The fucosylation index of alpha-fetoprotein as a possible prognostic indicator for patients with hepatocellular carcinoma

A Glycoform-Resolved Dual-Modal Ratiometric Immunoassay Improves the Diagnostic Precision for Hepatocellular Carcinoma

The glycosylation pattern of alpha fetoprotein (AFP) paves the basis for precise early diagnosis of hepatocellular carcinoma (HCC). However, existing analytical methods ignore the contribution of terminal sialic acid, which has been reported to be highly connected with HCC. Besides, the development of diagnostic assays is severely hindered by the preparation of anti-glycans antibodies. Molecularly imprinted polymers (MIPs), as synthetic antibody mimics, provide unique strengths to address these issues. Herein, we report a MIPs-based dual-modal ratiometric immunoassay for precise HCC diagnosis. Using a "pit one against ten" MIP to recognize a subset of glycans containing sialic acid and/or core fucose, we demonstrated our assay exhibited improved precision as compared with ELISA. This assay provided not only a glycoform-resolved method for precise HCC diagnosis, but also a new paradigm for developing antibody mimics via molecular imprinting towards challenging biomedical applications.

Molecularly Imprinted Polymers Outperform Lectin Counterparts and Enable More Precise Cancer Diagnosis

Accurately analysing the particular glycosylation status of protein biomarkers is of significant importance in the precise, early diagnosis of cancer. Existing methods mainly rely on the use of antibodies and lectins. However, due to the macroscopic and microscopic heterogeneity of glycans, precise analysis of glycosylation status still remains a challenge. Molecularly imprinted polymers (MIPs), as a synthetic alternative to antibodies or lectins, may provide new solutions but have not yet been explored. Herein, we report an appealing strategy called triple MIP-based plasmonic immunosandwich assay (triMIP-PISA) for precise cancer diagnosis in terms of the relative glycosylation expression of glycoprotein biomarkers. As proof of the principle, alpha fetoprotein (AFP), which has been used as a clinical biomarker for early detection of hepatocellular carcinoma (HCC), as well as its Lens culinaris agglutinin (LCA)-reactive fraction (AFP-L3), which is mainly composed of core-fucosylated glycans, were used as two target proteoforms to test in this study. Using two MIPs that can specifically recognize the peptide sequence of AFP as well as a fucose-imprinted MIP that can specifically recognize the AFP-L3 fraction, facile simultaneous plasmon-enhanced Raman detection of AFP and AFP-L3 in serum was achieved, which allowed HCC patients to be distinguished from healthy individuals. Due to the excellent recognition properties of the MIPs that are comparable to those of antibodies and superior to those of lectins, our triMIP-PISA method exhibited improved precision as compared with an antibody plus lectin-based immunofluorescence assay. Thus, this strategy opened a new avenue towards the precise diagnosis of cancer.

A triple molecularly imprinted polymer (MIP)-based plasmonic assay was developed for precise cancer diagnosis in terms of the relative glycosylation expression of glycoprotein biomarkers.

Uromodulin Isolation and Its N-Glycosylation Analysis by NanoLC-MS/MS

The glycoprotein uromodulin (UMOD) is the most abundant protein in urine, and N-glycans are critical for many biological functions of UMOD. Comprehensive glycan profiling of UMOD provides valuable information to understand the exact mechanisms of glycan-regulated functions. To perform comprehensive glycosylation analysis of UMOD from urine samples with limited volumes, we developed a streamlined workflow that included UMOD isolation from 5 mL of urine from 6 healthy adult donors (3 males and 3 females) and a glycosylation analysis using a highly sensitive and reproducible nanoLC-MS/MS based glycomics approach. In total, 212 N-glycan compositions were identified from the purified UMOD, and 17% were high-mannose glycans, 2% were afucosylated/asialylated, 3% were neutral fucosylated, 28% were sialylated (with no fucose), 46% were fucosylated and sialylated, and 4% were sulfated. We found that isolation of UMOD resulted in a significant decrease in the relative quantity of high-mannose and sulfated glycans with a significant increase of neutral fucosylated glycans in the UMOD-depleted urine relative to the undepleted urine, but depletion had little impact on the sialylated glycans. To our knowledge, this is the first study to perform comprehensive N-glycan profiling of UMOD using nanoLC-MS/MS. This analytical workflow would be very beneficial for studies with limited sample size, such as pediatric studies, and can be applied to larger patient cohorts not only for UMOD interrogation but also for global glycan analysis.

Characterizing human α-1,6-fucosyltransferase (FUT8) substrate specificity and structural similarities with related fucosyltransferases

Mammalian Asn-linked glycans are extensively processed as they transit the secretory pathway to generate diverse glycans on cell surface and secreted glycoproteins. Additional modification of the glycan core by α-1,6-fucose addition to the innermost GlcNAc residue (core fucosylation) is catalyzed by an α-1,6-fucosyltransferase (FUT8). The importance of core fucosylation can be seen in the complex pathological phenotypes of FUT8 null mice, which display defects in cellular signaling, development, and subsequent neonatal lethality. Elevated core fucosylation has also been identified in several human cancers. However, the structural basis for FUT8 substrate specificity remains unknown.Here, using various crystal structures of FUT8 in complex with a donor substrate analog, and with four distinct glycan acceptors, we identify the molecular basis for FUT8 specificity and activity. The ordering of three active site loops corresponds to an increased occupancy for bound GDP, suggesting an induced-fit folding of the donor-binding subsite. Structures of the various acceptor complexes were compared with kinetic data on FUT8 active site mutants and with specificity data from a library of glycan acceptors to reveal how binding site complementarity and steric hindrance can tune substrate affinity. The FUT8 structure was also compared with other known fucosyltransferases to identify conserved and divergent structural features for donor and acceptor recognition and catalysis. These data provide insights into the evolution of modular templates for donor and acceptor recognition among GT-B fold glycosyltransferases in the synthesis of diverse glycan structures in biological systems.

A Novel Mass Spectrometry Platform for Multiplexed N-Glycoprotein Biomarker Discovery from Patient Biofluids by Antibody Panel Based N-Glycan Imaging

A new platform for N-glycoprotein analysis from serum that combines matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) workflows with antibody slide arrays is described. Antibody panel based (APB) N-glycan imaging allows for the specific capture of N-glycoproteins by antibodies on glass slides and N-glycan analysis in a protein-specific and multiplexed manner. Development of this technique has focused on characterizing two abundant and well-studied human serum glycoproteins, alpha-1-antitrypsin and immunoglobulin G. Using purified standard solutions and 1 μL samples of human serum, both glycoproteins can be immunocaptured and followed by enzymatic release of N-glycans. N-Glycans are detected with a MALDI FT-ICR mass spectrometer in a concentration-dependent manner while maintaining specificity of capture. Importantly, the N-glycans detected via slide-based antibody capture were identical to that of direct analysis of the spotted standards. As a proof of concept, this workflow was applied to patient serum samples from individuals with liver cirrhosis to accurately detect a characteristic increase in an IgG N-glycan. This novel approach to protein-specific N-glycan analysis from an antibody panel can be further expanded to include any glycoprotein for which a validated antibody exists. Additionally, this platform can be adapted for analysis of any biofluid or biological sample that can be analyzed by antibody arrays.

Tumor-Derived α-Fetoprotein Suppresses Fatty Acid Metabolism and Oxidative Phosphorylation in Dendritic Cells

Cellular metabolism supports immune cell function. Here, we identify a reduction in fatty acid synthesis and mitochondrial metabolism in dendritic cells (DC) due to α-fetoprotein (AFP), a protein secreted by hepatocellular cancer (HCC). DCs cultured in the presence of AFP show reduced expression of the metabolic regulatory molecules SREBP-1 and PGC1-α. The negative effect of AFP on mitochondrial metabolism and ATP production was confirmed with observation of reduction in basal oxygen consumption rate (OCR) in DCs exposed to AFP derived from cord blood. More severe reduction in basal OCR was observed in tumor-derived DCs exposed to AFP due to downregulation of cytochrome c oxidase. We also showed reduced expression of PGC1-α in circulating myeloid DCs of patients with HCC and impaired capacity to stimulate antigen-specific effector functions. These data show the negative effects of AFP on DC metabolism. These findings elucidate a mechanism of immune suppression in HCC and may help generate therapeutic approaches to reverse such immunosuppression.

