compared between the two groups. With regard to VEGF genotype, 42 patients were C/C and 28 patients were T/T or C/T. The genotypes T/T or C/T were observed in 23 cases (51%) among the non-ascites group, but in only five cases (20%) among the ascites group. Serum levels of albumin and creatinine, and the VEGF genotypes were significantly different between the two groups. Multiple regression analysis showed that serum levels of creatinine and the VEGF genotypes were significantly correlated with ascites formation. Thus, it can be concluded that VEGF genotyping might be a valuable susceptibility marker for ascites formation in cirrhotic patients.

Identification of N-glycosylation sites on secreted proteins of human hepatocellular carcinoma cells with a complementary proteomics approach

N-linked glycosylation is prevalent in proteins destined for extracellular environments; nearly all secreted proteins are glycosylated. However, with respect to their glycosylation sites, little attention has been paid. Here, we report the analysis of N-glycosylation sites on secreted proteins of human hepatocellular carcinoma cells. For the enrichment of glycopeptides, capture methods with hydrophilic affinity (HA) and hydrazide chemistry (HC) were used complementarily. With the use of both methods in combination with nano-LC-ESI-MS/MS analysis, 300 different glycosylation sites within 194 unique glycoproteins were identified, and 172 glycosites have not been determined experimentally previously. A direct comparison between HA and HC methods was also investigated for the first time. In brief, in terms of selectivity for glycopeptides, HC is superior to HA (92.9% vs 51.3%); however, based on the number of glycosites identified, HA outweighs HC (265 vs 159). Furthermore, unavoidable contaminants such as actin and bovine serum albumin which are not N-glycosylated could be easily depleted by using this glycoproteomic strategy. As a consequence, more low-abundance and genuinely secreted proteins were identified. Among the glycoproteins identified, alpha-fetoprotein, CD44 and laminin have been reported to be implicated in HCC and its metastasis.

Cross-species hybridization of woodchuck hepatitis viral infection-induced woodchuck hepatocellular carcinoma using human, rat and mouse oligonucleotide microarrays

BACKGROUND AND AIM

We aimed to evaluate the transcriptional characteristics of viral infection-induced woodchuck hepatocellular carcinoma (HCC), to compare the use of human, rat and mouse gene arrays for cross-species hybridization, and to look into gene expression profiles in woodchuck HCC by the combined use of these arrays.

METHODS

Commercially available human, rat and mouse oligonucleotide microarrays were used to determine the gene expression profiles on the same woodchuck liver samples. Differentially expressed genes between HCC and the surrounding hepatic tissues found in the arrays were selected for quantitative reverse transcription polymerase chain reaction.

RESULTS

Despite the difference in the number of the probes from each array, the percentage of genes that were detectable was similar. Stringent microarray data analysis using both supervised and unsupervised methods identified 281 differentially expressed genes via the human array with a false discovery rate (FDR) of 0.99%, 107 genes via the rat array with an FDR of 1.85% and 78 genes via the mouse array with an FDR of 7.41%. Eleven genes were differentially changed in all three arrays that include the upregulation of NPM1, H2AFZ, EEF1G, HNRPAB, RPS18, EIF5, CKS2, ARIH1, RPS12 and RPS10, and the downregulation of EGR1. The quantitative reverse transcription polymerase chain reaction with woodchuck-specific primers confirmed the reliability of the microarray results.

CONCLUSION

This study further demonstrated the utility of cross-species hybridization of microarrays on woodchuck HCC. A combined use of three types of arrays identified more differential genes in HCC than individual arrays with the human array providing the richest information among the three arrays used.

Radiogenomics: creating a link between molecular diagnostics and diagnostic imaging

Studies employing high-throughput biological techniques have recently contributed to an improved characterization of human cancers, allowing for novel sub-classification, better diagnostic accuracy, and more precise prognostication. However, requirement of surgical procurement of tissue among other things limits the clinical application of such methods in everyday patient care. Radiographic imaging is routine in clinical practice but is currently histopathology based. The use of routine radiographic imaging provides a potential platform for linking specific imaging traits with specific gene expression patterns that inform the underlying cellular pathophysiology; imaging features could then serve as molecular surrogates that contribute to the diagnosis, prognosis, and likely gene-expression-associated treatment response of various forms of human cancer. This review focuses on high-throughput methods such as microarray analysis of gene expression, their role in cancer research, and in particular, on novel methods of associating gene expression patterns with radiographic imaging phenotypes, known as "radiogenomics." These findings underline a potential future role of both diagnostic and interventional radiologists in genetic assessment of cancer patients with radiographic imaging studies.

