Hepatocyte transformation is induced by laminin γ2 monomer.

Serum laminin-γ2 monomer (Lm-γ2m) is a potent predictive biomarker for hepatocellular carcinoma (HCC) onset in patients with hepatitis C infection who achieve a sustained virologic response with liver cirrhosis (LC) and for the onset of extrahepatic metastases in early-stage HCC. Although Lm-γ2m involvement in late-stage cancer progression has been well investigated, its precise roles in HCC onset remain to be systematically investigated. Therefore, we analyzed an HCC model, human hepatocytes and cholangiocytes, and surgically resected liver tissues from patients with HCC to understand the roles of Lm-γ2m in HCC onset. Ck-19- and EpCAM-positive hepatic progenitor cells (HPCs) in the liver of pdgf-c transgenic HCC mouse model with ductular reaction showed ectopic expression of Lm-γ2m. Forced expression of Lm-γ2m in hepatocytes adjacent to HPCs resulted in enhanced tumorigenicity, cell proliferation, and migration in immortalized hepatocytes, but not in cholangiocytes in vitro. Further, pharmacological inhibition of epidermal growth factor receptor (EGFR) and c-Jun activator JNK suppressed Lm-γ2m-induced hepatocyte transformation, suggesting the involvement of EGFR/c-Jun signaling in the transformation, leading to HCC development. Finally, immunohistochemical staining of HCC tissues revealed a high level of Lm-γ2 expression in the HPCs of the liver with ductular reaction in normal liver adjacent to HCC tissues. Overall, HPC-derived Lm-γ2m in normal liver with ductular reaction acts as a paracrine growth factor on surrounding hepatocytes and promotes their cellular transformation through the EGFR/c-Jun signaling pathway. Furthermore, this is the first report on Lm-γ2m expression detected in the normal liver with ductular reaction, a human precancerous lesion of HCC.

Successful second-line treatment with cabozantinib for hepatocellular carcinoma harboring cytoplasmic mesenchymal-epithelial transition factor amplification.

A 72-year-old man with metastatic hepatocellular carcinoma previously received first-line systemic therapy with atezolizumab plus bevacizumab. His disease was judged to be progressing 5 months after treatment initiation. Comprehensive genomic profiling revealed cytoplasmic mesenchymal-epithelial transition factor amplification. On the basis of an expert panel's recommendation, he received cabozantinib as second-line therapy. The tumors shrank markedly and continued to shrink 6 months after treatment. Comprehensive genomic profiling could provide useful information for selecting effective second-line treatments for patients with hepatocellular carcinoma after first-line immunotherapy.

BMP9-ID1 Pathway Attenuates N6-Methyladenosine Levels of CyclinD1 to Promote Cell Proliferation in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a highly lethal malignant neoplasm, and the involvement of bone morphogenetic protein 9 (BMP9) has been implicated in the pathogenesis of liver diseases and HCC. Our goal was to investigate the role of BMP9 signaling in regulating N6-methyladenosine (m6A) methylation and cell cycle progression, and evaluate the therapeutic potential of BMP receptor inhibitors for HCC treatment. We observed that elevated levels of BMP9 expression in tumor tissues or serum samples from HCC patients were associated with a poorer prognosis. Through in vitro experiments utilizing the m6A dot blotting assay, we ascertained that BMP9 reduced the global RNA m6A methylation level in Huh7 and Hep3B cells, thereby facilitating their cell cycle progression. This effect was mediated by an increase in the expression of the inhibitor of DNA-binding protein 1 (ID1). Additionally, using methylated RNA immunoprecipitation qPCR(MeRIP-qPCR), we showed that the BMP9-ID1 pathway promoted CyclinD1 expression by decreasing the m6A methylation level in the 5' UTR of mRNA. This occurred through the upregulation of the fat mass and obesity-associated protein (FTO) in Huh7 and Hep3B cells. In our in vivo mouse xenograft models, we demonstrated that blocking the BMP receptor with LDN-212854 effectively suppressed HCC growth and induced global RNA m6A methylation. Overall, our findings indicate that the BMP9-ID1 pathway promotes HCC cell proliferation by down-regulating the m6A methylation level in the 5' UTR of CyclinD1 mRNA. Targeting the BMP9-ID1 pathway holds promise as a potential therapeutic strategy for treating HCC.

