Glypican-3 as an emerging molecular target for hepatocellular carcinoma gene therapy. Tumour Biol. 2014;35:5857-5868. [PMID: 24633918 DOI: 10.1007/s13277-014-1776-5]

Diagnostic accuracy and prognostic significance of Glypican-3 in hepatocellular carcinoma: A systematic review and meta-analysis

Purpose

Glypican-3 (GPC-3) expression is abnormal in the occurrence and development of hepatocellular carcinoma (HCC). To explore whether GPC-3 has diagnostic accuracy and prognostic significance of HCC, we did a systematic review and meta-analysis.

Method

PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure were searched with keywords “GPC-3” and “HCC” and their MeSH terms from inception to July 2022. We applied the hierarchical summary receiver operating characteristic model and evaluated the diagnostic value of GPC-3 alone and combination, and the correlation between high and low GPC-3 expression on clinicopathological features and survival data in prognosis.

Results

Forty-one original publications with 6,305 participants were included, with 25 of them providing data for diagnostic value and 18 records were eligible for providing prognostic value of GPC-3. GPC-3 alone got good diagnostic value in patients with HCC when compared with healthy control and moderate diagnostic value when compared with patients with cirrhosis. In addition, combination of GPC-3 + AFP and GPC-3 + GP73 got great diagnostic value in HCC versus cirrhosis groups; the combination of GPC-3 can also improve the diagnostic accuracy of biomarkers. Moreover, we discovered that overexpression of GPC-3 was more likely found in HBV infection, late tumor stage, and microvascular invasion groups and causes shorter overall survival and disease free survival, which means poor prognosis.

Conclusion

GCP-3 could be used as a biomarker in HCC diagnosis and prognosis, especially in evaluated diagnostic value in combination with AFP or GP73, and in forecasting worse survival data of overexpression GPC-3

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier [CRD42022351566].

HLA-DQ Gene Polymorphisms Associated with Hepatitis B Virus in Patients with Hepatocellular Carcinoma Progression

Background:

The development and progression of hepatitis B (HBV)-related disease can lead to liver cirrhosis and hepatocellular carcinoma (LC and HCC, respectively). Human leukocyte antigen (HLA) DQ polymorphism has been reported in other recent studies to deal with the association between HBV and liver disease. Our study on the Egyptian population was introduced to assess the strong association between HLA-DQ polymorphism and HBV infection in addition to the progression of HCC.

Aim:

The aim of this work was to estimate HLA-DQ gene polymorphisms in HBV and HCC.

Methods:

HLA-DQ genotype polymorphism was assayed by using the ABI Taq Man allelic discrimination assay in different groups in this study. According to the relevant HLA Class II single nucleotide polymorphism (SNP) literature, one single nucleotide polymorphism (SNPs) was selected as the candidate site; it was an HLA-DQ, which showed minor allele frequencies AA, GA, and GG.

Results:

Haplotype analysis was performed on all the subjects in the study; AA haplotype was the most frequent haplotype in HCC cases (18%) in comparison with HBV and healthy individuals (3%). The haplotype GA was more frequent in the HCC group and slightly more frequent in LC when compared to HBV only cases and also when compared to the control group. In contrast, the GG haplotype was recorded less frequently in HCC individuals, but the HBV and LC groups showed more frequency of this haplotype compared with the HCC group. There was a correlation between AFP serum levels and the frequency of GA and AA polymorphism in HCC cases.

Conclusion:

We found that AA and GA haplotype was significantly most frequent in HCC. Our findings suggest that HLA-DQ AA and GG polymorphism might serve as a novel potential predictive marker for HCC and may function in tumorigenesis of HBV.