Fast and facile analysis of glycosylation and phosphorylation of fibrinogen from human plasma-correlation with liver cancer and liver cirrhosis

Hepatocellular carcinoma (HCC) is one of the deadliest cancers due to its late diagnosis with the main risk factor being liver cirrhosis (LC). Glycan structures from glycoproteins are usually altered in cancer. Blood plasma from 111 healthy and sick donors was analyzed to determine the post-translational modifications (PTM) of intact Aα-, Bβ-, and γ-subunits of fibrinogen, a glycoprotein predominantly produced in liver cells. Glycosylation and phosphorylation of the protein species were quantified by liquid chromatography coupled to mass spectrometry to correlate PTMs to pathological cases. Quantities of the PTMs were used for statistical classification by principal component analysis (PCA) and multivariate analysis of variance (MANOVA). As relevant clinical finding, patients with liver disease (HCC and/or LC) were distinguished from individuals without relevant chronic liver disease with 91% sensitivity and 100% specificity. Within the group of patients with liver disease, a robust separation between LC and HCC was not possible. In more detail, the phosphorylation of Aα-subunit is decreased in HCC patients, whereas the monophosphorylated state is significantly increased in LC patients. In terms of glycosylation, the amount of O-glycans in the Aα-subunit is decreased in LC patients, while sialylation and fucosylation of N-type glycans of Bβ- and γ-subunits are increased in LC and HCC. Based on PTM of fibrinogen, starting from plasma we can assign the status of an individual as healthy or as liver disease in less than 3 h.

Hepatic inflammatory pseudotumor associated with primary biliary cholangitis and elevated alpha-fetoprotein lectin 3 fraction mimicking hepatocellular carcinoma

Background

Hepatic inflammatory pseudotumor (IPT) is a rare benign lesion. Because there is no specific laboratory marker or radiographic appearance, the majority of reported cases of hepatic IPT have been diagnosed after surgery or at autopsy. The etiology of hepatic IPT remains unclear but several mechanisms have been postulated such as infection or immune reaction.

Case presentation

A 79-year-old woman had been seeing her family doctor for hypertension, and she had been diagnosed with liver dysfunction for about 10 years. She continued attending follow-ups because of her drinking habit. Two months before her visiting our institution, further elevation of hepatobiliary enzymes was noted, and abdominal ultrasonography showed a hepatic tumor 4 cm in diameter in the lateral segment, so she was referred to our hospital. Hepatocellular carcinoma (HCC) was suspected because alpha-fetoprotein (102 ng/ml) (AFP) and lectin 3 (L3) fraction (85.4%) were elevated and the appearance on enhanced computed tomography was not inconsistent with HCC. Thus, we performed laparoscopic hepatectomy. She recovered uneventfully and was discharged on postoperative day 7. Pathological diagnosis revealed that the tumor was hepatic IPT and that the background liver condition was primary biliary cholangitis (PBC). AFP and L3 fraction decreased to normal ranges after surgery.

Conclusions

In 7 of 29 patients (24.1%) with reported cases of tumor markers in liver IPT, carbohydrate antigen 19-9 was elevated and AFP was elevated in 2 of 58 patients (3.4%). AFP is also frequently elevated in benign liver diseases such as hepatitis and liver cirrhosis, and L3 fraction has been used as a tumor marker for HCC with high specificity. To our knowledge, this is the first report of a case diagnosed with liver IPT in which AFP and L3 fraction increased before surgery and decreased to the normal range after resection. This confirms the rarity of hepatic IPT associated with PBC and elevated AFP and L3 fraction.

Biological functions of fucose in mammals

Fucose is a 6-deoxy hexose in the l-configuration found in a large variety of different organisms. In mammals, fucose is incorporated into N-glycans, O-glycans and glycolipids by 13 fucosyltransferases, all of which utilize the nucleotide-charged form, GDP-fucose, to modify targets. Three of the fucosyltransferases, FUT8, FUT12/POFUT1 and FUT13/POFUT2, are essential for proper development in mice. Fucose modifications have also been implicated in many other biological functions including immunity and cancer. Congenital mutations of a Golgi apparatus localized GDP-fucose transporter causes leukocyte adhesion deficiency type II, which results in severe developmental and immune deficiencies, highlighting the important role fucose plays in these processes. Additionally, changes in levels of fucosylated proteins have proven as useful tools for determining cancer diagnosis and prognosis. Chemically modified fucose analogs can be used to alter many of these fucose dependent processes or as tools to better understand them. In this review, we summarize the known roles of fucose in mammalian physiology and pathophysiology. Additionally, we discuss recent therapeutic advances for cancer and other diseases that are a direct result of our improved understanding of the role that fucose plays in these systems.

The search for biomarkers of hepatocellular carcinoma and the impact on patient outcome

Hepatocellular carcinoma (HCC) is the 5th most common cancer, but the 3rd leading cause of cancer death globally with approximately 700,000 fatalities annually. The severity of this cancer arises from its difficulty to detect and treat. The major etiologies of HCC are liver fibrosis or cirrhosis from chronic viral infections, as well as metabolic conditions. Since most cases arise from prior pathologies, biomarker surveillance in high-risk individuals is an essential approach for early detection and improved patient outcome. While many molecular biomarkers have been associated with HCC, there are few that have made clinical impact for this disease. Here we review some major approaches used for HCC biomarker discovery-proteomics and glycomics-and describe new methodologies being tested for biomarker development.

FUT8: from biochemistry to synthesis of core-fucosylated N-glycans

Glycosylation is a major posttranslational modification of proteins. Modification in structure on N-glycans leads to many diseases. One of such modifications is core α-1,6 fucosylation, which is only found in eukaryotes. For this reason, lots of research has been done on approaches to synthesize core-fucosylated N-glycans both chemically and enzymatically, in order to have well defined structures that can be used as probes for glycan analysis and identifying functions of glycan-binding proteins. This review will focus on FUT8, the enzyme responsible for core fucosylation in mammals and the strategies that have been developed for the synthesis of core fucosylated N-glycans have been synthesized so far.

Identification of fucosylated Fetuin-A as a potential biomarker for cholangiocarcinoma

PURPOSE

Cholangiocarcinoma (CCA) is a malignancy of the bile ducts. The purpose of this discovery study was to identify effective serum markers for surveillance of cholangiocarcinoma.

EXPERIMENTAL DESIGN

Using a glycomic method, patients with CCA were determined to have increased levels of alpha-1,3 and alpha-1,6 linked fucosylated glycan. Proteomic analysis of the serum fucosylated proteome identified proteins such as alpha-2-macroglobulin, kininogen, hemopexin, fetuin-A, alpha-1 anti-trypsin, and ceruloplasmin as being hyperfucosylated in HCC. The levels of these glycoproteins in 109 patients with CCA, primary sclerosing cholangitis (PSC), and control patients were compared to the performance of CA-19-9, the current "gold standard" assay for cholangiocarcinoma.

RESULTS

Fucosylated Fetuin-A (fc-Fetuin-A) had the best ability to differentiate CCA from PSC, with an AUROC of 0.812 or 0.8665 at differentiating CCA from those with PSC or other liver disease. CA-19-9 had poor ability to differentiate PSC from cholangiocarcinoma (AUROC of 0.625).

CONCLUSION AND CLINICAL RELEVANCE

Using glycomic and proteomic methods we identified a set of proteins that contain altered glycan in the sera of those with CCA. One of these proteins, fucosylated Fetuin-A may have value in the surveillance of people at risk for the development of cholangiocarcinoma.