Aldo-keto reductase family 1 member B10 is regulated by nucleos(t)ide analogues for chronic hepatitis B.

The number of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) patients persists even under nucleos(t)ide analogues (NAs) treatment. Aldo-keto reductase family 1 member B10 (AKR1B10) expression has been reported in advanced chronic liver diseases as well as cancer tissues. We observed an association between related to HCC incidence and serum AKR1B10 by analyzing patients under treatment with NAs. Serum AKR1B10 levels measured by ELISA were higher in HCC cases under NA treatment compared with non-HCC cases and were associated with lamivudine- and adefovir pivoxil-, but not entecavir- or tenofovir alafenamide-treated cases. The latter drugs did not increase AKR1B10 values even in HCC cases, suggesting that they influence the reduction of AKR1B10 in any cases. This analysis was supported by in-vitro examination, which showed reduced AKR1B10 expression by entecavir and tenofovir via immunofluorescence staining. In conclusion there was a relationship between HBV-related HCC incidence and AKR1B10 under nucleos(t)ide analogues, especially in the use of lamivudine and adefovir pivoxil, but entecavir and tenofovir had suppressive effects of AKR1B10.

Plasma Antithrombin III Levels Can Be a Prognostic Factor in Liver Cirrhosis Patients with Portal Vein Thrombosis.

Liver function influences the plasma antithrombin (AT)-III levels. AT-III is beneficial for patients with portal vein thrombosis (PVT) and low plasma AT-III levels. However, whether these levels affect prognosis in patients with cirrhosis-associated PVT remains unknown. This retrospective study involved 75 patients with cirrhosis and PVT treated with danaparoid sodium with or without AT-III. The plasma AT-III level was significantly lower in patients with liver failure-related death than in those with hepatocellular carcinoma (HCC)-related death (p = 0.005), although the Child-Pugh and albumin-bilirubin (ALBI) scores were not significantly different between these two groups. Receiver operating characteristic curve analysis of the plasma AT-III levels showed cutoff values of 54.0% at 5-year survival. Low plasma AT-III levels (<54.0%) were associated with significantly worse prognosis than high levels in both overall survival (p = 0.0013) and survival excluding HCC-related death (p < 0.0001). Low plasma AT-III (<54.0%) was also associated with a significantly worse prognosis among patients with Child-Pugh A/B or ALBI grade 1/2 (p < 0.0001). Multivariate analyses indicated that low plasma AT-III levels (<54.0%) were an independent prognostic factor for poor survival outcome. Low plasma AT-III levels may be associated with mortality, particularly liver failure-related death, independent of liver function.

Beta-Hydroxyisovaleryl-Shikonin Eradicates Epithelial Cell Adhesion Molecule-Positive Liver Cancer Stem Cells by Suppressing dUTP Pyrophosphatase Expression.

Cancer stem cells (CSCs) play an essential role in tumorigenesis, chemoresistance, and metastasis. Previously, we demonstrated that the development of hepatocellular carcinoma (HCC) is dictated by a subset of epithelial cell adhesion molecule-positive (EpCAM+) liver CSCs with the activation of Wnt signaling. In this study, we evaluated the expression of dUTP pyrophosphatase (dUTPase), which plays a central role in the development of chemoresistance to 5-fluorouracil, in EpCAM+ HCC cells. We further evaluated the effect of beta-hydroxyisovaleryl-shikonin (ß-HIVS), an ATP-noncompetitive inhibitor of protein tyrosine kinases, on HCC CSCs. EpCAM and dUTPase were expressed in hepatoblasts in human fetal liver, hepatic progenitors in adult cirrhotic liver, and a subset of HCC cells. Sorted EpCAM+ CSCs from HCC cell lines showed abundant nuclear accumulation of dUTPase compared with EpCAM-negative cells. Furthermore, treatment with the Wnt signaling activator BIO increased EpCAM and dUTPase expression. In contrast, ß-HIVS treatment decreased dUTPase expression. ß-HIVS treatment decreased the population of EpCAM+ liver CSCs in a dose-dependent manner in vitro and suppressed tumor growth in vivo compared with the control vehicle. Taken together, our data suggest that dUTPase could be a good target to eradicate liver CSCs resistant to 5-fluorouracil. ß-HIVS is a small molecule that could decrease dUTPase expression and target EpCAM+ liver CSCs.

