Expression and role of epithelial cell adhesion molecule in dysplastic nodule and hepatocellular carcinoma

Detection of Hepatocellular Carcinoma in an Orthotopic Patient-Derived Xenograft with an Epithelial Cell Adhesion Molecule-Specific Peptide

Hepatocellular carcinoma (HCC) has emerged as a major contributor to the worldwide cancer burden. Improved methods are needed for early cancer detection and image-guided surgery. Peptides have small dimensions that can overcome delivery challenges to achieve high tumor concentrations and deep penetration. We used phage display methods to biopan against the extra-cellular domain of the purified EpCAM protein, and used IRDye800 as a near-infrared (NIR) fluorophore. The 12-mer sequence HPDMFTRTHSHN was identified, and specific binding to EpCAM was validated with HCC cells in vitro. A binding affinity of kd = 67 nM and onset of k = 0.136 min-1 (7.35 min) were determined. Serum stability was measured with a half-life of T1/2 = 2.6 h. NIR fluorescence images showed peak uptake in vivo by human HCC patient-derived xenograft (PDX) tumors at 1.5 h post-injection. Also, the peptide was able to bind to foci of local and distant metastases in liver and lung. Peptide biodistribution showed high uptake in tumor versus other organs. No signs of acute toxicity were detected during animal necropsy. Immunofluorescence staining of human liver showed specific binding to HCC compared with cirrhosis, adenoma, and normal specimens.

The Role of Epithelial Cell Adhesion Molecule Cancer Stem Cell Marker in Evaluation of Hepatocellular Carcinoma

Background and Objectives: Hepatocellular carcinoma (HCC) is a prevalent form of malignancy that is characterized by high mortality rates and prognosis that remain suboptimal, largely due to treatment resistance mechanisms. Recent studies have implicated cancer stem cells (CSCs), particularly those expressing epithelial cell adhesion molecule (EpCAM), in HCC progression and resistance. In the present study, we sought to assess EpCAM expression in HCC patients and its correlation with various clinicopathological parameters. Materials and Methods: Tissue samples from 42 HCC patients were subjected to immunohistochemical staining to evaluate EpCAM expression. Clinicopathological data were obtained including the size, grade and stage of tumors, vascular invasion status, alpha-fetoprotein levels, and cirrhosis status. The Chi square and Fisher's exact tests were employed to assess the association between categorical groups. Independent Student-t test or Mann-Whitney U test was used to investigate the association between continuous patient characteristics and survival. Results: Immunohistochemical analysis revealed EpCAM expression in 52.5% of HCC cases. EpCAM-positive tumors exhibited characteristics indicative of aggressive disease, including larger tumor sizes (p = 0.006), greater tumor multiplicity (p = 0.004), higher grades (p = 0.002), more advanced stages (p = 0.003), vascular invasion (p = 0.023), elevated alpha-fetoprotein levels (p = 0.013), and cirrhosis (p = 0.052). Survival analysis demonstrated that EpCAM expression was significantly associated with lower overall rates of survival and higher rates of recurrence in HCC patients. Conclusions: Our findings suggest that EpCAM expression may serve as a prognostic biomarker for HCC with a potential role in patient management. Targeting EpCAM-positive CSCs may represent a promising approach to overcome treatment resistance and improve clinical outcomes in HCC. However, further investigation into the molecular mechanisms underlying EpCAM's role in HCC progression is warranted to facilitate the development of personalized therapeutic interventions.

Clinicopathological and prognostic value of epithelial cell adhesion molecule in solid tumours: a meta-analysis

Background

Malignant tumors, mainly solid tumors, are a significant obstacle to the improvement of life expectancy at present. Epithelial cell adhesion molecule (EpCAM), a cancer stem cell biomarker, showed widespread expression in most normal epithelial cells and most cancers. Although the clinical significance of EpCAM in various malignant solid tumors has been studied extensively, the latent relationships between EpCAM and pathological and clinical characteristics in solid tumors and differences in the roles of EpCAM among tumors have not been clearly determined. The destination point of this study was to analyze the value of EpCAM in solid tumors in clinicopathological and prognostic dimension using a meta-analysis approach.

Method and materials

A comprehensive and systematic search of the researches published up to March 7th, 2022, in PubMed, EMBASE, Web of Science, Cochrane library and PMC databases was performed. The relationships between EpCAM overexpression, clinicopathological characteristics, and survival outcomes were analyzed. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) and odds ratios (ORs) were estimated as indicators of the degree of correlation. This research was registered on PROSPERO (International prospective register of systematic reviews), ID: CRD42022315070.