Heparan sulfate proteoglycans and their modification as promising anticancer targets in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of primary liver cancer. Despite advancements in the treatment strategies of HCC, there is an urgent requirement to identify and develop novel therapeutic drugs that do not lead to resistance. These novel agents should have the potential to influence the primary mechanisms participating in the pathogenesis of HCC. Heparan sulfate proteoglycans (HSPGs) are major elements of the extracellular matrix that perform structural and signaling functions. HSPGs protect against invasion of tumor cells by preventing cell infiltration and intercellular adhesion. Several enzymes, such as heparanase, matrix metalloproteinase-9 and sulfatase-2, have been reported to affect HSPGs, leading to their degradation and thus enhancing tumor invasion. In addition, some compounds that are produced from the degradation of HSPGs, including glypican-3 and syndecan-1, enhance tumor progression. Thus, the identification of enzymes that affect HSPGs or their degradation products in HCC may lead to the development of novel therapeutic targets. The present review discusses the main enzymes and compounds associated with HSPGs, and their involvement with the pathogenicity of HCC.

The Role of Tumor Associated Macrophages in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and represents a classic paradigm of inflammation-related cancer. Various inflammation-related risk factors jointly contribute to the development of chronic inflammation in the liver. Chronic inflammation, in turn, leads to continuous cycles of destruction-regeneration in the liver, contributing to HCC development and progression. Tumor associated macrophages are abundant in the tumor microenvironment of HCC, promoting chronic inflammation and HCC progression. Hence, better understanding of the mechanism by which tumor associated macrophages contribute to the pathogenesis of HCC would allow for the development of novel macrophage-targeting immunotherapies. This review summarizes the current knowledge regarding the mechanisms by which macrophages promote HCC development and progression, as well as information from ongoing therapies and clinical trials assessing the efficacy of macrophage-modulating therapies in HCC patients.

Macrophages and hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the most prevalent and lethal cancers in the human population. HCC is an inflammation-associated cancer caused by different etiological factors. The chronic inflammation leads to continuous cycles of hepatocytes destructive-regenerative process and contributes to HCC initiation and progression. Macrophages play a crucial role in chronic liver inflammation. The tumor microenvironment plays a key role in the progression of HCC. Tumor-associated macrophages are a well-known component of the tumor microenvironment and abundantly infiltrate HCC microenvironment. The roles of macrophages in the development and progression of HCC have been recognized. The deep understanding of macrophages in HCC will be critical for developing effective HCC therapy. Targeting of macrophages might provide novel therapeutic approaches for HCC patients and is an emerging field of interest. This review summarizes the knowledge on the contribution of macrophages in the development and progression of HCC, as well as potential immunotherapy being explored in targeting macrophages.

Key signaling pathways, genes and transcription factors associated with hepatocellular carcinoma

The purpose of the present study was to investigate the underlying molecular mechanism of hepatocellular carcinoma (HCC) using bioinformatics approaches. The microarray dataset GSE64041 was downloaded from the Gene Expression Omnibus database, which included 60 tumor liver samples and 60 matched control samples. Differentially expressed genes (DEGs) between HCC and control groups were identified. Then functional enrichment analyses, protein‑protein interaction (PPI) network, sub‑network and integrated transcription factor (TF)‑microRNA (miRNA)‑target network analyses were performed for these DEGs. A total of 378 DEGs were obtained, including 101 upregulated and 277 downregulated DEGs. In addition, functional enrichment analysis for DEGs in the sub‑network revealed 'cell division' and 'cell cycle' as key Gene Ontology (GO) terms and pathways. Topoisomerase (DNA) IIα (TOP2A) and integrin subunit α2 (ITGA2) were hub nodes in the PPI network. TOP2A, cyclin dependent kinase 1 (CDK1) and polo like kinase 1 (PLK1) were revealed to be hub nodes in the sub‑network. Finally, 4 TFs including forkhead box M1 (FOXM1), E2F transcription factor 4 (E2F4), SIN3 transcription regulator family member A (SIN3A) and transcription factor 7 like 1 (TCF7L1) were obtained through integrated network analysis. TOP2A, ITGA2, PLK1 and CDK1 may be key genes involved in HCC development. 'Cell division' and 'cell cycle' were indicated to act as key GO terms and Kyoto Encyclopedia of Genes and Genomes pathways in HCC. In addition, FOXM1, TCF7L1, E2F4 and SIN3A were revealed to be key TFs associated with HCC.

