The prognostic significance of clinical and pathological features in hepatocellular carcinoma

Does the presence of circulating hepatocellular carcinoma cells indicate a risk of recurrence after resection?

OBJECTIVES

Alpha-fetoprotein messenger RNA (AFP mRNA) in the peripheral blood (PB) of patients with hepatocellular carcinoma (HCC) has been considered to represent isolated tumor cells. We investigated its association with the prognosis after curative resection.

METHODS

Using a reverse-transcription polymerase chain reaction (RT-PCR)-based assay, AFP mRNA in the PB was determined prospectively in control and in 81 patients with curative resection for HCC.

RESULTS

Twenty-two (27.2%) and 19 (23.4%) of 81 HCC patients had AFP mRNA in their pre- and postoperative PB. Its presence preoperatively was not associated with an increased risk of HCC recurrence (54.5% vs 40.7%, p= 0.264). In contrast, the postoperative presence associated significantly with a higher incidence of recurrence (89.5% vs 30.6%, p < 0.001), irrespective of preoperative status. The odds ratio for HCC recurrence was 19.2 (95% confidence interval [CI]: 4.0- 91.7). The cmulative probability of recurrence-free survival was also much lower in patients with postoperatively positive AFP mRNA (p < 0.001). The Cox proportional hazards model also demonstrated a significant association with recurrence (p= 0.002). Preoperative serum AFP is also a significant factor and combination with postoperative AFP mRNA enhances the predictability, sensitivity (75.0%), specificity (93.3%), positive prediction (90.0%), and negative prediction (82.4%).

CONCLUSIONS

The postoperative detection of AFP mRNA in PB is associated with an increased risk of earlier HCC recurrence. Combination with preoperative serum AFP is useful in predictability.

Recent progress in predictive biomarkers for metastatic recurrence of human hepatocellular carcinoma: a review of the literature

Molecular markers (biomarkers) for hepatocellular carcinoma (HCC) metastasis and recurrence could provide additional information to that gained from traditional histopathological features. A large number of biomarkers have been shown to have potential predictive significance. One important aspect of this is to detect the transcripts of tumor-associated antigens (such as AFP, MAGEs, and CK19), which are proposed as predictive markers of HCC cells disseminated into the circulation and for metastatic recurrence. Another important aspect is to analyze the molecular markers for cellular malignancy phenotype, including DNA ploidy, cellular proliferation index, cell cycle regulators, oncogenes, and tumor suppressors (especially p53 gene), as well as telomerase activity. Molecular factors involved in the process of HCC invasion and metastasis, including adhesion molecules (E-cadherin, catenins, ICAM-1, laminin-5, CD44 variants, osteopontin), proteinases responsible for the degradation of extracellular matrix (MMPs, uPA system), as well as angiogenesis regulators (such as VEGF, intratumor MVD), have also been shown to be potential predictors for HCC metastatic recurrence and clinical outcomes. One important new trend is to widely delineate biomarkers with genomic and proteomic expression with reference to predicting metastatic recurrence, molecular diagnosis, and classification, which has been drawing more attention recently. Body fluid (particularly blood and urine) testing for biomarkers is easily accessible and more useful in clinical patients. The prognostic significance of circulating DNA in plasma or serum and its genetic alterations is another important direction. More attention should be paid to these areas in the future. As understanding of tumor biology deepens, more and more new biomarkers with high sensitivity and specificity for HCC metastatic recurrence could be found and routinely used in clinical assays. However, the combination of the pathological features and some of the biomarkers mentioned above seems to be more practical up to now.

Disruption of beta-catenin pathway or genomic instability define two distinct categories of liver cancer in transgenic mice

BACKGROUND & AIMS

Human liver cancer can be divided into 2 categories that are characterized by activation of beta-catenin and genomic instability. Here we investigate whether similar categories exist among 5 transgenic models of liver cancer, including c-myc, transforming growth factor-alpha, E2F-1, c-myc/transforming growth factor-alpha, and c-myc/E2F-1 mice.

METHODS

The random amplified polymorphic DNA method was used to assess the overall genomic instability, and chromosomal loci affected by genomic alterations were determined by microsatellite analysis. beta-Catenin mutations and deletions were analyzed by polymerase chain reaction and sequencing screening. Cellular localization of beta-catenin and expression of alpha-fetoprotein, a prognostic marker of hepatocellular carcinoma, were investigated by immunohistochemistry.

RESULTS

Liver tumors from the transgenic mice could be divided into 2 broad categories characterized by extensive genomic instability (exemplified by the c-myc/transforming growth factor-alpha mouse) and activation of beta-catenin (exemplified by the c-myc/E2F-1 mouse). The c-myc/transforming growth factor-alpha tumors displayed extensive genomic instability with recurrent loss of heterozygosity at chromosomes 1, 2, 4, 6, 7, 9, 12, 14, and X and a low rate of beta-catenin activation. The genomic instability was evident from the early dysplastic stage and occurred concomitantly with increased expression of alpha-fetoprotein. The c-myc/E2F-1 tumors were characterized by a high frequency of beta-catenin activation in the presence of a relatively stable genome and low alpha-fetoprotein levels.

