The role of serum alpha-fetoprotein estimation in the diagnosis and management of hepatocellular carcinoma

Levels and correlates of alpha-fetoprotein in normal pregnancies among Caucasian and Chinese women

Alpha-fetoprotein has been suggested to have anti breast cancer properties both in adult life and in utero. We studied correlates of maternal serum alpha-fetoprotein levels in normal singleton pregnancies. This was a prospective study relying on women attending maternal units in major teaching hospitals in Boston, USA and Shanghai, China. Specifically, 212 Caucasian women in Boston, and 196 Asian women in Shanghai provided blood samples at the 16th and 27th gestational week. Maternal serum alpha-fetoprotein levels were measured and correlated with maternal and newborn parameters through multiple regression procedures, controlling for a set of potential confounders, including maternal levels of measured hormones. Alpha-fetoprotein was strongly inversely associated with maternal prepregnancy body mass index (-4.73 ng/l at the 27th week per 1 kg/m of body mass index, with 95% confidence intervals -7.09 to -2.36), whereas it was not related to parity, gender of offspring or birth weight. Duration of gestation was inversely associated with maternal alpha-fetoprotein levels, particularly among Caucasian women (-0.22 weeks per 60 ng/l of alpha-fetoprotein at the 27th week, with 95% confidence intervals -0.39 to -0.05). In normal pregnancies, maternal alpha-fetoprotein is inversely related to prepregnancy body mass index and appears to have a physiologic role on duration of gestation rather than on birth weight.

Effects and mechanisms of silibinin on human hepatoma cell lines

AIM: To investigate in vitro effects and mechanisms of silibinin on hepatocellular carcinoma (HCC) cell growth.

METHODS: Human HCC cell lines were treated with different doses of silibinin. The effects of silibinin on HCC cell growth and proliferation, apoptosis, cell cycle progression, histone acetylation, and other related signal transductions were systematically examined.

RESULTS: We demonstrated that silibinin significantly reduced the growth of HuH7, HepG2, Hep3B, and PLC/PRF/5 human hepatoma cells. Silibinin-reduced HuH7 cell growth was associated with significantly up-regulated p21/CDK4 and p27/CDK4 complexes, down-regulated Rb-phosphorylation and E2F1/DP1 complex. Silibinin promoted apoptosis of HuH7 cells that was associated with down-regulated survivin and up-regulated activated caspase-3 and -9. Silibinin's anti-angiogenic effects were indicated by down-regulated metalloproteinase-2 (MMP2) and CD34. We found that silibinin-reduced growth of HuH7 cells was associated with increased activity of phosphatase and tensin homolog deleted on chromosome ten (PTEN) and decreased p-Akt production, indicating the role of PTEN/PI₃K/Akt pathway in silibinin-mediated anti-HCC effects. We also demonstrated that silibinin increased acetylation of histone H3 and H4 (AC-H3 and AC-H4), indicating a possible role of altered histone acetylation in silibinin-reduced HCC cell proliferation.

CONCLUSION: Our results defined silibinin's in vitro anti-HCC effects and possible mechanisms, and provided a rationale to further test silibinin for HCC chemoprevention.

Contribution of laser microdissection-based technology to proteomic analysis in hepatocellular carcinoma developing on cirrhosis

Hepatocellular carcinoma (HCC) is a major cause of cancer worldwide. Proteomic studies provide opportunities to uncover targets for the diagnosis and treatment of this disease. However, in HCC developing in a setting of cirrhosis, the detection of proteome alterations may be hampered by the increased cellular heterogeneity of tissue when analysing global liver homogenates. The aim of this study was to evaluate whether the identification of proteome alterations in these HCC cases was improved when the differential protein profile between tumour and non-tumour areas of liver was determined using hepatocytes isolated by laser microdissection (LM). Differential profiles established with LM-hepatocytes and liver section homogenates using 2-DE and MS exhibited noticeable differences: 30% of the protein spots with deregulated expression in tumorous LM-samples did not display any modification in homogenates; conversely 15% of proteins altered in tumorous homogenates were not impaired in LM-hepatocytes. These alterations resulted from the presence in cirrhotic liver of fibrotic stroma which displayed a protein pattern different from that determined in LM-hepatocytes. In conclusion, our data demonstrate the interest of LM in distinguishing between fibrotic and hepatocyte proteome alterations and thus the benefit of LM to proteome studies of HCC developing in a context of cirrhosis.

Identification of human hepatocellular carcinoma-related proteins by proteomic approaches

Hepatocellular carcinoma (HCC) is the most common malignant liver tumor. Analysis of human serum from HCC patients using two-dimensional gel electrophoresis (2DE) combined with nano-high-performance liquid chromatography electrospray ionization tandem mass spectrometry (nano-HPLC-ESI-MS/MS) identified fourteen different proteins differentially expressed between HCC patients and the control group. Twelve proteins were up-regulated and two down-regulated. By using nano-HPLC-MS/MS system to analyze proteome in human serum, 317 proteins were identified, twenty-nine of which to high confidence levels (protein matched at last two unique peptide sequences). Of these twenty-nine proteins, six were present only in HCC patients and may serve as biomarkers for HCC.

Single nucleotide polymorphism in the promoter region of human alpha-fetoprotein (AFP) gene and its significance in hepatocellular carcinoma (HCC)

BACKGROUND

Variations of serum AFP levels in HCC patients and cell lines are likely due to the differential activity of enhancer/silencer elements that control AFP. To understand the potential mechanism underlying the differential expression of AFP, we have examined the sequence of the AFP promoter in HCC.

METHODS

Direct DNA sequencing was carried out to sequence 980 bp of AFP promoter of DNA samples isolated from 83 HCC patients.

RESULTS

Three novel SNPs in the promoter region of the AFP gene, which have not been previously reported, were found at positions -330, -401 and -692. The level of serum AFP was significantly higher in HCC patients with the CT genotype of 330 SNP or the AG genotype of the 401 SNP. The genotype of CG in 692 SNP was also associated with a significant elevated level of serum AFP, and further this genotype appeared to be associated with the high risk of HCC development. 401 SNP and 692 SNP were located at the positions of known binding sites for transcription factors that have a role in the production of AFP and the growth of tumors.

CONCLUSIONS

The novel polymorphisms identified in the promoter region of the AFP gene may be pathologically significant in HCC.

Gene expression profiling reveals potential biomarkers of human hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC), a common cancer worldwide, has a dismal outcome partly due to the poor identification of early-stage HCC. Currently, one third of HCC patients present with low serum alpha-fetoprotein (AFP) levels, the only clinically available diagnostic marker for HCC. The aim of this study was to identify new diagnostic molecular markers for HCC, especially for individuals with low serum AFP.

EXPERIMENTAL DESIGN

We used the microarray technique to determine the expression profiles of 218 HCC specimens from patients with either high or low serum AFP. From the microarray study, we selected five candidate genes (i.e., GPC3, PEG10, MDK, SERPINI1, and QP-C), which were overexpressed in HCCs. Using quantitative real-time PCR analyses, we validated the expression of these five genes in 50 AFP-normal and 8 AFP-positive HCC specimens and 36 cirrhotic noncancerous hepatic specimens, which include 52 independent specimens not used in microarray analysis.

RESULTS

A significant increase in the expression of the five candidate genes could be detected in most of the HCC samples, including those with normal serum AFP and small tumors. GPC3, MDK, and SERPINI1 encode known serum proteins. Consistently, a significant increase in serum midkine, encoded by MDK, was associated with HCC patients, including those with normal serum AFP. Using prediction analysis of microarray, we showed that a combined score of these five genes can accurately classify noncancerous hepatic tissues (100%) and HCC (71%).

