A quartet of cancer stem cell niches in hepatocellular carcinoma

Hepatocellular Carcinoma (HCC), the most prevalent type of primary liver cancer, is known for its aggressive behavior and poor prognosis. The Cancer Stem Cell theory, which postulates the presence of a small population of self-renewing cells called Cancer Stem Cells (CSCs), provides insights into various clinical and molecular features of HCC such as tumor heterogeneity, metabolic adaptability, therapy resistance, and recurrence. These CSCs are nurtured in the tumor microenvironment (TME), where a mix of internal and external factors creates a tumor-supportive niche that is continuously evolving both spatially and temporally, thus enhancing the tumor's complexity. This review details the origins of hepatic CSCs (HCSCs) and the factors influencing their stem-like qualities. It highlights the reciprocal crosstalk between HCSCs and the TME (hypoxic, vascular, invasive, and immune niches), exploring the signaling pathways involved and how these interactions control the malignant traits of CSCs. Additionally, it discusses potential therapeutic approaches targeting the HCSC niche and their possible uses in clinical practice.

Stem cell therapy for hepatocellular carcinoma and end-stage liver disease

Hepatocellular carcinoma (HCC) is a major health problem worldwide, especially for patients who are suffering from end-stage liver disease (ESLD). The ESLD is considered a great challenge for clinicians due to the limited chance for liver transplantation, which is the only curative treatment for those patients. Stem cell-based therapy as a part of regenerative medicine represents a promising application for ESLD patients. Many clinical trials were performed to assess the utility of bone marrow-derived stem cells as a potential therapy for patients with liver diseases. The aim of the present study is to present and review the various types of stem cell-based therapy, including the mesenchymal stem cells (MSCs), BM-derived mononuclear cells (BM-MNCs), CD34 + hematopoietic stem cells (HSCs), induced pluripotent stem cells (iPSCs), and cancer stem cells.Though this type of therapy achieved promising results for the treatment of ESLD, however still there is a confounding data regarding its clinical application. A large body of evidence is highly required to evaluate the stem cell-based therapy after long-term follow-up, with respect to the incidence of toxicity, immunogenicity, and tumorigenesis that developed in many patients.

The ALKBH5/SOX4 axis promotes liver cancer stem cell properties via activating the SHH signaling pathway

Hepatocellular carcinoma (HCC), featured with high prevalence and poor prognosis, is the major cause of cancer-related deaths worldwide. As a subgroup of liver cancer cells capable of differentiation, tumorigenesis and self-renewal, liver cancer stem cells (LCSCs) serve as one of the reasons leading to HCC progression and therapeutic resistance. Therefore, in-depth exploration of novel molecular biomarkers related to LSCSs is of great necessity. In our study, we found that human AlkB homolog H5 (ALKBH5) expression was enriched in LCSCs, which could foster proliferation, invasion and migration of the HCC cells. Mechanically, ALKBH5 positively mediated the expression of SOX4 via demethylation, and SOX4 promoted SHH expression at the transcriptional level to activate sonic hedgehog (SHH) signaling pathway. Furthermore, exosomes derived from CD133+ HCC cells could transmit ALKBH5 into THP-1 cells, which might be associated with M2 polarization of macrophages. In summary, the ALKBH5/SOX4 axis plays a significant role in exacerbating LCSC properties via activating SHH signaling pathway, and ALKBH5 could be a critical effector related to macrophage M2 polarization. These findings might provide a promising new biomarker for HCC diagnosis and treatment.

Heterogeneity of Cholangiocarcinoma Immune Biology

Cholangiocarcinomas (CCAs) are aggressive tumors arising along the biliary tract epithelium, whose incidence and mortality are increasing. CCAs are highly desmoplastic cancers characterized by a dense tumor microenvironment (TME), in which each single component plays a fundamental role in shaping CCA initiation, progression and resistance to therapies. The crosstalk between cancer cells and TME can affect the recruitment, infiltration and differentiation of immune cells. According to the stage of the disease and to intra- and inter-patient heterogeneity, TME may contribute to either protumoral or antitumoral activities. Therefore, a better understanding of the effect of each immune cell subtype may open the path to new personalized immune therapeutic strategies for the management of CCA. In this review, we describe the role of immune cells in CCA initiation and progression, and their crosstalk with both cancer-associated fibroblasts (CAFs) and the cancer-stem-cell-like (CSC) niche.

