Alpha-fetoprotein enhances the proliferation of human hepatoma cells in vitro

Targeted therapy of cancer stem cells: inhibition of mTOR in pre-clinical and clinical research

Cancer stem cells (CSCs) are a type of stem cell that possesses not only the intrinsic abilities of stem cells but also the properties of cancer cells. Therefore, CSCs are known to have self-renewal and outstanding proliferation capacity, along with the potential to differentiate into specific types of tumor cells. Cancers typically originate from CSCs, making them a significant target for tumor treatment. Among the related cascades of the CSCs, mammalian target of rapamycin (mTOR) pathway is regarded as one of the most important signaling pathways because of its association with significant upstream signaling: phosphatidylinositol 3‑kinase/protein kinase B (PI3K/AKT) pathway and mitogen‑activated protein kinase (MAPK) cascade, which influence various activities of stem cells, including CSCs. Recent studies have shown that the mTOR pathway not only affects generation of CSCs but also the maintenance of their pluripotency. Furthermore, the maintenance of pluripotency or differentiation into specific types of cancer cells depends on the regulation of the mTOR signal in CSCs. Consequently, the clinical potential and importance of mTOR in effective cancer therapy are increasing. In this review, we demonstrate the association between the mTOR pathway and cancer, including CSCs. Additionally, we discuss a new concept for anti-cancer drug development aimed at overcoming existing drawbacks, such as drug resistance, by targeting CSCs through mTOR inhibition.

AFP-HSP90 mediated MYC/MET activation promotes tumor progression in hepatocellular carcinoma and gastric cancers

Alpha-fetoprotein (AFP) elevation is a well-known biomarker in various diseases, particularly in the diagnosis of hepatocellular carcinoma (HCC). Intracellular AFP has been previously implicated in promoting tumorigenesis. In this study, we discovered that AFP enhances the stability of oncoproteins c-MYC and c-MET, thereby facilitating the progression of liver and gastric tumors. Our findings suggest that AFP acts by stabilizing these oncoproteins, which are clients of heat shock protein 90 (HSP90), and prevents their degradation through ubiquitination. Intriguingly, we identified AFP as a novel co-chaperone of HSP90, demonstrating its ability to regulate the stabilization of HSP90 client proteins. Furthermore, our results indicate that inhibiting AFP or HSP90 enhances the cytotoxicity of chemotherapeutic agents in AFP-producing HCC and gastric cancer cells. These findings have significant implications for the development of therapeutic strategies targeting AFP-producing tumors, as the AFP-HSP90-mediated activation of c-MYC and c-MET provides new insights into potential treatment approaches. In summary, this study sheds light on the role of AFP in promoting tumor progression by stabilizing oncoproteins through its interaction with HSP90. The identification of this mechanism opens up new avenues for therapeutic interventions in AFP-producing tumors.

Pregnane X receptor (PXR) deficiency promotes hepatocarcinogenesis via induction of Akr1c18 expression and prostaglandin F2α (PGF2α) levels

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Pregnane X receptor (PXR), a xenobiotic-sensing nuclear receptor, plays a critical role in the metabolism of endogenous and exogenous substances in the liver. Here, we investigate whether PXR plays a role in pathogenesis of HCC. We show that liver tumors were developed in diethylnitrosamine (DEN)-treated in PXR knockout (KO) mice. Hepatic levels of prostaglandin F2α (PGF2α) and aldo-keto reductase family 1 member C18 (Akr1c18), a prostaglandin synthase of catalyzing reduction of PGH2 to PGF2α, were significantly elevated in DEN-treated PXR KO mice. Hepatic mRNA levels of alpha fetoprotein (AFP), cyclin D1 (Ccnd1), fibroblast growth factor 21 (FGF21), and inflammatory cytokine interleukin 6 (IL-6) were significantly increased in DEN-treated PXR KO mice. Other members of Akr1c family, liver metabolizing enzymes including Cyp1a2, Cyp2b10 and Cyp3a11, and bile acid synthesis enzyme Cyp7a1 mRNA levels were significantly decreased in DEN-treated PXR KO mice. Our findings revealed that PXR deficiency promoted DEN-induced HCC in mice via induction of Akr1c18 expression and PGF2α levels and the increased PGF2α levels synthetized by Akr1c18 enhanced hepatocytes proliferation and induced inflammatory cytokine production, which accelerated liver tumor development after DEN treatment, suggesting that PXR deficiency may create a microenvironment that is more prone to DEN-induced liver tumors and targeting PXR and Akr1c18 to reduce PGF2α biosynthesis may be a potential and novel therapeutic strategy for HCC.

Elevated serum alpha-fetoprotein levels are associated with poor prognosis of hepatocellular carcinoma after surgical resection: A systematic review and meta-analysis

BACKGROUND AND STUDY AIMS

The relationship between the alpha-fetoprotein (AFP) level and the prognosis of hepatocellular carcinoma (HCC) after surgical resection remains unknown. This study aims to assess this relationship.

PATIENTS AND METHODS

PubMed and Web of Science were systematically utilised. Meta-analysis was conducted for the outcomes of the recurrence-free survival (RFS) and the overall survival (OS) by comparing the high AFP group with the low AFP group.

RESULTS

The studies included 61 manuscripts with 35,461 patients. The summary hazard ratio (HR) for RFS was 1.501 (95% CI 1.355-1.662; Z = 7.81, P < 0.00001) when comparing the high AFP group with the low AFP group. Sensitivity analysis only included adjusted HRs, with the summary HR being 1.563 (95% CI 1.381-1.768; Z = 7.10, P < 0.00001). The summary HR for OS was 1.565 (95% CI 1.439-1.701; Z = 10.52, P < 0.00001) when comparing two AFP groups. Sensitivity analysis showed that the summary HR was 1.611 (95% CI 1.456-1.782; Z = 9.24, P < 0.00001).

CONCLUSION

Our meta-analysis indicated that elevated serum AFP levels are associated with poor prognosis of HCC after surgical resection.