A pilot study of salivary N-glycome in HBV-induced chronic hepatitis, cirrhosis, and hepatocellular carcinoma

Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus (HBV), which can lead to chronic liver disease and put people at high risk of death from cirrhosis of the liver and liver cancer. However, little is known about the correlation of salivary N-linked glycans related to HBV-infected liver diseases. Here we investigated N-linked glycome in saliva from 200 subjects (50 healthy volunteers (HV), 40 HBV-infected patients (HB), 50 cirrhosis patients (HC), and 60 hepatocellular carcinoma patients (HCC) using MALDI-TOF/TOF-MS. Representative MS spectra of N-glycans with signal-to-noise ratios >6 were annotated using the GlycoWorkbench program. A total of 40, 47, 29, and 33 N-glycan peaks were identified and annotated from HV, HB, HC, and HCC groups, respectively. There were 15 N-glycan peaks (e.g., m/z 1647.587, 1688.613 and 2101.755) were present in all groups. Three N-glycan peaks (m/z 2596.925, 2756.962, and 2921.031) were unique in HV group, 2 N-glycan peaks (m/z 1898.676 and 1971.692) were unique in HB group, 5 N-glycan peaks (m/z 1954.677, 2507.914, 2580.930, 2637.952, and 3092.120) were unique in HC group, and 3 N-glycan peaks (m/z 2240.830, 2507.914, and 3931.338) were unique in HCC group. The proportion of fucosylated N-glycans was apparently increased in the HCC group (84.8%) than in any other group (73.1% ± 0.01), however, the proportion of sialylated N-glycans was decreased in HCC group (12.1%) than in any other group (17.23% ± 0.003). Our data provide pivotal information to distinguish between HBV-associated hepatitis, cirrhosis and HCC, and facilitate the discovery of biomarkers for HCC during its early stages based on precise alterations of N-linked glycans in saliva.

Identification of IgM as a contaminant in lectin-FLISA assays for HCC detection

Liver disease, in the form of hepatocellular carcinoma (HCC) accounts for > 700,000 deaths worldwide. A major reason for this is late diagnosis of HCC. The currently used biomarker, serum alpha-fetoprotein (AFP) is elevated in 40-60% of those with HCC and other markers that can either compliment or replace AFP are desired. Our previous work has identified a number of proteins that contain altered glycans in HCC. Specifically, these altered glycans were increased levels of core and outer arm fucosylation. To determine the clinical usefulness of those identified glycoproteins, a plate based assay was developed that allowed for the detection of fucosylated glycoforms. While this method was applicable to a number of independent patient sets, it was unable to specifically detect fucosylated glycoforms in many patient samples. That is, some material was present in serum that led to non-specific signal in the lectin- fluorescence -linked immunosorbent assay (lectin-FLISA). To address this issue, a systematic process was undertaken to identify the material. This material was found to be increased levels of lectin reactive IgM. Removal of both IgG and IgM using a multi-step protein A/G incubation and filtration step removed the contaminating signal and allowed for the analysis of specific protein glycoforms. This assay was subsequently used on two sample sets, one that was shown previously to be unable to be tested via a lectin FLISA and in a larger independent sample set. The clinical usefulness of this assay in the early detection of HCC is discussed.

Substrate specificity of FUT8 and chemoenzymatic synthesis of core-fucosylated asymmetric N-glycans

Substrate specificity studies of human FUT8 using 77 structurally-defined N-glycans as acceptors showed a strict requirement towards the α1,3-mannose branch, but a great promiscuity towards the α1,6-mannose branch. Accordingly, a chemoenzymatic strategy was developed for the efficient synthesis of core-fucosylated asymmetric N-glycans.

Two-Dimensional N-Glycan Distribution Mapping of Hepatocellular Carcinoma Tissues by MALDI-Imaging Mass Spectrometry

A new mass spectrometry imaging approach to simultaneously map the two-dimensional distribution of N-glycans in tissues has been recently developed. The method uses Matrix Assisted Laser Desorption Ionization Imaging Mass Spectrometry (MALDI-IMS) to spatially profile the location and distribution of multiple N-linked glycan species released by peptide N-glycosidase F in frozen or formalin-fixed tissues. Multiple formalin-fixed human hepatocellular carcinoma tissues were evaluated with this method, resulting in a panel of over 30 N-glycans detected. An ethylation reaction of extracted N-glycans released from adjacent slides was done to stabilize sialic acid containing glycans, and these structures were compared to N-glycans detected directly from tissue profiling. In addition, the distribution of singly fucosylated N-glycans detected in tumor tissue microarray cores were compared to the histochemistry staining pattern of a core fucose binding lectin. As this MALDI-IMS workflow has the potential to be applied to any formalin-fixed tissue block or tissue microarray, the advantages and limitations of the technique in context with other glycomic methods are also summarized.

Route of antigen delivery impacts the immunostimulatory activity of dendritic cell-based vaccines for hepatocellular carcinoma

Background

Dendritic cells (DC) are uniquely equipped to capture, process, and present antigens from their environment. The context in which an antigen is acquired by DC helps to dictate the subsequent immune response. Cancer vaccination promotes antitumor immunity by directing an immune response to antigens expressed by tumors. We have tested the tumor-associated antigen alpha-fetoprotein (AFP) as an immunotherapy target. The majority of hepatocellular carcinomas (HCC) upregulate and secrete this oncofetal antigen.

Methods

To develop cancer vaccines for HCC capable of promoting potent tumor-specific T cell responses, we tested adenovirally-encoded synthetic AFP, with or without its signal sequence, as well as protein forms of AFP and compared intracellular routing and subsequent antigen-specific CD8+ and CD4+ T cell responses.

Results

Surprisingly, the secreted form of antigen was superior for both CD4+ and CD8+ T cell activation. We also examined the mechanism through which AFP protein is endocytosed and trafficked in human DC. We identify the mannose receptor (MR/CD206) as the primary uptake pathway for both normal cord blood-derived AFP (nAFP) and tumor-derived AFP (tAFP) proteins. While in healthy donors, nAFP and tAFP were cross-presented to CD8+ T cells similarly and CD4+ T cell responses were dependent upon MR-mediated uptake. In HCC patient cells, tAFP was more immunogenic, and CD4+ T cell responses were not MR-dependent.

Conclusions

Secreted, cytoplasmically retained, and endocytosed forms of AFP utilize unique uptake and processing pathways, resulting in different immunologic responses from the induced antigen-specific CD4+ and CD8+ T cells and between healthy donors and HCC patients. Collectively, these data elucidate pathways of spontaneous and induced anti-tumor immunity in HCC patients to this secreted antigen.

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-015-0077-x) contains supplementary material, which is available to authorized users.

Glycosylation and liver cancer

Liver cancer is the fifth most common cancer, but the second leading cause of cancer death, in the world, with more than 700,000 fatalities annually. The major etiology of liver cancer is infection with an hepatotropic virus such as hepatitis B virus or hepatitis C virus infection. While chronic viral infection remains the main cause of liver disease and risk of hepatocellular carcinoma (HCC), rates of nonviral-associated HCC are occurring at an alarmingly increasing rate. Like many cancers, survival rates are closely associated with time of detection. If HCC is caught early, survival rates can be as high as 50%. Regrettably, most cases of HCC are caught late where survival rates can be as low as 2-7%. Thus, there has been great interest in discovering serum biomarkers that could be used to identify those with HCC. To this end, many groups have examined the N-linked glycans to identify changes that occur with HCC. As the liver secretes the vast majority of proteins into the serum, this has often been a starting point for study. In serum, alterations in core fucosylation, outer-arm fucosylation, increased sialylation, and glycan branching have been observed in patients with HCC. Similar findings have been found directly in HCC tissue suggesting that these glycan changes may play a role in tumor formation and development.

Prognostic role of pre-treatment serum AFP-L3% in hepatocellular carcinoma: systematic review and meta-analysis

Background

Serum lens culinaris agglutinin-reactive fraction of α-fetoprotein (AFP-L3%) has been widely used for HCC diagnosis and follow-up surveillance as tumor serologic marker. However, the prognostic value of high pre-treatment serum AFP-L3% in patients with hepatocellular carcinoma (HCC) remains controversial. We therefore conduct a meta-analysis to assess the relationship between high pre-treatment serum AFP-L3% and clinical outcome of HCC.

Methods

Eligible studies were identified through systematic literature searches. A meta-analysis of fifteen studies (4,465 patients) was carried out to evaluate the association between high pre-treatment serum AFP-L3% and overall survival (OS) and disease-free survival (DFS) in HCC patients. Sensitivity and subgroup analyses were also conducted in this meta-analysis.