CONCLUSIONS

We have identified 2 prototype experimental models, i.e., c-myc/transforming growth factor-alpha and c-myc/E2F-1 mice, for the 2 categories of human hepatocellular carcinoma characterized by genomic instability and beta-catenin activation, respectively. These mouse models will assist in the elucidation of the molecular basis of human hepatocellular carcinoma.

From proteomic analysis to clinical significance: overexpression of cytokeratin 19 correlates with hepatocellular carcinoma metastasis

To better understand the mechanism underlying the hepatocellular carcinoma (HCC) metastasis and to search potential markers for HCC prognosis, differential proteomic analysis on two well-established HCC cell strains with high and low metastatic potentials, MHCC97-H and MHCC97-L, was conducted using two-dimensional gel electrophoresis followed by matrix-assisted laser desorption/time-of-flight mass spectrometry. Cytokeratin 19 (CK19) was identified and found to be overexpressed in MHCC97-H as compared with MHCC97-L. This result was further confirmed by two-dimensional Western blot analysis and immunofluorescence assay. Furthermore, one-dimensional Western blot analysis showed consistently increased CK19 expression in progressively more metastatic cells. Immunohistochemical study on 102 human HCC specimens revealed that more patients in the CK19-positive group had overt intrahepatic metastases (satellite nodules, p < 0.05; vascular tumor emboli, p < 0.001; tumor node metastatis staging, p < 0.001). CK19 fragment CYFRA 21-1 levels measured in sera from nude mice model of human HCC metastasis with radioimmunoassay increased in parallel with tumor progression and rose remarkably when pulmonary metastases occurred. The results demonstrated that overexpression of CK19 in HCC cells is related to metastatic behavior. Serum CK19 level might reflect the pathological progression in some HCC and may be a useful marker for predicting tumor metastasis and a therapeutic target for the treatment of HCC patients with metastases.

Total vascular exclusion technique for resection of hepatocellular carcinoma

AIM: To improve the low resection rate, poor prognosis and to control the massive hemorrhage during operation, total vascular exclusion (TVE) technique was used in hepatectomies of advanced and complicated hepatocellular carcinomas (HCCs).

METHODS: Five hundred and thirty patients with HCCs were admitted in our hospital. They were divided into TVE technique group (group A: n = 78), Pringle maneuver method group (group B: n = 176) and unresectable group (group C: n = 276). The clinical, operative, pathological parameters and outcome of the patients were statistically evaluated.

RESULTS: Group A had a significantly higher resection rate than group B (accounting for 47.92% and 33.21% respectively). There was no significant difference in blood loss, blood transfusion and perioperative mortality between groups A and B. Both groups had the similar median disease free survival time (14.6 vs 16.3 months) and 1 year survival rate (92.9% vs 95.5%). The TVE group had a medial survival time of 40.5 months and its 5-year survival rate was 34.6%.

CONCLUSION: As compared with Pringle maneuver method, the total vascular exclusion is a safe and effective technique to increase the total resection rate of advanced and complicated HCCs.

Expression and significance of RhoC gene in hepatocellular carcinoma

AIM: To investigate the expression of RhoC gene in hepatocellular carcinoma (HCC) and to evaluate the relationship between RhoC gene expression and invasion and metastasis of HCC.

METHODS: mRNA expression level of RhoC gene was examined by reverse transcription-polymerase chain reaction (RT-PCR) in 25 cases of HCC and para-cancerous normal liver tissues. In addition, mutation of RhoC gene was examined by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP).

RESULTS: The mRNA expression levels of RhoC in tumor tissues were significantly higher than those in para-cancerous normal liver tissues (1.8 ± 1.1 vs 1.0 ± 0.7, P < 0.01). The metastatic lesions outside of liver also showed significantly higher RhoC mRNA levels than corresponding tumor tissues in liver (3.3 ± 0.5 vs 2.0 ± 0.7, P < 0.01). There were significant associations between RhoC gene expression and certain clinical and pathological findings, including cell differentiation, vein invasion, number of tumor nodes and metastatic lesions. Mutation of RhoC gene was not found by PCR-SSCP.

CONCLUSION: The RhoC gene may be related to malignant transformation and development of HCC and may play an important role in the invasion and metastasis of HCC by overexpression but not mutation.

Combined interventional therapies of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world, responsible for an estimated one million deaths annually. It has a poor prognosis due to its rapid infiltrating growth and complicating liver cirrhosis. Surgical resection, liver transplantation and cryosurgery are considered the best curative options, achieving a high rate of complete response, especially in patients with small HCC and good residual liver function. In nonsurgery, regional interventional therapies have led to a major breakthrough in the management of unresectable HCC, which include transarterial chemoembolization (TACE), percutaneous ethanol injection (PEI), radiofrequency ablation (RFA), microwave coagulation therapy (MCT), laser-induced thermotherapy (LITT), etc. As a result of the technical development of locoregional approaches for HCC during the recent decades, the range of combined interventional therapies has been continuously extended. Most combined multimodal interventional therapies reveal their enormous advantages as compared with any single therapeutic regimen alone, and play more important roles in treating unresectable HCC.