Portal vein tumor thrombosis in hepatocellular carcinoma: molecular mechanism and therapy

Portal vein tumor thrombosis (PVTT), a common complication of advanced hepatocellular carcinoma (HCC), remains the bottleneck of the treatments. Liver cancer cells potentially experienced multi-steps during PVTT process, including cancer cells leave from cancer nest, migrate in extracellular matrix, invade the vascular barrier, and colonize in the portal vein. Accumulated evidences have revealed numerous of molecular mechanisms including genetic and epigenetic regulation, cancer stem cells, immunosuppressive microenvironment, hypoxia, et al. contributed to the PVTT formation. In this review, we discuss state-of-the-art PVTT research on the potential molecular mechanisms and experimental models. In addition, we summarize PVTT-associated clinical trials and current treatments for PVTT and suppose perspectives exploring the molecular mechanisms and improving PVTT-related treatment for the future.

Cancer Stem Cells in Hepatocellular Carcinoma: Intrinsic and Extrinsic Molecular Mechanisms in Stemness Regulation

Hepatocellular carcinoma (HCC) remains the most predominant type of liver cancer with an extremely poor prognosis due to its late diagnosis and high recurrence rate. One of the culprits for HCC recurrence and metastasis is the existence of cancer stem cells (CSCs), which are a small subset of cancer cells possessing robust stem cell properties within tumors. CSCs play crucial roles in tumor heterogeneity constitution, tumorigenesis, tumor relapse, metastasis, and resistance to anti-cancer therapies. Elucidation of how these CSCs maintain their stemness features is essential for the development of CSCs-based therapy. In this review, we summarize the present knowledge of intrinsic molecules and signaling pathways involved in hepatic CSCs, especially the CSC surface markers and associated signaling in regulating the stemness characteristics and the heterogeneous subpopulations within the CSC pool. In addition, we recapitulate the effects of crucial extrinsic cellular components in the tumor microenvironment, including stromal cells and immune cells, on the modulation of hepatic CSCs. Finally, we synopsize the currently valuable CSCs-targeted therapy strategies based on intervention in these intrinsic and extrinsic molecular mechanisms, in the hope of shedding light on better clinical management of HCC patients.

Babao Dan is a robust anti-tumor agent via inhibiting wnt/β-catenin activation and cancer cell stemness

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese Medicine (TCM) is being increasingly used worldwide due to its diverse efficacy and relatively low side effects. Babao Dan (BBD) is a well-known TCM formula that is currently used for the effective treatment of various cancers, however its underlying molecular mechanism remains unknown.

AIM OF THE STUDY

Tumor growth and tumor recurrence are characterized by two distinct populations of cells, namely the well-differentiated cancer cells composing the majority of tumor bulk, and cancer stem cells (CSCs) involved in tumor relapse, which are both strongly associated with excessive activation of Wnt/β-catenin signaling. Our study aims to elucidate the underlying molecular mechanisms associated with the anti-tumor proliferative effects of Babao Dan (BBD).

MATERIALS AND METHODS

We used a hepatoblastoma cell line HepG2 with stem cell-like traits that harbors a constitutively active mutant of β-catenin in order to study the anti-tumor ability of BBD via targeting Wnt/β-catenin signaling.

RESULTS

BBD robustly attenuated both the intrinsic and extrinsic activation of Wnt/β-catenin pathway in HepG2 hepatoblastoma cells, as well as Wnt target genes. Moreover, BBD significantly inhibited both the proliferation of well-differentiated cancer cells, as well as the stem-like property of CSCs as evidenced by EpCAM, a Wnt target gene and a novel marker of cancer cell stemness. In addition, mice administered with BBD using HepG2 cell line derived xenograft model had marked reductions in tumor size and weight, as well as significantly decreased expressions of Wnt target genes and cancer cell stemness.

CONCLUSION

Our findings elucidated the underlying molecular mechanisms associated with the robust anti-tumor effects of BBD via potent inhibition of Wnt/β-catenin signaling, and implicate its use in the clinical treatment of cancers.