Results

Our analysis results showed that high pre-treatment serum AFP-L3% implied poor OS (HR: 1.65, 95%CI: 1.45–1.89 p<0.00001) and DFS (HR: 1.80, 95% CI: 1.49–2.17 p<0.00001) of HCC. Subgroup analysis revealed that there was association between pre-treatment serum AFP-L3% and endpoint (OS and DFS) in low AFP concentration HCC patients (HR: 1.96, 95% CI: 1.24–3.10, p = 0.004; HR: 2.53, 95% CI: 1.09–5.89, p = 0.03, respectively).

Conclusion

The current evidence suggests that high pre-treatment serum AFP-L3% levels indicated a poor prognosis for patients with HCC and AFP-L3% may have significant prognostic value in HCC patients with low AFP concentration.

A comparison of statistical methods for the detection of hepatocellular carcinoma based on serum biomarkers and clinical variables

BACKGROUND

Currently, a surgical approach is the best curative treatment for those with hepatocellular carcinoma (HCC). However, this requires HCC detection and removal of the lesion at an early stage. Unfortunately, most cases of HCC are detected at an advanced stage because of the lack of accurate biomarkers that can be used in the surveillance of those at risk. It is believed that biomarkers that could detect HCC early will play an important role in the successful treatment of HCC.

METHODS

In this study, we analyzed serum levels of alpha fetoprotein, Golgi protein, fucosylated alpha-1-anti-trypsin, and fucosylated kininogen from 113 patients with cirrhosis and 164 serum samples from patients with cirrhosis plus HCC. We utilized two different methods, namely, stepwise penalized logistic regression (stepPLR) and model-based classification and regression trees (mob), along with the inclusion of clinical and demographic factors such as age and gender, to determine if these improved algorithms could be used to increase the detection of cancer.

RESULTS AND DISCUSSION

The performance of multiple biomarkers was found to be better than that of individual biomarkers. Using several statistical methods, we were able to detect HCC in the background of cirrhosis with an area under the receiver operating characteristic curve of at least 0.95. stepPLR and mob demonstrated better predictive performance relative to logistic regression (LR), penalized LR and classification and regression trees (CART) used in our prior study based on three-fold cross-validation and leave one out cross-validation. In addition, mob provided unparalleled intuitive interpretation of results and potential cut-points for biomarker levels. The inclusion of age and gender improved the overall performance of both methods among all models considered, while the stratified male-only subset provided the best overall performance among all methods and models considered.

CONCLUSIONS

In addition to multiple biomarkers, the incorporation of age and gender into statistical models significantly improved their predictive performance in the detection of HCC.

Cell surface glycan alterations in epithelial mesenchymal transition process of Huh7 hepatocellular carcinoma cell

Background and Objective

Due to recurrence and metastasis, the mortality of Hepatocellular carcinoma (HCC) is high. It is well known that the epithelial mesenchymal transition (EMT) and glycan of cell surface glycoproteins play pivotal roles in tumor metastasis. The goal of this study was to identify HCC metastasis related differential glycan pattern and their enzymatic basis using a HGF induced EMT model.

Methodology

HGF was used to induce HCC EMT model. Lectin microarray was used to detect the expression of cell surface glycan and the difference was validated by lectin blot and fluorescence cell lectin-immunochemistry. The mRNA expression levels of glycotransferases were determined by qRT-PCR.

Results

After HGF treatment, the Huh7 cell lost epithelial characteristics and obtained mesenchymal markers. These changes demonstrated that HGF could induce a typical cell model of EMT. Lectin microarray analysis identified a decreased affinity in seven lectins ACL, BPL, JAC, MPL, PHA-E, SNA, and SBA to the glycan of cell surface glycoproteins. This implied that glycan containing T/Tn-antigen, NA2 and bisecting GlcNAc, Siaα2-6Gal/GalNAc, terminal α or βGalNAc structures were reduced. The binding ability of thirteen lectins, AAL, LCA, LTL, ConA, NML, NPL, DBA, HAL, PTL II, WFL, ECL, GSL II and PHA-L to glycan were elevated, and a definite indication that glycan containing terminal αFuc and ± Sia-Le, core fucose, α-man, gal-β(α) GalNAc, β1,6 GlcNAc branching and tetraantennary complex oligosaccharides structures were increased. These results were further validated by lectin blot and fluorescence cell lectin-immunochemistry. Furthermore, the mRNA expression level of Mgat3 decreased while that of Mgat5, FucT8 and β3GalT5 increased. Therefore, cell surface glycan alterations in the EMT process may coincide with the expression of glycosyltransferase.

Conclusions

The findings of this study systematically clarify the alterations of cell surface glycan in cancer EMT, and may provide novel insight for HCC metastasis.

Value of highly sensitive fucosylated fraction of alpha-fetoprotein for prediction of hepatocellular carcinoma recurrence after curative treatment

BACKGROUND

The fucosylated fraction of alpha-fetoprotein (AFP-L3) has been used as a diagnostic marker for hepatocellular carcinoma (HCC). Recently, a highly sensitive immunoassay using an on-chip electrokinetic reaction and separation by affinity electrophoresis (micro-total analysis system; μTAS) has been developed.

AIM

The aim of this study was to investigate the relationship between changes in the serum AFP-L3 level measured by μTAS assay and recurrence of HCC after curative treatment.

METHODS

A total of 414 HCC patients who met the Milan criteria and underwent hepatectomy or radiofrequency ablation were investigated prospectively for the relationship between HCC recurrence and values of tumor markers.

RESULTS

There were significant differences in recurrence-free survival between groups with and without AFP-L3 elevation measured before and after treatment (p = 0.024 and p = 0.001 for before and after treatment, respectively). Multivariate analysis revealed that AFP-L3 status (p = 0.002) measured 1 month after treatment was a significant independent predictor of HCC recurrence after curative treatment.

CONCLUSIONS

Elevation of the serum AFP-L3 level before treatment is a predictor of HCC recurrence, and sustained elevation of the AFP-L3 level after treatment is an indicator of HCC recurrence. Repeated measurement of μTAS AFP-L3 should be performed for surveillance of HCC recurrence after curative treatment.

Whole-body insulin resistance is associated with elevated serum α-fetoprotein levels in patients with chronic hepatitis C

OBJECTIVE

Little is known about the relationship between elevated serum α-fetoprotein (AFP) levels and insulin resistance, which adversely influence the clinical course of chronic hepatitis C (CHC). Therefore, we investigated the association between serum AFP and insulin resistance in patients with CHC.

METHODS

We retrospectively investigated 300 patients with CHC without hepatoma who underwent liver biopsies and oral glucose tolerance tests. Patients taking antidiabetic drugs were excluded. We analyzed factors associated with elevated AFP levels (≥ 10.0 ng/mL) in 265 eligible patients. Twenty patients with a homeostasis model assessment for insulin resistance value of ≥ 2.0 and a whole-body insulin sensitivity index of <5.0 received prospective lifestyle intervention.

RESULTS

A univariate analysis showed that the body mass index, platelet count, levels of albumin, aspartate aminotransferase, alanine aminotransferase and γ-glutamyl transpeptidase, glucose metabolism, hepatic inflammation, fibrosis and steatosis were associated with elevated AFP levels. In a multivariate analysis, a platelet count of < 15 × 10(4) /μL, aspartate aminotransferase level of ≥ 50 IU/L, γ-glutamyl transpeptidase level of ≥ 35 IU/L, whole-body insulin sensitivity index of <5.0 and stage 3-4 fibrosis were independently associated with an elevated AFP level. A Bayesian Network analysis showed that the aspartate aminotransferase level, whole-body insulin sensitivity index and hepatic fibrosis were directly associated with an elevated AFP level. The lifestyle intervention significantly improved the serum AFP level, homeostasis model assessment for insulin resistance and whole-body insulin sensitivity index.

CONCLUSION

Whole-body insulin resistance is associated with an elevated serum AFP level in patients with CHC. Lifestyle interventions targeting insulin resistance can reduce the serum AFP level and may ameliorate the clinical course of CHC.

Prognostic significance of a combination of pre- and post-treatment tumor markers for hepatocellular carcinoma curatively treated with hepatectomy

BACKGROUND & AIMS

Previous studies reported that the combination of three tumor markers for hepatocellular carcinoma (HCC), alpha-fetoprotein (AFP), Lens culinaris agglutinin-reactive AFP (AFP-L3), and des-gamma-carboxy prothrombin (DCP), has the ability to discriminate survival among patients with HCC. In those studies, however, the study population included all patients with various treatment modalities, and tumor markers were measured only before treatment. We investigated the prognostic value of a combination of these tumor markers for HCC, measured before and after treatment, on survival and recurrence in patients treated with hepatectomy.