Role of preoperative selective portal vein embolization in two-step curative hepatectomy for hepatocellular carcinoma

AIM: To determine the feasibility and role of ultrasound-guided preoperative selective portal vein embolization (POSPVE) in the two-step hepatectomy of patients with advanced primary hepatocellular carcinoma (HCC).

METHODS: Fifty patients with advanced HCC who were not suitable for curative hepatectomy were treated by ultrasound-guided percutaneous transhepatic POSPVE with fine needles. The successful rate, side effects and complications of POSPVE, changes of hepatic lobe volume and two-step curative hepatectomy rate after POSPVE were observed.

RESULTS: POSPVE was successfully performed in 47 (94.0%) patients. In patients whose right portal vein branches were embolized, their right hepatic volume decreased and left hepatic volume increased gradually. The ratio of right hepatic volume to total hepatic volume decreased from 62.4% before POSPVE to 60.5%, 57.2% and 52.8% after 1, 2 and 3 weeks respectively. The side effects included different degree of pain in liver area (38 cases), slight fever (27 cases), nausea and vomiting (9 cases). The level of aspartate alanine transaminase (AST), alanine transaminase (ALT) and total bilirubin (TBIL) increased after POSPVE, but returned to preoperative level in 1 week. After 2-4 weeks, two-step curative hepatectomy for HCC was successfully performed on 23 (52.3%) patients. There were no such severe complications as ectopic embolization, local hemorrhage and bile leakage.

CONCLUSION: Ultrasound-guided percutaneous transhepatic POSPVE with fine needles is feasible and safe. It can extend the indications of curative hepatectomy of HCC, and increase the safety of hepatectomy.

Expression of telomerase activity and oxidative stress in human hepatocellular carcinoma with cirrhosis

AIM: To study the expression and significance of telomerase activity and oxidative stress in hepatocellular carcinoma (HCC) with cirrhosis.

METHODS: In this study, TRAP-ELISA assay was used to determine telomerase activity in 21 cases of HCC as well as in 23 cases of hepatic cirrhosis. Malondialdehyde (MDA), glutathione S-transferase (GST) and total anti-oxidative capacity (T-AOC) were also examined in the same samples with human MDA, GST and T-AOC kits.

RESULTS: Eighteen of 21 cases of HCC were found to have increased telomerase activity, whereas only three of the 23 non-cancerous cirrhotic samples were found to have weak telomerase activity, and the difference was significant (P < 0.001). No significant difference in telomerase activity was detected according to different tumor size, tumor stage, histological grade, HBsAg, contents of albumin, bilirubin, ALT, AFP, r-GT and platelet. There were significant differences between HCC and cirrhosis in the expression of MDA, GST and T-AOC respectively. Telomerase activity correlated positively with the content of MDA (P < 0.05).

CONCLUSION: Telomerase activation is the early event of carcinogenesis, which is not correlated with clinicopathological factors of HCC. The dysfunction of the anti-oxidative system is closely correlated with the progression from cirrhosis to hepatocellular carcinoma. Oxidative stress may contribute partly to telomerase activation.

Construction and expression of recombined human AFP eukaryotic expression vector

AIM: To construct a recombined human AFP eukaryotic expression vector for the purpose of gene therapy and target therapy of hepatocellular carcinoma (HCC).

METHODS: The full length AFP-cDNA of prokaryotic vector was digested, and subcloned to the multi-clony sites of the eukaryotic vector. The constructed vector was confirmed by enzymes digestion and electrophoresis, and the product expressed was detected by electrochemiluminescence and immunofluorescence methods.

RESULTS: The full length AFP-cDNA successfully cloned to the eukaryotic vector through electrophoresis, 0.9723 IU/mL AFP antigen was detected in the supernatant of AFP-CHO by electrochemiluminescence method. Compared with the control groups, the differences were significant (P < 0.05). AFP antigen molecule was observed in the plasma of AFP-CHO by immunofluorescence staining.

CONCLUSION: The recombined human AFP eukaryotic expression vector can express in CHO cell line. It provides experimental data for gene therapy and target therapy of hepatocellular carcinoma.

Preparation and characterization of polyclonal antibodies against ARL-1 protein

AIM: To prepare and characterize polyclonal antibodies against aldose reductase-like (ARL-1) protein.

METHODS: ARL-1 gene was inserted into the E. coli expression vector pGEX-4T-1(His)6C and vector pQE-30. Recombinant ARL-1 proteins named ARL-(His)₆ and ARL-GST were expressed. They were purified by affinity chromatography. Sera from domestic rabbits immunized with ARL-(His)₆ were purified by CNBr-activated sepharose 4B coupled ARL-GST. Polyclonal antibodies were detected by Western blotting.

