Noncancerous Liver Tissues Research Articles

Abstract 5320: Genome-wide DNA methylation analysis during nonalcoholic steatohepatitis-related multistage hepatocarcinogenesis: Comparison with hepatitis virus-related carcinogenesis

Abstract Aim: The aim of this study was to clarify the significance of DNA methylation alterations during non-alcoholic steatohepatitis (NASH)-related hepatocarcinogenesis. Background: The incidence of NASH, a precancerous condition for hepatocellular carcinoma (HCC), has shown an alarming increase in recent years. Although significance of DNA methylation alterations in NASH has been studies in animal models, only a limited number of papers focusing on genome-wide DNA methylation analysis in a cohort of patients with NASH and NASH-related HCC have been reported. It would be informative to understand the significance of DNA methylation alterations in NASH-related hepatocarcinogenesis, especially at the precancerous stage. Methods: Single-CpG-resolution genome-wide DNA methylation analysis was performed on 264 liver tissue samples, i.e. 55 samples of normal liver tissue (NLT), 113 samples of non-cancerous liver tissue showing NASH (NASH-N), 22 samples of NASH-related HCC (NASH-T), 37 samples of non-cancerous liver tissue showing chronic hepatitis or cirrhosis associated with Hepatitis B Virus (HBV) or Hepatitis C Virus (HCV) infection (viral-N) and 37 samples of HCC associated with HBV or HCV infection (viral-T). Results: After Bonferroni correction, 3,331 probes showed significant DNA methylation alterations in NASH-N samples as compared with NLT samples. Principal component analysis using the 3,331 probes revealed distinct DNA methylation profiles of NASH-N samples that were different from those of NLT samples and viral-N samples. Receiver operating characteristic curve analysis identified 194 probes that were able to discriminate NASH-N samples from viral-N samples with area under the curve values of more than 0.95, again indicating that the DNA methylation status of NASH was clearly different from that of viral hepatitis and cirrhosis. Jonckheere-Terptsra trend test revealed that DNA methylation alterations in NASH-N samples from patients without HCC were inherited by or strengthened in NASH-N samples from patients with HCC, and then inherited by or further strengthened in NASH-T themselves. NASH- and NASH-related HCC-specific DNA methylation alterations, which were not evident in viral-N and viral-T samples, were observed in tumor-related genes, such as the WHSC1 gene which encodes a histone H3 lysine 36 methyltransferase and the WDR6 gene which encodes a WD repeat family protein implicated in cell growth arrest, and were frequently associated with mRNA expression abnormalities. Conclusion: These data suggested that NASH-specific DNA methylation alterations observed at the precancerous stage were shown to be inherited by NASH-T and may continuously participate in NASH-related multistage hepatocarcingenesis, at least partly via alterations in the expression of the affected genes. Citation Format: Junko Kuramoto, Eri Arai, Ying Tian, Nobuaki Funahashi, Masaki Hiramoto, Takao Nammo, Yuichi Nozaki, Yoriko Takahashi, Nanako Ito, Ayako Shibuya, Hidenori Ojima, Aoi Sukeda, Yosuke Seki, Kazunori Kasama, Kazuki Yasuda, Yae Kanai. Genome-wide DNA methylation analysis during nonalcoholic steatohepatitis-related multistage hepatocarcinogenesis: Comparison with hepatitis virus-related carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5320.

Fatty acid binding protein 5 promotes tumor angiogenesis and activates the IL6/STAT3/VEGFA pathway in hepatocellular carcinoma

BackgroundTumor angiogenesis is an essential process for facilitating tumor growth and metastasis. Fatty acid binding protein 5(FABP5)is highly expressed in hepatocellular carcinoma (HCC). Thus, we investigated the role of FABP5 in tumor angiogenesis during HCC development. MethodsIn this study, the protein and mRNA levels of FABP5 in matched HCC and adjacent noncancerous liver tissues from 43 patients were determined using immunohistochemistry and real-time quantitative PCR, respectively. Two HCC cell lines (Huh7 and SMMC-7721) and human umbilical vein endothelial cells (HUVECS) were used to investigate the pro-angiogenic effect of FABP5 by tube formation, CCK8 and Transwell migration assays. The expression levels of interleukin 6 (IL6) and vascular endothelial growth factor A (VEGFA) secreted from HCC cells were detected by enzyme-linked immunosorbent assay (ELISA). ResultsIn 43 HCC patients, the expression of FABP5 mRNA was positively correlated with intratumoral VEGFA mRNA expression. FABP5 mRNA expression was also associated with adverse HCC characteristics. In vitro, cell viability, cell migration and tube formation in HUVECs were enhanced with increasing expression of FABP5 in HCC cells. Downregulation of FABP5 expression inhibited the IL6/STAT3/VEGFA pathway in HCC cells and inhibited tumor angiogenesis. ConclusionFABP5 was shown to promote angiogenesis and activate the IL6/STAT3/VEGFA pathway in HCC. FABP5 may be a potential antiangiogenic target in the treatment of HCC.