METHODS

A total of 173 patients who underwent hepatectomy for primary, non-recurrent HCC were analyzed. Tumor characteristics, postoperative survival, and recurrence rates were compared according to the number of elevated tumor markers measured before and after treatment.

RESULTS

The correlation between the number of elevated tumor markers before treatment and tumor size, rate of portal vein invasion, and tumor differentiation, respectively, was stronger than that between the number of elevated tumor markers after treatment. In contrast, the number of elevated tumor markers after treatment displayed an excellent ability to discriminate post-treatment survival and recurrence rates compared to that before treatment, and was an independent factor associated with survival and recurrence in multivariate analysis.

CONCLUSIONS

The combination of tumor markers measured after hepatectomy has a better discriminatory ability for postoperative survival and recurrence in HCC patients treated with hepatectomy in comparison to the combination of tumor markers measured before treatment.

Prediction of recurrence of hepatocellular carcinoma after curative hepatectomy using preoperative Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein

AIM

  Lens culinaris agglutinin A-reactive fraction of α-fetoprotein (AFP-L3) status has been reported to be an independent prognostic factor in patients with hepatocellular carcinoma (HCC). In this study, we evaluated the clinical usefulness of measuring preoperative AFP-L3 to predict the recurrence and prognosis of HCC after curative hepatectomy.

METHODS

  One hundred and forty-two HCC patients who underwent curative hepatectomy were examined for the correlation between preoperative tumor marker, including AFP, des-γ-carboxy prothrombin (DCP) and AFP-L3, and clinicopathological variables. The prognostic factors of disease-free survival rates and overall survival rates were also determined using clinicopathological variables including these three tumor markers.

RESULTS

  There were similar tendencies in the relationship between these three markers and malignant behaviors including lower grade tumor differentiation or vascular invasion. In multivariate analysis, increased AFP-L3 value (P = 0.019) was found to be an independent prognostic factor of disease-free survival after curative hepatectomy. In addition, elevated DCP (P = 0.013) and AFP-L3 values (P = 0.012) were found to be independent prognostic factors. Furthermore, the preoperative AFP-L3 value in the patients with early recurrence (within 1 year after hepatectomy) was significantly higher than that in those without early recurrence (26.9 ± 19.5 % vs 14.2 ± 19.8 %, P = 0.047).

CONCLUSION

  Preoperative AFP-L3 value was strongly correlated to disease-free and overall survival rate and the timing of recurrence, so it appears that it would be useful to predict the recurrence and prognosis of HCC after curative hepatectomy.

Lens culinaris agglutinin-reactive fraction of AFP is a useful prognostic biomarker for survival after repeat hepatic resection for HCC

BACKGROUND AND AIM

Repeat hepatic resection for recurrent hepatocellular carcinoma (HCC) is effective in improving long-term outcome in selected patients. In the present study, we attempted to identify the prognostic factors influencing overall and recurrence-free survival after the second hepatic resection.

METHODS

From 1 September 1997 to 30 September 2009, 329 consecutive patients with HCC underwent surgical exploration at Yamanashi University Hospital, Japan. Of these, 35 patients underwent curative, second hepatic resection. The survival results in the 35 patients were analyzed retrospectively, and prognostic factors were determined.

RESULTS

The univariate analysis revealed that Child-Pugh B, a Lens culinaris agglutinin-reactive fraction of α-fetoprotein (AFP-L3) value more than 15%, and multiple tumors, were associated with significantly worse overall survival (P=0.010, P=0.0003, and P=0.037, respectively) and only AFP-L3 >15% was associated with significantly worse recurrence-free survival after the second hepatic resection (P=0.008). By multivariate analysis, only AFP-L3 >15% was an independent predictor of adverse overall survival. The 1-, 3-, and 5-year survival rates after the second hepatic resection of 27 HCC patients with low AFP-L3 (≤15%) were 100%, 100%, and 91.7%, respectively, whereas the corresponding survival rates of eight HCC patients with high AFP-L3 (>15%) were 100%, 47.6%, and 23.8%, respectively.

CONCLUSIONS

The preoperative AFP-L3 level was a useful prognostic biomarker for survival after repeat hepatic resection.

A comparative evaluation of Golgi protein-73, fucosylated hemopexin, α-fetoprotein, and PIVKA-II in the serum of patients with chronic hepatitis, cirrhosis, and hepatocellular carcinoma

BACKGROUND

Golgi protein-73 (GP73) and fucosylated proteins have been proposed as potential serum markers for liver disease and/or hepatocellular carcinoma (HCC). The purpose of this study was to compare the sensitivity and specificity of serum GP73 and fucosylated hemopexin (Fuc-HPX) with α-fetoprotein (AFP) and with protein induced by the absence of vitamin K or antagonist-II (PIVKA-II) for diagnosing chronic hepatitis, cirrhosis, and HCC.

METHODS

The concentration of GP73 in human sera was determined using an enzyme-linked immunosorbent assay employing mouse monoclonal and rabbit polyclonal GP73 antibodies. Fuc-HPX was detected using a lectin chemiluminescence-linked immunosorbent assay using a mouse monoclonal anti-hemopexin antibody and Aleuria aurantia lectin. A total of 229 serum samples from patients with chronic hepatitis, cirrhosis, and HCC, as well as from normal individuals were evaluated using these four markers.

RESULTS

GP73 and Fuc-HPX showed significantly higher values in samples from patients with cirrhosis and HCC than in samples from patients with hepatitis and from normal individuals. The areas under the curves (AUCs) for GP73, Fuc-HPX, AFP, and PIVKA-II were 0.90, 0.77, 0.74, and 0.88, respectively, for liver cirrhosis and HCC samples vs. hepatitis and normal samples. The AUCs of GP73, Fuc-HPX, AFP, and PIVKA-II were 0.78, 0.72, 0.81, and 0.90, respectively, for HCC samples vs. all other samples.

CONCLUSIONS

PIVKA-II showed superior sensitivity and specificity for HCC compared with the other three markers. GP73 may be useful for detecting cirrhosis as a risk factor for HCC. Fuc-HPX showed inferior sensitivity and specificity compared to the other markers.

Alterations of glycan branching and differential expression of sialic acid on alpha fetoprotein among hepatitis patients

The level of serum glycoproteins and their glycosylation pattern change in liver diseases including hepatocellular carcinoma (HCC). Some of them, especially alpha fetoprotein (AFP), serve as useful biomarkers for HCC. The present investigation showed high level of AFP in hepatitis B cirrhosis (HBV-LC) and hepatitis C cirrhosis (HCV-LC) patients. However, increase of AFP level was not significantly high in chronic hepatitis B (HBV-CH) as determined by ELISA using monoclonal anti-human AFP (mAb-AFP). The differential expression of sialic acid linkage was observed in HBV-CH and HCV-LC by ELISA; the former bound strongly with Sambucus nigra agglutinin (SNA), which has exclusive binding specificity for NeuAcα2-6-, whereas HCV-LC reacted preferably with Maackia amurensis agglutinin (MAA) which recognizes NeuAcα2-3-. There was significantly high glycan branching in HBV-LC and HCV-LC in comparison to controls as illustrated by concanavalin A. This was further confirmed by Phaseolus vulgaris erythroagglutinin (E-PHA) and Datura stramonium agglutinin (DSA). Enhanced fucosylation of AFP was observed in HBV-LC, HCV-LC and HCC patients by ELISA using fucose binding Aleuria aurantia lectin; however, maximum binding was found in HCC. Fucosylation with α1-6 linkage was further confirmed by Lens culinaris agglutinin (LCA). From the above results it is concluded that the changes in concentration of AFP, differential expression of sialic acid, increase of glycan branching and fucosylation have a prognostic value of hepatitis and it could be possible that lectin-based assay with AFP can aid in diagnosis of hepatitis diseases besides clinical examination and routine laboratory investigation.