Suppression of N-Ras by shRNA-expressing plasmid increases sensitivity of HepG2 cells to vincristine-induced growth inhibition

Oncogenic ras genes relate to the development of human cancers. In this study, we used a plasmid-mediated short-hairpin RNA (shRNA) targeting N-ras gene to combine with clinical drug vincristine (VCR) for the treatment of human hepatoma cells. Our results showed that anti-N-Ras shRNA expression vector (pCSH1-shNR) knocked down the target mRNA and protein. Higher efficacy on growth inhibition was observed when pCSH1-shNR was combined with VCR. This synergistic effect was associated with abrogation of VCR-induced overexpressions of P-glycoprotein and multidrug resistance-associated protein 1 by pCSH1-shNR through downregulations of N-Ras and total Ras. Western blot analysis showed that pCSH1-shNR-induced downregulations of N-Ras and total Ras were potentiated by VCR. Following Ras downregulation, phosphorylations of ERK1/2 and Akt were dramatically inhibited by combinatory treatment. The data showed that pCSH1-shNR-induced inhibition of nuclear factor-kappaB was enhanced by VCR. In addition, the combination of pCSH1-shNR and VCR synergistically inhibited the growth of human hepatoma HepG2 in vivo. Our findings suggested that combination of gene-specific therapeutics and appropriate chemotherapeutic agents might be a promising approach for the treatment of human hepatocellular carcinoma.

Molecular prediction of early recurrence after resection of hepatocellular carcinoma

The prognosis of hepatocellular carcinoma (HCC) remains poor. Vascular invasion, tumour multiplicity and large tumour size are the conventional poor prognostic indicators related to early recurrence. However, it is difficult to predict prognosis of each HCC in the absence of these indicators. The purpose of this study is to predict early recurrence of HCC after radical resection based on whole human gene expression profiling. Microarray analyses were performed in 139 HCC primary tumours. A total of 88 cases lacking the conventional poor prognostic indicators were analysed to establish a molecular prediction system characteristic for early recurrence in 42 training cases with two polarised prognoses, and to test its predictive performance in 46 independent cases (group C). Subsequently, this system was applied to another 51 independent cases with some poor prognostic indicators (group D). The molecular prediction system accurately differentiated HCC cases into poor and good prognoses in both the independent group C (disease-free survival [DFS]: p=0.029, overall survival [OS]: p=0.0043) and independent group D (DFS: p=0.0011, OS, p=0.035). Multivariate Cox regression analysis indicated that the clinical value of molecular prediction system was an independent prognostic factor (p<0.0001, hazard ratio=3.29). Gene expression pattern related to early intrahepatic recurrence inherited in the primary HCC tumour can be useful for the prediction of prognosis.

Can E-cadherin and CD34 be used as indicators of prognosis for hepatocellular carcinoma patients?

BACKGROUND

The high postoperative recurrence of hepatocellular carcinoma (HCC) is a problem that would benefit from the identification of indicators of recurrence and prognosis. In the past few years, research has shown that E-cadherin and CD34 can be used as indicators of the invasion of malignant tumors. In the present study, we investigated the expression of E-cadherin and CD34 in HCC patients.

METHODS

Expression levels of E-cadherin and CD34 in 41 HCC samples were detected using two-step immunohistochemical methods and compared with clinical pathological parameters and survival rate.

RESULTS

The positive rates of E-cadherin and CD34 expression in 41 HCC cases were 48.78% and 100%, respectively. Expression of E-cadherin was significantly lower in patients with larger tumors, a high risk invasion and Edmondson classification III or IV (p<0.05). There was a significant relationship between CD34 expression and age and tumor invasiveness (p<0.05). There was no significant relationship between expression of CD34 and E-cadherin by Spearman statistical analysis (p>0.05). The survival rate in patients with negative expression of E-cadherin was significantly lower.

CONCLUSIONS

The expression of CD34 cannot be used singly as a prognostic indicator for HCC patients. The co-expression of E-cadherin and CD34 cannot be used as a prognostic indicator for HCC patients. Clin Chem Lab Med 2008;46:1122-6.