Overactivated neddylation pathway in human hepatocellular carcinoma.

Dysregulation of the neddylation pathway is related to various cancers. However, the specific role of the neddylation pathway in human hepatocellular carcinoma (HCC) remains largely unclear. In this study, the neddylation pathway in HCC and adjacent noncancerous liver (ANL) tissues was evaluated by immunohistochemistry (IHC), Western blotting, and qRT‐PCR (quantitative real‐time polymerase chain reaction). The results showed that the entire neddylation pathway, including NEDD8 (the IHC staining of NEDD8 represents the global‐protein neddylation), E1 NEDD8‐activating enzymes (NAE1 and UBA3), E2 NEDD8‐conjugating enzymes (UBE2F and UBE2M), E3 NEDD8‐ligases (MDM2, RBX1 and RNF7), and deneddylation enzymes (COPS5, UCHL1 and USP21), was overactivated in HCC. Furthermore, the upregulation of NEDD8 in HCC was correlated with aggressive characteristics and was an independent risk factor for overall survival (OS) and recurrence‐free survival (RFS) in patients with HCC after hepatectomy. The upregulation of NAE1, UBE2M, and UCHL1 in HCC was associated with aggressive characteristics and poor OS and RFS in patients with HCC after hepatectomy. In conclusion, our research reveals that the entire neddylation pathway is overactivated in HCC and associated with clinical characteristics and prognosis of patients with HCC.

TRIM50 suppressed hepatocarcinoma progression through directly targeting SNAIL for ubiquitous degradation

Tripartite motif-containing 50 (TRIM50) belongs to the tripartite motif (TRIM) protein family, which has been implicated in the pathogenesis of multiple cancers. However, the role of TRIM50 in hepatocellular carcinoma (HCC) remains to be clarified. Here we showed that TRIM50 expression was significantly decreased in liver cancer tissues compared with corresponding non-cancerous liver tissues, and its decreased expression was significantly correlated with advanced disease progression. Gain-of-function assay by exogenous overexpression of TRIM50 in HCC cells showed that proliferation, colony formation, migration and invasion of HCC cells were significantly inhibited, whereas loss-of-function assay by TRIM50 knockdown showed that these malignant behaviors of HCC cells were significantly increased. Further investigation showed that TRIM50 could directly bind with SNAIL and induced K-48 linked poly-ubiquitous degradation of SNAIL protein, which further reversed SNAIL-mediated epithelial-to-mesenchymal transition (EMT) process of HCC cells. In vivo assay by xenograft tumor model verified the antitumor effect of TRIM50 on HCC. Taken together, these results showed that TRIM50 acted as a tumor suppressor in HCC cells by directly targeting SNAIL and reversing EMT, which further indicated that positive modulation of TRIM50 might be a novel therapeutic strategy for SNAIL overexpressed HCC cells.

Targeting HSP60 by subcutaneous injections of jetPEI/HSP60-shRNA destabilizes cytoplasmic survivin and inhibits hepatocellular carcinoma growth.

Heat shock protein 60 (HSP60) overexpresses in various types of cancer, but its expression levels and functions in hepatocellular carcinoma (HCC) are still in dispute. We aim to clarify this issue and examine whether HSP60 could be a therapeutic target for HCC. We found drastically enhanced cell apoptosis and suppressed cell proliferation in two HCC cell lines with HSP60-silencing, and also indicated survivin was involved in this regulatory process in vitro and in vivo. However, HSP60-silencing in normal human hepatocytes only resulted in a minimal reduction of cell proliferation but without effects on cell apoptosis. We also showed HSP60 interacted with cytosolic but not mitochondrial survivin by immunoprecipitation assay. A rigorous method was used to standardize quantification from immunoblot assay to obtain more precise expression levels of HSP60 and survivin. The expression of HSP60 and survivin positively correlated in both cancerous and non-cancerous liver tissues (P < 0.001) after analyzing 145 surgically removed HCC tissues. A total of 56.6% of HCC patients overexpressed HSP60 in cancerous tissues, and 40.0% under-expressed HSP60. Higher expression of HSP60 and survivin in non-cancerous tissues both correlated with shorter overall survival (P = 0.029 and P < 0.001, respectively). Finally, we evaluated the therapeutic potential of HSP60 using extraneous delivery of jetPEI/shHSP60 complexes. The treatment results showed significant reduction of tumor weight by 44.3% (P < 0.05), accompanied by under-expression of survivin. These studies suggested that HSP60 not only served as a prognostic marker but also served as a novel therapeutic target for HCC.