RESULTS: Recombinant proteins of ARL-(His)₆ with molecular weight of 35.7 KD and ARL-GST with molecular weight of 60.8 KD were highly expressed. The expression levels of ARL-GST and ARL-(His)₆ were 15.1% and 27.7% among total bacteria proteins, respectively. They were soluble, predominantly in supernatant. After purification by non-denatured way, SDS-PAGE showed one band. In the course of polyclonal antibodies purification, only one elution peak could be seen. Western blotting showed positive signals in the two purified proteins and the bacteria transformed with pGEX-4T-1(His)₆ C-ARL and pQE-30-ARL individually.

CONCLUSION: Polyclonal antibodies are purified and highly specific against ARL-1 protein. ARL-GST and ARL-(His)₆ are highly expressed and purified.

Percutaneous cryoablation in treatment of liver cancer: a report of 31 cases

AIM

To describe the indication, efficacy and clinical significance of percutaneous cryoablation in the treatment of liver malignancy.

METHODS

Total 31 patients with histologically or clinically confirmed primary or metastatic malignancies were treated pucutaneously under ultrasound guidance using the cryocare surgical system from July 2001 to January 2002. All patients were followed up to determine the serum tumor marker, and reveal CT scans, MRI images or utra-sound images.

RESULTS

This therapy was performed in 31 patients including 26 cases with Child A liver reserve, 4 cases with Child B and 1 cases with Child C. There were 21 cases of primary liver cancer and 10 metastastic liver cancer. AFP positive small liver cancer became AFP negative in 80% patients. The rate of completely concreted necrosis in small hepatic cancer with negative AFP was 66.7%, shown by CT or MRI. The curative rate for metastasis liver cancer was 50% at CT, MRI or tumor marker level.

CONCLUSION

Percutaneous cryoablation is a kind of new palliative treatment for liver carcinoma. It is minimally invasive, safe and effective especially for patients with unresectable liver cancer.

Effect of arsenic trioxide on rat hepatocarcinoma and its renal cytotoxicity

AIM: To study the effect of arsenic trioxide (As₂O₃) on rat experimental hepatocarcinoma and its renal cytotoxicity.

METHODS: The hepatocarcinoma model was established by diethaylnitrosamine perfusion in stomach of 120 Wistar rats, and the treatment began at the end of 20 weeks. Before the treatment, the rat models were randomly divided into 5 groups. In the treatment groups, three doses of As₂O₃ were injected into rat abdominal cavity, the total time of drug administration was 4 weeks. Cisplatin control or the blank group was injected into abdominal cavity with equal amount of cisplatin or saline at the same time, respectively. On the 7^th, 14^th and 28^th day after the treatment, the hepatocarcinoma nodules were obtained and the morphologic changes of hepatocarcinoma cells were observed under light and electron microscopes; Immunohistochemistry (S-P methods) was employed to detect the expression of bcl-2, bax and PCNA in hepatocarcinoma tissues; flow cytometry (TUNEL assay) was used to detect the apoptosis of liver cancer cells and the change of cytokinetics. On the 28^th day, the kidneys were obtained and their histologic changes were observed under light microscope, and immunohistochemistry (SP stain) was also employed to detect the expression of bcl-2 and PCNA. Cisplatin and saline solution were used as the control.

RESULTS: As₂O₃ could induce the apoptosis of rat liver cancer cells and exhibited typical morphologic changes. The incidence of apoptosis of hapatocarcinoma cells was elevated (P = 0.001). The elevation was the most higher in the group of middle-dose of As₂O₃ (1 mg·kg^-1), significantly higher than that of the other arsenic groups and the controls (P = 0.001). Large dose of As₂O₃ (5 mg·kg^-1) was able to arise the incidence of apoptosis, but also produced a large amount of necrosis and inflammatory reaction. Middle dose of As₂O₃ dramatically increased the cell number in G2/M phase (P = 0.0001), and apoptosis happened apparently. The expression of bcl-2 and bax was related to the dose of As₂O₃. With the up-regulation of apoptotic incidence, the ratio of bcl-2/bak decreased. But the incidence of apoptosis was not the highest status and the ratio of bcl-2/bax was at the lowest when the highest-dose of As₂O₃ was used. There was significant difference among the PCNA indexes (PCNA L1) of the five groups. Of them, three arsenic groups all showed decrease of different degrees, and this down-regulation was most obvious in group A. There was significant difference among the three groups (P = 0.016). Under the light microscope, the rat kidney in the cisplatin group exhibited tubular epithelium swelling and degeneration, protein casts in collecting tubules; While all arsenic groups didn’t show the significant changes (P = 0.013). In the arsenic groups, the expression of bcl-2 in the renal tubular epithelium was increased (P = 0.005), no obvious changes happened to PCNA L1. But in the group of cisplatin, the PCNA L1 increased significantly (P = 0.001).

CONCLUSION: As₂O₃ can induce apoptosis of rat hepatocellular carcinoma cells. And there is optimum dose; too high dose will induce the cytotoxic effect, while certain dose of As₂O₃ is able to block the cell cycle at G2/M phase. As₂O₃ had the most remarkable influence on G2/M cells, and it can also induce apoptosis to cells at other phases. As₂O₃ can restrain the proliferation of rat hepatocellular carcinoma cells, in a dose-time dependent manner. Compared with cisplatin, As₂O₃ didn’t show obvious renal toxicity, which was related to the increasing expression of bcl-2 in renal tubular epithelium, the inhibition of apoptosis and the anti-oxidation effects.