Results

In total, 57 articles and 14184 cases were included in this study. High EpCAM expression had a significant coherence with a poorer overall survival (OS) (HR: 1.30, 95% CI: 1.08-1.58, P < 0.01) and a worse disease-free survival (DFS) (HR: 1.58, 95% CI: 1.28-1.95, P < 0.01), especially of gastrointestinal tumors' OS (HR: 1.50, 95% CI: 1.15-1.95, P < 0.01), and DFS (HR: 1.84, 95% CI: 1.52-2.33, P < 0.01). The DFS of head and neck tumors (HR: 2.33, 95% CI: 1.51-3.61, P < 0.01) was also associated with the overexpression of EpCAM. There were no positive relationships between the overexpression of EpCAM and sex (RR: 1.03, 95% CI: 0.99-1.07, P = 0.141), T classification (RR: 0.93, 95% CI: 0.82-1.06, P = 0.293), lymph node metastasis (RR: 0.85, 95% CI: 0.54-1.32, P = 0.461), distant metastasis (RR: 0.97, 95% CI: 0.84-1.10, P = 0.606), vascular infiltration (RR: 1.05, 95% CI: 0.85-1.29, P = 0.611), and TNM stage (RR: 0.93, 95% CI: 0.83-1.04, P = 0.187). However, the overexpression of EpCAM exhibited a significant association with the histological grades (RR: 0.88, 95% CI: 0.80-0.97, P < 0.01).

Conclusion

Based on pooled HRs, the positive expression of EpCAM was totally correlated to a worse OS and DFS in solid tumors. The expression of EpCAM was related to a worse OS in gastrointestinal tumors and a worse DFS in gastrointestinal tumors and head and neck tumors. Moreover, EpCAM expression was correlated with the histological grade. The results presented pointed out that EpCAM could serve as a prognostic biomarker for gastrointestinal and head and neck tumors.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42022315070.

Plasma Pattern of Extracellular Vesicles Isolated from Hepatitis C Virus Patients and Their Effects on Human Vascular Endothelial Cells

Hepatitis C virus (HCV) patients are at increased risk of cardiovascular disease (CVD). In this study, we aimed to evaluate the role of extracellular vesicles (EVs) as pathogenic factors for the onset of HCV-related endothelial dysfunction. Sixty-five patients with various stages of HCV-related chronic liver disease were enrolled in this case series. Plasma EVs were characterized and used to stimulate human vascular endothelial cells (HUVEC), which were examined for cell viability, mitochondrial membrane potential, and reactive oxygen species (ROS) release. The results showed that EVs from HCV patients were mainly of endothelial and lymphocyte origin. Moreover, EVs were able to reduce cell viability and mitochondrial membrane potential of HUVEC, while increasing ROS release. Those harmful effects were reduced by the pretreatment of HUVEC with the NLR family pyrin domain containing 3 (NLRP3)/AMP-activated protein kinase and protein kinase B blockers. In conclusion, in HCV patients, we could highlight a circulating pattern of EVs capable of inducing damage to the endothelium. These data represent a novel possible pathogenic mechanism underlying the reported increase of CVD occurrence in HCV infection and could be of clinical relevance also in relation to the widespread use of antiviral drugs.

rs62139665 Polymorphism in the Promoter Region of EpCAM Is Associated With Hepatitis C Virus-Related Hepatocellular Carcinoma Risk in Egyptians

Hepatocellular carcinoma (HCC) is a universal health problem that is particularly alarming in Egypt. The major risk factor for HCC is hepatitis C virus (HCV) infection which is a main burden in Egypt. The epithelial cell adhesion molecule (EpCAM) is a stem cell marker involved in the tumorigenesis and progression of many malignancies, including HCC. We investigated the association of -935 C/G single nucleotide polymorphism in EpCAM promoter region (rs62139665) with HCC risk, EpCAM expression and overall survival in Egyptians. A total of 266 patients (128 HCV and 138 HCC cases) and 117 age- and sex-matched controls participated in this study. Genotyping, performed using allelic discrimination and confirmed by sequencing, revealed a significant association between EpCAM rs62139665 and HCC susceptibility, with higher GG genotype and G allele distribution in HCC patients than in non-HCC subjects. Such association was not detected in HCV patients compared to controls. EpCAM gene expression levels, determined in blood by RT-qPCR, and its serum protein expression levels, determined by ELISA, were significantly higher in GG relative to GC+CC genotype carriers in HCV and HCC patients in a recessive model. ROC analysis of EpCAM protein levels revealed significant discriminatory power between HCC patients and non-HCC subjects, with improved diagnostic accuracy when combining α-fetoprotein and EpCAM compared to that of α-fetoprotein alone. Altogether, EpCAM rs62139665 polymorphism is significantly associated with HCC and with EpCAM gene and protein expression levels in the Egyptian population. Moreover, serum EpCAM levels may hold promise for HCC diagnosis and for improving the diagnostic accuracy of α-fetoprotein.