CONCLUSIONS

We suggest that a diagnostic signature approach using a combined score of these five biomarkers rather than a single marker may improve the prediction accuracy of HCC patients, including those with normal serum AFP and smaller-sized tumors.

Carcinoembryonic antigen, alpha-fetoprotein, and prostate-specific antigen in the sera of industrial workers exposed to phenol, formaldehyde, urea, and mixed vapors

Exposure to certain industrial agents has been thought to have carcinogenic potential, both for employees who work closely with agents and for the general population that comes into contact with them. The objective of the present study is to evaluate the changes at the cellular level or at the level of cellular metabolism products present in the biological fluid, and to detect early stages of the carcinogenic process resulting from the exposure of industrial environmental hazards. Carcinoembryonic antigen (CEA), alpha-fetoproteins (AFP), and prostate-specific antigen (PSA) were measured in sera of workers (n = 51), who were divided into 4 groups: group I, workers exposed to phenol; group II, workers exposed to formaldehyde; group III, workers exposed to urea; and group IV, workers exposed to mixed vapor, plus a reference control healthy group (n = 15). The results showed that 75% of the workers exposed to phenol, 75% of the workers exposed to urea, 83.3% of workers exposed to formalin, and 92.3% of the workers exposed to mixed vapors had raised values of serum CEA (S-CEA) above normal value of the control group. Also, 23% of workers exposed to mixed vapors, 44% of workers exposed to formalin, 50% of workers exposed to phenol, and 62.5% of workers exposed to urea had raised values of serum AFP (S-AFP) above normal value of control group. Finally, 16.6% of workers exposed to phenol, 23% of workers exposed to mixed vapors, and 33.3% of workers exposed to formalin had raised values of serum PSA (S-PSA) above the normal value of control group; there were no raised values of S-PSA in workers exposed to urea. No significant difference was found in the activities of AST and ALT in group I, but a highly significant increase was found in the AST activities for groups II and IV and the ALT activities for groups III and IV. A significant difference was found in the activity of ALT in group II and in AST for group III. There was no significant difference in the levels of albumin in groups I, II, and III, whereas albumin levels were significantly decreased in group IV. No significant change was found in the level of urea and creatinine in all groups except for group III, where serum levels of creatinine were significantly decreased. From our findings, we concluded that S-CEA can be used as an important prognostic screening marker for early prediction for malignancy, and for management of workers with lung cancer who are exposed to the environmental hazards in industrial factories. Furthermore, S-AFP can be used also as a biomarker if it is carried out and correlated with S-CEA.

Sensitivity and specificity of des-gamma-carboxy prothrombin for diagnosis of patients with hepatocellular carcinomas varies according to tumor size

OBJECTIVES

Serum levels of des-gamma-carboxy prothrombin (DCP) and alpha-fetoprotein (AFP) are known to be useful tumor markers for the diagnosis of hepatocellular carcinoma (HCC). The aim of this study was to examine the diagnostic efficacy of DCP and AFP in differentiating HCC from chronic liver diseases.

METHODS

We examined 1,377 HCC patients and 355 patients with chronic hepatitis or cirrhosis (non-HCC) who visited our institute and affiliated hospitals between June 1997 and September 2003.

RESULTS

The median values of DCP and AFP were 60 mAU/mL and 34 ng/mL in HCC patients, respectively, and 18 mAU/mL and 3 ng/mL in non-HCC patients, respectively. The areas under the receiver operating characteristic (ROC) curves of DCP and AFP were 0.812 and 0.887, respectively (p < 0.0001). The area under the DCP ROC curve was significantly smaller than that of AFP in tumors less than 3 cm in diameter (p < 0.0001). However, the ROC area of DCP was significantly larger than that of AFP in tumors greater than 5 cm in diameter (p < 0.0001).

CONCLUSIONS

The utility of DCP for the diagnosis of HCC was lower than that of AFP for small tumors, but higher than that of AFP for large tumors.

Cross-species hybridization of woodchuck hepatitis virus-induced hepatocellular carcinoma using human oligonucleotide microarrays

AIM: To demonstrate the feasibility of using woodchuck samples on human microarrays, to provide insight into pathways involving positron emission tomography (PET) imaging tracers and to identify genes that could be potential molecular imaging targets for woodchuck hepatocellular carcinoma.

METHODS: Labeled cRNA from woodchuck tissue samples were hybridized to Affymetrix U133 plus 2.0 GeneChips^®. Ten genes were selected for validation using quantitative RT-PCR and literature review was made.

RESULTS: Testis enhanced gene transcript (BAX Inhibitor 1), alpha-fetoprotein, isocitrate dehydrogenase 3 (NAD+) beta, acetyl-CoA synthetase 2, carnitine palmitoyltransferase 2, and N-myc2 were up-regulated and spermidine/spermine N1-acetyltransferase was down-regulated in the woodchuck HCC. We also found previously published results supporting 8 of the 10 most up-regulated genes and all 10 of the 10 most down-regulated genes.

CONCLUSION: Many of our microarray results were validated using RT-PCR or literature search. Hence, we believe that woodchuck HCC and non-cancerous liver samples can be used on human microarrays to yield meaningful results.

Lectin-reactive alpha-fetoprotein in patients with tyrosinemia type I and hepatocellular carcinoma

Despite the introduction of 2-(2-nitro-4-trifluormethyl-benzoyl)-1,3-cyclohexandion into the treatment of hereditary tyrosinemia type I (HT1), patients remain at risk of developing hepatocellular carcinoma (HCC). Serial total alpha-fetoprotein (AFP) levels are used to monitor the individual patient. Lectin-reactive alpha-fetoprotein (L3-AFP) is an AFP isoform that is expressed by malignant liver tumors. We investigated whether the analysis of L3-AFP could lead to earlier detection of HCC in HT1 compared with judgement based on total AFP alone. AFP electrophoresis using lectin-containing agarose gel identifies L3-AFP by the affinity of its specific carbohydrate chain to lectin. We report the retrospective analysis of sequential serum samples of 12 patients with HT1 and histologically proven HCC. AFP isoforms could be identified in all 12 patients. In 6 patients, the L3-AFP increased before the total AFP. In 3 patients, the rise in L3-AFP was parallel to the rise of total AFP; and in 3 patients, the L3-AFP was raised after the total AFP or did not increase at all. We were able to identify 6 of 12 patients with an early increase in the new tumor marker. Lectin-affinity electrophoresis may have a role in discriminating benign liver disease from HCC in HT1. We suggest the further evaluation of L3-AFP in HT1.

Changes in the serum proteome associated with the development of hepatocellular carcinoma in hepatitis C-related cirrhosis

Early diagnosis of hepatocellular carcinoma (HCC) is the key to the delivery of effective therapies. The conventional serological diagnostic test, estimation of serum alpha-fetoprotein (AFP) lacks both sensitivity and specificity as a screening tool and improved tests are needed to complement ultrasound scanning, the major modality for surveillance of groups at high risk of HCC. We have analysed the serum proteome of 182 patients with hepatitis C-induced liver cirrhosis (77 with HCC) by surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI). The patients were split into a training set (84 non-HCC, 60 HCC) and a ‘blind’ test set (21 non-HCC, 17 HCC). Neural networks developed on the training set were able to classify the blind test set with 94% sensitivity (95% CI 73–99%) and 86% specificity (95% CI 65–95%). Two of the SELDI peaks (23/23.5 kDa) were elevated by an average of 50% in the serum of HCC patients (P<0.001) and were identified as κ and λ immunoglobulin light chains. This approach may permit identification of several individual proteins, which, in combination, may offer a novel way to diagnose HCC.