Low glucose metabolism in hepatocellular carcinoma with GPC3 expression

AIM

To investigate the relationship between glucose metabolism and glypican-3 (GPC3) expression in hepatocellular carcinoma (HCC).

METHODS

Immunohistochemical staining of pathological samples for GPC3 and glucose transporter 1 (GLUT1), and whole-body ¹⁸F-FDG PET/CT for measuring tumour glucose uptake were performed in 55 newly diagnosed HCC patients. The maximum standard uptake value (SUV_max) and tumour-to-non-tumourous liver uptake (T/NT) ratio were used to quantify ¹⁸F-FDG uptake. In vitro¹⁸F-FDG uptake assay of GPC3-expressing HepG2 and non-GPC3-expressing RH7777 cells was used to examine the effect of GPC3 in cellular glucose metabolism. The relationships between GPC3 expression and ¹⁸F-FDG uptake, GLUT1 expression, tumour differentiation, and other clinical indicators were analysed using Spearman rank correlation, univariate and multiple logistic regression analyses.

RESULTS

Positive GPC3 expression was observed in 67.3% of HCC patients, including 75.0% of those with well or moderately differentiated HCC and 36.4% of those with poorly differentiated HCC. There was an inverse relationship between GPC3 expression and SUV_max (Spearman correlation coefficient = -0.281, P = 0.038) and a positive relationship between GLUT1 expression and SUV_max (Spearman correlation coefficient = 0.681, P < 0.001) in patients with HCC. Univariate analysis showed that two glucose metabolic parameters (SUV_max and T/NT ratio), tumour differentiation, lymph node metastasis, and TNM stage were all significantly associated with GPC3 expression (P < 0.05), whereas GLUT1 expression, sex, age, tumour size, intrahepatic lesion number, and distant metastasis showed no statistical association (P > 0.05). Further multivariate analysis revealed that only the T/N ratio was significantly correlated with GPC3 expression in patients with HCC (P < 0.05). In vitro assay revealed that the uptake of ¹⁸F-FDG in GPC3-expressing HepG2 cells was significantly lower than that of non-GPC3-expressing RH7777 cells (t = -20.352, P < 0.001).

CONCLUSION

The present study demonstrated that GPC3 expression is inversely associated with glucose metabolism, suggesting that GPC3 may play a role in regulating glucose metabolism in HCC.

Imaging the expression of glypican-3 in hepatocellular carcinoma by PET

The glypican-3 (GPC3) receptor is overexpressed in hepatocellular carcinoma (HCC) and is a potential diagnostic and therapeutic target. GPC3-targeted molecular imaging will be helpful to differentiate diagnosis and guide therapy. In the present study, we will develop a novel PET probe for imaging the expression of GPC-3. L5 (sequence: RLNVGGTYFLTTRQ), a GPC3 targeting peptide, was labeled with 5-carboxyfluorescein (FAM) and ¹⁸F-fluoride. Cell binding tests were performed to identify the binding specificity of FAM-L5 and ¹⁸F radiolabeled peptide. MicroPET/CT imaging was used to determine the potential of a novel PET tracer for visualizing HCC tumors with a high expression of GPC3. In vitro binding tests showed that the uptake of FAM-L5 in HepG2 cells (high expression of GPC3) was significantly higher than that of HL-7702 cells (negative expression of GPC3) (mean fluorescent intensity: 14,094 ± 797 vs. 2765 ± 314 events, t = 32.363, P = 0.000). Confocal fluorescent imaging identified that FAM-L5 accumulated where the GPC3 receptor was located. A novel PET tracer (¹⁸F-AlF-NODA-MP-6-Aoc-L5) was successfully labeled by chelation chemistry. In vitro cell uptake studies showed that ¹⁸F-AlF-NODA-MP-6-Aoc-L5 can bind to HepG2 tumor cells and was stable in PBS and mouse serum stability tests. MicroPET/CT showed that HepG2 tumors could be clearly visualized with a tumor/muscle ratio of 2.46 ± 0.53. However, the tumor/liver ratio was low (0.93 ± 0.16) due to the high physiological uptake in the liver. This study demonstrates that FAM and the ¹⁸F-labeled L5 peptide can selectively target HCC with a high expression of GPC3 in vitro and in vivo. ¹⁸F-AlF-NODA-MP-C6-L5 has the potential to be a GPC3 target tracer but requires some chemical modifications to achieve a high enough tumor/liver ratio for detection of the tumor in the liver.