Serum Laminin γ2 Monomer as a Diagnostic and Predictive Biomarker for Hepatocellular Carcinoma.

BACKGROUNDS AND AIMS: Structural dynamics of basement membrane components are still to be elucidated in the process of hepatocarcinogenesis. We evaluated the characteristics of HCC expressing laminin γ2 monomer (LG2m), a basement membrane component not detected in normal tissues, for HCC diagnosis. We further determined whether elevated serum LG2m is a risk factor for HCC development in patients with chronic hepatitis C (CHC). APPROACH AND RESULTS: In HCC cell lines, LG2m was expressed in alpha-fetoprotein (AFP)-negative, CD90-positive cells characterized by highly metastatic natures. Using 14 cell lines and 258 HCC microarray data, we identified that LG2m gene signature was associated with Hoshida's S1/Boyault's G3 molecular subclasses with poor prognosis, which could not be recognized by AFP. Serum LG2m was assessed in 24 healthy donors, 133 chronic liver disease patients, and 142 HCC patients, and sensitivity and specificity of LG2m testing for HCC diagnosis were 62.9% and 70.5%, respectively (cutoff, 30 pg/mL). We evaluated the consequence of LG2m elevation in two independent HCC cohorts (n = 47 and n = 81), and LG2m-high HCC showed poor prognosis with later development of distant organ metastasis (cutoff, 60 pg/mL). LG2m was slightly elevated in a subset of CHC patients, and Kaplan-Meier analysis indicated a high incidence of HCC (n = 70). For validation, we enrolled 399 CHC patients with sustained virological response (SVR) as a multicenter, prospective study, and serum LG2m elevation correlated with a high incidence of HCC in the CHC patients with SVR (P < 0.0001). CONCLUSIONS: LG2m is a predictive biomarker for the development of metastatic HCC. Elevated serum LG2m is an HCC risk in CHC patients who have achieved SVR.

Dickkopf-1 Promotes Angiogenesis and is a Biomarker for Hepatic Stem Cell-like Hepatocellular Carcinoma.

Cancer stemness evinces interest owing to the resulting malignancy and poor prognosis. We previously demonstrated that hepatic stem cell-like hepatocellular carcinoma (HpSC-HCC) is associated with high vascular invasion and poor prognosis. Dickkopf-1 (DKK-1), a Wnt signaling regulator, is highly expressed in HpSC-HCC. Here, we assessed the diagnostic and prognostic potential of serum DKK-1. Its levels were significantly higher in 391 patients with HCC compared with 205 patients with chronic liver disease. Receiver operating characteristic curve analysis revealed the optimal cutoff value of DKK-1 to diagnose HCC and predict the 3-year survival as 262.2 and 365.9 pg/mL, respectively. HCC patients with high-serum DKK-1 levels showed poor prognosis. We evaluated the effects of anti-DKK-1 antibody treatment on tumor growth in vivo and of recombinant DKK-1 on cell proliferation, invasion, and angiogenesis in vitro. DKK-1 knockdown decreased cancer cell proliferation, migration, and invasion. DKK-1 supplementation promoted angiogenesis in vitro; this effect was abolished by an anti-DKK-1 antibody. Co-injection of the anti-DKK-1 antibody with Huh7 cells inhibited their growth in NOD/SCID mice. Thus, DKK-1 promotes proliferation, migration, and invasion of HCC cells and activates angiogenesis in vascular endothelial cells. DKK-1 is a prognostic biomarker for HCC and a functional molecule for targeted therapy.

BMP9-ID1 Signaling Activates HIF-1α and VEGFA Expression to Promote Tumor Angiogenesis in Hepatocellular Carcinoma.