Aptamer-mediated doxorubicin delivery reduces HCC burden in 3D organoids model

Epithelial cell adhesion molecule (EpCAM) is a surface marker which is frequently overexpressed in hepatocellular carcinoma (HCC) but minimally expressed on mature hepatocytes. We developed a specific aptamer against EpCAM (EpCAM-apt) and tested its potential as a drug delivery agent for HCC. The targeting ability of EpCAM-apt was confirmed in vitro and in vivo after which the complex was conjugated with doxorubicin (Dox) to form EpCAM-apt-Dox. The targeting efficacy of the drug-loaded complex against liver cancer stem-like cells (LCSCs) and therapeutic effects in HCC were evaluated. EpCAM-expressing (EpCAM⁺) HCC cells showed characteristics of stem like cells including greater proliferative capacity and tumour sphere formation. EpCAM-apt-Dox selectively delivered Dox to EpCAM⁺ HCC cells with high drug retention and accumulation versus control. EpCAM-apt-Dox reduced the self-renewal capacity and stem-like cell frequency in vitro. Elimination of cancer stem-like cells (CSCs) with EpCAM-apt-Dox significantly inhibited the growth of HCC cells and patient-derived HCC organoids but exerted minimal cytotoxicity to normal liver organoids. Moreover, EpCAM-apt-Dox suppressed the growth of xenograft tumours derived from HCC organoids in vivo and prolonged mouse survival without inducing adverse effects to major organs. Thus, aptamer-based drug delivery to the stem-like cell population is a promising strategy for HCC treatment.

Immunotoxins Immunotherapy against Hepatocellular Carcinoma: A Promising Prospect

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world. Therefore, fighting against such cancer is reasonable. Chemotherapy drugs are sometimes inefficient and often accompanied by undesirable side effects for patients. On the other hand, the emergence of chemoresistant HCC emphasizes the need for a new high-efficiency treatment strategy. Immunotoxins are armed and rigorous targeting agents that can purposefully kill cancer cells. Unlike traditional chemotherapeutics, immunotoxins because of targeted toxicity, insignificant cross-resistance, easy production, and other favorable properties can be ideal candidates against HCC. In this review, the characteristics of proper HCC-specific biomarkers for immunotoxin targeting were dissected. After that, the first to last immunotoxins developed for the treatment of liver cancer were discussed. So, by reviewing the strengths and weaknesses of these immunotoxins, we attempted to provide keynotes for designing an optimal immunotoxin against HCC.

Advances in Liver Cancer Stem Cell Isolation and their Characterization

Over the last decade research on cancer stem cells (CSC) significantly contributed to a better understanding of tumor biology. Given their similarity to normal stem cells, i.e. self-renewal and pluripotency the need arises to develop robust protocols for the isolation and characterization of CSCs. As with other malignancies, hepatic tumors are composed of a heterogeneous population of cells including liver cancer stem cells (LCSC). Yet, a precise understanding of why stem cells become cancerous is still lacking. There is unmet need to develop robust protocols for the successful isolation of LCSCs from human tissue resection material as to assist in the development of molecular targeted therapies. Here we review the research progress made in the isolation and characterization of LCSCs by considering a wide range of cell surface markers and sorting methods, as applied to side populations, microsphere cultures and the gradient centrifugation method. We emphasize the different fluorescence activated cell sorting methods and the possibility to enrich LCSCs by immunomagnetic beads. We review the specificity of functional assays by considering ABCG transporter and ALDH1 enzyme activities and evaluate the in vivo tumorigenicity of LCSCs in highly sensitive bioassays. Finally, we evaluate different LCSC markers in association with viral and non-viral liver disease and explore the potential of novel drug delivery systems targeting CD133, EpCAM, CD13 and CD90 for the development of molecular targeted therapies. Graphical Abstract.

Hepatocellular carcinoma: Intratumoral EpCAM-positive cancer stem cell heterogeneity identifies high-risk tumor subtype

BACKGROUND

The translational interest in the intratumoral heterogeneity of hepatocellular carcinoma (HCC) has been increasing. The dismal prognosis of this pathology is linked to the features of the HCC harbouring cancer stem cells (CSC), represented by EpCAM-expression. However, the extent of the impact of intratumoral distribution of CSC-features, both on the recurrence after curative resection and on clinical outcome, remains unknown. To address this, we investigated the spatial heterogeneity of CSC-features with the aim of identifying the unique HCC patient subgroups amenable to adjuvant treatment.

METHODS

We designed a tissue microarray (TMA) from patients who had received liver resection between 2011 and 2017. Tumor specimens were sampled at multiple locations (n = 3-8). EpCAM-positivity was assessed for intensity and proportion by applying a score dividing three groups: (i) negative (E-/-); (ii) heterogeneous (E-/+); and (iii) homogeneous (E+/+). The groups were further analysed with regard to time-to-recurrence (TTR) and recurrence-free-survival (RFS).