Glypican-3: A promising biomarker for hepatocellular carcinoma diagnosis and treatment

Liver cancer is the second leading cause of cancer-related deaths, and hepatocellular carcinoma (HCC) is the most common type. Therefore, molecular targets are urgently required for the early detection of HCC and the development of novel therapeutic approaches. Glypican-3 (GPC3), an oncofetal proteoglycan anchored to the cell membrane, is normally detected in the fetal liver but not in the healthy adult liver. However, in HCC patients, GPC3 is overexpressed at both the gene and protein levels, and its expression predicts a poor prognosis. Mechanistic studies have revealed that GPC3 functions in HCC progression by binding to molecules such as Wnt signaling proteins and growth factors. Moreover, GPC3 has been used as a target for molecular imaging and therapeutic intervention in HCC. To date, GPC3-targeted magnetic resonance imaging, positron emission tomography, and near-infrared imaging have been investigated for early HCC detection, and various immunotherapeutic protocols targeting GPC3 have been developed, including the use of humanized anti-GPC3 cytotoxic antibodies, treatment with peptide/DNA vaccines, immunotoxin therapies, and genetic therapies. In this review, we summarize the current knowledge regarding the structure, function, and biology of GPC3 with a focus on its clinical potential as a diagnostic molecule and a therapeutic target in HCC immunotherapy.

Novel specific markers for hepatocellular carcinoma: Perspective on clinical applications

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Despite continuous global efforts aimed at HCC eradication and improvements in various treatment techniques, the prognosis of HCC remains very poor. How to monitor malignant transformation of hepatocytes or diagnose HCC at early stage is still a medical challenge. A growing understanding of the multiple pathogenic factors including hepatitis B virus or hepatitis C virus infection, lipid accumulation, aflatoxin B1 intake and so on suggests that hepatocarcinogenesis is a multistep process. A large number of oncogenes or tumor suppressor genes have been identified. Early screening of HCC patients has been reported to confer a survival benefit. Although serum alpha-fetoprotein (AFP) and hepatoma-specific AFP have been used as conventional tumor markers, they often show false-positive results and lack sufficient sensitivity and specificity. In order to provide optimal treatment for each patient with HCC, more precise and effective biomarkers are urgently needed in all phases of management from early detection to staging, treatment monitoring, and prognosis evaluation. Recently, numerous studies have shown the clinical utility of novel blood-based biomarkers, such as circulating tumor cells, key signal molecules or specific proteins, long non-coding RNAs, and microRNAs. In this article, we will review some novel HCC-related biomarkers and discuss their future perspective on clinical applications.

Advances in the study of oncofetal antigen glypican-3 expression in HBV-related hepatocellular carcinoma

Early specific diagnosis and effective treatment of hepatocellular carcinoma (HCC) are crucial. Expression of membrane-associated heparan sulfate proteoglycan glypican-3 (GPC-3) was recently found to increase as part of the malignant transformation of hepatocytes, and this increase is especially marked in patients with hepatitis B virus (HBV) infection, periportal cancerous embolus, or extra-hepatic metastasis. According to data from basic and clinical studies, the oncofetal antigen GPC-3 is a highly specific diagnostic biomarker of HCC and an indicator of its prognosis, and GPC-3 is also a promising target molecule for HCC gene therapy since it may play a crucial role in cell proliferation, metastasis, and invasion and it may mediate oncogenesis and oncogenic signaling pathways. This review summarizes recent advances in the use of oncofetal antigen GPC-3 to diagnose HBV-related HCC, estimate its prognosis, and its targeted therapy.