Assessment of KL-6 as a tumor marker in patients with hepatocellular carcinoma

AIM: To investigate the clinical significance of KL-6 as a tumor marker of HCC in two different ethnic groups with chronic liver disease consecutively encountered at outpatient clinics.

METHODS: Serum KL-6 was measured by the sandwich enzyme immunoassay method using the KL-6 antibody (Ab) as both the capture and tracer Ab according to the manufacturer’s instructions (Eisai, Tokyo, Japan). Assessment of alpha fetoprotein (AFP) and protein induced vitamin K deficiency or absence (PIVKA-II) was performed in both groups using commercially available kits.

RESULTS: A significantly higher mean serum KL-6 (556±467 U/L) was found in HCC in comparison with non-HCC groups either with (391±176 U/L; P<0.001) or without (361±161 U/L; P<0.001) liver cirrhosis (LC). Serum KL-6 level did not correlate with either AFP or PIVKA-II serU/Levels. Using receiver operating curve analysis for KL-6 as a predictor for HCC showed that the area under the curve was 0.574 (95%CI = 0.50-0.64) and the KL-6 level that gave the best sensitivity (61%) was found to be 334 U/L but according to the manufacturer’s instructions; a cut-off point of 500 U/L was used that showed the highest specificity (80%) in comparison with AFP and PIVKA-II (78% vs 72% respectively). Combining the values of the three markers improved specificity of AFP for HCC diagnosis from 78% for AFP alone; 93% for AFP plus PIVKA-II to 99% for both plus KL-6 value (P<0.001). Mean serum alkaline phosphatase level was significantly higher in KL-6 positive (564±475) in comparison with KL-6 negative (505±469) HCC patients (P = 0.021), but such a difference was not found among non-HCC corresponding groups.

CONCLUSION: KL-6 is suggested as a tumor for HCC. Its positivity may reflect HCC-associated cholestasis and/or local tumor invasion.

Soluble mesothelin-related protein--a blood test for mesothelioma

Identification of tumor marker for mesothelioma (MM) might prove useful in diagnosis as well as for monitoring tumor in response to therapy and for screening at-risk individuals. We tested the hypothesis that soluble mesothelin-related protein (SMRP), a mesothelin family member, in the serum would be such a marker. Our data show that determination of SMRP in serum is a marker of MM with a sensitivity of sensitivity 83% and specificity 95% in the first 48 MM patients tested. Changes in serum SMRP levels parallel clinical course/tumor size and SMRP is elevated in 75% of patients at diagnosis. SMRP should also be useful for monitoring disease progression, and importantly, may prove useful for screening asbestos-exposed individuals for early MM.

Glypican-3 and alphafetoprotein as diagnostic tests for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumor. It is usually asymptomatic in the early stages and tends to be intravascularly and intrabiliary invasive. Therefore, most patients present with incurable disease at the time of detection and early diagnosis of HCC is critical for a good prognosis. The imaging-based diagnosis of small tumors is relatively inaccurate, as cirrhotic and dysplastic nodules mimic HCC radiologically. The availability of a suitable serological marker to distinguish between HCC and benign liver lesions would, therefore, be very useful for early diagnosis. The only serological marker currently widely used for the diagnosis of HCC is alphafetoprotein (AFP). However, the sensitivity of this marker is limited (41-65%). Given the high heterogeneity of HCC, it is currently thought that an optimal serological test for HCC will be based on the simultaneous measurement of two or three highly specific serological markers.Several laboratories have recently reported that glypican-3 (GPC3), a membrane-bound proteoglycan, is expressed by a large proportion of HCCs, but is undetectable in normal hepatocytes and non-malignant liver disease. Furthermore, various studies demonstrated that GPC3 could be used as a serological test for the diagnosis of patients with HCC. Although the specificity of the test was very high in the context of a population with chronic liver disease, the sensitivity was limited (within the same range as AFP). Interestingly, in most cases, elevated GPC3 values did not correlate with elevated AFP values. As a consequence, the serological level of at least one of the two markers was elevated in a large majority of HCC patients. These results suggest that the sensitivity of the diagnostic test can be significantly improved without compromising specificity with the simultaneous measurement of both GPC3 and AFP.

Glypican-3 and alphafetoprotein as diagnostic tests for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumor. It is usually asymptomatic in the early stages and tends to be intravascularly and intrabiliary invasive. Therefore, most patients present with incurable disease at the time of detection and early diagnosis of HCC is critical for a good prognosis. The imaging-based diagnosis of small tumors is relatively inaccurate, as cirrhotic and dysplastic nodules mimic HCC radiologically. The availability of a suitable serological marker to distinguish between HCC and benign liver lesions would, therefore, be very useful for early diagnosis. The only serological marker currently widely used for the diagnosis of HCC is alphafetoprotein (AFP). However, the sensitivity of this marker is limited (41-65%). Given the high heterogeneity of HCC, it is currently thought that an optimal serological test for HCC will be based on the simultaneous measurement of two or three highly specific serological markers.Several laboratories have recently reported that glypican-3 (GPC3), a membrane-bound proteoglycan, is expressed by a large proportion of HCCs, but is undetectable in normal hepatocytes and non-malignant liver disease. Furthermore, various studies demonstrated that GPC3 could be used as a serological test for the diagnosis of patients with HCC. Although the specificity of the test was very high in the context of a population with chronic liver disease, the sensitivity was limited (within the same range as AFP). Interestingly, in most cases, elevated GPC3 values did not correlate with elevated AFP values. As a consequence, the serological level of at least one of the two markers was elevated in a large majority of HCC patients. These results suggest that the sensitivity of the diagnostic test can be significantly improved without compromising specificity with the simultaneous measurement of both GPC3 and AFP.

Artifactual isoform profile modification following treatment of human plasma or serum with protease inhibitor, monitored by 2-dimensional electrophoresis and mass spectrometry

The inclusion of protease inhibitors in serum or plasma samples has been found to significantly impact the isoform profile of selected plasma proteins as seen on 2-dimensional electrophoresis (2-DE) gels. With the addition of a protease inhibitor cocktail, several human plasma protein trains [depleted of albumin and immunoglobulin G (IgG)] exhibited higher isoelectric point (pI) isoforms. This shift was especially apparent for apolipoprotein A1 (apo A1), a relatively high abundance protein. The six protease inhibitor components of the cocktail were individually investigated with albumin and IgG depleted human plasma, and it was shown that the observed effects were caused by 4-(2-aminoethyl) benzenesulfonyl fluoride (AEBSF), a serine protease inhibitor that covalently modifies proteins and/or peptides. Several serine-and/or tyrosine-containing peptides of apo A1 were modified with a concomitant mass increase of 183 Da, which is consistent with the mass increase expected following reaction with AEBSF. These modifications were observed with increasing propensity in the higher pI spots. An increase in both the number and proportion of modified peptides with increasing pI was also observed. A model is proposed for the random or stochastic coupling of AEBSF-derived moieties to serine and/or tyrosine residues throughout apo A1 and potentially other plasma proteins.

Specificity and significance of expression of imprinted gene PEG10 in hepatocellular carcinoma

AIM: To study the specificity and significance of the expression of imprinted gene PEG10 in hepatocellular carcinoma (HCC) and to evaluate the feasibility for PEG10 as a novel molecular target of gene therapy for HCC.

METHODS: The total RNA was extracted from different tumor cell lines (liver cancer HepG2, gastric cancer SGC7901, colorectal cancer Lovo, pancreatic cancer PC3, melanoma A375 and T lymphoma Jurkat cells), normal human fetal liver cell line L02, human HCC (n = 32) and the corresponding cancer-adjacent tissues (n = 32), benign liver tissues (n = 10) and peripheral blood cells (n = 10). Then the expression of PEG10 was detected by reverse transcription polymerase chain reaction (RT-PCR). Simultaneously, AFP expression was detected in human HCC and the corresponding cancer-adjacent tissues.