Downregulation of CPT2 promotes tumorigenesis and chemoresistance to cisplatin in hepatocellular carcinoma

BackgroundCancer cells often have characteristic changes in metabolism. Besides Warburg effect, abnormal lipid metabolism is also considered as one of the most typical metabolic symbols of cancer. Thus, understanding the mechanisms of cell metabolic reprogramming may provide a potential avenue for cancer treatment.Materials and methodsIn total, 41 pairs of matched samples of primary hepatocellular carcinoma (HCC) and adjacent non-cancerous liver tissues were collected. Afterward, we performed quantitative reverse transcriptase polymerase chain reaction to investigate carnitine palmitoyltransferase-2 (CPT2) expression and then systematically analyzed its relationship with clinicopathologic features. We further performed proliferation, colony formation, migration and invasion, drug resistance, and lipogenesis assays to determine the function of CPT2 in HCC.ResultsIn this study, we have identified CPT2 which is the rate-limiting enzyme of fatty acid oxidation, downregulated in HCC and was significantly associated with tumor histological differentiation and venous invasion. In vitro studies demonstrated that knockdown of CPT2 remarkably enhanced the tumorigenic activity and metastatic potential of hepatoma cells. In addition, CPT2 silencing induced chemoresistance to cisplatin. Mechanistically, low expression of CPT2 promoted cancer cell lipogenesis via upregulation of stearoyl-CoA desaturase-1, the key enzyme involved in the synthesis of monounsaturated fatty acids, at both mRNA and protein levels in hepatoma cell line.ConclusionAltogether, our findings demonstrate that CPT2 has a critical role in HCC progression and chemoresistance and may potentially serve as a novel prognostic marker and therapeutic target for HCC treatment.

MicroRNA-124-3p expression and its prospective functional pathways in hepatocellular carcinoma: A quantitative polymerase chain reaction, gene expression omnibus and bioinformatics study.

The present study aimed to explore the potential clinical significance of microRNA (miR)-124-3p expression in the hepatocarcinogenesis and development of hepatocellular carcinoma (HCC), as well as the potential target genes of functional HCC pathways. Reverse transcription-quantitative polymerase chain reaction was performed to evaluate the expression of miR-124-3p in 101 HCC and adjacent non-cancerous tissue samples. Additionally, the association between miR-124-3p expression and clinical parameters was also analyzed. Differentially expressed genes identified following miR-124-3p transfection, the prospective target genes predicted in silico and the key genes of HCC obtained from Natural Language Processing (NLP) were integrated to obtain potential target genes of miR-124-3p in HCC. Relevant signaling pathways were assessed with protein-protein interaction (PPI) networks, Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Protein Annotation Through Evolutionary Relationships (PANTHER) pathway enrichment analysis. miR-124-3p expression was significantly reduced in HCC tissues compared with expression in adjacent non-cancerous liver tissues. In HCC, miR-124-3p was demonstrated to be associated with clinical stage. The mean survival time of the low miR-124-3p expression group was reduced compared with that of the high expression group. A total of 132 genes overlapped from differentially expressed genes, miR-124-3p predicted target genes and NLP identified genes. PPI network construction revealed a total of 109 nodes and 386 edges, and 20 key genes were identified. The major enriched terms of three GO categories included regulation of cell proliferation, positive regulation of cellular biosynthetic processes, cell leading edge, cytosol and cell projection, protein kinase activity, transcription activator activity and enzyme binding. KEGG analysis revealed pancreatic cancer, prostate cancer and non-small cell lung cancer as the top three terms. Angiogenesis, the endothelial growth factor receptor signaling pathway and the fibroblast growth factor signaling pathway were identified as the most significant terms in the PANTHER pathway analysis. The present study confirmed that miR-124-3p acts as a tumor suppressor in HCC. miR-124-3p may target multiple genes, exerting its effect spatiotemporally, or in combination with a diverse range of processes in HCC. Functional characterization of miR-124-3p targets will offer novel insight into the molecular changes that occur in HCC progression.