URRENT CONCEPT OF THE STRUCTURAL AND FUNCTIONAL PROPERTIES OF ALFA-FETOPROTEIN AND THE POSSIBILITIES OF ITS CLINICAL APPLICATION

This paper was aimed to review the literature data from native and foreign sources accumulated for 40-years period of research of the features of the molecular structure, functions, production and application of human alpha-fetoprotein (AFP), which is known as one of the most studied and increasingly demanded proteins. Results of fundamental studies performed with the use of modern methods, including various types of electrophoresis, chromatography, electron microscopy and immunoassay, in order to characterize the principal physicochemical capacities and localization of free and bound forms of AFP, as well as polypeptide structure, heterogeneity and topography of AFP receptors are highlighted here. The data on the mechanisms of AFP synthesis, its conformational features, binding sites and intracellular metabolism are also presented. The concepts of physiological functions and mechanisms of AFP transport in an organism are presented. Data on AFP isolation from the natural primary products and its production by means of recombinant and synthetic methods are shown. This review also summarizes information on the current possibilities of clinical application of AFP and the prospects for its usage in anticancer therapy for targeted delivery of chemotherapy drugs, with emphasis on the description of the recent progress in this field.

Stereotactic radiotherapy for hepatocellular carcinoma induced by hepatitis C and the relationships of changes in carbohydrate antigen 19-9 with AFP and PIVKA-II

PURPOSE

Assessing the therapeutic effects of stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC) takes time. Purpose of our study was to explore the relationships of changes in carbohydrate antigen 19-9 (CA 19-9) with those in the existing markers alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II).

PATIENTS AND METHODS

The subjects were 16 patients who underwent SBRT for solitary HCC ≤3cm induced by hepatitis C between June 2016 and July 2019. Observation periods ranged from 8-43 (median: 28) months, ages from 59-85 (median: 65) years.

RESULTS

Changes in CA 19-9 levels after SBRT were categorised into three patterns: 1) a transient elevation followed by a decline (75%); 2) a transient decline followed by an elevation (18.8%); and 3) no change (6.3%). Among patients showing a transient CA 19-9 elevation followed by a decline, which was the most frequent pattern, 75% showed these changes in synchronisation with AFP and preceded the changes in PIVKA-II, while in the other 25%, CA 19-9 changes were in synchronisation with PIVKA-II and preceded those in AFP. At the time of recurrence, 62.5% showed a continuous CA 19-9 elevation, either in synchronisation with other markers or by itself.

CONCLUSIONS

This is the first investigation of changes in CA 19-9 levels after SBRT for HCC induced by hepatitis C. Characteristic changes in CA 19-9, AFP, and PIVKA-II levels were observed as responses after treatment. As for its correlations with tumour markers, the acute responses of PIVKA-II tended to be slower than those of CA 19-9 and AFP. Although the sample size was small, our findings raise the possibility that measuring these 3 biomarkers after SBRT may be useful for monitoring patients for HCC recurrence.

Changes in Tumor Markers and Their Implications in Selecting Liver Transplantation for Patients With Hepatocellular Carcinoma

BACKGROUND AND AIM

It has been suggested that tumor markers can provide additional information over tumor size and number-based liver transplantation (LT) criteria. We aimed to assess if changes in tumor markers are associated with the risk of tumor recurrence after LT for hepatocellular carcinoma (HCC) who received loco-regional therapies (LRTs).

METHODS

A total of 129 patients who received LT with pre-LT LRTs for HCC were analyzed. Milan criteria and tumor markers, alpha-fetoprotein, and protein induced by vitamin K antagonist II, at diagnosis and at transplant were assessed. The primary outcome was tumor recurrence.

RESULTS

When patients were stratified by radiologic criteria, cumulative recurrence rates at 3 years for patients who were not down-staged (outside Milan to outside Milan), progressed (within Milan to outside Milan), down-staged (outside Milan to within Milan), and bridged (within Milan to within Milan) were 66.7%, 58.3%, 18.7%, and 8.5%, respectively (P < .001). Among patients who were transplanted within Milan criteria at transplant (n = 113), cumulative recurrence rates at 3 years were highest for those with persistently high tumor markers (high to high, 21.7%), followed by those with increase in tumor markers (low to high, 11.1%), those with normalization of tumor markers (high to low, 5.6%), and those with persistently low tumor markers (low to low, 0%), respectively, after LRTs (P = .035).

CONCLUSIONS

Changes of tumor markers can provide additional information on the risk of recurrence after LT among HCC patients who received LRTs, indicating that they could be used to refine current LT selection criteria.

Biology and significance of alpha-fetoprotein in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related deaths globally due, in part, to the majority of patients being diagnosed with intermediate or advanced stage disease. Our increased understanding of the heterogeneous molecular pathogenesis of HCC has led to significant developments in novel targeted therapies. Despite these advances, there remains a high unmet need for new treatment options. HCC is a complex disease with multiple pathogenic mechanisms caused by a variety of risk factors, making it difficult to characterize with a single biomarker. In fact, numerous biomarkers have been studied in HCC, but alpha-fetoprotein (AFP) remains the most widely used and accepted serum marker since its discovery over 60 years ago. This review summarizes the most relevant studies associated with the regulation of AFP at the gene and protein levels; the pathophysiology of AFP as a pro-proliferative protein; and the correlation of AFP with molecular HCC subclasses, the vascular endothelial growth factor pathway and angiogenesis. Also described are the historical and current uses of AFP for screening and surveillance, diagnosis, its utility as a prognostic and predictive biomarker and its role as a tumour antigen in HCC. Taken together, these data demonstrate the relevance of AFP for patients with HCC and identify several remaining questions that will benefit from future research.

Microcantilever Array Biosensor for Simultaneous Detection of Carcinoembryonic Antigens and α-Fetoprotein Based on Real-Time Monitoring of the Profile of Cantilever

A microcantilever array biosensor based on a sandwich structure has been developed for simultaneously measuring two biomarkers carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) via an optical readout technique-real-time monitoring of the profile of cantilever. First, the aptamers of CEA and AFP were self-assembled on their respective cantilevers. After the adsorption of the mixture of CEA and AFP, further specific interaction was performed via the addition of the antibodies specific to each target. The compressive stress on the cantilever was generated by the aptamer-antigen-antibody sandwich structure formed on the gold surface, resulting in cantilever bending. The profile of cantilever could be monitored in real time. The relationship between the deflection value at the 90% position of the cantilever and the target concentration served as a calibration curve, and the detection sensitivity was 1.3 ng/mL for CEA and 0.6 ng/mL for AFP, respectively. This work demonstrated the ability of simultaneously measuring two biomarkers via a microcantilever array biosensor, giving great potential for further application in detecting several targets simultaneously for early clinical diagnosis.