RESULTS: After amplification, the length of PEG10 and AFP fragment was 455 bp and 140 bp respectively. PEG10 was markedly expressed in HepG2 cells, and weakly expressed in SGC7901, PC3, Lovo cells. PEG10 expression was found negative in L02 and other tumor cell lines. The positive rates of PEG10 expression in HCC and the corresponding tissues were 78.1% and 0%, but the ones for AFP were 93.8% and 59.4% respectively. There was no significant difference between PEG10 and AFP expression in HCC tissues (P>0.05), whereas the expression of AFP (19/32) was significantly higher than that of PEG10 in cancer-adjacent tissues (0/32) (c²_0.01,1 = 17.05, P<0.01). PEG10 wasn't detected in benign liver tissues and normal peripheral blood cells.

CONCLUSION: PEG10 is more specifically expressed in HCC than AFP, which provides evidence for PEG10 as a novel molecular target of gene therapy for HCC.

Hepatitis B 1762T/1764A mutations, hepatitis C infection, and codon 249 p53 mutations in hepatocellular carcinomas from Thailand

Hepatocellular carcinoma is one of the leading causes of cancer death worldwide. The etiology of liver cancer is multifactorial, and infection with hepatitis B virus (HBV), whose pathogenesis is exacerbated by the acquisition of mutations that accelerate carcinogenesis, or hepatitis C virus (HCV) and dietary exposure to aflatoxin B(1) all contribute to elevating one's risk for this disease. In this study, we sought to determine the contributions of these agents by measuring the occurrence of an HBV 1762(T)/1764(A) double mutation, an aflatoxin-specific 249(G-->T) mutation of the p53 gene, and HCV in plasma of 34 HCC cases and 68 age- and gender-matched controls, and in 25 liver tumors from northern Thailand. In total, 14 cases, 5 controls, and 19 tumors had detectable levels of HBV DNA. All 14 cases, 2 controls (2.9%), and 17 tumors (89.5%) were positive for the HBV double mutation. Nine cases (26.5%), 10 controls (14.7%), and 6 tumors (24%) were positive for the p53 mutation. Five cases (14.7%), no controls, and 4 tumors (16%) had both mutations. The median age of HCC diagnosis in these 5 cases was 34 years versus 51 years for other cases. Five cases (14.7%) and 1 control (1.5%) were HCV enzyme immunoassay positive. Thus, specific HBV, HCV, and aflatoxin biomarkers reveal the complexity of risks contributing to HCC in northern Thailand and suggest further application of these biomarkers as intermediate end points in prevention, intervention trials, and etiologic investigations.

Screening tests for hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) is rising throughout the world. HCC meets the criteria for which a disease benefits from screening or surveillance: it is an important health problem; those with cirrhosis are the targets for surveillance; there is acceptable treatment if diagnosed early; surveillance using alpha-fetoprotein and ultrasound has been shown to be cost effective; surveillance is widely implemented by health care professionals and accepted by patients; standardized recall procedures exists; and the screening tests must achieve an acceptable level of accuracy in the population undergoing screening. The latter point is the main limitation of surveillance for HCC. In this review we will discuss the currently available tests for the surveillance of HCC.

The impact of pre-operative loco-regional therapy on outcome after liver transplantation for hepatocellular carcinoma

No prior studies have shown that pre-operative loco-regional therapy for hepatocellular carcinoma (HCC) improves survival following orthotopic liver transplantation (OLT). We performed subgroup analyses according to pathologic HCC stage among 168 patients who underwent OLT to test the hypothesis that pre-operative loco-regional therapy confers a survival advantage in a subgroup at intermediate risk for HCC recurrence. Patients with pathologic T3 HCC meeting the proposed UCSF expanded criteria (single lesion not exceeding 6.5 cm or two to three lesions none > 4.5 cm with total tumor diameter within 8 cm) had a similar 5-year recurrence-free survival as patients with pathologic T2 HCC (88.5% vs. 93.8%; p = 0.56). In the subgroup with pathologic T2 or T3 HCC, the 5-year recurrence-free survival was 93.8% for the 85 patients who received pre-operative loco-regional therapy, versus 80.6% for the other 41 patients without treatment (p = 0.049). The treatment benefit, according to 5-year recurrence-free survival, appeared greater for pathologic T3 (85.9% vs. 51.4%; p = 0.05) than T2 HCC (96.4% versus 87.1%; p = 0.12). In conclusion, although the lack of a randomized controlled design precludes drawing firm conclusions, our results suggest that pre-operative loco-regional therapy may confer a survival benefit after OLT in the subgroup with pathologic T2 and T3 HCC.

General management

Hepatocellular carcinoma is one of the most common malignancies worldwide. The general management of hepatocellular carcinoma begins with an accurate diagnosis. With advances in imaging studies, noninvasive diagnosis has become an accepted standard of care for hepatocellular carcinoma, though pathologic examination is still required in selected cases. Following diagnosis, accurate staging is the next most important step in selecting the most appropriate treatment modality. Patients with localised tumor and compensated liver disease should be considered for partial hepatectomy, and patients with poor hepatic function but early tumor stage are candidates for liver transplantation. Patients who do not qualify for either of these curative treatments may be evaluated for palliative therapy, of which transarterial chemoembolisation is most widely used. This review will discuss the role of biopsy, the pros and cons of noninvasive and pathologic tissue diagnosis as well as the general approach to choose the most appropriate treatment for patients with hepatocellular carcinoma.

Spontaneous tumor-specific humoral and cellular immune responses to NY-ESO-1 in hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) is the fifth most common cancer around the world. Although several therapeutic approaches for treatment of HCC are available, survival rates for HCC patients are still very poor because of inefficient treatment options. For HCC, as well as other tumors, antigen-specific immunotherapy remains a viable approach that is dependent on the definition of tumor-associated antigens. NY-ESO-1, a member of the cancer testis antigen family, is one possible candidate for a tumor-specific antigen in HCC. The aim of this study was to show the relevance of NY-ESO-1 in hepatocellular carcinoma.

EXPERIMENTAL DESIGN

Sera samples from 189 HCC patients were analyzed for NY-ESO-1-specific antibodies. Forty-nine HCC patients were screened for NY-ESO-1 mRNA expression in HCC tissue. Selected patients were followed for up to 3 years to correlate their immune response with their clinical course of events. NY-ESO-1-specific CD4+ and CD8+ T-cell responses from NY-ESO-1 seropositive patients were analyzed and a NY-ESO-1+ specific cytotoxic T-cell line was generated.

RESULTS

Twelve of 49 analyzed tumor samples expressed NY-ESO-1 mRNA and 23 of 189 patients showed NY-ESO-1-specific antibody responses. These humoral immune responses were accompanied by NY-ESO-1-specific functional CD4+ and CD8+ T-cell responses. Finally, NY-ESO-1 humoral responses were dependent on the presence of NY-ESO-1-expressing tumors.

CONCLUSIONS

This is the first report of a spontaneous immune response in HCC patients to a known tumor-specific antigen, NY-ESO-1 protein. Our data favor the possibility of immunotherapeutic strategies for the treatment of HCC.

Molecular profiling of hepatocellular carcinomas by cDNA microarray

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world. Conventional diagnosis and treatment of this malignancy have been dismal and should be complemented by novel tools. The development and progress of HCC are believed to be caused by the accumulation of genetic changes resulting in altered expression of thousands of cancer-related genes, which can be measured by globe genetic analysis. Gene expression profiling of HCC has been employed to elucidate hepatocarcinogenesis and disclose molecular mechanisms underlying complex clinical features. Identifying phenotype-associated genes/profiles has impacts on current diagnosis and management strategy of HCC. In spite of some pitfalls of this technology and challenges in improving the research process, scrutinous validation of profiling data of HCC combined with other approaches will eventually benefit the patients.