Hypermethylation of NF-κB-Activating Protein-Like (NKAPL) Promoter in Hepatocellular Carcinoma Suppresses Its Expression and Predicts a Poor Prognosis

Hepatocellular carcinoma (HCC) is a complicated disease with low survival rate partially due to frequent recurrence and no efficient therapy. Promoter hypermethylation of tumor suppressor genes has been demonstrated as one of the molecular mechanisms contributing to tumorigenesis and progression in HCC. This study aims to investigate regulation of NKAPL expression by promoter methylation and its clinical relevance as a biomarker for HCC. We measured mRNA expression of NKAPL in 5 HCC cell lines and a cohort of 62 pairs of primary HCC tumor and their adjacent non-cancer liver tissues. NKAPL protein expression on HCC cell lines and clinical samples was assessed by Western blot and immunohistochemistry, respectively. Association analyses between NKAPL expression and clinicopathologic characteristics in the cohort were conducted. Methylation statuses of NKAPL promoter in 18 pairs of tumor and adjacent non-tumor HCC samples were studied using methylation-specific PCR. Biological functions of NKAPL in HCC were investigated by ectopic expression of NKAPL in HCC cells, and cell viability and cell cycle analyses were performed. Our present study showed suppressed expression and promoter hypermethylation are common events in HCC. Demethylation experiment in HCC cells demonstrated that the NKAPL expression was regulated by promoter methylation. In addition, high methylation level of NKAPL and its low expression predict poor outcome. Furthermore, ectopic expression of NKAPL in the HCC cells inhibited cell growth. Our findings suggest that methylation of NKAPL is a frequent event and is a potential prognosis biomarker in HCC.

Long noncoding RNA miR503HG, a prognostic indicator, inhibits tumor metastasis by regulating the HNRNPA2B1/NF-κB pathway in hepatocellular carcinoma.

Long noncoding RNAs (lncRNAs) have been associated with hepatocellular carcinoma (HCC), but the underlying molecular mechanisms of their specific association with hepatocarcinogenesis have not been fully explored.Methods: miR503HG was identified by microarray and validated by real-time PCR. Survival analysis was evaluated using the Kaplan-Meier method and assessed using the log-rank test. In vitro and in vivo assays were preformed to explore the biological effects of miR503HG in HCC cells. The interaction of miR503HG with HNRNPA2B1 was identified by RNA pull-down and RNA immunoprecipitation. Expression of HNRNPA2B1 was examined by western blotting, immunofluorescence and immunohistochemical analyses, while HNRNPA2B1 ubiquitination was detected by immunoprecipitation.Results: We have identified 713 differentially expressed lncRNAs in 12 pairs of HCC tissues compared with corresponding noncancerous liver tissues. One of these lncRNAs, miR503HG, the host gene of miR503, is markedly decreased in HCC. Expression level of miR503HG is significantly associated with the time to recurrence and overall survival and is an independent risk factor for recurrence and survival. Enhanced expression of miR503HG could noticeably inhibit HCC invasion and metastasis in vitro and in vivo. Further investigation suggested that miR503HG could specifically interact with the heterogeneous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1). miR503HG promoted HNRNPA2B1 degradation via the ubiquitin-proteasome pathway, which reduced the stability of p52 and p65 mRNA, and simultaneously suppressed the NF-κB signaling pathway in HCC cells. In addition, miR503HG can function synergistically with miR503 to inhibit HCC migration.Conclusion: Our findings support a role for miR503HG in tumor recurrence risk and survival prediction in HCC patients. We demonstrate a novel mechanism by which miR503HG inhibits the NF-κB signaling pathway and exerts its metastatic tumor suppression function through modulating the ubiquitination status of HNRNPA2B1.