DT389-YP7, a Recombinant Immunotoxin against Glypican-3 That Inhibits Hepatocellular Cancer Cells: An In Vitro Study

Hepatocellular carcinoma (HCC) is one of the high-metastatic types of cancer, and metastasis occurs in one-third of patients with HCC. To maintain the effectiveness of drug compounds on cancer cells and minimize their side effects on normal cells, it is important to use new approaches for overcoming malignancies. Immunotoxins (ITs), an example of such a new approach, are protein-structured compounds consisting of toxic and binding moieties which can specifically bind to cancer cells and efficiently induce cell death. Here, we design and scrutinize a novel immunotoxin against an oncofetal marker on HCC cells. We applied a truncated diphtheria toxin (DT389) without binding domain as a toxin moiety to be fused with a humanized YP7 scFv against a high-expressed Glypican-3 (GPC3) antigen on the surface of HCC cells. Cytotoxic effects of this IT were investigated on HepG2 (GPC3⁺) and SkBr3 (GPC3⁻) cell lines as positive- and negative-expressed GPC3 antigens. The dissociation constant (Kd) was calculated 11.39 nM and 18.02 nM for IT and YP7 scfv, respectively, whereas only IT showed toxic effects on the HepG2 cell line, and decreased cell viability (IC50 = 848.2 ng/mL). Changing morphology (up to 85%), cell cycle arrest at G2 phase (up to 13%), increasing intracellular reactive oxygen species (ROSs) (up to 50%), inducing apoptosis (up to 38% for apoptosis and 23% for necrosis), and an almost complete inhibition of cell movement were other effects of immunotoxin treatment on HepG2 cells, not on SkBr3 cell line. These promising results reveal that this new recombinant immunotoxin can be considered as an option as an HCC inhibitor. However, more extensive studies are needed to accomplish this concept.

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.

Exosome-based hybrid nanostructures for enhanced tumor targeting and hyperthermia therapy

Recently, natural exosomes have attracted attention as an ideal drug carrier to overcome the limitations of existing drug delivery systems which are toxicity induction and low cancer-targeting performance. In this study, we propose an exosome-based hybrid nanostructure (EHN) with improved targeting ability and therapeutic efficacy against colorectal cancer by using exosomes isolated from the tumor cell line as a drug carrier. The proposed EHN can have high biocompatibility by using exosomes, a biologically derived material, and show improved targeting performance by adding a tumor-targeting ligand (folic acid). In addition, the proposed EHN is capable of chemotherapy because doxorubicin, an anticancer drug, is encapsulated by the exosome with high efficiency, and it can induce hyperthermia therapy because of the magnetic nanoparticles (MNPs) attached to the surface of exosomes. Through in vitro and in vivo experiments using a xenograft tumor mouse model, it was confirmed that the proposed EHN could exhibit increased apoptosis and excellent tumor growth inhibition ability. Therefore, the proposed EHN is expected to overcome the limitations of existing drug delivery systems and be utilized as an effective drug delivery system in cancer treatment.

Biomedical Entity Explorer: A Web Server for Biomedical Entity Exploration

Biomedical Entity Explorer (BEE) is a web server that can search for biomedical entities from a database of six biomedical entity types (gene, miRNA, drug, disease, single nucleotide polymorphism [SNP], pathway) and their gene associations. The search results can be explored using intersections, unions, and negations. BEE has integrated biomedical entities from 16 databases (Ensemble, PharmGKB, Genetic Home Reference, Tarbase, Mirbase, NCI Thesaurus, DisGeNET, Linked life data, UMLS, GSEA MsigDB, Reactome, KEGG, Gene Ontology, HGVD, SNPedia, and dbSNP) based on their gene associations and built a database with their synonyms, descriptions, and links containing individual details. Users can enter the keyword of one or more entities and select the type of entity for which they want to know the relationship for and by using set operations such as union, negation, and intersection, they can navigate the search results more clearly. We believe that BEE will not only be useful for biologists querying for complex associations between entities, but can also be a good starting point for general users searching for biomedical entities. BEE is accessible at (http://bike-bee.snu.ac.kr).