Following up tumour angiogenesis: from the basic laboratory to the clinic

Preceded by three decades of intense basic research on tumour angiogenesis, we are assisting to the translation of anti-antiangiogenic therapies as medical oncologists are increasingly using pioneering anti-angiogenic drugs in combination with standard treatments. While basic knowledge in the field of angiogenesis is reaching maturity and our level of understanding of the complex process of vessel development and growth in health and disease has been enriched at the molecular and cellular levels, the translation of this knowledge to the clinic is still in its infancy. Identifying the most suitable drugs, and the optimal dosage and schedule, as well as monitoring patients' responses to anti-angiogenic therapy, remain challenging issues that currently limit the benefit of this new therapeutic approach in cancer. This review will focus on a comprehensive description of the experimental assays in which angiogenesis research has been founded and how the different assays complement and provide relevant information for the task of characterising the angiogenic properties of diverse tumours, giving us a variety of tools to follow up tumour angiogenesis in research models. Following up tumour angiogenesis in patients and their response to antiangiogenic therapy is a more challenging task that will benefit in the near future from the use of non-invasive imaging methods as well as molecular and cellular biomarkers of angiogenesis suitable for clinical oncology. As both the design of the anti-angiogenic therapies and monitoring of the response are improved in the coming years to properly tailor them to the angiogenic profile of every patient, we hope to achieve increasing response and benefit of including antiangiogenic drugs as standard in cancer therapy.

Relationship between microvessel count and post-hepatectomy survival in patients with hepatocellular carcinoma

AIM: To elucidate the relationship between the microvessel count (MVC) by CD34 analyzed by immunohistochemical method and prognosis in hepatocellular carcinoma (HCC) patients who underwent hepatectomy based on our preliminary study.

METHODS: We examined relationships between MVC and clinicopathological factors in 128 HCC patients. The modified Japan Integrated Staging score (mJIS) was applied to examine subsets of HCC patients.

RESULTS: Median MVC was 178/mm², which was used as a cut-off value. MVC was not significantly associated with any clinicopathologic factors or postoperative recurrent rate. Lower MVC was associated with poor disease-free and overall survivals by univariate analysis (P = 0.039 and P = 0.087, respectively) and lower MVC represented an independent poor prognostic factor in disease-free survival by Cox’s multivariate analysis (risk ratio, 1.64; P = 0.024), in addition to tumor size, vascular invasion, macroscopic finding and hepatic dysfunction. Significant differences in disease-free and overall survivals by MVC were observed in HCC patients with mJIS 2 (P = 0.046 and P = 0.0014, respectively), but not in those with other scores.

CONCLUSION: Tumor MVC appears to offer a useful prognostic marker of HCC patient survival, particularly in HCC patients with mJIS 2.

Circulating matrix metalloproteinase-2 is associated with cystatin C level, posttransplant duration, and diabetes mellitus in kidney transplant recipients

Studies have indicated that matrix metalloproteinase-2 (MMP-2) is vital for the patient's condition after renal transplantation. Although the allograft survival rate has been improved, the relationships between various clinical parameters in stable graft function and serum MMP-2 still need to be clarified. In this study, gelatin zymography and enzyme-linked immunosorbent assay were employed to measure MMP-2 level in the plasma of 152 kidney transplant recipients, 41 chronic kidney disease patients, and 50 healthy control subjects. The creatinine and the MMP-2 levels in the transplant recipients were significantly greater (P < 0.001) than those of control subjects. Univariate and stepwise regression analysis demonstrated the MMP-2 level was associated with cystatin C level (P < 0.001), creatinine level (P = 0.036), proteinuria (P = 0.043), posttransplant days (P = 0.025), and posttransplant diabetes mellitus (P = 0.03). We conclude that circulating MMP-2 is associated with cystatin C, posttransplant duration, and diabetes mellitus in kidney transplant recipients and suggest that MMP-2 may be critical for graft survival.