Celastrol delays hepatic steatosis and carcinogenesis in a rapid AKT/c-Met-transfected hepatocellular carcinoma model via suppressing fatty acid synthase expression and AKT/ERK phosphorylation

Although the suppressing effects of celastrol on hepatocellular carcinoma (HCC) have been demonstrated, evidence for the targeting of fatty acid synthetase (FASN) in the development of HCC by celastrol is still rare. In this study, the effect of celastrol on a rapid HCC model featuring co-activation of AKT/c-Met oncogenes in mice was studied. The effect of celastrol on the alpha-fetoprotein level in the liver and serum was also investigated. Protein expressions of PCNA, Ki67 and FASN in celastrol-treated AKT/c-Met HCC mice were observed. The molecular mechanism of celastrol on the AKT/c-Met signaling pathway was elucidated. The results revealed that celastrol significantly repressed the AKT/c-Met induced HCC development and down-regulated the mRNA expression of AFP in the liver and the AFP level in serum. Furthermore, the expression of proliferation-associated proteins in the HCC tissues was reduced by celastrol treatment. Moreover, the abundant steatosis that resulted from FASN accumulation in the liver in AKT/c-Met mice was also attenuated. Finally, the phosphorylation of AKT and ERK1/2 in HCC mice was repressed by celastrol treatment. Overall, our data demonstrate that celastrol exerts an antiproliferative and novel lipid-decreasing effect by targeting AKT/ERK and FASN in HCC development in vivo.

Dynamic noninvasive markers predict hepatocellular carcinoma in chronic hepatitis C patients without sustained virological response after interferon-based therapy: Prioritize who needs urgent direct-acting antiviral agents

Some patients with hepatitis C virus (HCV) infections who fail to achieve sustained virological responses (SVRs) after interferon (IFN) therapy do not develop hepatocellular carcinoma (HCC). Risk stratification of these patients may help identify those who would benefit most from treatment with direct-acting antivirals (DAAs).A total of 552 HCV-infected patients with non-SVR status were enrolled. Laboratory data before and after IFN treatment were analyzed to determine the relationship of changes in serum markers with development of HCC during the 7-year study period.HCC developed in 93 patients. The risk factors for HCC were pre-existing liver cirrhosis, low hemoglobin level at baseline, low pretreatment platelet count, high post-treatment alpha-fetoprotein (AFP) level (≥15 ng/mL), and high post-treatment Fibrosis 4 (FIB4) index (>3.25). For patients without pre-existing cirrhosis, those with high post-treatment AFP level and FIB4 index had the highest risk of HCC (1 year: 6.7%; 3 years: 10.9%; 5 years: 29.7%), followed by those with high post-treatment AFP level and low post-treatment FIB4 index (5 years: 25%), and those with low post-treatment AFP level and high post-treatment FIB4 index (1 year: 3.7%; 3 years: 5.2%; 5 years: 10.6%). The risk was even lower for patients with low post-treatment AFP level and FIB4 index (1 year: 0%; 3 years: 0.4%; 5 years: 2.5%). None of the patients with FIB4 indexes consistently below 1.45 developed HCC.The combined use of post-treatment AFP level and FIB4 index was useful for risk stratification of HCV-infected patients with non-SVR status after IFN therapy. These data may help clinicians to identify patients who most urgently need DAA treatment.

Graphene and the immune system: Challenges and potentiality

In the growing area of nanomedicine, graphene-based materials (GBMs) are some of the most recent explored nanomaterials. For the majority of GBM applications in nanomedicine, the immune system plays a fundamental role. It is necessary to well understand the complexity of the interactions between GBMs, the immune cells, and the immune components and how they could be of advantage for novel effective diagnostic and therapeutic approaches. In this review, we aimed at painting the current picture of GBMs in the background of the immune system. The picture we have drawn looks like a cubist image, a sort of Picasso-like portrait looking at the topic from all perspectives: the challenges (due to the potential toxicity) and the potentiality like the conjugation of GBMs to biomolecules to develop advanced nanomedicine tools. In this context, we have described and discussed i) the impact of graphene on immune cells, ii) graphene as immunobiosensor, and iii) antibodies conjugated to graphene for tumor targeting. Thanks to the huge advances on graphene research, it seems realistic to hypothesize in the near future that some graphene immunoconjugates, endowed of defined immune properties, can go through preclinical test and be successfully used in nanomedicine.

Does alpha-fetoprotein contribute to the mortality and morbidity of human hepatocellular carcinoma? A commentary

The fifth most common cancer worldwide is hepatocellular carcinoma (HCC), while being the third leading cause of global cancer-related deaths. Although HCC incidence is less frequent in North America, it is a common malignancy in Asia and Africa associated with a high rate of mortality and morbidity due to ineffective therapies against cancer growth, invasion, and metastasis. It is well established that serum alpha-fetoprotein (AFP) is the "gold standard" biomarker for liver cancer; however, less known are the biological activities of AFP regarding carcinogenesis, growth, proliferation, and metastasis. Clinicians are well aware that increasing AFP serum levels parallel disease progression of HCC patients, but many are less knowledgeable in the lethal growth-promoting properties of AFP as an autocrine stimulator of hepatoma cell proliferation. This commentary addresses the mortality and morbidity concerning AFP in the genesis, growth, progression, and spread of HCC and emphasizes the perilous consequences of AFP-supported growth in human liver cancer even after liver resection and transplantation. Thus, AFP is not just a biomarker for HCC but also an ardent promoter of liver cancer growth and progression.

Dynamic α-fetoprotein, platelets and AST-to-platelet ratio index predict hepatocellular carcinoma in chronic hepatitis C patients with sustained virological response after antiviral therapy

BACKGROUND

Hepatitis C virus (HCV)-infected patients who achieve viral eradication may still develop hepatocellular carcinoma (HCC). Little is known about the impact of dynamic change of serum markers on HCC development.