PLGA nanoparticles containing α-fetoprotein siRNA induce apoptosis and enhance the cytotoxic effects of doxorubicin in human liver cancer cell line

Hepatocellular carcinoma (HCC) is one of the most common cancers and is a leading cause of death. Delivery of therapeutic molecules, e.g., siRNA, to HCC cells could potentially be an alternative treatment for HCC. In this study, the siRNA targeting α-fetoprotein (AFP) mRNA was found to specifically induce apoptosis and significant cell death in HepG2 cells. It also enhanced the cytotoxic effects of doxorubicin by about two-fold, making it the candidate therapeutic molecule for HCC treatment. To deliver the siRNAs into HCC cells, the AFP siRNAs were loaded into the nanoparticles based on poly (lactic-co-glycolic) acid (PLGA). These nanoparticles induced apoptosis in HepG2 cells and synergistically increased the cytotoxicity of doxorubicin. In summary, the delivery of the AFP siRNA-loaded PLGA nanoparticles in combination with doxorubicin could be a very promising approach for the treatment of HCC.

Hepatocellular Carcinoma-The Influence of Immunoanatomy and the Role of Immunotherapy

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related morbidity and mortality worldwide. Most patients are diagnosed with advanced disease, limiting their options for treatment. While current treatments are adequate for lower staged disease, available systemic treatments are limited, with marginal benefit at best. Chimeric antigen receptor (CAR) T cell therapy, effective in treating liquid tumors such as B-cell lymphoma, presents a potentially promising treatment option for advanced HCC. However, new challenges specific to solid tumors, such as tumor immunoanatomy or the immune cell presence and position anatomically and the tumor microenvironment, need to be defined and overcome. Immunotherapy currently in use must be re-engineered and re-envisioned to treat HCC with the hopes of ushering in an answer to advanced stage solid tumor disease processes. Future therapy options must address the uniqueness of the tumors under the umbrella of HCC. This review strives to summarize HCC, its staging system, current therapy and immunotherapy medications currently being utilized or studied in the treatment of HCC with the hopes of highlighting what is being done and suggesting what needs to be done in the future to champion this therapy as an effective option.

Cancer Stem Cell Functions in Hepatocellular Carcinoma and Comprehensive Therapeutic Strategies

Hepatocellular carcinoma (HCC) is a significant cause of cancer-related mortality owing to resistance to traditional treatments and tumor recurrence after therapy, which leads to poor therapeutic outcomes. Cancer stem cells (CSC) are a small subset of tumor cells with the capability to influence self-renewal, differentiation, and tumorigenesis. A number of surface markers for liver cancer stem cell (LCSC) subpopulations (EpCAM, CD133, CD44, CD13, CD90, OV-6, CD47, and side populations) in HCC have been identified. LCSCs play critical roles in regulating HCC stemness, self-renewal, tumorigenicity, metastasis, recurrence, and therapeutic resistance via genetic mutations, epigenetic disruption, signaling pathway dysregulation, or alterations microenvironment. Accumulating studies have shown that biomarkers for LCSCs contribute to diagnosis and prognosis prediction of HCC, supporting their utility in clinical management and development of therapeutic strategies. Preclinical and clinical analyses of therapeutic approaches for HCC using small molecule inhibitors, oncolytic measles viruses, and anti-surface marker antibodies have demonstrated selective, efficient, and safe targeting of LCSC populations. The current review focuses on recent reports on the influence of LCSCs on HCC stemness, tumorigenesis, and multiple drug resistance (MDR), along with LCSC-targeted therapeutic strategies for HCC.

High RPS11 level in hepatocellular carcinoma associates with poor prognosis after curative resection

Background

Ribosomal protein S11 (RPS11), a member of ribosomal protein family, is reported to overexpress in diverse malignancies and correlates with tumor recurrence. However, our current knowledge on RPS11 in hepatocellular carcinoma (HCC) remains limited. In this study, we are going to explore the potential prognostic value of RPS11 in HCC patients after curative resection.

Methods

Immunohistochemistry (IHC) was performed to evaluate RPS11 expression on tissue microarrays in training cohort comprising 182 HCC patients and validation cohort enrolling 90 HCC patients in Zhongshan Hospital, Fudan University. Western blot and quantitative reverse transcription PCR (qRT-PCR) were also used to determine the expression level of RPS11 in liver cell lines. Two nomograms, calibration curves and decision curve analysis (DCA) were further performed to assess the performance of RPS11 level in predicting clinical outcomes of HCC patients. Additionally, single-sample gene-set enrichment analysis (ssGSEA) was conducted in TCGA liver cancer database to investigate the potential biological pathways involved in RPS11.