Since hepatocellular carcinoma (HCC) is a typical hypervascular malignant tumor with poor prognosis, targeting angiogenesis is an important therapeutic strategy for advanced HCC. Involvement of bone morphologic protein 9 (BMP9), a transforming growth factor-beta superfamily member, has recently been reported in the development of liver diseases and angiogenesis. Here, we aimed to elucidate the role of BMP9 signaling in promoting HCC angiogenesis and to assess the antiangiogenic effect of BMP receptor inhibitors in HCC. By analyzing HCC tissue gene expression profiles, we found that BMP9 expression was significantly correlated with angiogenesis-associated genes, including HIF-1α and VEGFR2. In vitro, BMP9 induced HCC cell HIF-1α/VEGFA expression and VEGFA secretion. Silencing of the inhibitor of DNA-binding protein 1 (ID1), a transcription factor targeted by BMP9 signaling, suppressed BMP9-induced HIF-1α/VEGFA expression and VEGFA secretion, resulting in decreased human umbilical vein endothelial cell (HUVEC) lumen formation. BMP receptor inhibitors, which inhibit BMP9-ID1 signaling, suppressed BMP9-induced HIF-1α/VEGFA expression, VEGFA secretion, and HUVEC lumen formation. In vivo, the BMP receptor inhibitor LDN-212854 successfully inhibited HCC tumor growth and angiogenesis by inhibiting BMP9-ID1 signaling. In summary, BMP9-ID1 signaling promotes HCC angiogenesis by activating HIF-1α/VEGFA expression. Thus, targeting BMP9-ID1 signaling could be a pivotal therapeutic option for advanced HCC.

FOXM1 Is a Novel Molecular Target of AFP-Positive Hepatocellular Carcinoma Abrogated by Proteasome Inhibition.

Alpha-fetoprotein (AFP) is an oncofetal protein that is elevated in a subset of hepatocellular carcinoma (HCC) with poor prognosis, but the molecular target activated in AFP-positive HCC remains elusive. Here, we demonstrated that the transcription factor forkhead box M1 (FOXM1) is upregulated in AFP-positive HCC. We found that FOXM1 expression was highly elevated in approximately 40% of HCC cases, and FOXM1-high HCC was associated with high serum AFP levels, a high frequency of microscopic portal vein invasion, and poor prognosis. A transcriptome and pathway analysis revealed the activation of the mitotic cell cycle and the inactivation of mature hepatocyte metabolism function in FOXM1-high HCC. The knockdown of FOXM1 reduced AFP expression and induced G2/M cell cycle arrest. We further identified that the proteasome inhibitor carfilzomib attenuated FOXM1 protein expression and suppressed cell proliferation in AFP-positive HCC cells. Carfilzomib in combination with vascular endothelial growth factor receptor 2 (VEGFR2) blockade significantly prolonged survival by suppressing AFP-positive HCC growth in a subcutaneous tumor xenotransplantation model. These data indicated that FOXM1 plays a pivotal role in the proliferation of AFP-positive liver cancer cells. Carfilzomib can effectively inhibit FOXM1 expression to inhibit tumor growth and could be a novel therapeutic option in patients with AFP-positive HCC who receive anti-VEGFR2 antibodies.

Development of novel diagnostic system for pancreatic cancer, including early stages, measuring mRNA of whole blood cells.

Pancreatic ductal adenocarcinoma (PDAC) is the most life-threating disease among all digestive system malignancies. We developed a blood mRNA PDAC screening system using real-time detection PCR to detect the expression of 56 genes, to discriminate PDAC from noncancer subjects. We undertook a clinical study to assess the performance of the developed system. We collected whole blood RNA from 53 PDAC patients, 102 noncancer subjects, 22 patients with chronic pancreatitis, and 23 patients with intraductal papillary mucinous neoplasms in a per protocol analysis. The sensitivity of the system for PDAC diagnosis was 73.6% (95% confidence interval, 59.7%-84.7%). The specificity for noncancer volunteers, chronic pancreatitis, and patients with intraductal papillary mucinous neoplasms was 64.7% (54.6%-73.9%), 63.6% (40.7%-82.8%), and 47.8% (26.8%-69.4%), respectively. Importantly, the sensitivity of this system for both stage I and stage II PDAC was 78.6% (57.1%-100%), suggesting that detection of PDAC by the system is not dependent on the stage of PDAC. These results indicated that the screening system, relying on assessment of changes in mRNA expression in blood cells, is a viable alternative screening strategy for PDAC.