METHODS

We enrolled 1351 HCV-infected patients who achieved sustained virological response (SVR). Laboratory data were collected at least 1 year after IFN-based therapy and to the latest follow-up. Data on α-fetoprotein (AFP) were obtained >6 months prior to HCC development to exclude HCC-related AFP elevation.

RESULTS

HCC developed in 49 patients. Risk factors for HCC in SVR patients were old age, liver cirrhosis, higher pre- and post-treatment AFP and high post-treatment AST-to-platelet ratio index (APRI). Patients with pre-AFP ≥15 ng/mL → post-AFP ≥15 ng/mL (at 1 year, 23.1%; 5 years, 42.3%) and pre-AFP <15 ng/mL → post-AFP ≥15 ng/mL (at 1 year, 25%; 5 years, 50%) had the highest risk of HCC development, followed by pre-AFP ≥15 ng/mL → post-AFP <15 ng/mL (at 1 year, 5.2%; 5 years, 7.6%) and pre-AFP <15 ng/mL → post-AFP ng/mL <15 ng/mL (at 1 year, 0.5%; 5 years, 0.9%) (P < 0.001). The pattern was similar for platelets and APRI (P < 0.001). SVR patients with pre-APRI ≥0.7 → post-APRI ≥0.7 had the highest risk of HCC development, followed by comparable risks among the other three groups.

CONCLUSIONS

SVR patients with a persistently high AFP level (≥15 ng/mL) and a high APRI (≥0.7) before and after treatment had the highest incidence of HCC development. Patients with a reduction of AFP and APRI to the normal range after treatment had a markedly decreased risk of HCC. The risk was lowest for patients who kept persistently normal AFP and APRI before and after treatment.

Nanonets Collect Cancer Secretome from Pericellular Space

Identifying novel cancer biomarkers is important for early cancer detection as it can reduce mortality rates. The cancer secretome, the collection of all macromolecules secreted by a tumor cell, alters its composition compared to normal tissue, and this change plays an important role in the observation of cancer progression. The collection and accurate analysis of cancer secretomes could lead to the discovery of novel biomarkers, thus improving outcomes of cancer treatment. We unexpectedly discovered that enzyme-instructed self-assembly (EISA) of a D-peptide hydrogelator results in nanonets/hydrogel around cancer cells that overexpress ectophosphatases. Here we show that these nanonets are able to rapidly collect proteins in the pericellular space (i.e., near the surface) of cancer cells. Because the secretory substances are at their highest concentration near the cell surface, the use of pericellular nanonets to collect the cancer secretome maximizes the yield and quality of samples, reduces pre-analytical variations, and allows the dynamic profiling of secretome samples. Thus, this new approach has great potential in identifying the heterotypic signaling in tumor microenvironments thereby improving the understanding of tumor microenvironments and accelerating the discovery of potential biomarkers in cancer biology. Data are available via ProteomeXchange with identifier PXD003924.

An optionality further amplification of an sandwich-type electrochemical immunosensor based on biotin–streptavidin–biotin strategy for detection of alpha fetoprotein

An optionality further amplification of sandwich-type electrochemical immunosensor based on biotin–streptavidin–biotin strategy.

Role of alpha-fetoprotein in hepatitis B virus-induced hepatocellular carcinoma: Prospect in clinical application

Mammalian alpha-fetoprotein (AFP) as a fetal specific alpha-globulin that has been used as a serum fetal defect/tumor marker for diagnosis and prediction of liver disease. Over the past decade, research indicates that AFP as an intracellular signal molecule is not only a biomarker but also interacts with hepatitis B virus (HBV) and hepatitis B virus protein x and plays multifarious roles in the development of hepatocellular carcinoma, especially in HBV-induced liver cancer.

Alpha fetoprotein mediates HBx induced carcinogenesis in the hepatocyte cytoplasm

Although tumor-associated fetal protein AFP has demonstrated utility as a clinical tumor marker, the significance of intracellular AFP is still unclear. The aim of this study was to explore the role of cytoplasmic AFP during HBx induced carcinogenesis, which had not previously been recognized; 614 HCC patients were analyzed for correlation of HBV infection with AFP level, and much higher AFP levels were found in HBsAg positive patients. Tumor tissue specimens from 20 HCC patients were used for analysis of AFP and GADD45α. Analysis of HCC specimens showed that upregulation of cytoplasmic AFP is associated with down-regulation of GADD45α in neoplastic tissue. Transfected HBx promotes transcription of AFP by acting on the elements in the AFP gene regulatory region. HBx itself did not directly impact transcription of GADD45α. However, the obstruction of RAR signaling by HBx induced elevation of AFP, which led to down-regulation of GADD45α. Cytoplasmic AFP was able to interact with RAR, disrupting its entrance into the nucleus and binding to the elements in the regulatory region of the GADD45α gene. Knockdown of AFP in siRNA-transfected AFP positive cell lines was synchronously associated with an incremental increase of RAR binding to DNA, as well as upregulation of GADD45α and it was contrary in AFP gene-transfected AFP negative cell lines. These results indicate cytoplasmic AFP is not only a histochemical tumor biomarker for human hepatoma but is also an intracellular signal molecule and potential participant in HBx induced hepatocarcinogenesis.

Effect of pre- and post-treatment α-fetoprotein levels and tumor size on survival of patients with hepatocellular carcinoma treated by resection, transarterial chemoembolization or radiofrequency ablation: a retrospective study

Background

We evaluated treatment modalities and survival in patients with hepatocellular carcinoma (HCC), by pre-treatment and 3-month post-treatment serum alpha-fetoprotein (AFP) levels and pre-treatment tumor diameters.

Methods

We retrospectively reviewed 57 patients treated for HCC in our department from January 2002 to December 2012, including their sex, type of hepatitis, Child class, pre-treatment tumor size, pre-treatment levels of albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), red blood cells, hemoglobin, and total bilirubin, pre- and 3-month post-treatment serum AFP, and treatment modality (transarterial chemoembolization, resection or radiofrequency ablation). Survival was analyzed at 1, 3, and 5 years after treatment.