Results

Both increased mRNA and protein levels of RPS11 were observed in most HCC cell lines when compared to the normal hepatocytes, and high tumor RPS11 level was associated with shorter overall survival (OS) and recurrence-free survival (RFS) of HCC patients after curative resection. Univariate and multivariate analysis indicated that RPS11 was an independent prognostic factor in HCC. Two nomograms, calibration and DCA curves were further established and displayed a superior prognostic accuracy of OS and RFS, and showed more clinical benefits than traditional staging systems in HCC. Furthermore, several pathways and molecules related to tumor resistance, survival and recurrence were enriched in high RPS11 expression by ssGSEA.

Conclusions

Tumorous RPS11 acts as a potential prognostic biomarker for HCC patients who received curative resection.

Epithelial Cell Adhesion Molecule mRNA Can be a Potential Marker to Predict Metastasis in Hepatocellular Carcinoma Patients

OBJECTIVES

Epithelial cell adhesion molecule [EpCAM] is a surface marker of cancer stem cells that can maintain the capacity for malignant proliferation, invasion, metastasis, and tumor recurrence; hence its detection among hepatocellular carcinoma [HCC] patients may be an important prognostic factor. The aim of this study was to detect EpCAM mRNA expression in the whole blood of HCC patients and normal control subjects to elucidate its clinico-pathological significance among patients with HCC.

METHODS

This study was conducted on 74 newly diagnosed HCC patients and forty normal control subjects. Both groups were subjected to the detection of EpCAM mRNA in the whole blood using reverse transcriptase polymerase chain reaction [RT- PCR] technique. EpCAM expression was compared with some of the established prognostic factors of HCC.

RESULTS

EpCAM was detected in 17.5% of the HCC cases and was not expressed in any of the normal control subjects. EpCAM positive cases showed higher serum levels of alpha- feto protein [AFP] and carcinoembryonic antigen [CEA]. Prevalence of EpCAM positivity gave significant results with distant metastasis, lymph node metastasis, and portal vein thrombosis.

CONCLUSION

EpCAM proved high specificity among HCC patients and its expression was associated with metastasis and portal vein thrombosis. Higher serum levels of CEA among the EpCAM positive patients may attract the attention to a subgroup of HCC patients who are more liable to develop metastasis.<br />.

Novel immunotherapeutic approaches for hepatocellular carcinoma treatment

INTRODUCTION

The introduction of immune checkpoint inhibitors has been lately proposed for the treatment of hepatocellular carcinoma (HCC) with respect to other cancer types. Several immunotherapeutic approaches are now under evaluation for HCC treatment including: i) antibodies acting as immune checkpoint inhibitors; ii) antibodies targeting specific tumor-associated antigens; iii) chimeric antigen receptor redirected T (CAR-T) cells targeting specific tumor-associated antigens; iv) vaccination strategies with tumor-specific epitopes. Areas covered: The review provides a wide description of the clinical trials investigating the efficacy of the main immunotherapeutic approaches proposed for the treatment of patients affected by HCC. Expert opinion: The balancing between immunostimulative and immunosuppressive factors in the context of HCC tumor microenvironment results in heterogeneous response rates to immunotherapeutic approaches such as checkpoint inhibitors, among HCC patients. In this context, it becomes crucial the identification of predictive factors determining the treatment response. A multiple approach using different biomarkers could be useful to identify the subgroup of HCC patients responsive to the treatment with a checkpoint inhibitor (as an example, nivolumab) as single agent, and to identify those patients in which other treatment regimens, such as the combination with sorafenib, or with locoregional therapies, could be more effective.

Cancer stem cells in hepatocellular carcinoma: an overview and promising therapeutic strategies

The poor clinical outcome of hepatocellular carcinoma (HCC) patients is ascribed to the resistance of HCC cells to traditional treatments and tumor recurrence after curative therapies. Cancer stem cells (CSCs) have been identified as a small subset of cancer cells which have high capacity for self-renewal, differentiation and tumorigenesis. Recent advances in the field of liver CSCs (LCSCs) have enabled the identification of CSC surface markers and the isolation of CSC subpopulations from HCC cells. Given their central role in cancer initiation, metastasis, recurrence and therapeutic resistance, LCSCs constitute a therapeutic opportunity to achieve cure and prevent relapse of HCC. Thus, it is necessary to develop therapeutic strategies to selectively and efficiently target LCSCs. Small molecular inhibitors targeting the core stemness signaling pathways have been actively pursued and evaluated in preclinical and clinical studies. Other alternative therapeutic strategies include targeting LCSC surface markers, interrupting the CSC microenvironment, and altering the epigenetic state. In this review, we summarize the properties of CSCs in HCC and discuss novel therapeutic strategies that can be used to target LCSCs.