Improvement of liver cancer detection with simultaneous assessment of circulating levels of free alpha-fetoprotein (AFP) and AFP-IgM complexes

We assessed the presence of alpha-fetoprotein (AFP) complexed with IgM (AFP-IgM IC) in serum of patients affected by hepatocellular carcinoma (HCC), cirrhosis and chronic hepatitis as well as in healthy subjects by means of a dedicated ELISA assay. The amount of AFP-IgM IC was expressed in arbitrary units (AU) on a reference standard curve. Free AFP (FAFP) levels were determined in parallel in each sample by means of an automated immunoassay system. The mean serum concentration of AFP-IgM IC was significantly higher in HCC patients (mean +/- SD: 1378.3 +/- 2935.7 AU/mL) than in cirrhotic patients (129.8 +/- 261.4 AU/mL) and in patients with chronic hepatitis (80.9 +/- 168.9 AU/mL) (p < 0.01). HCC patients had FAFP values above the 20 ng/mL cutoff in 44% of cases (22/50) and AFP-IgM IC values above the 120 AU/mL cutoff in 60% of cases (30/50). The occurrence of the free and IgM-complexed form of circulating AFP did not overlap, and 82% of patients (41/50) were positive for at least one marker. The results indicate that AFP-IgM IC is a complementary serological marker to FAFP and that the combination of these biomarkers may be useful in the diagnosis of liver cancer.

Diagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is responsible for a large proportion of cancer deaths worldwide. HCC is frequently diagnosed after the development of clinical deterioration at which time survival is measured in months. Long-term survival requires detection of small tumors, often present in asymptomatic individuals, which may be more amenable to invasive therapeutic options. Surveillance of high-risk individuals for HCC is commonly performed using the serum marker alpha-fetoprotein (AFP) often in combination with ultrasonography. Various other serologic markers are currently being tested to help improve surveillance accuracy. Diagnosis of HCC often requires more sophisticated imaging modalities such as CT scan and MRI, which have multiphasic contrast enhancement capabilities. Serum AFP used alone can be helpful if levels are markedly elevated, which occurs in fewer than half of cases at time of diagnosis. Confirmation by liver biopsy can be performed under circumstances when the diagnosis of HCC remains unclear.

Identification of a new marker of hepatocellular carcinoma by serum protein profiling of patients with chronic liver diseases

Surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF MS) is a proteomic technique that enables the profiling of proteins present in any biological material studied. We used this approach to identify new biomarkers of hepatocellular carcinoma (HCC) in the sera of patients with cirrhosis. Sera from 82 patients with cirrhosis, either without (n = 38) or with (n = 44) HCC, were analyzed by SELDI-TOF MS, and the results of the two groups were compared. The most efficient protein peaks leading to discrimination of patients with HCC were selected (receiver operative characteristic curves). The highest-scoring peak combination was established in a first group of serum samples (multinomial regression) and was tested in an independent group. The protein corresponding to the highest discrimination was purified and characterized further. The intensity of 30 protein peaks significantly differed between cirrhotic patients with and without HCC. An algorithm including the six highest-scoring peaks allowed correct classification (presence or absence of HCC) of 92.5% of patients in the test sample set and 90% in the validation sample set. The highest discriminating peak (8900 Da) was purified further and was characterized as the C-terminal part of the V10 fragment of vitronectin. An in vitro study suggested that the increase of the 8900-Da fragment in the serum of patients with HCC may proceed from the cleavage of native vitronectin with metalloproteases, a family of enzymes whose activity is enhanced in HCC. In conclusion, global protein profiling is an efficient approach that enabled us to identify a catalytic fragment ofvitronectin as a new serum marker of HCC in patients with chronic liver diseases.

Use of Yttriurn-90 TheraSphere for the Treatment of Unresectable Hepatocellular Carcinoma

This is a retrospective analysis of a new treatment modality, intra-arterial administration of Yttrium-90 TheraSphere, for unresectable hepatocellular carcinoma (HCC). Patients with HCC not amenable to surgical treatment who had satisfactory physiological function without comorbid disease or significant pulmonary shunting were eligible for treatment. Patients were categorized into complete, partial, or no response based on serum alpha-fetoprotein (AFP) levels and CT or MRI imaging. Fourteen patients were considered candidates for treatment. Three patients were excluded due to significant hepatopulmonary shunting. Eleven patients were treated with TheraSphere. One patient (9%) had a complete response, eight patients (78%) had a partial response, and two patients (18%) showed no response. Partial and complete responders with AFP-associated HCC demonstrated a median decrease in AFP levels of 79 per cent at 73 days. No patients developed liver toxicity nor died due to treatment. Five patients (45%) died of progressive disease at a median of 7 months post-treatment. Six patients (54%) were alive at a median of 11 months (range, 9 to 20 months). Okuda stage 2 and 3 patients showed a median survival of 11 months and 7 months, respectively. Yttrium-90 TheraSphere treatment for unresectable hepatocellular carcinoma is well tolerated and appears to extend survival.

The human cervical cancer oncogene protein is a biomarker for human hepatocellular carcinoma

Human cervical cancer oncogene (HCCR) was identified and appeared to function as a negative regulator of p53 gene. The objective of this study was to validate HCCR expression as a candidate marker for human hepatocellular carcinoma. HCCR epitope was identified as Y(355)LGTRR(360). According to immunofluorescence study, HCCR was predominantly localized in the plasma membrane and cytoplasm of hepatocellular carcinoma. HCCR proteins were overexpressed in the tumorous compared with the nontumorous cirrhosis tissues. However, HCCR was not detected in normal liver tissue. Concentration of HCCR protein in the serum was measured in a total of 570 subjects, and comparisons were made to alpha-fetoprotein. Serological studies revealed 78.2% sensitivity of HCCR (cutoff value, 15 microg/ml), which was significantly higher than 64.6% of alpha-fetoprotein (P = 0.0098) and 95.7% specificity for hepatocellular carcinoma. Forty of 52 (76.9%) patients with carcinoma negative for alpha-fetoprotein showed positive values for HCCR. A positive rate of 69.2% in carcinoma patients with tumor sizes <2 cm was found to be a higher rate than measurement of alpha-fetoprotein. Furthermore, HCCR expression was also detected in liver cirrhosis at an intermediate level between carcinoma and normal groups, which gave 88.1% sensitivity and 79.0% specificity using 8 microg/ml as a cutoff value. In summary, the HCCR assay may have an advantage over the alpha-fetoprotein assay in that it is elevated according to disease progression from liver cirrhosis to carcinoma, and it is more frequently positive in patients with early, small hepatocellular carcinoma.

Reduction of double-stranded RNA-activated protein kinase in hepatocellular carcinoma associated with hepatitis B virus

Chronic hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC) in Asia. Double-stranded RNA (dsRNA)-activated protein kinase (PKR) is an interferon-induced, serine/threonine protein kinase. Recent studies have suggested that PKR is involved in the pathogenesis of HCC with hepatitis virus C infection by inhibiting viral and cellular proteins related to cell growth and proliferation. In the present study, PKR was examined in both tumor and non-tumor tissues from HCC livers infected with HBV. The expression of PKR was determined by TaqMan real-time PCR and immunohistochemical methods. The level of PKR was also analyzed in relation to pathological changes observed in HCC. The result showed that PKR was reduced in tumor tissues of HCC from HBV carriers with low serum viral load (<0.7 x 10(6) copies/ml) compared to those with higher serum viral load. However, the overall PKR level was much lower in tumor tissues than that in non-tumor tissues, irrespective of HBV carrier status or serum viral load. PKR level tended to be lower in HCC samples with alpha-fetoprotein (AFP) more than 500 ng/ml (mean: 4024.2 ng/ml) than those with AFP less than 500 ng/ml (mean: 50.6 ng/ml). There was no significant difference in the expression of PKR between tumor tissues with well differentiation and those with poor or moderate differentiation. In conclusion, the level of PKR was reduced in HCC tumor tissues, suggesting a possible role of PKR in promoting the growth of tumor. HBV may participate in altering the level of PKR, but factors other than HBV should play a more determining role in the regulation of PKR in HCC. The association between PKR and AFP levels may offer an alternative tumor marker for HCC.