Results

The 57 patients included 44 men and 13 women, of whom 44 had hepatitis C virus (HCV) infection, 3 had hepatitis B virus (HBV) infection, 3 had both HBV and HCV infection, 1 had both HBV and hepatitis D virus infection, and 3 had alcohol-related liver cirrhosis. Both pre- and post-treatment serum AFP levels significantly correlated with recurrent tumor size (P < 0.05 for both). Pre-treatment tumor size did not correlate with recurrent tumor size. Patients who underwent hepatic resection survived significantly longer than those who underwent transarterial chemoembolization or radiofrequency ablation (P < 0.05).

Conclusions

Serum AFP level is useful in diagnosing tumor recurrence and predicting prognosis in HCC patients treated by hepatic resection, transarterial chemoembolization, and radiofrequency ablation. Hepatic resection remains the treatment of choice for HCC in suitable patients.

Alpha fetoprotein can induce malignant transformation of liver cells and be used as a therapeutic target for hepatocellular carcinoma

Alpha-fetoprotein (AFP) is associated with the development of hepatocellular carcinoma (HCC) and widely used as a golden tumor marker for diagnosing HCC since the AFP gene is activated in the early stage of malignant transformation of liver cells. However, the molecular mechanisms responsible for the role of AFP in hepatocarcinogenesis remain poorly understood. Recently, we found that hepatitis B virus (HBV) preferentially induces the expression of AFP when triggering malignant transformation of hepatocytes, and AFP activates phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) signaling by inhibiting the activity of phosphatase and tensin homolog deleted on chromosome ten (PTEN). Our results also indicated that AFP not only impedes all-trans retinoid acid receptor-β (RAR-β) regulated expression of target genes, but also blocks the transduction of apoptotic signaling by suppressing the activity of Caspase3. Inhibited expression of AFP is able to augment HCC sensitivity to tumor necrosis factor-related apoptosis-induced ligand (TRAIL) and all-trans retinoid acid. These data indicate that AFP can drive the malignant transformation of liver cells and antagonize apoptosis induced by agents for HCC. Taken together, these findings suggest that AFP may drive the malignant transformation of liver cells and can be used as a target for therapy of HCC.

Alpha-fetoprotein: a renaissance

Alpha-fetoprotein (AFP) is a major mammalian embryo-specific and tumor-associated protein that is also present in small quantities in adults at normal conditions. Discovery of the phenomenon of AFP biosynthesis in carcinogenesis by G. Abelev and Yu. Tatarinov 50 years ago, in 1963, provoked intensive studies of this protein. AFPs of some mammalian species were isolated, purified and physico-chemically and immunochemically characterized. Despite the significant success in study of AFP, its three-dimensional structure, mechanisms of receptor binding along with a structure of the receptor itself and, what is the most important, its biological role in embryo- and carcinogenesis remain still obscure. Due to difficulties linked with methodological limitations, research of AFP was to some extent extinguished by the 1990 s. However, over the last decade a growing number of investigations of AFP and its usage as a tumor-specific biomarker have been observed. This was caused by the use of new technologies, primarily, computer-based and genetic engineering approaches in studying of this very important oncodevelopmental protein. Our review summarizes efforts of different scientific groups throughout the world in studying AFP for 50 years with emphasis on detailed description of recent achievements in this field.

Kinetic-exclusion analysis-based immunosensors versus enzyme-linked immunosorbent assays for measurement of cancer markers in biological specimens

Kinetic exclusion analysis (KinExA)-based immunosensors and enzyme-linked immunosorbent assays (ELISA) have been developed and validated for measurement of five different cancer markers in biological specimens. These markers were: 2'-deoxycytidine (dCyd), 8-hydroxy-2'-deoxyguanosine (8HdG), carbohydrate antigen (CA15-3), α-fetoprotein (AFP), and β-subunit of human chorionic gonadotropin (β-HCG). The KinExA-based assays were conducted on the KinExA™ 3200 instrument. The ELISA assays employed the competitive immunoassay format for dCyd and 8HdG, however they employed the direct sandwich-type format for CA15-3, AFP, and β-HCG. Each assay was validated in terms of its limit of detection, working range, precision profile, and accuracy. The analytical performances of the KinExA-based sensors were found to be superior to the ELISA for the five markers. The data demonstrated that the format of the assay may influence its performance characteristics (sensitivity, precision, etc.), even when exactly the same reagents are employed. The superior performance of the KinExA format is most likely due to: (1) the high surface area of beads containing the immobilized capture in the flow cell of the instrument, (2) the high flow rate of the reagents passing through the beads, which minimizes the diffusion limitations at the reaction surface, and (3) the limited time that the antibody is in contact with the capture reagent. The KinExA-based assays exhibited three noteworthy properties compared with ELISA: (1) avoiding the problems of mass transport limitations, and mobility effects, (2) KinExA analysis with automated sampling increase the assay convenience; and (3) providing high sensitivity with a lower limit of detection and better precision than ELISA. The proposed KinExA-based immunosensors are anticipated to have a great value in measurement of the cancer markers where more confident results are needed.

Glycoprotein 96 and α-fetoprotein cross-linking complexes elicited specific antitumor immunity

Hepatocellular carcinoma (HCC) is one of the most common malignant gastroenterological cancers over the world. α-fetoprotein (AFP) is an oncofetal protein produced during HCC development that could generate weaker and less reproducible antitumor protection, and it may serve as a target for immunotherapy. Therefore, it is imperative to enhance its immunogenicity and develop therapeutic vaccines to eliminate AFP-expressing tumors. In this study, by way of glutaraldehyde cross-linking, we constructed a potential therapeutic protein vaccine, glycoprotein 96 (gp96)/AFP. Our results demonstrated that AFP and gp96 synergistically exhibited significant increase in AFP-specific CD8⁺ T-cell responses and impressive cytotoxic antitumor effect against AFP-expressing tumors. Priming mice with the reconstructed vaccine, we elicited robust strong protective immunity. Our study suggests that tumor vaccine by cross-linking tumor antigen and gp96 is a promising approach to cancer therapy.