Precision medicine based on surgical oncology in the era of genome-scale analysis and genome editing technology

Accumulated evidence suggests that multiple molecular and cellular interactions promote cancer evolution in vivo. Surgical oncology is of growing significance to a comprehensive understanding of the malignant diseases for therapeutic application. We have analyzed more than 1000 clinical samples from surgically resected tissue to identify molecular biomarkers and therapeutic targets for advanced malignancies. Cancer stemness and mitotic instability were then determined as the essential predictors of aggressive phenotype with poor prognosis. Recently, whole genome/exome sequencing showed a mutational landscape underlying phenotype heterogeneity in caners. In addition, integrated genomic, epigenomic, transcriptomic, metabolic, proteomic and phenomic analyses elucidated several molecular subtypes that cluster in liver, pancreatic, biliary, esophageal and gastroenterological cancers. Identification of each molecular subtype is expected to realize the precise medicine targeting subtype‐specific molecules; however, there are obstacle limitations to determine matching druggable targets or synthetic lethal interactions. Current breakthroughs in genome editing technology can provide us with unprecedented opportunity to recapitulate subtype‐specific pathophysiology in vitro and in vivo. Given a great potential, on‐demand editing system can design actionable strategy and revolutionize precision cancer medicine based on surgical oncology.

The Recent Advances on Liver Cancer Stem Cells: Biomarkers, Separation, and Therapy

As the third major reason of mortality related to cancer in the world, liver cancer is also the fifth most frequent cancer. Unluckily, a majority of patients succumb and relapse though many progresses have been made in detection and therapy of liver cancer. It has been put forward that in liver cancer, cancer stem cells (CSCs) hold main responsibility for the formation, invasion, metastasis, and recurrence of tumor. Strategies that are intended to target liver CSCs are playing a more and more significant role in supervising the development of liver cancer treatment and assessing new therapeutic methods. Herein, a brief review about molecule markers, signal pathways, separation, and treatment on liver cancer stem cells (LCSCs) is provided in this paper.

Glypican-3 Targeting Immunotoxins for the Treatment of Liver Cancer

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer, yet no effective therapeutics exist. This review provides an overview of the recent development of recombinant immunotoxins for the treatment of glypican-3 (GPC3) expressing HCC. GPC3 is a cell surface heparan sulfate proteoglycan that is overexpressed in HCC, but is absent from normal adult human tissues. Treatment of HCC with anti-GPC3 immunotoxins represents a new therapeutic option. Using phage display and hybridoma technologies, three high affinity antibodies (HN3, HS20 and YP7) have been generated against GPC3. Two of these antibodies (HN3 and HS20) have demonstrated the ability to inhibit Wnt/Yap signaling, leading to a reduction in liver cancer cell proliferation. By combining the HN3 antibody capable of inhibiting Wnt/Yap signaling with the protein synthesis inhibitory domain of the Pseudomonas exotoxin, a recombinant immunotoxin that exhibits a dual inhibitory mechanism was generated. This immunotoxin was found to be highly effective in the treatment of human HCCs in mouse xenograft models. Engineering of the toxin fragment to reduce the level of immunogenicity is currently being explored. The development of immunotoxins provides opportunities for novel liver cancer therapies.

Expression of connective tissue growth factor in the livers of non-viral hepatocellular carcinoma patients with metabolic risk factors

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) associated with metabolic risk factors, such as diabetes and obesity, has been increasing. However, the underlying mechanism that links these diseases remains unclear.

METHODS

We performed genome-wide expression analysis of human liver tissues of non-viral HCC patients with or without metabolic risk factors. The upregulated genes that associated with diabetes and obesity were investigated by in vitro and in vivo experiments, and immunohistochemistry of human liver tissues was performed.