Experimental study on the feasibility and safety of radiofrequency ablation for secondary splenomagely and hypersplenism

AIM: To assess the feasibility and safety of radiofrequency ablation (RFA) in treatment of secondary splenomagely and hypersplenism.

METHODS: Sixteen healthy mongrel dogs were randomly divided into two groups, group I (n = 4) and group II (n = 12). Congestive splenomegaly was induced by ligation of splenic vein and its collateral branches in both groups. At the end of 3rd week postoperation, RFA in spleen was performed in group II via laparotomy, complications of RFA were observed, CT scan was performed and the spleens were obtained. The radiofrequency (RF) thermal lesions and histopathology of spleen were examined regularly.

RESULTS: No complication or death was observed in both groups; CT revealed that the splenomegaly lasted over 2 months after ligation of splenic vein; the segmental RF lesions included hyperintense zone of coagulative necrosis and more extensive peripheral hypointense infarcted zone, the latter was called “bystander effect”. The infarcted zone would be absorbed and subsequently disappeared in 4-6 weeks after RFA accompanied with shrinkage of the remnant spleen. The fundamental histopathological changes of splenic lesions caused by RF thermal energy included local coagulative necrosis, peripheral thrombotic infarction zone, subsequent tissue absorption and fibrosis in the zone of thrombotic infarction, the occlusion of vessels in remnant viable spleen, deposition of extensive fibrous protein, and disappearance of congestive splenic sinusoid - “splenic carnification”. Those pathologic changes were underline of shrinkage of spleen.

CONCLUSION: It is feasible and safe to perform RFA in spleen to treat experimental splenomegaly and hypersplenism. The RFA could be safely performed clinically via laparotomy or laparoscopic procedure while spleen was strictly separated from surrounding organs.

Glycylproline dipeptidyl aminopeptidase isoenzyme in diagnosis of primary hepatocellular carcinoma

AIM: To investigate the role of glycylproline dipeptidyl aminopeptidase (GPDA) isoenzyme in the diagnosis of primary hepatocellular carcinoma (PHC), especially in patients with negative alpha-fetoprotein (AFP).

METHODS: A stage gradient polyacrylamide gel discontinuous electrophoresis system was developed to separate serum GPDA isoenzymes, which were determined in 102 patients with PHC, 45 cases with liver cirrhosis, 24 cases with chronic hepatitis, 35 cases with benign liver space-occupying lesions, 20 cases with metastatic liver cancer and 50 cases with extra-hepatic cancer, as well as 80 healthy subjects. The relationships between GPDA isoenzymes and AFP, the sizes of tumors, as well as alanine aminotransferase (ALT) were also analyzed.

RESULTS: Serum GPDA was separated into two isoenzymes, GPDA-S and GPDA-F. The former was positive in all subjects, while the latter was found mainly in majority of PHC (85.3%) and a few cases with liver cirrhosis (11.1%), chronic hepatitis (33.3%), metastatic liver cancer (15.0%) and non-hepatic cancer (16.0%). GPDA-F was negative in all healthy subjects and patients with benign liver space-occupying lesions, including abscess, cysts and angioma. There was no correlation between GPDA-F and AFP concentration or tumor size. GPDA-F was consistently positive and not correlated with ALT in PHC, but GPDA-F often converted to negative as decline of ALT in benign liver diseases. The electrophoretic migration of GPDA-F became sluggish after the treatment of neuraminidase.

CONCLUSION: GPDA-F is a new useful serum marker for PHC. Measurement of serum GPDA-F is helpful in diagnosis of PHC, especially in patients with negative AFP. GPDA-F is one kind of glycoproteins rich in sialic acid.

Docetaxel inhibits SMMC-7721 human hepatocellular carcinoma cells growth and induces apoptosis

AIM: To investigate the in vitro anti-hepatocellular carcinoma (HCC) activity of docetaxel against SMMC-7721 HCC cells and its possible mechanism.

METHODS: The HCC cells were given different concentrations of docetaxel and their growth was measured by colony forming assay. Cell cycle and apoptosis were analyzed by flow cytometry and fluorescence microscopy (acridine orange/ethidium bromide double staining, AO/EB), as well as electronic microscopy. The SMMC-7721 HCC cell reactive oxygen species (ROS) and glutathione (GSH) were measured after given docetaxel.

RESULTS: Docetaxel inhibited the hepatocellular carcinoma cells growth in a concentration dependent manner with IC₅₀ 5 × 10^-10 M. Marked cell apoptosis and G2/M phase arrest were observed after treatment with docetaxel ≥ 10^-8 M. Docetaxel promoted SMMC-7721 HCC cells ROS generation and GSH deletion.

CONCLUSION: Docetaxel suppressed the growth of SMMC-7721 HCC cells in vitro by causing apoptosis and G2/M phase arrest of the human hepatoma cells, and ROS and GSH may play a key role in the inhibition of growth and induction of apoptosis.