RESULTS

We included 314 tumor spots from 69 patients (76.8% male, median age 66, liver cirrhosis/fibrosis 75.8%). The risk factors were alcohol abuse (26.2%), NASH (13.1%), HBV (15.5%), HCV (17.9%) and others (27.4%), representative of a typical Western cohort. E+/+ patients experienced significantly shorter TTR and RFS compared to E+/- and E-/- patients (TTR 5 vs. 19 months, p = 0.022; RFS 5 vs. 14 vs. 21 months, p = 0.016). Only homogeneous EpCAM-positivity correlated with higher AFP levels (> 400 ng/ml, p = 0.031).

CONCLUSIONS

Spatial heterogeneity of EpCAM-expression was markedly present in the cohort. Of note, only homogeneous EpCAM-expression correlated significantly with early recurrence, whereas heterogeneous EpCAM-expression was associated with clinical endpoints comparable to EpCAM-negativity. We identified a unique HCC subtype associated with a high risk of tumor recurrence.

Anti-Epcam Aptamer (Syl3c)-Functionalized Liposome for Targeted Delivery Of Doxorubicin: In Vitro And In Vivo Antitumor Studies in Mice Bearing C26 Colon Carcinoma

In this study, we have surface-functionalized PEGylated-nanoliposomal doxorubicin (DOX) with anti-EpCAM (epithelial cell adhesion molecule) aptamer via post-insertion of anti-EpCAM aptamer-conjugated DSPE-mPEG2000 into Caelyx® (ED-lip). The size, charge, release profile, and cytotoxicity and cellular uptake of formulation were determined. The characterization of the ED-lip demonstrated the slightly increase in size and PDI along with the decrease in zeta potential which indicated that post-insertion efficiently done. The results of flow cytometry and fluorescent microscopy have shown that ED-lip enhanced the rate of cell uptake on C26 cell line compared to Caelyx®. The ED-lip also had more cytotoxic effects than Caelyx® which indicated the efficacy of anti-EpCAM aptamer as targeting ligand. The pharmacokinetic and tissue biodistribution of formulations in mice bearing C26 tumors demonstrated that ED-lip did not affect the distribution profile of DOX compared to Caelyx® in animal model. In addition, ED-lip effectively improved the tumor accumulation of DOX and promoted survival of animals compared to Caelyx®. These results suggest that the functionalization of Caelyx® with anti-EpCAM aptamer is promising in cancer treatment and merits further investigation.

Genome-Wide RNAi Screen Identifies PMPCB as a Therapeutic Vulnerability in EpCAM+ Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a genetically heterogeneous disease for which a dominant actionable molecular driver has not been identified. Patients with the stem cell-like EpCAM+AFP+ HCC subtype have poor prognosis. Here, we performed a genome-wide RNAi screen to identify genes with a synthetic lethal interaction with EpCAM as a potential therapeutic target for the EpCAM+AFP+ HCC subtype. We identified 26 candidate genes linked to EpCAM/Wnt/β-catenin signaling and HCC cell growth. We further characterized the top candidate PMPCB, which plays a role in mitochondrial protein processing, as a bona fide target for EpCAM+ HCC. PMPCB blockage suppressed EpCAM expression and Wnt/β-catenin signaling via mitochondria-related reactive oxygen species production and FOXO activities, resulting in apoptosis and tumor suppression. These results indicate that a synthetic lethality screen is a viable strategy to identify actionable drivers of HCC and identify PMPCB as a therapeutically vulnerable gene in EpCAM+ HCC subpopulations. SIGNIFICANCE: This study identifies PMPCB as critical to mitochondrial homeostasis and a synthetic lethal candidate that selectively kills highly resistant EpCAM+ HCC tumors by inactivating the Wnt/β-catenin signaling pathway.

Overexpression of epithelial cell adhesion molecule as a predictor of poor outcome in patients with hepatocellular carcinoma

Cancer growth, metastasis and development are regulated by a number of genes, whose expression mediates important processes, including cellular plasticity, motility and internal interactions in the tumor microenvironment. The epithelial cell adhesion molecule (EpCAM) serves an important role in cell-cell migration and tumorigenicity, particularly metastasis. The aim of the present study was to measure EpCAM expression using immunohistochemistry and to investigate the association between clinicopathological features and prognosis in hepatocellular carcinoma (HCC). The results revealed that EpCAM expression may be a biomarker for poor prognosis in patients with HCC and may therefore be used to predict clinical outcome. The present study suggests that EpCAM expression in HCC can be considered as a routine biomarker for unfavorable prognosis and may provide a basis for the future development of anti-EpCAM-targeted therapy.

Immunohistochemical Coexpression of Epithelial Cell Adhesion Molecule and Alpha-Fetoprotein in Hepatocellular Carcinoma

BACKGROUND AND AIM

The epithelial cell adhesion molecule (EpCAM) has been proposed as a marker for cancer stem cells in human hepatocellular carcinoma (HCC) as well as in the development of novel target therapies. This study aimed to investigate the immunohistochemical expression of EpCAM and alpha-fetoprotein (AFP) in HCC patients and their association with clinicopathological characteristics.