Danaparoid sodium-based anticoagulation therapy for portal vein thrombosis in cirrhosis patients.

BACKGROUND: Portal vein thrombosis (PVT) is a common complication of cirrhosis. However, in patients with PVT and cirrhosis, there is no clear evidence supporting effective treatment modalities. In this study, we examined the effectiveness and safety of anticoagulation therapy using danaparoid sodium for PVT in patients with cirrhosis. METHODS: This retrospective study assessed 52 cirrhotic patients with PVT treated with danaparoid sodium for 2 weeks between November 2008 and September 2018. The primary outcome measure was the post-treatment status of PVT assessed by reduction in thrombus volume and safety of the therapeutic intervention. PVT status was evaluated with contrast-enhanced computed tomography (CECT). All patients received 1250 units of danaparoid sodium twice daily by intravenous injection for 14 days. Patients on antithrombin III (AT-III) combination therapy were additionally administered 1500 units of AT-III on days 1-5 and days 8-12. Effectiveness was evaluated by CECT from between days 13 and 18. The secondary outcome measure was the prognosis of PVT. RESULTS: All patients showed reduction in PVT volume without complications. Return of plasma AT-III level to > 70% during the treatment period contributes to ≥75% reduction of PVT volume. The prognosis in PVT patients depends on hepatic reserve capacity. When limited to Child-Pugh B and C liver cirrhosis patients, a ≥ 75% reduction of PVT volume improved the prognosis. CONCLUSIONS: Danaparoid sodium-based anticoagulation therapy was effective and safe for PVT in patients with cirrhosis. Return of plasma AT-III level to the normal range during the treatment period contributes to reduction of PVT volume. A reduction of ≥75% in PVT volume may improve the prognosis of Child-Pugh B and C decompensated cirrhosis patients with PVT.

The evolving concept of liver cancer stem cells.

Liver cancer is an often fatal malignant tumor with a high recurrence rate and chemoresistance. The major malignant phenotypes of cancer, including recurrence, metastasis, and chemoresistance, are related to the presence of cancer stem cells (CSCs). In the past few decades, CSCs have been identified and characterized in many tumors including liver cancer. Accumulated evidence has revealed many aspects of the biological behavior of liver CSCs and the mechanism of their regulation. Based on these findings, a number of studies have investigated eradication of liver CSCs. This review focuses on the recent advances in our understanding of the biology of liver CSCs and the development of strategies for their treatment.

Jagged1 DNA Copy Number Variation Is Associated with Poor Outcome in Liver Cancer.

Notch signaling abnormalities are reported to be involved in the acceleration of malignancy in solid tumors and stem cell formation or regeneration in various organs. We analyzed specific genes for DNA copy number variations in liver cancer cells and investigated whether these factors relate to clinical outcome. Chromosome 20p, which includes the ligand for Notch pathways, Jagged1, was found to be amplified in several types of hepatoma cells, and its mRNA was up-regulated according to α-fetoprotein gene expression levels. Notch inhibition using Jagged1 shRNA and γ-secretase inhibitors produced significant suppression of cell growth in α-fetoprotein-producing cells with suppression of downstream genes. Using in vivo hepatoma models, the administration of γ-secretase inhibitors resulted in reduced tumor sizes and effective Notch inhibition with widespread apoptosis and necrosis of viable tumor cells. The γ-secretase inhibitors suppressed cell growth of the epithelial cell adhesion molecule-positive fraction in hepatoma cells, indicating that Notch inhibitors could suppress the stem cell features of liver cancer cells. Even in clinical liver cancer samples, the expression of α-fetoprotein and Jagged1 showed significant correlation, and amplification of the copy number of Jagged1 was associated with Jagged1 mRNA expression and poor survival after liver cancer surgical resection. In conclusion, amplification of Jagged1 contributed to mRNA expression that activates the Jagged1-Notch signaling pathway in liver cancer and led to poor outcome.