Ghrelin in chronic liver disease

BACKGROUND/AIMS

Ghrelin is a novel endogenous ligand for the growth hormone (GH) secretagogue receptor involved in energy metabolism, glucose homeostasis and food intake. We investigated the role of ghrelin and insulin-like growth factor-1 (IGF-1), the mediator of the GH axis, in patients with chronic liver diseases (CLD).

METHODS

Ghrelin and IGF-1 serum levels were determined in 105 CLD patients and 97 healthy controls and correlated with clinical and biochemical parameters.

RESULTS

Ghrelin was significantly elevated and IGF-1 reduced in CLD patients compared with healthy controls. IGF-1 serum levels inversely correlated with Child's classification. Ghrelin levels were significantly elevated in Child C cirrhosis patients independent of the aetiology of liver disease. Ghrelin levels did not correlate with liver function. In contrast, there was a correlation of ghrelin with clinical (gastrointestinal bleeding, ascites, encephalopathy) and biochemical (anaemia, inflammatory markers, hypoglycaemia, renal dysfunction) parameters. In a subgroup of patients with CLD and hepatocellular carcinoma (HCC), we observed a strong inverse correlation between alpha-fetoprotein (AFP) and ghrelin levels.

CONCLUSIONS

Unlike IGF-1, ghrelin is not correlated with liver function, but increases in Child C cirrhosis and with complications of CLD. The inverse correlation with AFP in HCC patients requires further studies on the potential impact of ghrelin on the pathogenesis of anorexia-cachexia syndrome.

Expression of DNA repair genes hMTH1 and hOGG1 and repair of oxidative damage of DNA in hepatocellular carcinoma

AIM: To study the regulatory effect of expression of hMTH1 and hOGG1 genes on the oxidative DNA-adduct 8-OHdG levels in hepatocellular carcinoma (HCC) and non-tumourous liver tissue in order to elucidate the role of the DNA repair enzymes in hepatocarcinogenesis.

METHODS: A reverse transcription (RT)/real-time-polymerase chain reaction (PCR) assay was used to semi-quantify mRNA of hMTH1 and hOGG1 in HCC and non-tumourous liver tissue from 23 patients with HCC. 8-OHdG levels were determined by HPLC/ECD.

RESULTS: The median of 8-OHdG levels in non-tumourousliver tissue was significantly (133 vs 56 nmol/g DNA, P < 0.01) higher than that in HCC tissue. This was correlated with the severity of inflammation in non-tumourous liver tissues. The expression of hMTH1 was significantly (0.476 vs 0.256, P < 0.05) higher in HCC tissue than that in non-tumourous liver tissue. No difference of expression of hOGG1 between non-tumourous liver and HCC tissue was seen. A significant correlation was detected between the expression of hMTH₁ and hOGG₁ (r = 0.81, P < 0.01).

CONCLUSION: Elevated 8-OHdG levels in non-tumourousliver are likely due to the increased generation of reactive oxygen intermediates by infiltrating inflammatory cells. The expression of DNA repair enzymes hOGG1 and hMTH1 may involve cooperatively in the repair oxidative DNA adduct 8-OHdG and have a potential role in hepatocarcinogenesis.

The microcell mediated transfer of human chromosome 8 into highly metastatic rat liver cancer cell line C5F

AIM: Our previous research on the surgical samples of primary liver cancer with CGH showed that the loss of human chromosome 8p had correlation with the metastatic phenotype of liver cancer. In order to seek the functional evidence that there could be a metastatsis suppressor gene (s) for liver cancer on human chromosome 8, we tried to transfer normal human chromosome 8 into rat liver cancer cell line C5F, which had high metastatic potential to lung.

METHODS: Human chromosome 8 randomly marked with neo gene was introduced into C5F cell line by MMCT and positive microcell hybrids were screened by double selections of G418 and HAT. Single cell isolation cloning was applied to clone microcell hybrids. Finally, STS-PCR and WCP-FISH were used to confirm the introduction.

RESULTS: Microcell hybrids resistant to HAT and G418 were obtained and 15 clones were obtained by single-cell isolation cloning. STS-PCR and WCP-FISH proved that human chromosome 8 had been successfully introduced into rat liver cancer cell line C5F. STS-PCR detected a random loss in the chromosome introduced and WCP-FISH found a consistent recombination of the introduced human chromosome with the rat chromosome.

CONCLUSION: The successful introduction of human chromosome 8 into highly metastatic rat liver cancer cell line builds the basis for seeking functional evidence of a metastasis suppressor gene for liver cancer harboring on human chromosome 8 and its subsequent cloning.

Gene cloning of murine alpha-fetoprotein gene and construction of its eukaryotic expression vector and expression in CHO cells

To clone the murine alpha-fetoprotein (AFP) gene, construct the eukaryotic expression vector of AFP and express in CHO cells, total RNA were extracted from Hepa 1-6 cells, and then the murine alpha-fetoprotein gene was amplified by RT-PCR and cloned into the eukaryotic expression vector pcDNA3.1. The recombinant of vector was identified by restriction enzyme analysis and sequencing. After transient transfection of CHO cells with the vector, Western blotting was used to detect the expression of AFP. It is concluded that the 1.8 kb murine alpha-fetoprotein gene was successfully cloned and its eukaryotic expression vector was successfully constructed.