The chimeric multi-domain proteins mediating specific DNA transfer for hepatocellular carcinoma treatment

AIM

This study was aimed to evaluate the therapeutic efficiency of a non-virus based specific chimeric multi-domain DNA transferred with apoptin in human hepatocellular carcinoma (HCC) HepG-2 cells in vitro and in mice H22 cells in vivo.

METHODS

We firstly constructed the multi-domain recombinant chimeric proteins based on recombinant proteins [G (yeast GAL4), NG (none GAL4), TG (GAL4 + Tat protein) and TNG (Tat protein)] and pUAS-Apoptin plasmid, and transfected them into human HepG-2 cells. The antitumor effect of this multi-domain recombinant chimeric proteins to HCC cells were detected by MTT assay, AO/EB staining, DAPI staining and Annexin V assay. In order to find the pathway of cell apoptosis, the Caspase (1, 3, 6 and 8) activity was detected. We then constructed the H22 liver cancer mice model and analyzed the anti-tumor rate and mice survival rate after treated with G/pUAS-Apoptin NG/pUAS-Apoptin TG/pUAS-Apoptin, and TNG/pUAS-Apoptin.

RESULTS

MTT results showed that the Tat protein (TG and TNG) significantly induced cell death in a time dependent manner. AO/EB, DAPI, Annexin V and Caspases assay results indicated that the Caspase 1, 3, 6 and 8 were highly expressed in TG/pUAS-Apoptin, and TNG/pUAS-Apoptin treated mouse groups. The antitumor rate and survival rate in TG/pUAS-Apoptin, and TNG/pUAS-Apoptin treated mouse groups were higher than in the other groups.

CONCLUSION

The Tat-apoptin is a potential anti-tumor agent for HCC treatment with remarkable anti-tumor efficacy and high safety based on non-virus gene transfer system. The anti-tumor function may be associated with high expression of Caspase 1, 3, 6 and 8.

Expression of oncofetal antigen glypican-3 associates significantly with poor prognosis in HBV-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with poor prognosis. However, its prognostic evaluation is still an urgent problem. The objectives of this present study were to investigate oncofetal antigen glypican-3 (GPC-3) expression in HCC and their match para-cancerous tissues by the array technology with immunohistochemistry and estimate its value as a novel prognostic marker for HCC. The incidence of GPC-3 expression was 95.7 % in the cancerous tissues with significantly higher (χ2 = 33.824, P < 0.001) than that in the para-cancerous tissues (52.2 %). Abnormal expression of GPC-3 in HCC tissues was markedly related to poor or moderate differentiation (P < 0.001), hepatitis B virus (HBV) infection (P = 0.004), periportal cancer embolus (P = 0.043), and tumor-node- metastasis staging (P = 0.038). According to the univariate and multivariate analysis, the overall survival of HCC patients with high GPC-3 level was significantly worse than those with low or without GPC-3 expression (P < 0.001), suggesting that abnormal GPC-3 expression should be an independent prognostic factor for HBV-related HCC patient's survival.

Genetic polymorphism of HLA-DQ confers susceptibility to hepatitis B virus-related hepatocellular carcinoma: a case-control study in Han population in China

Several recent genome-wide studies showed that the genetic polymorphisms in the HLA-DQ region (rs9275572 and rs2856718) were related to chronic hepatitis B virus (HBV) infection and chronic hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC). We analyzed the two single-nucleotide polymorphisms for major HBV outcomes in Han Chinese. A total of 1291 samples were involved and peripheral blood samples were collected in this study. Matrix-assisted laser desorption/ionization time of flight mass spectrometry were used to genotype the single-nucleotide polymorphisms in the HLA-DQ region. Our study indicated the clear relationship between the HLA-DQ rs9275572 and HBV-related HCC after control for the effects of sex, drinking, and smoking. Health subjects with the HLA-DQ rs9275572 GA genotype would have a 0.641 (95 % CI 0.416, 0.985; P = 0.043) times lower odds of having HCC, and those with the AA genotype would have a 0.256 (95 % CI 0.106, 0.618; P = 0.002) times lower odds of having HCC, whereas the values of the other covariates were fixed. Whereas there was no significant difference found for the HLA-DQ rs2856718 AG and GG genotype. Our study suggested that HLA-DQ loci (rs9275572) were associated with HBV-related HCC as a protective factor in Han Chinese.