Tumor suppressor and hepatocellular carcinoma

A few signaling pathways are driving the growth of hepatocellular carcinoma. Each of these pathways possesses negative regulators. These enzymes, which normally suppress unchecked cell proliferation, are circumvented in the oncogenic process, either the over-activity of oncogenes is sufficient to annihilate the activity of tumor suppressors or tumor suppressors have been rendered ineffective. The loss of several key tumor suppressors has been described in hepatocellular carcinoma. Here, we systematically review the evidence implicating tumor suppressors in the development of hepatocellular carcinoma.

Prognostic factors and recurrence of small hepatocellular carcinoma after hepatic resection or microwave ablation: a retrospective study

PURPOSE

This study aims to analyze the long-term therapeutic results of small HCC less than 5 cm in diameter after microwave ablation (MA) or hepatic resection (HR) and choose factors that could predict metastasis and recurrence of small HCC.

MATERIALS AND METHODS

The metastasis and recurrence of 194 patients with one HCC less than 5 cm in diameter who underwent curative HR or MA between January 1995 and December 2004 were reviewed retrospectively; immunohistochemistry was used to analyze the expressions of VEGF, bFGF, and c-Met in HCC tissues. Posttreatment prognostic factors were evaluated by multivariate analysis using Cox's proportional hazards model. The variables included the expressions of these three proteins in HCC tissues, the clinical and pathologic characteristics of the patients.

RESULTS

The retrospective study showed that 1-, 3-, and 5-year disease-free survival rates of patients with single HCC of diameter <5 cm were 71.3, 57.0 and 32.5%, respectively. Furthermore, 1-, 3-, and 5-year disease-free survival rates of the patients in MA group and resection group were 72.8, 54.0 and 33.0%; 68.5, 60.0, and 25.6%, respectively. There was no significant difference in disease-free survival rates between these two groups. The result of multivariate analysis showed that differentiation degree of HCC and the expressions of VEGF and c-Met in HCC tissues could be as the independent prognostic factors affecting metastasis and recurrence in patients with small HCC, whereas the methods of therapy had no impact on prognosis.

CONCLUSIONS

The metastasis and recurrence rate after MA is similar to that after HR, and the methods of therapy do not affect the prognosis of small HCC. The metastasis and recurrence of patients with small HCC will differ depending on tumor differentiation, expressions of VEGF and c-Met in HCC tissues.

New perspectives and strategy research biomarkers for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Cirrhosis caused by hepatitis B virus, hepatitis C virus or chronic alcohol intake is associated with major risk. Systematic screening for HCC of asymptomatic patients with cirrhosis is needed for earlier detection of small tumors requiring treatment (liver transplantation, surgical resection, percutaneous techniques). The recommended screening strategy among cirrhotic patients is based on regular liver ultrasonography associated with serum alpha-fetoprotein (AFP) assay. As the performance of AFP is not satisfactory, additional tumoral markers are proposed (des-gamma-carboxyprothrombin, glycosylated AFP-L3 fraction). Currently, diagnosis of HCC in cirrhotic patients includes non-invasive tests (imaging after contrast administration, AFP assay); diagnostic biopsy is performed when imaging is limited. After treatment, tumor recurrence is assessed by regular follow-up (AFP assay and imaging). Despite the lack of accurate markers, recent developments in genomic and proteomic approaches will allow the discovery of new biomarkers for primary tumors, as well as for recurrence. This review summarizes the current state of biomarkers for screening, diagnosis and follow-up of HCC, and highlights new perspectives in the field.

Analysis of microdissected cells by two-dimensional LC-MS approaches

Laser capture microdissection (LCM) is a powerful tool that enables the isolation of specific cell types from tissue sections, overcoming the problem of tissue heterogeneity and contamination. We combined the LCM with isotope-coded affinity tag (ICAT) technology and two-dimensional liquid chromatography to investigate the qualitative and quantitative proteomes of hepatocellular carcinoma (HCC). The effects of three different histochemical stains on tissue sections have been compared, and toluidine blue stain was proved as the most suitable stain for LCM followed by proteomic analysis. The solubilized proteins from microdissected HCC and non-HCC hepatocytes were qualitatively and quantitatively analyzed with two-dimensional liquid chromatography tandem mass spectrometry (2D-LC-MS/MS) alone or coupled with cleavable isotope-coded affinity tag (cICAT) labeling technology. A total of 644 proteins were qualitatively identified and 261 proteins were unambiguously quantified. These results showed that the clinical proteomic method using LCM coupled with ICAT and 2D-LC-MS/MS can carry out not only large-scale but also accurate qualitative and quantitative analysis.