Clinical short-term results of radiofrequency ablation in liver cancers

AIM: To study local therapeutic efficacy, side effects, and complications of radiofrequency ablation (RFA), which is emerging as a new method for the treatment of patients with hepatocellular carcinoma (HCC) with cirrhosis or chronic hepatitis and metastatic liver cancer.

METHODS: Thirty-six patients with primary and secondary liver cancers (21 with primary hepatocellular carcinoma, 12 with colorectal cancer liver metastases and 3 with other malignant liver metastases), which were considered not suitable for curative resection, were include in this study. They were treated either with RFA (RITA2000, Mountain View, California, USA) percutaneously (n = 20) or intraoperatively (n = 16). The procedures were performed using the ultrasound guidance. The quality of RFA were based on monitoring of equipments and subject feeling of the practitioners. Patients treated with RFA was followed according to clinical findings, radiographic images, and tumor markers.

RESULTS: Thirty-six patients underwent RFA for 48 nodules. RFA was used to treat an average 1.3 lesions per patient, and the median size of treated lesions was 2.5 cm (range, 0.5-9 cm). The average hospital stay was 5.6 d overall (2.8 d for percutaneous cases and 7.9 d for open operations). Seven patients underwent a second RFA procedure (sequential ablations). Sixteen HCC patients with a high level of alpha fetoprotein (AFP) and 9 colorectal cancer liver metastases patients with a high level of serum carcinoembryonic antigen (CEA) have a great reduction benefited from RFA. Four (11.1%) patients had complications: one skin burn; one postoperative hemorrhage; one cholecystitis and one hepatic abscess associated with percutaneous ablations of a large lesion. There were 4 deaths: 3 patients died from local and system diseases (1 at 7 month, 1 at 9 month, and 1 at 12 month), 1 patients died from cardiovascular shock, but no RFA-related death. At a median follow-up of 10 mo (range, 1-24 mo), 6 patients (16.7%) had recurrences at an RFA site, and 20 patients (56.7%) remained clinically free of disease.

CONCLUSION: RF ablation appears to be an effective, safe, and relatively simple procedure for the treatment of unresectable liver cancers. The rate and severity of complications appear acceptable. However, further study is necessary to assess combination with other therapies, long-term recurrence rates and effect on overall survival.

Intergrin gene expression profiles of humanhepatocellular carcinoma

AIM: To investigate gene expression profiles of intergrin genes in hepatocellular carcinoma (HCC) through the usage of Atlas Human Cancer Array membranes, semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Northern blot.

METHODS: Hybridization of cDNA array membrane was performed with α³²P-labeled cDNA probes synthesized from RNA isolated from hepatocellular carcinoma and adjacent non-cirrhotic liver. AtlasImage, which is a software specific to array, was used to analyze the result. RT-PCR of 24 pairs specimen and Northern blot of 4 pairs specimen were used to confirm the expression pattern of some intergrin genes identified by Atlas arrays hybridization.

RESULTS: Among 588 genes spotted in membrane, 17 genes were related to intergrin. Four genes were up-regulated, such as intergrin alpha8, beta1, beta7 and beta8 in HCC. Whereas there were no genes down-regulated in HCC. RT-PCR and Northern blot analysis of intergrin beta1 gene gave results consistent with cDNA array findings.

CONCLUSION: Investigation of these intergrin genes should help to disclose the molecular mechanism of the cell adhesion, invasive and metastasis of HCC. A few genes are reported to have changed in HCC for the first time. The quick and high-throughout method of profiling gene expression by cDNA array provides us overview of key factors that may involved in HCC, and may find the clue of the study of HCC metastasis and molecular targets of anti-metastasis therapy. The precise relationship between the altered genes and HCC is a matter of further investigation.

Role and limitation of FMPSPGR dynamic contrast scanning in the follow-up of patients with hepatocellular carcinoma treated by TACE

AIM

To evaluate the role and limitation of fast multiplanar spoiled gradient-recalled (FMPSPGR) MR dynamic contrast scanning in the follow-up of patients with HCC treated by transarterial chemoembolization (TACE).

METHODS

Twenty-two patients with 24 HCC lesions confirmed by biopsy or surgical resection underwent MR imaging in 4-9wks after TACE with a superconducting 1.5 T MR scanner, including SE T(1)WI, T(2)WI and FMPSPGR dynamic contrast scanning. The signal intensities of all lesions on SE T(1)WI,T(2)WI and the enhancement patterns on FMPSPGR dynamic contrast scanning were observed, and the comparison was made between MRI findings and pathological results in all the cases.