Clinical advantage of highly sensitive on-chip immunoassay for fucosylated fraction of alpha-fetoprotein in patients with hepatocellular carcinoma

BACKGROUND

Alpha-fetoprotein (AFP) has been widely used as a diagnostic master for hepatocellular carcinoma (HCC), and the fucosylated fraction of AFP (AFP-L3) has been reported to be a specific marker for HCC. However, AFP-L3 has not always been reliable in cases with low serum AFP concentrations. Recently, a novel automated immunoassay for AFP-L3, the micro-total analysis system (μ-TAS), has been developed.

AIM

The aim of this study is to evaluate the clinical usefulness of μ-TAS AFP-L3.

METHODS

Serum AFP-L3 was measured in 295 patients with HCC and in 350 with benign liver diseases. The diagnostic accuracy of μ-TAS AFP-L3 was compared with that of the conventional assay (liquid-phase binding assay; LiBASys). The relationship between μ-TAS AFP-L3 and clinical features was investigated.

RESULTS

When the cutoff value was set at 7%, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of μ-TAS AFP-L3 were 60.0%, 90.3%, 76.4%, 83.9%, and 72.8%, respectively. Its sensitivity was particularly good (41.1%) in HCC subgroups with lower AFP concentrations (<20 ng/ml). The positivity rates for μ-TAS AFP-L3 were higher at each tumor stage than those of LiBASys AFP-L3 (μ-TAS/LiBASys: stage I, 44.2%/16.3%; stage II, 52.9%/37.5%; stage III, 66.4%/44.5%; stage IV, 82.8%/65.5%).

CONCLUSIONS

μ-TAS AFP-L3 is more sensitive for discriminating HCC than the conventional LiBASys AFP-L3, particularly in subgroups with lower AFP concentrations and early-stage HCC.

Linkage specific fucosylation of alpha-1-antitrypsin in liver cirrhosis and cancer patients: implications for a biomarker of hepatocellular carcinoma

Background

We previously reported increased levels of protein-linked fucosylation with the development of liver cancer and identified many of the proteins containing the altered glycan structures. One such protein is alpha-1-antitrypsin (A1AT). To advance these studies, we performed N-linked glycan analysis on the five major isoforms of A1AT and completed a comprehensive study of the glycosylation of A1AT found in healthy controls, patients with hepatitis C- (HCV) induced liver cirrhosis, and in patients infected with HCV with a diagnosis of hepatocellular carcinoma (HCC).

Methodology/Principal Findings

Patients with liver cirrhosis and liver cancer had increased levels of triantennary glycan-containing outer arm (α-1,3) fucosylation. Increases in core (α-1,6) fucosylation were observed only on A1AT from patients with cancer. We performed a lectin fluorophore-linked immunosorbent assay using Aleuria Aurantia lectin (AAL), specific for core and outer arm fucosylation in over 400 patients with liver disease. AAL-reactive A1AT was able to detect HCC with a sensitivity of 70% and a specificity of 86%, which was greater than that observed with the current marker of HCC, alpha-fetoprotein. Glycosylation analysis of the false positives was performed; results indicated that these patients had increases in outer arm fucosylation but not in core fucosylation, suggesting that core fucosylation is cancer specific.

Conclusions/Significance

This report details the stepwise change in the glycosylation of A1AT with the progression from liver cirrhosis to cancer and identifies core fucosylation on A1AT as an HCC specific modification.

Fucosylated fraction of alpha-fetoprotein as a predictor of prognosis in patients with hepatocellular carcinoma after curative treatment

AIM

The aim of this study was to evaluate the clinical usefulness of measuring the Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) for prognostic predictor in patients with hepatocellular carcinoma (HCC).

METHODS

A total of 477 HCC patients who underwent percutaneous ablative therapy or hepatectomy were enrolled. Overall survival and recurrence-free survival were respectively evaluated retrospectively and prospectively. Multivariate analyses of clinical prognostic factors were performed by Cox's stepwise proportional hazard model.

RESULTS

AFP-L3 status was a statistically significant independent prognostic factor of long-term survival (P = 0.013) and recurrence-free survival (P = 0.006) in patients who underwent percutaneous ablative therapy. In contrast, AFP-L3 did not affect prognosis in patients who underwent hepatectomy.

CONCLUSIONS

AFP-L3 had different impacts on prognosis in patients with HCC who underwent percutaneous ablative therapy and hepatectomy. Our results suggest that AFP-L3 positivity (>or=15%) might be a promising indicator for choosing therapeutic modalities in HCC patients.

Genomic and proteomic biomarkers for diagnosis and prognosis of hepatocellular carcinoma

Hepatocellular carcinoma is one of the most deadly liver malignancies found worldwide, with hepatitis virus infection being the prominent risk factor for this lesion. Patients with hepatocellular carcinoma are usually first diagnosed when in the advanced stage; thus, long-term clinical outcomes are poor and patients have limited treatment options. Currently, surveillance of hepatocellular carcinoma relies upon serological testing of alpha-fetoprotein levels and hepatic ultrasonography, which have low sensitivity and specificity, and are sometimes operator-dependent, respectively. Therefore, discovery of new biomarkers for early and accurate detection of hepatocellular carcinoma would be of great clinical value. Genomic and proteomic approaches are two major laboratory platforms for the identification of candidate hepatocellular carcinoma biomarkers based on profiling and validating with tumor and nontumor clinical samples. Frequently, these diagnostic markers have been found in association with genetic aberrations, protein-level alterations, post-translational modifications and immune functions. With the discovery of these biomarkers, earlier detection of hepatocellular carcinoma in high-risk subjects (e.g., cirrhosis and hepatitis carriers) becomes possible, which will enable clinicians to offer patients better clinical management and more effective treatment modalities.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for use of tumor markers in liver, bladder, cervical, and gastric cancers

BACKGROUND

Updated National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.

METHODS

Published reports relevant to use of tumor markers for 4 cancer sites--liver, bladder, cervical, and gastric--were critically reviewed.

RESULTS

Alpha-fetoprotein (AFP) may be used in conjunction with abdominal ultrasound for early detection of hepatocellular carcinoma (HCC) in patients with chronic hepatitis or cirrhosis associated with hepatitis B or C virus infection. AFP concentrations >200 microg/L in cirrhotic patients with typical hypervascular lesions >2 cm in size are consistent with HCC. After a diagnosis of HCC, posttreatment monitoring with AFP is recommended as an adjunct to imaging, especially in the absence of measurable disease. Although several urine markers have been proposed for bladder cancer, none at present can replace routine cystoscopy and cytology in the management of patients with this malignancy. Some may, however, be used as complementary adjuncts to direct more effective use of clinical procedures. Although carcinoembryonic antigen and CA 19-9 have been proposed for use gastric cancer and squamous cell carcinoma antigen for use in cervical cancer, none of these markers can currently be recommended for routine clinical use.

CONCLUSIONS

Implementation of these recommendations should encourage optimal use of tumor markers for patients with liver, bladder, cervical, or gastric cancers.

Novel fucosylated biomarkers for the early detection of hepatocellular carcinoma

Changes in glycosylation, most notably fucosylation, have been associated with the development of hepatocellular carcinoma (HCC). In this report, the levels of fucosylated kininogen (Fc-Kin) and fucosylated alpha-1-antitrypsin were analyzed individually and in combination with the currently used marker, alpha-fetoprotein, and a previously identified biomarker, Golgi protein 73 (GP73), for the ability to distinguish between a diagnosis of cirrhosis and HCC. This analysis was done on serum from 113 patients with cirrhosis and 164 serum samples from patients with cirrhosis plus HCC. The levels of Fc-Kin and fucosylated alpha-1-antitrypsin were significantly higher in patients with HCC compared with those with cirrhosis (P < 0.0001). Greatest performance was achieved through the combination of Fc-Kin, alpha-fetoprotein, and GP73, giving an optimal sensitivity of 95%, a specificity of 70%, and an area under the receiver operating characteristic of 0.94. In conclusion, the altered glycosylation of serum glycoproteins can act as potential biomarkers of primary HCC when used independently or in combination with other markers of HCC.