Prediction and preliminary screening of HLA-A*0201-restricted epitope peptides of human GPC3

In response to the limited therapeutic option for hepatocellular carcinoma (HCC), immunotherapy as a promising approach points out a new direction to the cure of tumours through specific recognition and elimination of tumour cells by the immunity-enhanced autologous immunocytes of patients. Few effective tumour antigens, however, are alternative in addition to alpha fetoprotein or tumour cell lysates. Recent studies have demonstrated that glypican-3 (GPC3) is not only a promising diagnostic marker, but also ideal therapeutic target to HCC. In this study, potential HLA-A*0201 GPC3 peptides were screened with three epitope prediction software, the binding affinity of 13 predicted epitopes with high scores was determined by T2 cells binding assay and four optimal epitopes were identified. This is the first study in which the optimal HLA-A*0201 GPC3 epitopes were screened from a large number of candidates predicted by three software. The optimized HLA-A*0201 GPC3 peptides will provide new epitope candidates for HCC immunotherapy.

Glypican-3 is a biomarker and a therapeutic target of hepatocellular carcinoma

BACKGROUND

The carcinogenesis of hepatocellular carcinoma (HCC) is a multi-factorial, multi-step and complex process. Early diagnosis and effective treatments are of utmost importance. This review summarized the recent studies of oncofetal glypican-3 (GPC-3), a membrane-associated heparan sulfate proteoglycan, in the diagnosis and treatment of HCC.

DATA SOURCES

English-language reports published from June 2001 to September 2014 were searched from MEDLINE. The key words searched included: GPC-3, biomarker, target and HCC. The sensitivity, specificity, positive and negative predictive values were extracted, and the effect of GPC-3 targeted therapy on HCC was also evaluated.

RESULTS

GPC-3 plays a crucial role in HCC cell proliferation and metastasis. It mediates oncogenesis involving signaling pathways during hepatocyte malignant transformation. GPC-3 expression is increased in atypical hyperplasia and cancerous tissues. GPC-3 levels in HCC patients are related to HBV infection, TNM stage, periportal cancerous embolus, and extrahepatic metastasis. The diagnostic accuracy of the combination of serum GPC-3 and alpha-fetoprotein in HCC is up to 94.3%. Down-regulation of GPC-3 with specific siRNA or anti-GPC-3 antibody alters cell migration, metastasis and invasion behaviors. The nude mice xenograft tumor growth is inhibited by silencing GPC-3 gene transcription.

CONCLUSION

Oncofetal GPC-3 is a highly specific biomarker for the diagnosis of HCC and a promising target molecule for HCC gene therapy.

Genetic polymorphisms in antioxidant enzyme genes and susceptibility to hepatocellular carcinoma in Chinese population: a case-control study

An increased oxidant burden has been implicated in hepatocarcinogenesis, and several antioxidant enzymes counteract potential oxidative damage. So, polymorphisms in the genes encoding antioxidant enzymes may play an important role in the development of hepatocellular carcinoma (HCC). To test this hypothesis, we investigated the association of polymorphisms in antioxidant enzyme genes, including three superoxide dismutases (SODs), catalase (CAT), and glutathione peroxidase (GPx), with HCC in a Chinese population consisting of 434 HCC patients and 480 control subjects. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were estimated by unconditional logistic regression. For the ECSOD Ala40Thr polymorphism, a significant association was observed between this polymorphism and HCC risk in non-hepatitis B virus (HBV) carriers but not in HBV carriers, and individuals with one 40Thr allele (Ala/Thr genotype) (OR = 2.13, 95 % CI = 1.25-3.64, P = 0.006) or at least one 40Thr allele (Ala/Thr and Thr/Thr genotype) (OR = 1.90, 95 % CI = 1.15-3.15, P = 0.012) showed significantly higher risk to HCC, compared with Ala/Ala genotype. No significant associations were observed between three other polymorphisms (MnSOD Ala16Val, CAT-262C/T, GPx Pro198Leu) and HCC susceptibility in both HBV carriers and non-HBV carriers. Furthermore, no other signs of combined effects, except for a combined effect of ECSOD Ala40Thr and MnSOD Val16Ala in non-HBV carriers, were observed for each combination of these four polymorphisms. In conclusion, our results indicate that the antioxidant enzyme gene polymorphisms at least partially contribute to the susceptibility to HCC.