Sporadic PCDH18 somatic mutations in EpCAM-positive hepatocellular carcinoma.

BACKGROUND: The relationship between specific genome alterations and hepatocellular carcinoma (HCC) cancer stem cells (CSCs) remains unclear. In this study, we evaluated the relationship between somatic mutations and epithelial cell adhesion molecule positive (EpCAM+) CSCs. METHODS: Two patient-derived HCC samples (HCC1 and HCC2) were sorted by EpCAM expression and analyzed by whole exome sequence. We measured PCDH18 expression level in eight HCC cell lines as well as HCC1 and HCC2 by real-time quantitative RT-PCR. We validated the identified gene mutations in 57 paired of HCC and matched non-cancerous liver tissues by Sanger sequence. RESULTS: Whole exome sequencing on the sorted EpCAM+ and EpCAM- HCC1 and HCC2 cells revealed 19,263 nonsynonymous mutations in the cording region. We selected mutations that potentially impair the function of the encoded protein. Ultimately, 60 mutations including 13 novel nonsense and frameshift mutations were identified. Among them, PCDH18 mutation was more frequently detected in sorted EpCAM+ cells than in EpCAM- cells in HCC1 by whole exome sequences. However, we could not confirm the difference of PCDH18 mutation frequency between sorted EpCAM+ and EpCAM- cells by Sanger sequencing, indicating that PCDH18 mutation could not explain intracellular heterogeneity. In contrast, we found novel PCDH18 mutations, including c.2556_2557delTG, c.1474C>G, c.2337A>G, and c.2976G>T, were detected in HCC1 and 3/57 (5.3%) additional HCC surgical specimens. All four HCCs with PCDH18 mutations were EpCAM-positive, suggesting that PCDH18 somatic mutations might explain the intertumor heterogeneity of HCCs in terms of the expression status of EpCAM. Furthermore, EpCAM-positive cell lines (Huh1, Huh7, HepG2, and Hep3B) had lower PCDH18 expression than EpCAM-negative cell lines (PLC/PRL/5, HLE, HLF, and SK-Hep-1), and PCDH18 knockdown in HCC2 cells slightly enhanced cell proliferation. CONCLUSIONS: Our data suggest that PCDH18 is functionally suppressed in a subset of EpCAM-positive HCCs through somatic mutations, and may play a role in the development of EpCAM-positive HCCs.

Serum cytokine profiles predict survival benefits in patients with advanced hepatocellular carcinoma treated with sorafenib: a retrospective cohort study.

BACKGROUND: Sorafenib is a multiple receptor tyrosine kinase inhibitor known to prolong overall survival in patients with advanced hepatocellular carcinoma (HCC). Predicting this drug's survival benefits is challenging because clinical responses are rarely measurable during treatment. In this study, we hypothesized that serum cytokines levels could predict the survival of advanced HCC patients, as sorafenib targets signaling pathways activated in the tumor stromal microenvironment and potentially affects serum cytokine profiles. METHODS: Of 143 patients with advanced-stage HCC, 104 who were recruited between 2003 and 2007 received hepatic arterial infusion chemotherapy (HAIC) that mainly targets tumor epithelial cells at S-phase (cohort 1); additionally, 39 recruited between 2010 and 2012 received sorafenib, which primarily targets the stromal vascular endothelial cells. Serum samples were collected and aliquoted prior to the treatment. Serum EGF, bFGF, HGF, IFN-γ, IL-10, IL-12, IL-2, IL-4, IL-5, IL-6, IL-8, IP-10, MIG, PDGF-BB, SCF, SDF1, TGF-ß, TGF-α, TNF-α, and VEGF-A were measured via enzyme-linked immunosorbent assays. The Modified Response Evaluation Criteria in Solid Tumors were used to assess tumor responses. RESULTS: The median survival time of HCC patients in cohorts 1 (HAIC-treated) and 2 (sorafenib-treated) were 12.0 and 12.4 months, respectively. Kaplan-Meier analysis revealed no significant survival differences between the 2 groups. Patients who survived more than 2 years after sorafenib treatment exhibited higher serum levels of IL-10, IL-12, TNF-a, IL-8, SDF-1, EGF, PDGF-BB, SCF, and TGF-α. Furthermore, cohort 2 patients with higher serum IL-5 (>12 pg/mL), IL-8 (>10 pg/mL), PDGF-BB (>300 pg/mL), and VEGF-A (>50 pg/mL) levels achieved longer survival; cohort 1 patients did not. Hierarchical cluster analysis of 6 cytokines robustly enriched for comparison analysis between cohorts 1 and 2 (IL-5, IL-8, TGF-α, PDGF-BB, CXCL9, and VEGF-A) revealed that elevation of these cytokines correlated with better survival when treated with sorafenib but not with HAIC. CONCLUSIONS: Patients who exhibited survival benefits owing to sorafenib treatment tended to present higher serum cytokines levels, potentially reflecting the activation of stromal signaling in the tumor microenvironment. Our study thus introduces novel biomarkers that may identify advanced HCC patients who may experience survival benefits with sorafenib treatment.