Comparative analysis of core-fucose-binding lectins from Lens culinaris and Pisum sativum using frontal affinity chromatography

Lens culinaris lectin (LCA) is a useful probe for the detection in serum of a core-fucosylated alpha-fetoprotein, called AFP-L3 fraction, which is a well-known marker for the diagnosis and prognosis of hepatocellular carcinoma. Here we performed a systematic quantitative interaction analysis of LCA and its close homolog, Pisum sativum lectin (PSA), by frontal affinity chromatography with 143 pyridylaminated (PA) glycans including a series of core-fucosylated glycans. Both lectins showed binding affinity to core-fucosylated, mono- and bi-antennary N-glycans, but not to their tri- and tetra-antennary forms, indicating that the addition of the GlcNAc residue at the N-acetylglucosaminyltransferase IV position abrogates the binding affinity. However, their specificities are distinguishable: while LCA showed the highest affinity to the core-fucosylated, agalactosylated, bi-antennary N-glycan (K(a)=1.1 x 10(5) M(-1)), PSA showed the highest affinity to the core-fucosylated, trimannosyl structure (K(a)=1.2 x 10(5) M(-1)). Glycan-binding specificities of LCA and PSA were also analyzed by glycoconjugate microarray compared to other core-fucose-binding lectins from Aspergillus oryzae (AOL) and Aleuria auratia (AAL). LCA and PSA bound specifically to core fucose, whereas AOL and AAL exhibited broad specificity to fucosylated glycans. These results explain why LCA is appropriate as a specific probe for AFP-L3, which mainly contains a core-fucosylated, biantennary N-glycan, but not its highly branched forms.

Utility of Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein and des-gamma-carboxy prothrombin, alone or in combination, as biomarkers for hepatocellular carcinoma

BACKGROUND & AIMS

Des-gamma-carboxy prothrombin (DCP) and Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) are surveillance markers used to detect hepatocellular carcinoma (HCC) in Japan. This study evaluated their utility, alone or in combination, in a North American population.

METHODS

Patients with hepatitis C virus-related cirrhosis were followed up prospectively for 2 years.

RESULTS

Of 372 patients, HCC developed in 34 of 298 who were free of HCC at entry. The overall sensitivity, specificity, and positive and negative predictive values for only AFP (>20 ng/mL) were 61%, 71%, 34%, and 88%, respectively; for only AFP-L3% (>10) were 37%, 92%, 52%, and 85%, respectively; and for only DCP (>7.5 ng/mL) were 39%, 90%, 48%, and 86%, respectively. Values increased when AFP values were combined with AFP-L3% and DCP to 77%, 59%, 32%, and 91%, respectively. Among patients with increases in AFP levels to 20 to 200 ng/mL, AFP-L3% and DCP were highly specific markers (86.6% and 90.2%, respectively). Of 29 HCC patients with AFP levels less than 20 ng/mL, 13 had increased levels of AFP-L3% or DCP. Increased alanine aminotransferase levels were associated with increased total AFP but not AFP-L3% or DCP levels. Both AFP-L3%- and DCP-positive patients showed significant differences in lower cumulative HCC-free rates compared with the overall group (P < .0001 and P = .0005, respectively).

CONCLUSIONS

AFP-L3% and DCP levels have higher correlation values with an absence of HCC, as well as a higher specificity and negative predictive value, than total AFP. Although this combination of markers only marginally improves surveillance for early HCC, it could identify individuals with negative imaging results who would benefit from follow-up evaluation.

Influence of the etiology of liver cirrhosis on the response to combined intra-arterial chemotherapy in patients with advanced hepatocellular carcinoma

PURPOSE

We have previously reported that intra-arterial chemotherapy prolongs the survival of patients with advanced HCC (aHCC); however, whether the response to intra-arterial chemotherapy depends on the etiology of underlying liver cirrhosis (LC) is still unknown.

AIM

The aim of this study was to assess any influences of the etiology of LC on the response to combined intra-arterial chemotherapy for aHCC.

METHODS

A total of 53 adult Japanese LC patients (46 men and 7 women) with aHCC were treated with combined intra-arterial chemotherapy between 2002 and 2007 at our hospital. All of the patients had a Japan Integrated Staging (JIS) score of 3 or 4. Their tumors were inoperable according to computed tomography findings. Combined intra-arterial chemotherapy was administered via the proper hepatic artery every 5 days for 4 weeks and the chemotherapy regimen was continued for as long as possible.

RESULTS

There were 15 patients with HBV infection (B-LC group), 29 patients with HCV infection (C-LC group), and nine patients with alcoholic cirrhosis (A-LC group). The percentage of patients with a complete or partial response after 4 weeks of chemotherapy was 0% in the B-LC group versus 31.0% in the C-LC group and 44.4% in the A-LC group. The survival of the A-LC and C-LC groups was significantly longer than that of the B-LC group with the median survival time being 688, 368, and 211 days, respectively.

CONCLUSIONS

Combined intra-arterial chemotherapy might be more effective for aHCC in patients with A-LC or C-LC than in patients with B-LC.

A new prognostic staging system for hepatocellular carcinoma: value of the biomarker combined Japan integrated staging score

OBJECTIVES

The Japan Integrated Staging (JIS) score has been reported to have good stratification ability in patients with hepatocellular carcinoma (HCC). However, the JIS score could not estimate malignant grade of HCC. The aim of this study was to evaluate the performance of a new staging system: the biomarker combined JIS (bm-JIS) which includes three tumor markers: alpha-fetoprotein (AFP), Lens culinaris agglutinin-reactive AFP and des-gamma-carboxy prothrombin with the conventional JIS score.

METHODS

A total of 1,924 HCC patients were included in this study. We compared their overall survival, the stratification ability and suitability as a prognostic model according to the bm-JIS score and the conventional JIS score.

RESULTS

There were significant differences between the survival curves for all bm-JIS scores. For the conventional JIS scores of 0, 1, 2 and 3, the survival curves differed greatly according to the bm-JIS score (p < 0.0001). The independent homogenizing ability and the stratification value of the JIS score and the bm-JIS score determined by the likelihood ratio test using the Cox proportional hazard regression model showed the bm-JIS score to have a higher value(chi2 = 717.348) than the JIS score (chi2 = 668.91).

CONCLUSIONS

The bm-JIS score showed superior stratification ability and thus was found to be a better predictor of the prognosis than the conventional JIS score, especially for the patients with good prognosis.

N-linked glycosylation of the liver cancer biomarker GP73

The association between elevated circulating levels of GP73 (and fucosylated GP73 in particular) and hepatocellular carcinoma suggests that a thorough analysis of the extent of GP73 glycosylation is warranted. Detailed analysis of the glycosylation patterns of such low abundance proteins are hampered by technical difficulties. Using conventional lectin affinity chromatography, we have established that three quarters of the GP73 secreted from a cell line derived from HCC is fucosylated. Using mass spectrometry, we have established that at least two of three potential sites of N-linked glycosylation are occupied on most molecules of GP73 secreted from cultured hepatoma cells. Furthermore, the oligosaccharides added to recombinant GP73 resemble those present in the bulk of secreted protein, mostly bi-antennary with core fucose, with a smaller fraction of tri- and tetra-antennary structures. The frequency of fucosylation observed on the recombinant protein agrees well with the pattern of lectin binding of the endogenous secreted protein. Finally, we have developed a method to interrogate the glycans added to either the near full length protein or at a particular sequon, providing proof of concept that a small peptide embedded in a heterologous context can preserve both fucosylation and a high level of branching of oligosaccharides added.

AFP-L3 in chronic liver diseases with persistent elevation of alpha-fetoprotein

BACKGROUND

Alpha-fetoprotein (AFP) is an important marker for hepatocellular carcinoma (HCC). However, persistent elevation of AFP is found in patients with chronic liver diseases. The value of AFP-L3, which is more specific than AFP, was examined in such patients.

METHODS

We enrolled patients without image-detectable tumor, but with transient AFP value > 900 ng/mL (group A) or with persistent AFP value > 50 ng/mL for longer than 6 months (group B). Forty-one patients with HCC and AFP value > 50 ng/mL were included as the HCC control group (group C). AFP-L3 measurement was done by lectin-affinity electrophoresis coupled with antibody-affinity blotting. The study patients were followed with AFP, liver biochemistry and abdominal ultrasound at 3- to 6-month intervals. Additional studies were done when a tumor was suspected.