Transporter expression in non-cancerous and cancerous liver tissue from subjects with hepatocellular carcinoma and chronic hepatitis C infection quantified by LC-MS/MS proteomics

Transporter expression in non-cancerous and cancerous liver tissue from subjects with hepatocellular carcinoma and chronic hepatitis C infection quantified by LC-MS/MS proteomics

Circular RNA Hsa_Circ_0091579 Serves as a Diagnostic and Prognostic Marker for Hepatocellular Carcinoma

Background/Aims: An increasing number of studies have suggested that circular RNAs (circRNAs) have vital roles in carcinogenesis and tumor progression. However, the function of circRNAs in hepatocellular carcinoma (HCC) remains poorly characterized. Methods: We investigated the levels of circRNAs in patients with HCC to identify potential diagnostic biomarkers. We examined circRNA expression profiles in liver tumors and paired non-cancerous liver tissues from three HCC patients with cancer thrombus using a circRNA microarray. Bioinformatics analysis was performed to find circRNAs with significantly altered expression levels between tumors and their paired non-tumor tissues. We confirmed our initial findings by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Receiver operating characteristic (ROC) curves were also applied to identify a candidate circRNA with the optimal specificity and sensitivity. Finally, X-tile software was adopted to calculate the most efficient cut-off value for hsa_circ_0091579 expression. Results: Microarray analysis identified 20 unique circRNAs that were differentially expressed between tumor and non-tumor tissues (P < 0.05). The expression of these 20 circRNAs was verified by qRT-PCR. The expression of hsa_circ_16245-1 and hsa_circ_0091579 mRNA was consistent with their levels as tested by the microarray. The ROC curves showed that both hsa_circ_16245-1 and hsa_circ_0091579 had favorable specificity and sensitivity. We further confirmed that hsa_circ_0091579 was significantly upregulated in HCC and its high expression was intimately associated with a worse overall survival in patients with HCC. Conclusion: Hsa_circ_0091579 may play a critical role in HCC progression and serve as a potential biomarker for the prognosis of patients with HCC.

PRMT1 Promoted HCC Growth and Metastasis In Vitro and In Vivo via Activating the STAT3 Signalling Pathway

Background/Aims: Although it has been widely accepted that protein arginine methyltransferase 1 (PRMT1) is a cancer-promoting gene in various cancers, the mechanism of PRMT1 in hepatocellular carcinoma (HCC) requires more exploration. This study aimed to investigate the role of PRMT1 in HCC growth and metastasis. Methods: We compared PRMT1 expression and clinicopathological characteristics using paired HCC and adjacent noncancerous liver tissues from 210 patients and immunohistochemistry analyses. Cell proliferation, colony formation and migration were determined in HCC cell lines with PRMT1 overexpression or downregulation through MTT, crystal violet and Boyden chamber assays. Tumour growth was monitored in a xenograft model, and intrahepatic metastasis models were established. Results: PRMT1 expression was greatly increased in clinical HCC samples and strongly associated with poor prognosis and recurrence; PRMT1 expression was also positively correlated with microvascular invasion (P = 0.024), tumour differentiation (P = 0.014), tumour size (P = 0.002), and portal vein tumour thrombus (PVTT) (P = 0.028). Cell proliferation, colony formation and migration in vitro were enhanced by PRMT1 upregulation and decreased by PRMT1 downregulation in HCC cell lines. Moreover, low PRMT1 expression resulted in slow tumour growth and decreased tumour weight in vivo, as well as tumour metastasis. These phenotypes were associated with STAT3 signalling pathway activation. Cryptotanshinone, a STAT3 inhibitor, inhibited STAT3 phosphorylation and reversed the HCC phenotype of PRMT1 expression. Conclusions: We revealed a significant role for PRMT1 in HCC progression and metastasis in vitro and in vivo via STAT3 signalling pathway activation. PRMT1 may be a potential novel prognostic biomarker and new therapeutic target for HCC.

Prognostic significance of sodium-potassium ATPase regulator, FXYD3, in human hepatocellular carcinoma.

The clinical significance of the sodium-potassium ATPase regulator FXYD domain-containing ion transport regulator 3 (FXYD3) has been demonstrated in a number of types of cancer. However, the role of this protein in human hepatocellular carcinoma (HCC) remains to be elucidated. In the present study, 217 HCC tissue samples were analyzed to evaluate the expression and prognostic significance of FXYD3 in HCC. Reverse transcription-quantitative polymerase chain reaction was used to analyze the mRNA expression of FXYD3 in 80 primary HCC specimens and paired non-cancerous liver tissue samples, while western blotting was used to analyze the protein expression level of FXYD3 in another 24 pairs. These analyses demonstrated that the expression level of FXYD3 was significantly increasedb at the mRNA and protein levels in HCC tumor tissues compared with adjacent non-cancerous tissues. Immunohistochemical analysis of 137 paraffin-embedded HCC tissue samples indicated that the expression of FXYD3 was associated with HCC clinicopathological characteristics. Kaplan-Meier analysis demonstrated that patients with high FXYD3 protein expression (n=60) experienced significantly poorer overall survival time compared with patients with low FXYD3 protein expression (n=77) (P<0.001). Multivariate analysis demonstrated that FYXD3 protein expression level (hazard ratio, 2.137; 95% confidence interval, 1.224–3.732; P=0.008) was an independent prognostic factor in patients with HCC. Overall, the results indicated that FXYD3 expression levels were higher in HCC tumor tissues than in adjacent non-cancerous tissues, and that the FXYD3 protein may serve as a prognostic marker for HCC.