Defeating EpCAM(+) liver cancer stem cells by targeting chromatin remodeling enzyme CHD4 in human hepatocellular carcinoma.

BACKGROUND & AIMS: Hepatocellular carcinoma is composed of a subset of cells with enhanced tumorigenicity and chemoresistance that are called cancer stem (or stem-like) cells. We explored the role of chromodomain-helicase-DNA-binding protein 4, which is encoded by the CHD4 gene and is known to epigenetically control gene regulation and DNA damage responses in EpCAM(+) liver cancer stem cells. METHODS: Gene and protein expression profiles were determined by microarray and immunohistochemistry in 245 and 144 hepatocellular carcinoma patients, respectively. The relationship between gene/protein expression and prognosis was examined. The functional role of CHD4 was evaluated in primary hepatocellular carcinoma cells and in cell lines in vitro and in vivo. RESULTS: CHD4 was abundantly expressed in EpCAM(+) hepatocellular carcinoma with expression of hepatic stem cell markers and poor prognosis in two independent cohorts. In cell lines, CHD4 knockdown increased chemosensitivity and CHD4 overexpression induced epirubicin chemoresistance. To inhibit the functions of CHD4 that are mediated through histone deacetylase and poly (ADP-ribose) polymerase, we evaluated the effect of the histone deacetylase inhibitor suberohydroxamic acid and the poly (ADP-ribose) polymerase inhibitor AG-014699. Treatment with either suberohydroxamic acid or AG-014699 reduced the number of EpCAM(+) liver cancer stem cells in vitro, and suberohydroxamic acid and AG-014699 in combination successfully inhibited tumor growth in a mouse xenograft model. CONCLUSIONS: CHD4 plays a pivotal role in chemoresistance and the maintenance of stemness in liver cancer stem cells and is therefore a good target for the eradication of hepatocellular carcinoma.

Gd-EOB-DTPA-enhanced magnetic resonance imaging and alpha-fetoprotein predict prognosis of early-stage hepatocellular carcinoma.

UNLABELLED: The survival of patients with hepatocellular carcinoma (HCC) is often individually different even after surgery for early-stage tumors. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) has been introduced recently to evaluate hepatic lesions with regard to vascularity and the activity of the organic anion transporter OATP1B3. Here we report that Gd-EOB-DTPA-enhanced MRI (EOB-MRI) in combination with serum alpha-fetoprotein (AFP) status reflects the stem/maturational status of HCC with distinct biology and prognostic information. Gd-EOB-DTPA uptake in the hepatobiliary phase was observed in ∼15% of HCCs. This uptake correlated with low serum AFP levels, maintenance of hepatocyte function with the up-regulation of OATP1B3 and HNF4A expression, and good prognosis. By contrast, HCC showing reduced Gd-EOB-DTPA uptake with high serum AFP levels was associated with poor prognosis and the activation of the oncogene FOXM1. Knockdown of HNF4A in HCC cells showing Gd-EOB-DTPA uptake resulted in the increased expression of AFP and FOXM1 and the loss of OATP1B3 expression accompanied by morphological changes, enhanced tumorigenesis, and loss of Gd-EOB-DTPA uptake in vivo. HCC classification based on EOB-MRI and serum AFP levels predicted overall survival in a single-institution cohort (n=70), and its prognostic utility was validated independently in a multi-institution cohort of early-stage HCCs (n=109). CONCLUSION: This noninvasive classification system is molecularly based on the stem/maturation status of HCCs and can be incorporated into current staging practices to improve management algorithms, especially in the early stage of disease.