RESULTS

Among the upregulated genes, connective tissue growth factor (CTGF) expression was induced to a greater extent by combined glucose and insulin administration to human hepatoma cells. Genome-wide expression analysis revealed upregulation of a chemokine network in CTGF-overexpressing hepatoma cells, which displayed an increased ability to induce in vitro activation of macrophages, and in vivo infiltration of liver macrophages. Immunohistochemistry of human liver tissues validated the correlations between CTGF expression and diabetes or obesity as well as activation of liver macrophages in patients with non-viral HCC. Recurrence-free survival was significantly poorer in the CTGF-positive patients compared with the CTGF-negative patients (p = 0.002). Multivariate analysis determined that CTGF expression (HR 2.361; 95 % CI 1.195-4.665; p = 0.013) and vascular invasion (HR 2.367; 95 % CI 1.270-4.410; p = 0.007) were independent prognostic factors for recurrence of non-viral HCC.

CONCLUSIONS

Our data suggest that CTGF could be involved in oncogenic pathways promoting non-viral HCC associated with metabolic risk factors via induction of liver inflammation and is expected to be a novel HCC risk biomarker and potential therapeutic target.

Nuclear EpICD expression and its role in hepatocellular carcinoma

Regulated intramembrane proteolysis of epithelial cell adhesion molecule (EpCAM) results in shedding of the extracellular domain (EpEX) and release of the intra-cellular domain (EpICD) into the cytoplasm. Released EpICD associates with FHL2, β-catenin and Lef-1 to form a nuclear complex and triggers oncogenic signaling. This study was conducted to examine the nuclear expression of EpICD in hepatocellular carcinoma (HCC) and to assess the role of EpICD in HCC. EpICD immunoexpression was examined in 100 cases of HCC using tissue microarrays and correlated with clinicopathological parameters. We also examined the role of EpICD in HCC using EpICD cDNA transfected HCC cell line and EpCAM silenced HCC cell line by small interfering RNA (siRNA). Nuclear expression of EpICD was observed in 19 of 100 (19%) cases. Nuclear expression of EpICD significantly correlated with nuclear expression of β-catenin, and Ki-67 labeling index. In addition, nuclear expression of EpICD was associated with higher histologic grade and advanced T category. Forced overexpression of EpICD in the HCC cell significantly increased the cell proliferation, migration and invasion. The overexpression of EpICD also increased the expression levels of the active form of β-catenin and c-myc and cyclin D1. In contrast, downregulation of EpCAM by siRNA decreased the cell proliferation, migration, invasion and the expression of active form of β-catenin, c-myc and cyclin D1. Our present data suggest that EpICD plays important roles in HCC progression by modulating expression of target genes of EpCAM.

The Therapeutic Targets of miRNA in Hepatic Cancer Stem Cells

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide malignancy and the third leading cause of cancer death in patients. Several studies demonstrated that hepatic cancer stem cells (HCSCs), also called tumor-initiating cells, are involved in regulation of HCC initiation, tumor progression, metastasis development, and drug resistance. Despite the extensive research, the underlying mechanisms by which HCSCs are regulated remain still unclear. MicroRNAs (miRNAs) are able to regulate a lot of biological processes such as self-renewal and pluripotency of HCSCs, representing a new promising strategy for treatment of HCC chemotherapy-resistant tumors. In this review, we synthesize the latest findings on therapeutic regulation of HCSCs by miRNAs, in order to highlight the perspective of novel miRNA-based anticancer therapies for HCC treatment.

Cancer stem cells in hepatocellular carcinoma: Therapeutic implications based on stem cell biology

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third most frequent cause of cancer-related death worldwide. Despite advances in its diagnosis and treatment, the prognosis of patients with advanced HCC remains unfavorable. Recent advances in stem cell biology and associated technologies have enabled the identification of minor components of tumorigenic cells, termed cancer stem cells (CSC) or tumor-initiating cells, in cancers such as HCC. Furthermore, because CSC play a central role in tumor development, metastasis and recurrence, they are considered to be a therapeutic target in cancer treatment. Hepatic CSC have been successfully identified using functional and cell surface markers. The analysis of purified hepatic CSC has revealed the molecular machinery and signaling pathways involved in their maintenance. In addition, epigenetic transcriptional regulation has been shown to be important in the development and maintenance of CSC. Although inhibitors of CSC show promise as CSC-targeting drugs, novel therapeutic approaches for the eradication of CSC are yet to be established. In this review, we describe recent progress in hepatic CSC research and provide a perspective on the available therapeutic approaches based on stem cell biology.