Specific diagnosis of gamma-glutamyl transferase subfraction and its genotyping for hepatocellular carcinoma

Abnormal expression of total γ-glutamyl transferase (GGT, EC 2.3.2.2) activity can be found in patients with different liver diseases and extrahepatic tumors. Circulating GGT from hepatocellular carcinoma (HCC) patients can be divided into different isoforms (Ⅰ, Ⅰ', Ⅱ, Ⅱ', β, δ, ε, φA, ⅦB, φC, γA, γB) by using PAGE. Some of these isoforms (Ⅰ', Ⅱ and Ⅱ', and hepatoma-specific GGT, HS-GGT) can be detected in sera of HCC patients. Hepatic GGT gene expression may be closely related to the development of HCC. The human cDNA sequences from fetal liver, placenta and HepG2 cells (H) were investigated. The genotype H was predominant in cancerous tissues of HCC. Both HS-GGT and genotype H were confirmed as useful specific HCC markers, with higher specificity and sensitivity, and their analysis may be useful for HCC diagnosis and differentiation.

Decreased expression of ING2 gene and its clinicopathological significance in hepatocellular carcinoma

The inhibitor of growth (ING) family member 2 (ING2) is a newly discovered member of ING family that can regulate a wide range of cellular processes including cell growth arrest, apoptosis, and DNA repair. Researches have shown that ING2 can activate p53 and p53-mediated apoptotic pathway involved in the hepatocarcinogenesis. To investigate the role of ING2 in hepatocellular carcinoma (HCC) pathogenesis, we analyzed the correlations between the ING2 expression level and clinicopathologic factors and studied its prognostic role in primary HCC. Using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, ING2 transcription and post-transcription level was found to be downregulated in the majority of tumors compared with matched non-tumors liver tissues (p=0.004 and p=0.014, respectively). The immunohistochemistry data indicated significant reduction of ING2 expression level in 44 of 84 (52.4%) HCC cases. In addition, the expression level of ING2 correlated with tumor size, histopathologic classification, serum AFP (p<0.05). Kaplan-Meier curves demonstrated that patients with reduced ING2 expression were at significantly increased risk for shortened survival time (p=0.009). Using multivariate analysis, ING2 expression was found to be an independent prognostic factor. Our data suggest that ING2 is involved in the progression of HCC, therefore it is considered to be a candidate tumor suppressor gene and its significantly decreased expression in HCC may lead to an unfavorable prognosis.

Liver angiogenesis as a risk factor for hepatocellular carcinoma development in hepatitis C virus cirrhotic patients

AIM: To evaluate the predictive value of hepatocyte proliferation and hepatic angiogenesis for the occurrence of Hepatocellular carcinoma (HCC) in hepatitis C virus (HCV) cirrhotic patients.

METHODS: One hundred-five patients (69 males, 36 females; age range, 51-90 year; median 66 year) with biopsy proven HCV cirrhosis were prospectively monitored for HCC occurrence for a median time of 64 mo. Angiogenesis was assessed by using microvessel density (MVD), hepatocyte turnover by MIB1 and PCNA indexes at inclusion in liver biopsies.

RESULTS: Forty six patients (43.8%) developed HCC after a median time of 55 (6-120) mo while 59 (56.2%) did not. Patients were divided into two groups according to the median value of each index. The difference between patients with low (median MVD = 3; range 0-20) and high (median MVD = 7; range 1-24) MVD was statistically significant (χ² = 22.06; P < 0.0001) which was not the case for MIB1 or PCNA (MIB-1: χ² = 1.41; P = 0.2351; PCNA: χ² = 1.27; P = 0.2589). The median MVD was higher in patients who developed HCC than in those who did not. HCC-free interval was significantly longer in patients with the MVD ≤ 4 (P = 0.0006). No relationship was found between MIB₁ or PCNA and MVD (MIB-1 r² = 0.00007116, P = 0.9281; PCNA: r² = 0.001950; P = 0.6692). MVD only was able to predict the occurrence of HCC in these patients. Among other known risk factors for HCC, only male sex was statistically associated with an increased risk.

CONCLUSION: Liver angiogenesis has a role for in HCV-related liver carcinogenesis and for defining patients at higher risk.