RESULTS

One of 17 patients in group A and 13 of 39 patients in group B developed HCC within 2 years. When the cutoff value of AFP-L3 ratio was 15%, both the sensitivity and specificity were 71% for prediction of HCC during the next 2 years in all patients. Ninety percent of tumors larger than 5 cm had AFP-L3 > 15%, compared with only 60% for tumors smaller than 2 cm. Three patients in group A had AFP-L3 ratio > 17.5%. One patient developed HCC 10 months later; the other 2 patients were associated with hepatic failure.

CONCLUSION

AFP-L3 provides a clue in HCC detection in patients with persistent elevation of AFP. However, AFP-L3 could be highly elevated in severe hepatitis.

Proteomic analysis of serum associated fucosylated glycoproteins in the development of primary hepatocellular carcinoma

Changes in N-linked glycosylation are known to occur during the development of cancer. For example, increased branching of oligosaccharides has been associated with metastasis and has been correlated to tumor progression in human cancers of the breast, colon and melanomas. Increases in core fucosylation have also been associated with the development of hepatocellular carcinoma (HCC). Chronic infection with the hepatitis B virus is associated with more than 55% of all cases of hepatocellular carcinoma. We show here that increased levels of core fucosylation can be observed via glycan analysis of total serum and are associated with the development of HCC. In a blinded study, the serum glycoproteins derived from people diagnosed with HBV induced liver cancer were found to possess a dramatically higher level of fucosylation. This change occurs on both immunoglobulin molecules and on other serum glycoproteins. Targeted glycoproteomic analysis was used to identify those glycoproteins that are hyperfucosylated in cancer. In total, 19 proteins were found to be hyperfucosylated in cancer. The potential of these proteins as biomarkers of cancer is discussed.

An N-glycan structure correlates with pulmonary metastatic ability of cancer cells

N-Glycan structures on the surface of cancer cells have diverse structures and play significant roles in metastatic process. However, little is known about their roles in organ-selective metastasis. Our study revealed that an alpha1,6-fucosylated biantennary N-glycan structure designated A2G2F is characteristic of lungs, with far more abundant expression in normal human and murine lungs than in other organs. In this study, we further examined the role of A2G2F in pulmonary metastasis. We stained metastatic cancers by alpha1,6-fucose-specific Lens culinaris agglutinin lectin and revealed that pulmonary metastatic nodules more abundantly expressed alpha1,6-fucosylated N-glycans than hepatic metastatic nodules from common primary cancers. The most specific alpha1,6-fucosylated N-glycan structure in pulmonary metastatic cancer was identified to be A2G2F. Using a B16 melanoma cell metastasis model, we showed that A2G2F-rich B16 cells formed more pulmonary metastatic nodules than A2G2F-poor cells. Our results suggest that A2G2F plays a critical role in pulmonary metastasis.

Long-term outcomes of hepatectomy vs percutaneous ablation for treatment of hepatocellular carcinoma ≤ 4 cm

AIM: To determine which treatment modality - hepatectomy or percutaneous ablation - is more beneficial for patients with small hepatocellular carcinoma (HCC) (≤ 4 cm) in terms of long-term outcomes.

METHODS: A retrospective analysis of 149 patients with HCC ≤ 4 cm was conducted. Eighty-five patients underwent partial hepatectomy (anatomic in 47 and non-anatomic in 38) and 64 underwent percutaneous ablation (percutaneous ethanol injection in 37, radiofrequency ablation in 21, and microwave coagulation in 6). The median follow-up period was 69 mo.

RESULTS: Hepatectomy was associated with larger tumor size (P < 0.001), whereas percutaneous ablation was significantly associated with impaired hepatic functional reserve. Local recurrence was less frequent following hepatectomy (P < 0.0001). Survival was better following hepatectomy (median survival time: 122 mo) than following percutaneous ablation (median survival time: 66 mo; P = 0.0123). When tumor size was divided into ≤ 2 cm vs > 2 cm, the favorable effects of hepatectomy on long-term survival was seen only in patients with tumors >2 cm (P = 0.0001). The Cox proportional hazards regression model revealed that hepatectomy (P = 0.006) and tumors ≤ 2 cm (P = 0.017) were independently associated with better survival.

CONCLUSION: Hepatectomy provides both better local control and better long-term survival for patients with HCC ≤ 4 cm compared with percutaneous ablation. Of the patients with HCC ≤ 4 cm, those with tumors > 2 cm are good candidates for hepatectomy, provided that the hepatic functional reserve of the patient permits resection.

Prognostic significance of simultaneous measurement of three tumor markers in patients with hepatocellular carcinoma

BACKGROUND & AIMS

We conducted a prospective study to evaluate the significance of simultaneous measurement of 3 currently used tumor markers in the evaluation of tumor progression and prognosis of patients with hepatocellular carcinoma (HCC).

METHODS

Three tumor markers for HCC, alpha-fetoprotein (AFP), Lens culinaris agglutinin A-reactive fraction of AFP (AFP-L3), and des-gamma-carboxy prothrombin (DCP), were measured in the same serum samples obtained from 685 patients at the time of initial diagnosis of HCC. Positivity for AFP >20 ng/dL, AFP-L3 >10% of total AFP, and/or DCP >40 mAU/mL was determined. In addition, tumor markers were measured after treatment of HCC.

RESULTS

Of the 685 patients, 337 (55.8%) were positive for AFP, 206 (34.1%) were positive for AFP-L3, and 371 (54.2%) were positive for DCP. In a comparison of patients positive for only 1 tumor marker, patients positive for AFP-L3 alone had a greater number of tumors, whereas patients positive for DCP alone had larger tumors and a higher prevalence of portal vein invasion. When patients were compared according to the number of tumor markers present, the number of markers present clearly reflected the extent of HCC and patient outcomes. The number of markers present significantly decreased after treatment.

CONCLUSIONS

Tumor markers AFP-L3 and DCP appear to represent different features of tumor progression in patients with HCC. The number of tumor markers present could be useful for the evaluation of tumor progression, prediction of patient outcome, and treatment efficacy.

Serological markers of liver cancer

Serological markers for hepatocellular carcinoma (HCC) are important for early diagnosis, as well as monitoring of tumour aggressiveness, treatment responsiveness, recurrence and survival. The three most common markers are total alpha-fetoprotein (AFP), Lens culinaris agglutinin-reactive AFP (AFP-L3) and protein induced by vitamin K absence or antagonist-II (PIVKA-II). Total AFP has the sensitivity of 60% and specificity of 90% for the detection of HCC. Increase in the percentage of AFP-L3 over the total AFP (>10%) is very specific for small HCC. PIVKA-II is also more specific than total AFP in detecting HCC. AFP-L3 and PIVKA-II levels correlate with tumour aggressiveness and prognosis. All three markers are useful for monitoring treatment responsiveness and tumour recurrence. Since the levels of the three markers are independent of each other, combination of measurement of two or three markers will increase the sensitivity and diagnostic accuracy. Some novel markers including glypican-3 are being extensively studied.

Use of targeted glycoproteomics to identify serum glycoproteins that correlate with liver cancer in woodchucks and humans

Chronic infection with hepatitis B virus (HBV) is associated with the majority of hepatocellular carcinoma (HCC). The diagnosis of HCC is usually made in the late stages of the disease, when treatment options are limited and prognosis is poor. We therefore have developed a method of glycoproteomic analysis in an attempt to discover serum markers that can assist in the early detection of HBV-induced liver cancer. Briefly, a comparative method for analysis of oligosaccharides released from serum glycoproteins and for recovery and identification of proteins with aberrant glycosylation, as a function of cancer diagnosis, is described. The model we have used is the woodchuck (Marmota monax), which shares similarities in the glycosylation pattern associated with liver proteins in human HCC. In this report, we show that woodchucks diagnosed with HCC have dramatically higher levels of serum-associated core alpha-1,6-linked fucose, as compared with woodchucks without a diagnosis of HCC. The coupling of this methodology with 2D gel proteomics has permitted the identification of several glycoproteins with altered glycosylation as a function of cancer. One such glycoprotein, Golgi Protein 73 (GP73), was found to be elevated and hyperfucosylated in animals with HCC. Further, the study showed GP73 to be elevated in the serum of people with a diagnosis of HCC, providing a validation of our approach. The potential of this technology for biomarker discovery and the implications of increased levels of GP73 in liver cancer are discussed.