METHODS

This study included Child-Pugh A HCC patients undergoing curative surgical resection.

RESULTS

A significant difference was observed in the ratio between the different phenotypes (p = 0.002), identifying 12 (29.3%) EPCAM positive tumors and 29 (70.7%) negative tumors. EpCAM+ expression was associated with AFP + (OR = 12.5, 95% CI, 1.9-84.1, p<0.001). In univariate analysis, a significant association was observed between AFP+ and EPCAM+ and the serum AFP level. A diameter of ≤ 5 cm was associated with EPCAM+, while angiolymphatic invasion was associated with APF+. In a multivariate analysis, only tumors of ≤ 5 cm were significantly associated with EpCAM+ (OR = 8.7; 95%CI, 1.27-100.0; p = 0.022). The overall survival rate was 74.9%, 69.4%, 69.4%, and 53.5% at 12, 24, 36, and 48 months, respectively.

CONCLUSION

A considerable number of patients with EpCAM+ HCC would benefit from a specific target therapy.

Surface markers of liver cancer stem cells and innovative targeted-therapy strategies for HCC

Liver cancer stem cells (LCSCs) have important roles in the occurrence, development, recurrence, therapy resistance and metastasis of hepatocellular carcinoma (HCC). Therefore, intensive studies are undergoing to identify the mechanisms by which LCSCs contribute to HCC invasion and metastasis, and to design more efficient treatments for this disease. With continuous efforts in LCSC research over the years, therapies targeting LCSCs are thought to have great potential for the clinical treatment and prognosis of liver cancer. Novel LCSC surface markers are continuously discovered and several have been used in targeted therapies to reduce HCC recurrence, metastasis, and drug resistance following tumor resection. The present review describes the surface markers characterizing LCSCs and the recent progress in therapies targeting these markers, including antibodies and polypeptides.

Clinicopathology of EpCAM and EGFR in Human Epithelial Ovarian Carcinoma

The objective of this study was to explore the expression of EpCAM and EGFR in human epithelial ovarian cancer (EOC) and their correlation with clinicopathological parameters.

The protein expression levels of epithelial cell adhesion molecule (EpCAM) and epidermal growth factor receptor (EGFR) were evaluated by immunohistochemistry in formalin-fixed paraffin-embedded specimens from 30 patients with epithelial ovarian carcinoma and 15 normal ovary tissues. Clinicopathological characteristics were gathered by retrospective review of the patients’ files. The correlation between EpCAM and EGFR expression, as well as their association with clinical pathological parameters were investigated. The SPSS 17.0 package was used to perform statistical analyses.

The positive expression rates of EpCAM and EGFR were significantly elevated in epithelial ovarian cancer tissues than in normal ovary tissues. The positive expressions of EpCAM and EGFR in EOC were associated with International Federation of Gynecology and Obstetrics (FIGO) stage and tumor differentiation, lymph node metastasis. Spearman correlation analysis demonstrated a significant positive association between EpCAM and EGFR expression in EOC.

The co-expression of EpCAM and EGFR may play an important role in the carcinogenesis of EOC and might provide a promising molecular therapeutic target.

Role of several cytokines and adhesion molecules in the diagnosis and prediction of survival of hepatocellular carcinoma

BACKGROUND AND STUDY AIMS

There is still need for accurate markers for early diagnosis of hepatocellular carcinoma (HCC) and assessment of prognosis. The aim of this study is to investigate interleukin (IL)-32, IL-1 beta, IL-18, vascular cell adhesion molecule (VCAM)-1, and epithelial cell adhesion molecule (EpCAM) in the diagnosis and assessment of prognosis of HCC.

PATIENTS AND METHODS

Fifty patients with HCC and 15 healthy volunteers were enroled into this prospective study. Serum samples were obtained at the first admission before any treatment was given. Serum IL-32, IL-1 beta, IL-18, VCAM-1, and EpCAM levels were determined using ELISA kits.

RESULTS

The mean age of the patient group and controls was 60±9years and 56±8years, respectively. The mean serum level of IL-32 was higher in patients with HCC than in the control subjects (65.1 vs. 14.1pg/mL; p<0.001). IL-18 levels were significantly higher in the HCC group (546.5 vs. 157.8pg/mL; p<0.001). EpCAM (20.3 vs. 1.5pg/mL; p<0.001) and VCAM (6.5 vs. 1.8μg/mL; p<0.001) levels were also higher in patients with HCC. The mean level of IL-1 beta in the HCC group was similar to that in the control subjects (1.9 vs. 1.9pg/mL; p=0.97). Fifty-eight per cent of the patients with HCC died at 7.3months (median). Cytokine levels except EpCAM did not correlate with survival (p>0.05). Alpha-foetoprotein, IL-32, IL-18, EpCAM, and VCAM had valuable cutoff levels to differentiate between patients with HCC and control group (p<0.001).