HSP72 and gp96 in gastroenterological cancers

Heat shock protein 72 (HSP72) and glycoprotein 96 (gp96) are highly expressed in cancer tissues. Recent studies indicate the possible roles of HSP72 and gp96 in the development and progression of gastrointestinal carcinomas but detailed mechanisms are still ambiguous. Human esophageal cancer, gastric cancer, colon cancer and liver cancer are common gastrointestinal malignant carcinomas in the world. The studies indicated that there existed a significant correlation between the expression of HSP72, gp96 and the development and progression of digestive carcinomas. HSP72 and gp96 expression were significantly associated with the presence of tumor infiltration, lymph node and remote metastasis. Interestingly, studies have found that HSP72 chaperoned alpha-fetoprotein (AFP), HBx in hepatocellular carcinoma, and CD44 in colonic carcinomas. The further researches demonstrated that HSP72-AFP or gp96-AFP recombined vaccine could elicit specific anti-tumor immunity. The high-level expression of HSP72 and gp96 may be not only used as diagnostic or prognostic markers for gastrointestinal carcinomas but also as better immunotherapeutic vaccines in the cancers.

Villin 1 is a predictive factor for the recurrence of high serum alpha-fetoprotein-associated hepatocellular carcinoma after hepatectomy

The prognostic assessment of patients with hepatocellular carcinoma (HCC) after resection is an important clinical issue. The present study investigated those genes associated with high serum alpha-fetoprotein (AFP), and their clinical significance, including prognosis and recurrence after hepatectomy. Based on gene expression analysis of 110 training HCC cases, 20 genes whose mRNA expression levels were significantly upregulated and 50 genes that were downregulated correlated with high serum AFP-associated HCC patients. Gene expression profiles of Villin1 (Vil1) were obtained in high serum AFP-associated HCC tumor tissues. In the present analysis, only VIL1 was significantly correlated with the recurrence of HCC. The results were validated independently using Taqman gene expression assays and immunostaining analysis. Results showed that the upregulation of VIL1 mRNA was also correlated with high serum PIVKAII, vascular invasion (P < 0.05), poor differentiation, an advanced cancer stage (P < 0.01) and recurrence-free survival (P = 0.017). The upregulation of VIL1 mRNA was observed more frequently in the early recurrence patients as compared to the late recurrence patients. Cox regression univariate and multivariate analyses indicated that high serum AFP levels (overall survival, HR 1.675, P = 0.002; FRS, HR 1.359, P = 0.039) and Vil1 protein expression (overall survival, HR 0.253, P = 0.009; FRS, HR 0.401, P = 0.041) were independent, unfavorable prognostic factors for overall and recurrence-free survival of patients. We demonstrated that the VIL1 gene is a potential candidate molecular marker for high serum AFP-associated HCC and a predictive candidate for the postoperative recurrence and poorer prognosis of HCC.

Regression of hepatocarcinoma cells using RNA aptamer specific to alpha-fetoprotein

Alpha-fetoprotein (AFP) is a cancer-associated fetal protein and has long been utilized as a serum fetal defect/tumor marker to monitor distress/disease progression. In addition, AFP is closely associated with the proliferation of hepatocellular carcinoma. Thus, direct targeting of AFP has been recommended for a therapeutic strategy against hepatocellular carcinoma. In this study, we developed and characterized an RNA aptamer that specifically bound to the alpha-fetoprotein using SELEX technology. The aptamer interacted with the AFP with a K(D) of ∼33 nM. Importantly, the identified aptamer specifically and efficiently inhibited the AFP-mediated proliferation of hepatocarcinoma cells in a dose dependent manner. Moreover, the aptamer efficiently down-regulated AFP-induced expression of oncogenes in the cells. These results indicate that an AFP-specific RNA aptamer could be a useful therapeutic and diagnostic agent against AFP-related hepatocellular carcinoma.

α-fetoprotein involvement during glucocorticoid-induced precocious maturation in rat colon

AIM: To investigate the role of α-fetoprotein (AFP), a cancer-associated fetal glycoprotein, in glucocorticoid-induced precocious maturation in rat colon.

METHODS: Colons from suckling Sprague-Dawley rats were used in this study. Corticosterone acetate at a dose of 100 μg/g body weight was given to normal pups on days 7, 9 and 11 after birth to induce hypercorticoidism. Control animals were injected with identical volumes of normal saline. Some rats receiving corticosterone 7 d after birth were also treated with mifepristone (RU38486), a glucocorticoid cytoplasm receptor antagonist to investigate the effects of glucocorticoids (GCs). The morphological changes of the crypt depth and villous height of the villous zone in colon were observed as indices of colon maturation. Expression levels of AFP in colons were detected by reverse transcriptase polymerase chain reaction and Western blotting. To identify the cellular localization of AFP in developing rat colons, double-immunofluorescent staining was performed using antibodies to specific mesenchymal cell marker and AFP.

RESULTS: Corticosterone increased the crypt depth and villous height in the colon of 8- and 10-d-old rats with hypercorticoidism compared with that in the control animals (120% in 8-d-old rats and 118% in 10-d-old rats in villous height, P = 0.021; 145% in 8-d-old rats and 124% in 10-d-old rats in crypt depth, P = 0.017). These increases were accompanied by an increase of AFP expression in both mRNA and protein (2.5-folds in 8-d-old and 2.5-folds in 10-d-old rats higher than in control animals, P = 0.035; 1.8-folds in 8-d-old and 1.3-folds in 10-d-old rats higher than in control animals, P = 0.023). Increased crypt depth and villous height and increased expression of AFP in the colon of rats with hypercorticoidism were blocked by mifepristone. Both had positive staining for AFP or vimentin, and overlapped in mesenchymal cells at each tested colon.

CONCLUSION: GCs promote the development of rat colon. AFP appears to be involved, in part, in mediating the effects of GCs in the developmental colon.

Data mining reveals complex interactions of risk factors and clinical feature profiling associated with the staging of non-hepatitis B virus/non-hepatitis C virus-related hepatocellular carcinoma

AIM

  Non-hepatitis B virus/non-hepatitis C virus-related hepatocellular carcinoma (NBNC-HCC) is often detected at an advanced stage, and the pathology associated with the staging of NBNC-HCC remains unclear. Data mining is a set of statistical techniques which uncovers interactions and meaningful patterns of factors from a large data collection. The aims of this study were to reveal complex interactions of the risk factors and clinical feature profiling associated with the staging of NBNC-HCC using data mining techniques.