Construction, expression, and characterization of a recombinant immunotoxin targeting EpCAM

Epithelial cell adhesion molecule (EpCAM) is a type I transmembrane glycoprotein overexpressed in human epithelioma but with relatively low expression in normal epithelial tissues. To exploit this differential expression pattern for targeted cancer therapy, an EpCAM-targeted immunotoxin was developed and its antitumor activity was investigated in vitro. An immunotoxin (scFv2A9-PE or APE) was constructed by genetically fusing a truncated form (PE38KDEL) of Pseudomonas aeruginosa exotoxin with an anti-EpCAM single-chain variable fragment (scFv). ELISA and flow cytometry were performed to verify immunotoxin (scFv2A9-PE or APE) antigen-binding activity with EpCAM. Cytotoxicity was measured by MTT assay. Confocal microscopy was used to observe its cellular localization. The results of ELISA and flow cytometry revealed that the immunotoxin efficiently recognized recombinant and natural EpCAM. Its antigen-binding activity was relatively lower than 2A9. MTT assay confirmed potent reduction in EpCAM-positive HHCC (human hepatocellular carcinoma) cell viability (IC₅₀ 50 pM). Immunofluorescence revealed that the immunotoxin localized to endoplasmic reticulum 24 h later. In conclusion, we described the development of an EpCAM-targeted immunotoxin with potent activity against tumor cells, which may lay the foundation for future development of therapeutic antibody for the treatment of EpCAM-positive tumors.

Cancer stem cells as therapeutic targets of hepato-biliary-pancreatic cancers

Heterogeneity is one of the essential hallmarks of malignancies. Within bulk cancer cells, a striking variability differs in biological characteristics including the proliferation rate, cell-cell interaction, metastatic tendency and even sensitivity to anticancer therapies. Such diversity makes the investigation and treatment of the cancers complicated. Increasing evidence suggests this plasticity of cancers is a result of self-renewing and differentiation of a small subpopulation of cancer cells with stem-like properties, called cancer stem cells (CSCs). More importantly, CSCs are believed to be responsible for the resistance to conventional therapies and metastatic abilities in clinical practice. This review summarizes the molecular pathogenesis of hepato-biliary-pancreatic CSCs on the basis of the recent studies, and promising strategy of novel therapy targeting the signal transduction pathways or potentially epigenetic addictions of CSCs.

Magnetic-EpCAM nanoprobe as a new platform for efficient targeting, isolating and imaging hepatocellular carcinoma

Herein, magnetic-EpCAM nanoparticle (EpCAM-MNP) was developed and exploited as nanoprobe for targeting, isolating and imaging hepatocellular carcinoma.

Knockdown of EpCAM enhances the chemosensitivity of breast cancer cells to 5-fluorouracil by downregulating the antiapoptotic factor Bcl-2

Resistance to fluoropyrimidine-based chemotherapy is the main reason for the failure of cancer treatment, and drug resistance is associated with an inability of tumor cells to undergo apoptosis in response to treatment. Alterations in the expression of epithelial cell adhesion molecule (EpCAM) affect the sensitivity or resistance of tumor cells to anticancer treatment and the activity of intracellular signaling pathways. However, the role of EpCAM in the induction of apoptosis in breast cancer cells remains unclear. Here, we investigated the effect of EpCAM gene knockdown on chemosensitivity to 5-fluorouracil (5-FU) in MCF-7 cells and explored the underlying mechanisms. Our results showed that knockdown of EpCAM promoted apoptosis, inhibited cell proliferation and caused cell-cycle arrest. EpCAM knockdown enhanced the cytotoxic effect of 5-FU, promoting apoptosis by downregulating the expression of the anti-apoptotic protein Bcl-2 and upregulating the expression of the pro-apoptotic proteins Bax, and caspase3 via the ERK1/2 and JNK MAPK signaling pathways in MCF-7 cells. These results indicate that knockdown of EpCAM may have a tumor suppressor effect and suggest EpCAM as a potential target for the treatment of breast cancer.