CONCLUSIONS

Although cytokines can be a diagnostic marker for HCC, they did not have any significant prognostic value in patients with HCC. Only EpCAM may be used to determine the prognosis of HCC, thereby assisting with treatment management.

Cancer stem cells in hepatocellular carcinoma--an immunohistochemical study with histopathological association

Background & objectives:

Cancer stem cells (CSCs) may be responsible for tumour recurrence and resistance to chemotherapy in hepatocellular carcinoma (HCC). This study was carried out to evaluate the association between histological parameters and liver CSCs (LCSC) in HCC, and to compare distribution of liver CSCs in HCC associated with and without hepatitis B virus (HBV) infection.

Methods:

Seventy nine tumours (49 surgical resections from 46 patients, and 30 from autopsy) were reviewed. Immunohistochemical staining for the LCSC marker EpCAM (epithelial cell adhesion molecule), liver progenitor cell (LPC) markers CK19 (cytokeratin 19) and neural cell adhesion molecule (NCAM) were performed and were associated with histological features of tumour behaviour.

Results:

Thirty three tumours (41.8%) showed positive staining for EpCAM. CK19 and NCAM expression were seen in 26 (32.9%) and four (5.1%) tumours, respectively. The expression of EpCAM and CK19 was significantly associated with each other (P<0.001). EpCAM expression was significantly associated with clinical and histological features indicating aggressive tumour behaviour, including younger age of onset, higher serum alpha foetoprotein (AFP) levels, tumour cell dedifferentiation, increased mitotic activity, and vascular invasiveness. There was no significant difference in expression of EpCAM, CK19 and NCAM between HBV positive and negative HCC.

Interpretation & conclusions:

The LCSC marker EpCAM was expressed in less than half of HCC, was independent of HBV aetiology, and was strongly associated with clinical and histological features of aggressive tumour behaviour. Positive staining for CK19 suggests a possible LPC origin of the EpCAM positive HCCs.

Hepatic stellate cells promote upregulation of epithelial cell adhesion molecule and epithelial-mesenchymal transition in hepatic cancer cells

Microenvironment plays an important role in epithelial-mesenchymal transition (EMT) and stemness of cells in hepatocellular carcinoma (HCC). Epithelial cell adhesion molecule (EpCAM) is known as a tumor stemness marker of HCC. To investigate the relationship between microenvironment and stemness, we performed an in vitro co-culture assay. Four HCC cell lines (HepG2, Hep3B, HuH-7 and PLC/PRF/5) were co-cultured with the TWNT-1 immortalized hepatic stellate cells (HSCs), which create a microenvironment with HCC. Cell proliferation ability was analyzed by flow cytometry (FCM) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while migration ability was assessed by a wound healing assay. Expression of EpCAM was analyzed by immunoblotting and FCM. HCC cell lines were co-cultured with TWNT-1 treated with small interfering RNA (siRNA) for TGF-β and HB-EGF; we then analyzed proliferation, migration ability and protein expression using the methods described above. Proliferation ability was unchanged in HCC cell lines co-cultured with TWNT-1. Migration ability was increased in HCC cell lines (HepG2, Hep3B, HuH-7 and PLC/PRF/5) directly (216.2±67.0, 61.0±22.0, 124.0±66.2 and 51.5±40.3%) and indirectly (102.5±22.0, 84.6±30.9, 86.1±25.7 and 73.9±29.7%) co-cultured with TWNT-1 compared with the HCC uni-culture. Immunoblot analysis revealed increased EpCAM expression in the HCC cell lines co-cultured with TWNT-1. Flow cytometry revealed that the population of E-cadherin-/N-cadherin+ and EpCAM-positive cells increased and accordingly, EMT and stemness in the HCC cell line were activated. These results were similar in the directly and indirectly co-cultured samples, indicating that humoral factors were at play. Conversely, HCC cell lines co-cultured with siRNA‑treated TWNT-1 showed decreased migration ability, a decreased population of EpCAM-positive and E-cadherin-/N-cadherin+ cells. Taken together, humoral factors secreted from TWNT-1 promote upregulation of EpCAM and EMT in hepatic cancer cells.

Management of hepatocellular carcinoma: Predictive value of immunohistochemical markers for postoperative survival

Hepatocellular carcinoma (HCC) accounts for over 90% of all primary liver cancers. With an ever increasing incidence trend year by year, it has become the third most common cause of death from cancer worldwide. Hepatic resection is generally considered to be one of the most effective therapies for HCC patients, however, there is a high risk of recurrence in postoperative HCC. In clinical practice, there exists an urgent need for valid prognostic markers to identify patients with prognosis, hence the importance of studies on prognostic markers in improving the prediction of HCC prognosis. This review focuses on the most promising immunohistochemical prognostic markers in predicting the postoperative survival of HCC patients.