Clinical significance of elevated alpha-fetoprotein (AFP) in patients with chronic hepatitis C, but not hepatocellular carcinoma

BACKGROUND

Although elevated serum alpha-fetoprotein (AFP) is often seen in patients with chronic hepatitis C (CHC), its prevalence, risk factors, and clinical significance remain to be determined.

AIMS

The present study assessed the frequency of, the risk factors for, and the clinical significance of elevated AFP in patients with CHC, but not hepatocellular carcinoma.

METHODS

This retrospective study utilized systematic chart review and statistical analyses to investigate 357 U.S. patients with CHC from a university medical center and a regional veteran administration medical center.

RESULTS

The prevalence of elevated serum AFP (i.e., >/=10.0 microg/L) was 23.0%, including 15.3% (28/183), 24.5% (25/102), and 42.0% (29/69) in patients with chronic hepatitis C and stage 0-II, III, and IV hepatic fibrosis, respectively. After adjusting for age, HCV load, and hepatic steatosis, stage III/IV fibrosis, elevated aspartate aminotransferase (AST), and prolonged prothrombin time as measured by international normalized ratio (INR) remained independently associated with elevated serum AFP in these patients. A serum AFP level of 15.0 microg/L was 22.8% sensitive and 94.5% specific for stage III/IV fibrosis.

CONCLUSIONS

In patients with chronic hepatitis C, 23.0% had elevated serum AFP that is independently associated with stage III/IV hepatic fibrosis, elevated level of AST, and prolonged INR.

Triple-phase MDCT of hepatocellular carcinoma

OBJECTIVE

The purpose of this study was to describe the appearances of hepatocellular carcinoma including intralesional contrast washout using a triple-phase liver protocol on an MDCT scanner.

MATERIALS AND METHODS

Fifty-one patients with newly diagnosed hepatocellular carcinoma underwent standardized triple-phase CT using a multidetector scanner. Pathologic proof was obtained in 35 patients (69%); in 16 patients (31%), hepatocellular carcinoma was diagnosed on clinical and laboratory findings. Two radiologists independently reviewed the CT studies for the appearance and attenuation of the lesions. Intralesional washout of contrast material was evaluated subjectively and objectively. Statistical analysis was performed using Fisher's exact test to analyze the relationships between tumor appearance and alpha-fetoprotein level, tumor grade, and risk factor. Correlation between tumor size and appearance was analyzed using the Student's t test and Wilcoxon's rank sum test.

RESULTS

The most common enhancement pattern for hepatocellular carcinoma was hypervascularity on hepatic arterial phase images with a mosaic pattern on both arterial and portal venous images; this finding was seen in 86% and 78% of lesions by the two observers, respectively. A hypervascular component was seen in 96% of lesions by both observers, and the observers recorded 86% and 63% of lesions as showing washout, respectively. Objective washout was present in 76% of lesions. Both subjective and objective washout correlated with an elevated alpha-fetoprotein level (p = 0.01).

CONCLUSION

The appearances of hepatocellular carcinoma on images obtained using MDCT scanners are similar to those described for images obtained using single-detector helical scanners. However, the prevalence of hypervascular hepatocellular carcinoma on MDCT images is higher than previously described on single-detector helical images and most lesions showed washout on portal venous MDCT images.

Identification of Soluble NH2-Terminal Fragment of Glypican-3 as a Serological Marker for Early-Stage Hepatocellular Carcinoma

For detection of hepatocellular carcinoma (HCC) in patients with liver cirrhosis, serum alpha-fetoprotein has been widely used, but its sensitivity has not been satisfactory, especially in small, well-differentiated HCC, and complementary serum marker has been clinically required. Glypican-3 (GPC3), a heparan sulfate proteoglycan anchored to the plasma membrane, is a good candidate marker of HCC because it is an oncofetal protein overexpressed in HCC at both the mRNA and protein levels. In this study, we demonstrated that its NH(2)-terminal portion [soluble GPC3 (sGPC3)] is cleaved between Arg(358) and Ser(359) of GPC3 and that sGPC3 can be specifically detected in the sera of patients with HCC. Serum levels of sGPC3 were 4.84 +/- 8.91 ng/ml in HCC, significantly higher than the levels seen in liver cirrhosis (1.09 +/- 0.74 ng/ml; P < 0.01) and healthy controls (0.65 +/- 0.32 ng/ml; P < 0.001). In well- or moderately-differentiated HCC, sGPC3 was superior to alpha-fetoprotein in sensitivity, and a combination measurement of both markers improved overall sensitivity from 50% to 72%. These results indicate that sGPC3 is a novel serological marker essential for the early detection of HCC.

Identification of discriminators of hepatoma by gene expression profiling using a minimal dataset approach

The severity of hepatocellular carcinoma (HCC) and the lack of good diagnostic markers and treatment strategies have rendered the disease a major challenge. Previous microarray analyses of HCC were restricted to the selected tissue sample sets without validation on an independent series of tissue samples. We describe an approach to the identification of a composite discriminator cassette by intersecting different microarray datasets. We studied the global transcriptional profiles of matched HCC tumor and nontumor liver samples from 37 patients using cDNA (cDNA) microarrays. Application of nonparametric Wilcoxon statistical analyses (P < 1 x 10(-6)) and the criteria of 1.5-fold differential gene expression change resulted in the identification of 218 genes, including BMI-1, ERBB3, and those involved in the ubiquitin-proteasome pathway. Elevated ERBB2 and epidermal growth factor receptor (EGFR) expression levels were detected in ERBB3-expressing tumors, suggesting the presence of ERBB3 cognate partners. Comparison of our dataset with an earlier study of approximately 150 tissue sets identified multiple overlapping discriminator markers, suggesting good concordance of data despite differences in patient populations and technology platforms. These overlapping discriminator markers could distinguish HCC tumor from nontumor liver samples with reasonable precision and the features were unlikely to appear by chance, as measured by Monte Carlo simulations. More significantly, validation of the discriminator cassettes on an independent set of 58 liver biopsy specimens yielded greater than 93% prediction accuracy. In conclusion, these data indicate the robustness of expression profiling in marker discovery using limited patient tissue specimens as well as identify novel genes that are highly likely to be excellent markers for HCC diagnosis and treatment.