Oncofetal glypican-3: Specific diagnosis and targeted-therapy for primary liver cancer

The development and progression of primary hepatocellular cancer (PHC) are a multi- factorial, multi-step, and multi-center complex process. Its early diagnosis and effective treatments are of the most importance. Glypican-3 (GPC-3) plays a crucial role in PHC progression. Increased GPC-3 expression has been found during hepatocyte malignant transformation. GPC-3 levels in PHC patients are related to HBV infection, TNM stage, periportal cancerous embolus, and extra-hepatic metastasis. Circulating GPC-3 or GPC-3 mRNA with AFP enhances the positive rate up to 94.3% for PHC diagnosis. Down-regulating GPC-3 by specific siRNA could alter liver cancer cell biological behaviors such as migration, metastasis, and invasion; and inhibit nude mouse xenograft growth with decreased β-catenin, p-GSK3β, and cyclin D1 expression, suggesting that oncofetal GPC-3 is not only a specific diagnostic biomarker for PHC, but also a promising target for PHC therapy.

Targeting the tumor stroma in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and deadly cancers worldwide. In ninety percent of the cases it develops as a result of chronic liver damage and it is thus a typical inflammation-related cancer characterized by the close relation between the tumor microenvironment and tumor cells. The stromal environment consists out of several cell types, including hepatic stellate cells, macrophages and endothelial cells. They are not just active bystanders in the pathogenesis of HCC, but play an important and active role in tumor initiation, progression and metastasis. Furthermore, the tumor itself influences these cells to create a background that is beneficial for sustaining tumor growth. One of the key players is the hepatic stellate cell, which is activated during liver damage and differentiates towards a myofibroblast-like cell. Activated stellate cells are responsible for the deposition of extracellular matrix, increase the production of angiogenic factors and stimulate the recruitment of macrophages. The increase of angiogenic factors (which are secreted by macrophages, tumor cells and activated stellate cells) will induce the formation of new blood vessels, thereby supplying the tumor with more oxygen and nutrients, thus supporting tumor growth and offering a passageway in the circulatory system. In addition, the secretion of chemokines by the tumor cells leads to the recruitment of tumor associated macrophages. These tumor associated macrophages are key actors of cancer-related inflammation, being the main type of inflammatory cells infiltrating the tumor environment and exerting a tumor promoting effect by secreting growth factors, stimulating angiogenesis and influencing the activation of stellate cells. This complex interplay between the several cell types involved in liver cancer emphasizes the need for targeting the tumor stroma in HCC patients.

Metformin sensitizes hepatocellular carcinoma to arsenic trioxide-induced apoptosis by downregulating Bcl2 expression

Hepatocellular carcinoma (HCC) is a highly malignant tumor that can evolve rapidly to acquire resistance to conventional chemotherapies. Arsenic trioxide (ATO) is a traditional Asian medicine, and a phase II study has shown that treatment with ATO alone was not effective against HCC. Bcl2 is an antiapoptotic protein that regulates chemotherapy in HCC. Metformin is reported to decrease Bcl2 expression, and the purpose of this study was to verify whether metformin could potentiate the anti-HCC efficacy of ATO in vitro. In the present study, we used metformin and ATO alone or in combination and then tested proliferation, apoptosis, and Bcl2 level of HCC cells. The results showed that metformin enhanced both the proliferation-inhibiting and apoptosis-inducing effects of ATO on HCC cell lines HepG2 and BEL7402. Furthermore, this activity proceeded via a mechanism involving metformin-induced downregulation of Bcl2. A combination of ATO and metformin is therefore a potentially promising approach for HCC therapy.