Proliferative ductular reactions correlate with hepatic progenitor cell and predict recurrence in HCC patients after curative resection

Background

Ductular reactions (DRs) are well documented in many acute and chronic liver disease.The DRs are thought to be the transit amplifying cells deriving from activation of the stem/progenitor cell compartments of the liver. The aim of this study was to examine the presence of proliferative index of DR (PI-DR) and HPC markers’ expression in HCCs after curative hepatectomy, as well as their relationship with clinicopathological features and prognosis.

Results

Tissue microarray with peritumoral and intratumoral tissue samples of 120 HCCs after hepatectomy was analysed for peritumoral expression of proliferating cell nuclear antigen for PI-DR. Peritumoral and intratumoral expression status of HPC markers including EpCAM, OV6, CD133 and c-kit were also examined by immunohistochemistry. TMA analysis of HCCs revealed that peritumoral PI-DR strongly correlated with the degree of inflammation and fibrosis. The peritumoral PI-DR positively correlated with peritumoral HPC markers EpCAM, OV6, CD133 and c-kit expression. Moreover, there were highly significant correlations between peritumoral PI-DR and intratumoral HPC markers EpCAM, OV6, CD133 and c-kit expression. Further, multivariate analysis showed that peritumoral PI-DR was the independent prognostic factor for overall survival (HR; 3.316, P < 0.001), and peritumoral PI-DR had a better power to predict disease-free survival (HR; 2.618, P < 0.001).

Conclusions

Peritumoral PI-DR, as a valid surrogate for peritumoral and intratumoral expression of HPC markers, could be served as a potential prognostic marker for recurrence and survival in HCC after hepatectomy.

The role of nuclear EpICD in extrahepatic cholangiocarcinoma: association with β-catenin

After intramembranous proteolysis-mediated loss of the extracellular domain of the epithelial cell adhesion molecule (EpEx) and release of an intracellular domain (EpICD) into the cytoplasm, EpICD sequentially associates with FHL2 to form a nuclear complex with β-catenin and Lef-1. This association induces gene transcription involved in the activation of the oncogenic potential of epithelial cell adhesion molecule (EpCAM). We examined the localization and expression of EpEx, EpICD and β-catenin in surgical specimens of extrahepatic cholangiocarcinoma (ECC) from 79 patients and focused on the relationship between nuclear expression of EpICD and β-catenin. We also examined the role of EpICD by transfecting the EpICD cDNA in cholangiocarcinoma (CC) cell lines. There was a significant correlation between the nuclear expression of EpICD and β-catenin in ECC tissues. Frequent nuclear co-localization of EpICD and β-catenin was observed in cancer cells forming the invasive front. Nuclear expression of EpICD also significantly correlated with histologic grade of tumor. Overexpression of EpICD in the CC cells significantly increased the cell growth and proliferation. The overexpression of EpICD in the CC cells also increased the expression levels of the active form of β-catenin and EpCAM target genes, such as c-myc and cyclin D1. Furthermore, the overexpression of EpICD significantly enhanced the migration and invasiveness of CC cells. Conversely, the inhibition of EpCAM in EpCAM-overexpressing cells by siRNA significantly decreased cell proliferation, migration and invasion. These results indicate that the spatial localization of EpICD and its mutual interaction with β-catenin may be important in ECC progression and invasion.

Genetic variants in the EPCAM gene is associated with the prognosis of transarterial chemoembolization treated hepatocellular carcinoma with portal vein tumor thrombus

The epithelial cell adhesion molecule (EPCAM) is involved in the tumorigenesis and progression of many malignancies, including hepatocellular carcinoma (HCC). Single nucleotide polymorphisms (SNPs) of EPCAM have been reported to be with the risk and prognosis of several malignancies. However, the association of SNPs in EPCAM gene with the prognosis of HCC patients has never been investigated. In this study, two functional SNPs (rs1126497 and rs1421) in the EPCAM gene were selected and genotyped in a cohort of 448 unresectable Chinese HCC patients treated by TACE. The association of the two SNPs with the overall survival (OS) of patients was assessed by univariate and multivariate Cox proportional hazards model and Kaplan-Meier curve. Our data showed that there was no significant association between either SNP and OS of patients. However, in the stratified analysis, the variant-containing genotypes (WV+VV) of SNP rs1126497 exhibited a significant association with poorer OS in HCC patients who had portal vein tumor thrombus (PVTT) in multivariate analysis of Cox proportional hazard model (hazard ratio, 1.71; 95% confidence interval, 1.16–2.53, P = 0.007), and in Kaplan-Meier curve analysis (P = 0.023), comparing to those carrying wild-type genotype. Our results suggest that SNP rs1126497 in the EPCAM gene may serve as an independent prognosis biomarker for unresectable HCC patient with PVTT, which warranted further validating investigation.