Specific mutations of hepatitis B virus in plasma predict liver cancer development

A major risk factor for hepatocellular carcinoma (HCC) is hepatitis B virus (HBV), whose pathogenesis is exacerbated by the acquisition of mutations that accelerate carcinogenesis. We examined, with mass spectrometry, the temporality of an HBV 1762(T)/1764(A) double mutation in plasma and tumors. Initial studies found that 52 of 70 (74.3%) tumors from patients residing in Qidong, People's Republic of China, contained this HBV mutation. Paired plasma samples were available for six of the tumor specimens; four tumors had the HBV 1762(T)/1764(A) mutation, whereas three of the paired plasma samples were also positive. The potential predictive value of this biomarker was explored by using stored plasma samples from a study of 120 residents of Qidong who had been monitored for aflatoxin exposure and HBV infection. After 10 years of passive follow-up, there were six cases of major liver disease including HCC (four cases), hepatitis (one case), and cirrhosis (one case). All six cases had detectable levels of the HBV 1762(T)/1764(A) mutation up to 8 years before diagnosis. Finally, 15 liver cancers were selected from a prospective cohort of 1,638 high-risk individuals in Qidong on the basis of available plasma samples spanning the years before and after diagnosis. The HBV 1762(T)/1764(A) mutation was detected in 8 of the 15 cases (53.3%) before cancer. The persistence of detection of this mutation was statistically significant (P = 0.022, two-tailed). We therefore found that a prediagnosis biomarker of specific HBV mutations can be measured in plasma and suggest this marker for use as an intermediate endpoint in prevention and intervention trials.

Rising plasma nociceptin level during development of HCC: a case report

AIM

Although liver cirrhosis is a predisposing factor for hepatocellular carcinoma (HCC), relatively few reports are available on HCC in primary biliary cirrhosis. High plasma nociceptin (N/OFQ) level has been shown in Wilson disease and in patients with acute and chronic pain.

METHODS

We report a follow-up case of HCC, which developed in a patient with primary biliary cirrhosis. The tumor appeared 18 years after the diagnosis of PBC and led to death within two years. Alfa fetoprotein and serum nociceptin levels were monitored before and during the development of HCC. Nociceptin content was also measured in the tumor tissue.

RESULTS

The importance and the curiosity of the presented case was the novel finding of the progressive elevation of plasma nociceptin level up to 17-fold (172 pg/mL) above the baseline (9.2+/-1.8 pg/mL), parallel with the elevation of alpha fetoprotein (from 13 ng/mL up to 3 480 ng/mL) during tumor development. Nociceptin content was more than 15-fold higher in the neoplastic tissue (0.16 pg/mg) than that in the tumor-free liver tissue samples (0.01 pg/mg) taken during the autopsy.

CONCLUSION

Results are in concordance with our previous observation that a very high plasma nociceptin level may be considered as an indicator for hepatocellular carcinoma.

Mesothelin-family proteins and diagnosis of mesothelioma

BACKGROUND

Mesothelioma is a highly aggressive tumour for which there are no reliable serum tumour markers. Identification of such a marker would be useful in diagnosis of mesothelioma and for monitoring responses to treatment and screening at-risk individuals.

METHODS

We assayed serum concentrations of soluble mesothelin-related proteins (SMR) using a double determinant (sandwich) ELISA in a blinded study of serum samples from 44 patients with histologically proven mesothelioma; 68 matched healthy controls, 40 of whom had been exposed to asbestos; and 160 patients with other inflammatory or malignant lung and pleural diseases.

FINDINGS

37 (84%) of 44 patients with mesothelioma had raised concentrations of SMR at a serum dilution of 1/80, compared with three (2%) of 160 patients with other cancers or other inflammatory lung or pleural diseases, and with none of 28 controls who had not been exposed to asbestos. SMR concentrations correlated with tumour size and increased during tumour progression. Seven of the 40 asbestos-exposed individuals had increased serum concentrations of SMR; three of those seven developed mesothelioma and one developed lung carcinoma within 1-5 years. None of the 33 asbestos-exposed participants whose serum samples had normal concentrations of SMR and who were followed up over 8 years developed mesothelioma.

INTERPRETATION

Determination of SMR in serum could be a useful marker for diagnosis of mesothelioma and to monitor disease progression. It might also prove helpful for screening asbestos-exposed individuals for early evidence of mesothelioma.

Glypican-3: a novel serum and histochemical marker for hepatocellular carcinoma

BACKGROUND & AIMS

Early detection of hepatocellular carcinoma (HCC) is critical for successful treatment. However, the differential diagnosis between HCC and benign hepatic lesions is sometimes difficult and new biochemical markers for HCC are required. It has been reported that glypican-3 (GPC3) messenger RNA (mRNA) is significantly increased in most HCCs compared with benign liver lesions or normal liver. The goal of this study is to determine whether GPC3 is also overexpressed at the protein level and whether GPC3 is detectable in the serum of patients with HCC.

METHODS

GPC3 was assessed in liver tissue sections by immunohistochemistry and in serum by enzyme-linked immunosorbent assay. Serum alpha-fetoprotein (AFP) level was also measured in the same patients.

RESULTS

Immunohistochemical studies showed that GPC3 is expressed in 72% of HCCs (21 of 29), whereas it is not detectable in hepatocytes from normal liver and benign liver diseases. Consistent with this, GPC3 was undetectable in the serum of healthy donors and patients with hepatitis, but its levels were significantly increased in 18 of 34 patients (53%) with HCC. In addition, only 1 of 20 patients with hepatitis plus liver cirrhosis displayed elevated levels of serum GPC3. Interestingly, in most cases, there was no correlation between GPC3 and AFP values. Thus, at least 1 of the 2 markers was elevated in 82% of the patients with HCC.

CONCLUSIONS

GPC3 is specifically overexpressed in most HCCs and is elevated in the serum of a large proportion of patients with HCC. The simultaneous determination of GPC3 and AFP may significantly increase the sensitivity for diagnosis of HCC.

Mutation of p53 in recurrent hepatocellular carcinoma and its association with the expression of ZBP-89

p53 has recently been identified as a downstream target of ZBP-89, a zinc finger transcription factor. ZBP-89 promotes growth arrest through stabilization of the p53 protein. The aim of this study is to determine the status of the p53 gene in recurrent human hepatocellular carcinoma (HCC) and test the link between the expression of ZBP-89 and the p53 gene. The results showed that mutations in the p53 gene were frequently detected in recurrent HCC. The interval between surgical resection and the recurrence of HCC was significantly longer in patients with the wild-type p53 gene than those with mutations, strongly suggesting a pathological role for the mutant p53 gene in HCC recurrence. Among those positive for the p53 protein, nearly 85% (18 of 21) showed nuclear localization of the p53 protein while only about 14% (3 of 21) were positive for the p53 protein in the cytoplasm. ZBP-89 co-localized with p53 in the nucleus in about 67% (12 of 18) of all cases positive for the nuclear p53 protein, suggesting that ZBP-89 may play a role in the nuclear accumulation of the p53 protein in a subset of recurrent HCC. With accumulation of p53 protein in the nucleus, tumor cells undergo apoptosis and thus are more susceptible to radiotherapy and chemotherapy. Therefore, co-localization of p53 protein with ZBP-89 may define a subgroup of recurrent HCC that is more sensitive to treatment.

Dramatic reduction of the alpha-fetoprotein level after lamivudine treatment of patients with chronic hepatitis B virus infection and cirrhosis

Markedly elevated alpha-fetoprotein levels in the range of >1,000 ng/mL are highly suspicious for the presence of hepatocellular carcinoma. This report describes three patients with cirrhosis and replicating hepatitis B virus infection who presented with initial serum alpha-fetoprotein levels of >1,000 ng/mL without clear evidence of hepatocellular carcinoma based on multiple abdominal imaging studies. Initiation of lamivudine treatment led to rapid and dramatic reductions in the alpha-fetoprotein level to the normal range within 12 weeks in one patient and by >1 log at 7 and 16 weeks in the other two patients. One of the three patients previously developed lamivudine resistance, and discontinuation of lamivudine led to a severe flare of hepatitis B before lamivudine treatment was restarted. During a follow-up period of 14 to 36 months, all three patients maintained stable alpha-fetoprotein levels and had no signs of hepatocellular carcinoma demonstrated by serial abdominal imaging studies. The dramatic decrease in the alpha-fetoprotein levels in these patients is unlikely to be a spontaneous event but is possibly due to suppression of viral replication and associated hepatic inflammatory activities by lamivudine. These observations may be helpful in the diagnostic evaluation and management of patients with markedly elevated alpha-fetoprotein levels and chronic hepatitis B-related cirrhosis.