The transcription factor SALL4 regulates stemness of EpCAM-positive hepatocellular carcinoma.

BACKGROUND & AIMS: Recent evidence suggests that hepatocellular carcinoma can be classified into certain molecular subtypes with distinct prognoses based on the stem/maturational status of the tumor. We investigated the transcription program deregulated in hepatocellular carcinomas with stem cell features. METHODS: Gene and protein expression profiles were obtained from 238 (analyzed by microarray), 144 (analyzed by immunohistochemistry), and 61 (analyzed by qRT-PCR) hepatocellular carcinoma cases. Activation/suppression of an identified transcription factor was used to evaluate its role in cell lines. The relationship of the transcription factor and prognosis was statistically examined. RESULTS: The transcription factor SALL4, known to regulate stemness in embryonic and hematopoietic stem cells, was found to be activated in a hepatocellular carcinoma subtype with stem cell features. SALL4-positive hepatocellular carcinoma patients were associated with high values of serum alpha fetoprotein, high frequency of hepatitis B virus infection, and poor prognosis after surgery compared with SALL4-negative patients. Activation of SALL4 enhanced spheroid formation and invasion capacities, key characteristics of cancer stem cells, and up-regulated the hepatic stem cell markers KRT19, EPCAM, and CD44 in cell lines. Knockdown of SALL4 resulted in the down-regulation of these stem cell markers, together with attenuation of the invasion capacity. The SALL4 expression status was associated with histone deacetylase activity in cell lines, and the histone deacetylase inhibitor successfully suppressed proliferation of SALL4-positive hepatocellular carcinoma cells. CONCLUSIONS: SALL4 is a valuable biomarker and therapeutic target for the diagnosis and treatment of hepatocellular carcinoma with stem cell features.

Discrete nature of EpCAM+ and CD90+ cancer stem cells in human hepatocellular carcinoma.

UNLABELLED: Recent evidence suggests that hepatocellular carcinoma (HCC) is organized by a subset of cells with stem cell features (cancer stem cells; CSCs). CSCs are considered a pivotal target for the eradication of cancer, and liver CSCs have been identified by the use of various stem cell markers. However, little information is known about the expression patterns and characteristics of marker-positive CSCs, hampering the development of personalized CSC-targeted therapy. Here, we show that CSC markers EpCAM and CD90 are independently expressed in liver cancer. In primary HCC, EpCAM+ and CD90+ cells resided distinctively, and gene-expression analysis of sorted cells suggested that EpCAM+ cells had features of epithelial cells, whereas CD90+ cells had those of vascular endothelial cells. Clinicopathological analysis indicated that the presence of EpCAM+ cells was associated with poorly differentiated morphology and high serum alpha-fetoprotein (AFP), whereas the presence of CD90+ cells was associated with a high incidence of distant organ metastasis. Serial xenotransplantation of EpCAM+ /CD90+ cells from primary HCCs in immune-deficient mice revealed rapid growth of EpCAM+ cells in the subcutaneous lesion and a highly metastatic capacity of CD90+ cells in the lung. In cell lines, CD90+ cells showed abundant expression of c-Kit and in vitro chemosensitivity to imatinib mesylate. Furthermore, CD90+ cells enhanced the motility of EpCAM+ cells when cocultured in vitro through the activation of transforming growth factor beta (TGF-ß) signaling, whereas imatinib mesylate suppressed TGFB1 expression in CD90+ cells as well as CD90+ cell-induced motility of EpCAM+ cells. CONCLUSION: Our data suggest the discrete nature and potential interaction of EpCAM+ and CD90+ CSCs with specific gene-expression patterns and chemosensitivity to molecular targeted therapy. The presence of distinct CSCs may determine the clinical outcome of HCC.