METHODS

  A database was created from 663 patients with NBNC-HCC at 20 institutions. The Milan criteria were used as staging of HCC. Complex associations of variables and clinical feature profiling with the Milan criteria were analyzed by graphical modeling and decision tree algorithm methods, respectively.

RESULTS

  Graphical modeling identified six factors independently associated with the Milan criteria: diagnostic year of HCC; diagnosis of liver cirrhosis; serum aspartate aminotransferase (AST); alanine aminotransferase (ALT); α-fetoprotein (AFP); and des-γ-carboxy prothrombin (DCP) levels. The decision trees were created with five variables to classify six groups of patients. Sixty-nine percent of the patients were within the Milan criteria, when patients showed an AFP level of 200 ng/mL or less, diagnosis of liver cirrhosis and an AST level of less than 93 IU/mL. On the other hand, 18% of the patients were within the Milan criteria, when patients showed an AFP level of more than 200 ng/mL and ALT level of 20 IU/mL or more.

CONCLUSION

  Data mining disclosed complex interactions of the risk factors and clinical feature profiling associated with the staging of NBNC-HCC.

Biological functions of alpha-fetoprotein

Alpha-fetoprotein (AFP) is a well-known biomarker for the diagnosis of hepatocellular carcinoma. Extracellular AFP can act as a carrier to transport a variety of ligands or as a growth regulator to control the growth of tumor cells, while intracellular AFP can bind to and interact with transcription factors or some key proteins and function as a signal molecule to regulate cell proliferation or apoptosis. This paper provides novel insights into the mechanisms underlying the role of AFP in carcinogenesis and tumor chemotherapy.

Long-term outcome and hepatocellular carcinoma development in chronic hepatitis B or cirrhosis patients after nucleoside analog treatment with entecavir or lamivudine

AIM

  We conducted this prospective study to elucidate the long-term outcome and incidence of hepatocellular carcinoma (HCC) development after nucleos(t)ide analog (NA) treatment in patients with chronic hepatitis B (CHB) or cirrhosis.

METHODS

  CHB or cirrhosis patients without past NA treatment or HCC were started on entecavir (ETV) or lamivudine (LVD), and prospectively followed up with monthly blood tests, and with abdominal imaging every 6 months in CHB and every 3 months in cirrhosis patients.

RESULTS

  A total of 256 subjects with CHB (n = 194) or cirrhosis (n = 62) received ETV (n = 129) or LVD (n = 127) for 4.25 years (range: 0.41-10.0). After NA treatment, serum HBV DNA, alanine aminotransferase and α-fetoprotein (AFP) dropped significantly, along with significant increases in serum albumin and prothrombin time. Drug-resistance developed in 60 cases in the LVD group and in only one case in the ETV group. HCC developed in 35 patients, and the incidence at years 1, 3, 5, 7 and 10 was significantly higher in patients with cirrhosis (8.1%, 17.5%, 43.2%, 46.7% and 53.4%, respectively) than chronic hepatitis (1.6%, 3.5%, 3.5%, 7.1% and 29.6%, respectively), with no difference between ETV and LVD. After NA treatment, the sensitivity/specificity for HCC of AFP and des-γ-carboxy prothrombin (DCP) was 45.7%/97.3% and 33.3%/96.2%, respectively, with the specificity of AFP being higher than at baseline (64.4%), at the cut-off of 10 ng/mL.

CONCLUSION

  NA exerted a long-term efficacy and improved hepatic reservation in CHB and cirrhosis. After NA treatment, AFP dropped to lower than 10 ng/mL with marked elevation of specificity, leading to an earlier detection of HCC.

Alpha-fetoprotein: a new member of intracellular signal molecules in regulation of the PI3K/AKT signaling in human hepatoma cell lines

Despite its well-defined role as a serum growth factor during fetal liver development and hepatic oncogenesis, the biological significance of cytoplasmic alpha-fetoprotein (AFP) remains incompletely understood. Here, we provide evidence to illustrate that cytoplasmic AFP may function as a regulator in the phosphatidylinositol 3-kinase (PI3K)/AKT pathway in human hepatocellular carcinoma cells. The results demonstrated colocalization and interaction of AFP and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in the cytoplasm of AFP-producing Bel 7402 and HepG2 cells, with an interaction distance of 12.6 ± 2.7 Å as determined with the fluorescence resonance energy transfer technique. Knockdown of AFP mRNA or inhibition of AFP expression by all trans-retinoic acid resulted in enhancement of the PTEN level with a synchronous decrease in phosphorylated AKT. Transfection of the afp gene into HLE cells (originally AFP negative) led to a significant activation of AKT signaling. The inhibition of PI3K signaling by LY 294002 was simultaneously reversed by transfection, accompanied by diminution of all trans-retinoic acid-induced upregulation of PTEN and enhancement of cell growth. In conclusion, these results demonstrate that cytoplasmic AFP is involved in regulation of hepatocellular growth and tumorigenesis.

Anti-alpha-enolase autoantibodies are down-regulated in advanced cancer patients

OBJECTIVE

Elevation of serum autoantibodies to alpha-enolase (ENO1) is often seen in inflammation diseases. However, it is unclear whether the levels of serum ENO1 autoantibodies could be affected during tumor progression. Hence, we attempted to determine the relative serum ENO1 autoantibody levels in healthy individuals and various stages of patients with lung and breast cancers.

METHODS

Sera were obtained from 99 normal individuals, 21 patients with non-cancer-associated diseases and 178 cancer patients, including Stage I, II and IV non-small cell lung cancer, small cell lung cancer and breast cancer. The ENO1 autoantibody levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Compared with the healthy individuals, the levels of ENO1 autoantibodies were significantly decreased in Stage IV non-small cell lung cancer, small cell lung cancer and breast cancer patients. Consistently, this phenomenon was also observed in tumor-grafted mice. Using logistic regression analyses, data show that the titer status of ENO1 autoantibody level is highly associated with the late stage of lung and breast cancers when compared with those of healthy controls. In contrast, there were no statistic differences between healthy controls and early stages of non-small cell lung cancer patients, and total amounts of serum immunoglobulin A, immunoglobulin G and immunoglobulin M levels in Stage IV non-small cell lung cancer patients were not significantly distinct from those of the healthy controls. Thus, the decreased ENO1 autoantibody event in malignant stage of cancer patients is not contributed by reduction in total immunoglobulin.