Comprehensive proteomic profiling identifies serum proteomic signatures for detection of hepatocellular carcinoma and its subtypes

BACKGROUND

Detection of hepatocellular carcinoma (HCC) in patients with chronic liver disease (CLD) is difficult. We investigated the use of comprehensive proteomic profiling of sera to differentiate HCC from CLD.

METHODS

Proteomes in sera from 20 CLD patients with alpha-fetoprotein (AFP) <500 microg/L (control group) and 38 HCC patients (disease group) were profiled by anion-exchange fractionation (first dimension), two types (IMAC3 copper and WCX2) of ProteinChip Arrays (second dimension), and time-of-flight mass spectrometry (third dimension). Bioinformatic tests were used to identify tumor-specific proteomic features and to estimate the values of the tumor-specific proteomic features in the diagnosis of HCC. Cross-validation was performed, and we also validated the models with pooled sera from the control and disease groups, serum from a CLD patient with AFP >500 microg/L, and postoperative sera from two HCC patients.

RESULTS

Among 2384 common serum proteomic features, 250 were significantly different between the HCC and CLD cases. Two-way hierarchical clustering differentiated HCC and CLD cases. Most HCC cases with advanced disease were clustered together and formed two subgroups that contained significantly more cases with lymph node invasion or distant metastasis. For differentiation of HCC and CLD by an artificial network (ANN), the area under the ROC curve was 0.91 (95% confidence interval, 0.82-1.01; P <0.0005) for all cases and 0.954 (95% confidence interval, 0.881-1.027; P <0.0005) for cases with nondiagnostic serum AFP (<500 microg/L). At a specificity of 90%, the sensitivity was 92%. Both cluster analysis and ANN correctly classified the pooled serum samples, the CLD serum sample with increased AFP, and the HCC patient in complete remission.

CONCLUSION

Tumor-specific proteomic signatures may be useful for detection and classification of hepatocellular cancers.

Translational strategies for cancer prevention in liver

Unlike many other types of human cancer, the aetiology of liver cancer is well understood. Infection with hepatitis viruses, coupled with dietary exposure to the fungal toxin aflatoxin, increases the risk of the disease. Although primary prevention, based on vaccination and avoiding exposure to these agents, is an appealing option, such strategies will require considerable investment of time and resources to be successful. In the developing world--where the burden of liver cancer is highest--immediate, practical and economical approaches are essential. So, targeted chemoprevention might be most appropriate for the present generation of individuals at risk.

Large-scale delineation of secreted protein biomarkers overexpressed in cancer tissue and serum

Genetic alterations in tumor cells often lead to the emergence of growth-stimulatory autocrine and paracrine signals, involving overexpression of secreted peptide growth factors, cytokines, and hormones. Increased levels of these soluble proteins may be exploited for cancer diagnosis and management or as points of therapeutic intervention. Here, we combined the use of controlled vocabulary terms and sequence-based algorithms to predict genes encoding secreted proteins from among approximately 12,500 sequences represented on oligonucleotide microarrays. Expression of these genes was queried in 150 carcinomas from 10 anatomic sites of origin and compared with 46 normal tissues derived from the corresponding sites of tumor origin and other body tissues and organs. Of 74 different genes identified as overexpressed in cancer tissues, several encode proteins with demonstrated clinical diagnostic application, such as alpha-fetoprotein in liver carcinoma, and kallikreins 6 and 10 in ovarian cancer, or therapeutic utility, such as gastrin-releasing peptide/bombesin in lung carcinomas. We show that several of the other candidate genes encode proteins with high levels of tumor-associated expression by immunohistochemistry on tissue microarrays and further demonstrate significantly elevated levels of another novel candidate protein, macrophage inhibitory cytokine 1, a distant member of the transforming growth factor-beta superfamily, in the serum of patients with metastatic prostate, breast, and colorectal carcinomas. Our results suggest that the combination of annotation/protein sequence analysis, transcript profiling, immunohistochemistry, and immunoassay is a powerful approach for delineating candidate biomarkers with potential clinical significance and may be broadly applicable to other human diseases.

Dramatic elevation of plasma metastin concentrations in human pregnancy: metastin as a novel placenta-derived hormone in humans

Metastin is a novel peptide that was recently isolated from human placenta as the endogenous ligand of an orphan heptahelical receptor, hOT7T175. Metastin has been shown to suppress the motility of hOT7T175-transfected melanoma cells; however, studies of the physiological function of metastin have begun only recently. To investigate the possibility that metastin is an endocrine peptide, we determined the immunoreactive (ir-) metastin concentration in human plasma using our newly developed, sensitive, and specific two-site enzyme immunoassay. The plasma concentrations of ir-metastin in males and females were 1.30 +/- 0.14 (n = 12) and 1.31 +/- 0.37 fmol/ml (n = 10), respectively. As metastin is known to be abundant in human placenta, the ir-metastin concentration in the maternal plasma was then determined. The ir-metastin concentrations were 1230 +/- 346 fmol/ml (n = 11) in the first trimester, 4590 +/- 555 (n = 16) in the second trimester, and 9590 +/- 1640 (n = 12) in the third trimester. On d 5 after delivery, the ir-metastin concentration returned to nearly the nonpregnant level (7.63 +/- 1.33 fmol/ml; n = 10), suggesting that ir-metastin increases in pregnancy and is derived mainly from the placenta. The plasma from both nonpregnant and pregnant women showed a single ir-metastin peak at the same retention time as authentic metastin on reverse phase HPLC analysis, indicating that the major portion of the circulating metastin, as determined by our two-site enzyme immunoassay, represents endogenous metastin. Histochemical studies of human placenta localized metastin mRNA and immunoreactivity to the syncytiotrophoblasts. The present study provides evidence for metastin as a novel placenta-derived hormone in humans.

Screening for hepatocellular carcinoma: why, when, how?

Hepatocellular carcinoma (HCC) is a major public health concern in many areas of the world, and its incidence is increasing in the United States and other countries. Screening for HCC in patients with cirrhosis has been advocated to identify those with small lesions who would benefit from transplantation or surgical resection. Despite these recommendations, several issues regarding screening remain controversial. No randomized, controlled trials have confirmed that surveillance for HCC reduces disease-specific mortality. In addition, the most appropriate screening test and optimal screening interval have not yet been defined. Clearly, these unresolved questions have a major impact on the cost-effectiveness of a screening program either at the population or the clinic level. A few studies, however, have suggested that screening may be cost-effective because a minor survival benefit could result in a cost that is acceptable to decision makers.

Gene expression patterns in human liver cancers

Hepatocellular carcinoma (HCC) is a leading cause of death worldwide. Using cDNA microarrays to characterize patterns of gene expression in HCC, we found consistent differences between the expression patterns in HCC compared with those seen in nontumor liver tissues. The expression patterns in HCC were also readily distinguished from those associated with tumors metastatic to liver. The global gene expression patterns intrinsic to each tumor were sufficiently distinctive that multiple tumor nodules from the same patient could usually be recognized and distinguished from all the others in the large sample set on the basis of their gene expression patterns alone. The distinctive gene expression patterns are characteristic of the tumors and not the patient; the expression programs seen in clonally independent tumor nodules in the same patient were no more similar than those in tumors from different patients. Moreover, clonally related tumor masses that showed distinct expression profiles were also distinguished by genotypic differences. Some features of the gene expression patterns were associated with specific phenotypic and genotypic characteristics of the tumors, including growth rate, vascular invasion, and p53 overexpression.