Expression of stemness markers (CD133 and EpCAM) in prognostication of hepatocellular carcinoma

AIMS

The expression of stemness markers in hepatocellular carcinoma (HCC) is suggested to be associated with poor clinical outcome after surgical resection. There are few data on their independent prognostic role in addition to the existing AJCC TNM staging system.

METHODS AND RESULTS

The immunohistochemical expression of CD133, EpCAM, CK19 and CD56 was studied in a cohort of 282 surgical specimens collected from patients undergoing resection of primary HCC. CD133-positive HCCs were usually smaller in size (P = 0.002) and arose more frequently in cirrhotic liver (P = 0.002). CD133 expression was an independent prognostic factor for overall survival (hazard ratio 2.30, P < 0.001), and a highly potent prognostic factor in patients with stage I disease (hazard ratio 3.91, P = 0.001). EpCAM expression was associated with younger age (P < 0.001), smaller tumour size (P = 0.018) and poorer histological differentiation (P = 0.042). EpCAM immunoreactivity was an independent factor for disease-free survival in HCCs at all stages (hazard ratio 2.05, P = 0.001), stage II (hazard ratio 3.66, P = 0.010) and stages III/IV (hazard ratio 3.22, P = 0.001). Neither CK19 nor CD56 offered any independent prognostic value.

CONCLUSION

The prognostic role of CD133 was most significant in TNM stage I disease, while the prognostic role of EpCAM was more apparent in more advanced TNM stages.

An EpCAM/CD3 bispecific antibody efficiently eliminates hepatocellular carcinoma cells with limited galectin-1 expression

There have been several studies suggesting that cancer stem cells (CSCs) contribute to the high rates of recurrence and resistance to therapies observed in hepatocellular carcinoma (HCC). Epithelial cell adhesion molecule (EpCAM) has been demonstrated to be a biomarker of CSCs and a potential therapeutic target in HCC. Here, we prepared two anti-EpCAM monoclonal antibodies (1H8 and 2F2) and an anti-EpCAM bispecific T cell engager (BiTE) 1H8/CD3, which was derived from 1H8, and used them to treat HCC in vitro and in vivo. The results demonstrated that all of the developed anti-EpCAM antibodies specifically bound to EpCAM. Neither anti-EpCAM monoclonal antibody had obvious anti-HCC activities in vitro or in vivo. However, anti-EpCAM BiTE 1H8/CD3 induced strong peripheral blood mononuclear cell-dependent cellular cytotoxicity in Huh-7 and Hep3B cells but not EpCAM-negative SK-Hep-1 cells. Notably, 1H8/CD3 completely inhibited the growth of Huh-7 and Hep3B xenografts in vivo. Treatment of the Huh-7 HCC xenografts with 1H8/CD3 significantly suppressed tumor proliferation and reduced the expression of most CSC biomarkers. Intriguingly, galectin-1 (Gal-1) overexpression inhibited 1H8/CD3-induced lymphocytotoxicity in HCCs while knockdown of Gal-1 increased the lymphocytotoxicity. Collectively, these results indicate that anti-EpCAM BiTE 1H8/CD3 is a promising therapeutic agent for HCC treatment. Gal-1 may contribute to the resistance of HCC cells to 1H8/CD3-induced lysis.

Childhood hepatocellular carcinoma: a clinicopathological study of 12 cases with special reference to EpCAM

AIMS

To elucidate the characteristics of hepatocellular carcinoma (HCC) in children.

METHODS AND RESULTS

A retrospective search of our database identified 12 children with HCC (aged 10 months to 11 years; male/female ratio of 5:7). Their pathological features were compared with those of adult HCCs (n = 20), fibrolamellar HCCs (n = 14), and hepatoblastomas (n = 15). All childhood HCCs developed on a background of cirrhosis resulting from tyrosinaemia type 1 (n = 4), bile salt export transporter deficiency (n = 4), biliary atresia (n = 3), and long-standing total parenteral nutrition (n = 1). HCCs in cases of tyrosinaemia type 1 always had clear cell changes, solid architecture, and only mild nuclear atypia, whereas the morphological features of HCCs in the other conditions were basically similar to those of adult HCCs. On immunostaining, all cases of childhood HCC were positive for epithelial cell adhesion molecule (EpCAM); expression was diffuse (>50% of cancer cells) in 11 cases, and particularly strong in six children, all aged <3 years. In contrast, EpCAM was only focally expressed in three cases of adult HCC (15%). EpCAM was also expressed in most fibrolamellar HCCs and hepatoblastomas, but these two neoplasms differed from childhood HCCs in the expression of CK7, β-catenin, and p53.

CONCLUSIONS

The diffuse expression of EpCAM characterizes childhood HCC, and may indicate immaturity of neoplastic cells.