CONCLUSIONS

Marked decrease in the basal level of serum ENO1 autoantibodies is a common malignant event of lung and breast cancers, suggesting that ENO1 autoantibody may serve as a prognostic marker to monitor the disease progression of these cancer patients.

Role of alpha-fetoprotein in hepatocellular carcinoma: prognostication, treatment monitoring or both?

Despite recent breakthroughs in the treatment for both early and advanced hepatocellular carcinoma, the development of markers for prognostication and treatment monitoring remains to be explored. Serum alpha-fetoprotein has been frequently measured at diagnosis and serially during treatment by clinicians for decades, with an aim for prognostication of disease and monitoring of treatment response. In this review, the evidence regarding the prognostic value of serum alpha-fetoprotein and the value of serial alpha-fetoprotein in the monitoring of treatment efficacy will be discussed, with emphasis on recent data.

Amperometric immunosensor for the determination of α-1-fetoprotein based on multiwalled carbon nanotube-silver nanoparticle composite

A new amperometric immunosensor for the determination of α-1-fetoprotein (AFP) has been constructed. First, a multiwalled carbon nanotube-silver (MWNT-Ag) composite was modified on the surface of a glassy carbon electrode. Then, chitosan-MnO(2) (CS-MnO(2)) with excellent film forming ability was dipped onto the MWNT-Ag-modified electrode. Subsequently, gold nanoparticles were electrodeposited on the electrode to immobilize anti-AFP. The assembly processes were characterized with cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. MWNT-Ag composite was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-vis spectroscopy. The system was optimized to realize a reliable determination of AFP in the range of 0.25-250 ng/ml with a detection limit of 0.08 ng/ml (S/N=3). The proposed immunosensor showed a rapid and highly sensitive amperometric response to AFP with acceptable stability and reproducibility.

Alpha-fetoprotein gene polymorphisms and risk of HCC and cirrhosis

BACKGROUND

Elevated level of alpha fetoprotein (AFP) is found in approximately 60% of hepatocellular carcinoma (HCC) cases. Other liver diseases including cirrhosis and chronic hepatitis are related with an increased level of AFP. The regulation of AFP gene expression has been relatively less studied although the gene has been suggested to play a role in HCC development. This study aimed at identifying genetic variations in AFP that might be associated with the presence of HCC and cirrhosis among ethnic Indonesians.

METHODS

Direct DNA sequencing was carried out to sequence AFP promoter, exons, and 3' untranslated region (UTR) in DNA samples isolated from 119 HCC, 119 cirrhosis and 105 control subjects. For each sample serum AFP level was determined and association studies with single nucleotide polymorphisms (SNPs) and haplotypes were performed.

RESULTS

In this study we identified 47 SNPs in the AFP gene. Statistically significant associations with HCC and cirrhosis were detected for six individual SNPs in the AFP promoter, AFP intron 1 and intron 2 (rs6834059, rs3796678, rs3796677, rs3796676, rs28532518 and rs4646038). Furthermore, we identified two SNPs in AFP intron 7 and 3'UTR, rs2298839 and rs10020432, which are associated with increased risk of cirrhosis.

CONCLUSION

Genetic variants in the AFP gene may be associated with HCC and cirrhosis risk for ethnic Indonesians.

Serum alpha-fetoprotein levels during and after interferon therapy and the development of hepatocellular carcinoma in patients with chronic hepatitis C

The association between serum alpha-fetoprotein (AFP) levels during and after interferon (IFN) therapy and the development of hepatocellular carcinoma (HCC) was evaluated in patients with chronic hepatitis C (CHC). A total of 263 patients treated by IFN with or without ribavirin were enrolled in the study. Serum AFP levels during and after IFN therapy were investigated retrospectively, and statistical analysis was performed to identify the factors associated with HCC development. During IFN therapy, serum AFP levels significantly decreased, regardless of virologic response to treatment. Increased serum AFP levels (>or=10 ng/ml) at the end of IFN therapy (EOT) was a close-to-significant variable affecting the development of HCC (P = 0.057), and a significantly higher cumulative incidence of HCC was seen in patients with increased serum AFP levels at EOT (P = 0.021). Serum AFP level at EOT is a possible predictor of HCC in CHC patients after IFN therapy.

Long-term outcomes and prognostic factors of elderly patients with hepatocellular carcinoma undergoing hepatectomy

OBJECTIVE

The present study aimed to evaluate the long-term outcomes and prognostic factors of elderly patients with hepatocellular carcinoma (HCC) undergoing hepatectomy.

MATERIAL AND METHODS

From January 1983 to December 2006, 2,283 patients with HCC received hepatectomy in Sun Yat-sen University Cancer Center. The clinicopathological data and treatment outcomes of 67 elderly HCC patients (elderly group, > or =70 years of age) and 268 patients (control group, <70 years of age) who were selected randomly from the 2216 younger patients were compared retrospectively.

RESULTS

The elderly HCC patients had lower hepatitis B surface antigen-positive rate (P < 0.001), lower rate of marked alpha-fetoprotein elevation (P = 0.004), higher infection rate of hepatitis C virus (P = 0.010), more preoperative comorbidities (P < 0.001), higher rate of tumor encapsulation (P = 0.040), and better overall survival rate (P = 0.017); whereas there were no significant differences between these two groups in other factors, including gender ratio, liver function, accompanying cirrhosis, pathological tumor-node-metastasis (pTNM) staging, satellite nodules, vascular invasion, tumor rupture, resection margin, intraoperative blood loss, incidence of postoperative complications, hospital mortality, and disease-free survival rate. Multivariate analysis showed that pTNM staging was an independent prognostic factor of long-term survival in elderly patients with HCC.

CONCLUSION

HCC in the elderly was less HBV-associated, less advanced, and less aggressive. Hepatectomy for selected elderly patients with HCC possibly have a better curative effect compared with younger patients. For the elderly patients without preoperative comorbidities or with controlled comorbidities, hepatectomy is a safe and effective treatment. pTNM staging is the only independent predictor of postoperative overall survival in elderly HCC patients.