RESULTS

Of the 24 lesions, the signal intensities were various on SE T(1)WI and T(2)WI. On T(1)WI, 13 lesions appeared as hyperintense, 4 lesions were isointense and the other 7 lesions were hypointensese. Histologically, hyperintense lesions showed on T(1)WI were viable tumor or hemorrhage; isointensities were coagulative necrosis or inflammatory infiltration; hypointensities were tumor, liquified necrosis, coagulative necrosis or inflammatory infiltration. On T(2)WI, 15 lesions appeared as hyperintense, 3 lesions were isointense and the other 6 lesions were hypointensese. Hyperintense lesions showed on T(2)WI were residuals of viable tumor, hemorrhage, liquefied necrosis or inflammatory infiltration; isointense lesions were residuals of viable tumor or inflammatory infiltration; hypointense lesions were coagulative necrosis. On FMPSPGR dynamic contrast scanning, 18 of the 24 lesions enhanced on early-phase dynamic scanning corresponding to residuals of viable tumor and the other 6 lesions had no enhancement at this phase because complete necrosis were seen in the histologic examination. On delayed-phase dynamic scanning, 6 lesions had permanent enhancement appeared as inhomogeneous hyperintensity and both residuals of viable tumor and inflammatory infiltration were found by histologic examination. 18 lesions were hypointense at this phase and 8 of them coexisted with peripheral ring-like enhancement of the lesions resulting from viable tumors or inflammatory infiltration.

CONCLUSION

FMPSPGR MR dynamic contrast scanning can reflect the pathologic changes of HCC treated by TACE. Especially, early-phase dynamic scanning can evaluate accurately residuals of viable tumor and necrosis in HCC lesions. FMPSPGR dynamic contrast scanning is useful in the follow-up of patients with HCC treated by TACE combined with SE T(1)WI and T(2)WI, but it is difficult to differentiate peripheral viable tumors from inflammatory infiltration.

Radiofrequence ablation of liver cancers

Primary and secondary malignant liver cancers are some of most common malignant tumors in the world. Chemotherapy and radiotherapy are not very effective against them. Surgical resection has been considered the only potentially curtive option, but the majority of patients are not candidates for resection because of tumor size, location near major intrahepatic blood vessels and bile ducts, precluding a margin-negative resection, cirrhotic, hepatitis virus infection or multifocial. Radiofrequence ablation (RFA), which is a new evolving effective and minimally invasive technique, can produce coagulative necrosis of malignant tumors. RFA should be used percutaneously, laparscopically, or during the open laparotomy under the guidance of ultrasound, CT scan and MRI. RFA has lots of advantages superior to other local therapies including lower complications, reduced costs and hospital stays, and the possibility of repeated treatment. In general, RFA is a safe, effective treatment for unresectable malignant liver tumors less than 7.0 cm in diameter. We review the principle, mechanism, procedures and experience with RFA for treating malignant liver tumors.

The prognostic molecular markers in hepatocellular carcinoma

The prognosis of hepatocellular carcinoma (HCC) still remains dismal, although many advances in its clinical study have been made. It is important for tumor control to identify the factors that predispose patients to death. With new discoveries in cancer biology, the pathological and biological prognostic factors of HCC have been studied quite extensively. Analyzing molecular markers (biomarkers) with prognostic significance is a complementary method. A large number of molecular factors have been shown to associate with the invasiveness of HCC, and have potential prognostic significance. One important aspect is the analysis of molecular markers for the cellular malignancy phenotype. These include alterations in DNA ploidy, cellular proliferation markers (PCNA, Ki-67, Mcm2, MIB1, MIA, and CSE1L/CAS protein), nuclear morphology, the p53 gene and its related molecule MD M2, other cell cycle regulators (cyclin A, cyclin D, cyclin E, cdc2, p27, p73), oncogenes and their receptors (such as ras, c-myc, c-fms, HGF, c-met, and erb-B receptor family members), apoptosis related factors (Fas and FasL), as well as telomerase activity. Another important aspect is the analysis of molecular markers involved in the process of cancer invasion and metastasis. Adhesion molecules (E-cadherin, catenins, serum intercellular adhesion molecule-1, CD44 variants), proteinases involved in the degradation of extracellular matrix (MMP-2, MMP-9, uPA, uPAR, PAI), as well as other molecules have been regarded as biomarkers for the malignant phenotype of HCC, and are related to prognosis and therapeutic outcomes. Tumor angiogenesis is critical to both the growth and metastasis of cancers including HCC, and has drawn much attention in recent years. Many angiogenesis-related markers, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived endothelial cell growth factor (PD-ECGF), thrombospondin (TSP), angiogenin, pleiotrophin, and endostatin (ES) levels, as well as intratumor microvessel density (MVD) have been evaluated and found to be of prognostic significance. Body fluid (particularly blood and urinary) testing for biomarkers is easily accessible and useful in clinical patients. The prognostic significance of circulating DNA in plasma or serum, and its genetic alterations in HCC are other important trends. More attention should be paid to these two areas in future. As the progress of the human genome project advances, so does a clearer understanding of tumor biology, and more and more new prognostic markers with high sensitivity and specificity will be found and used in clinical assays. However, the combination of some items, i.e., the pathological features and some biomarkers mentioned above, seems to be more practical for now.