Clinical role and biological function of CDK5 in hepatocellular carcinoma: A study based on immunohistochemistry, RNA-seq and in vitro investigation.

To investigate the clinical role and biological function of cyclin-dependent kinase 5 (CDK5) in hepatocellular carcinoma (HCC), 412 surgically resected tissue samples (HCC, n=171; non-HCC=241) were obtained and analyzed with immunohistochemistry. The diagnostic and prognostic values of CDK5 expression levels in HCC were clarified. Moreover, RNA-seq data or microarray datasets from The Cancer Genome Atlas (TCGA) (HCC, n=374; normal, n=50) or other public databases (HCC, n=1864; non-tumor=1995) regarding CDK5 in HCC were extracted and examined. Several bioinformatic methods were performed to identify CDK5-regulated pathways. In vitro experiments were adopted to measure proliferation and apoptosis in HCC cells after CDK5 mRNA was inhibited in the HCC cell lines HepG2 and HepB3. Based on immunohistochemistry, CDK5 expression levels were notably increased in HCC tissues (n=171) compared with normal (n=33, P<0.001), cirrhosis (n=37, P<0.001), and adjacent non-cancerous liver (n=171, P<0.001) tissues. The up-regulation of CDK5 was associated with higher differentiation (P<0.001), metastasis (P<0.001), advanced clinical TNM stages (P<0.001), portal vein tumor embolus (P=0.003) and vascular invasion (P=0.004). Additionally, TCGA data analysis also revealed significantly increased CDK5 expression in HCC compared with non-cancerous hepatic tissues (P<0.001). The pooled standard mean deviation (SMD) based on 36 included datasets (HCC, n=2238; non-cancerous, n=2045) indicated that CDK5 was up-regulated in HCC (SMD=1.23, 95% CI: 1.00-1.45, P<0.001). The area under the curve (AUC) of the summary receiver operating characteristic (SROC) curve was 0.88. Furthermore, CDK5 knock-down inhibited proliferation and promoted apoptosis. In conclusion, CDK5 plays an essential role in the initiation and progression of HCC, most likely via accelerating proliferation and suppressing apoptosis in HCC cells by regulating the cell cycle and DNA replication pathways.

Eukaryotic Initiation Factor 5A2 Contributes to the Maintenance of CD133(+) Hepatocellular Carcinoma Cells via the c-Myc/microRNA-29b Axis.

Cancer stem cells (CSCs)/cancer-initiating cells (CICs) are suggested responsible for driving cancer resistance to conventional therapies and for cancer recurrence and/or metastasis. CD133 is served as a key biomarker to identify and characterize this subpopulation of cells in hepatocellular carcinoma (HCC). Our previous study indicated that overexpression of eukaryotic initiation factor 5A2 (EIF5A2) promotes HCC cell metastasis and angiogenesis. In this study, we demonstrated that EIF5A2 might play a crucial role in CSCs regulation and investigated its potential molecular mechanisms. Using quantitative real-time polymerase chain reaction assay, we observed that the expression of EIF5A2 positively correlated with CD133 levels in a cohort of cancerous and noncancerous liver tissues and cells. Next, HCC cells with high expression of EIF5A2 have a strong capacity to form undifferentiated tumor spheres in vitro and show elevated levels of stem cell-related genes, leading to an increased ability to develop tumors when subcutaneously injected into nude mice. Furthermore, differential microRNA expression was profiling between two EIF5A2-depleted HCC cell lines and their control one identified a decreased expression of miR-29b in EIF5A2-depleted cell lines. Further functional studies illustrated that downregulated miR-29b level is responsible for EIF5A2-maintained HCC cell stemness either in vitro or in vivo. Moreover, enforced expression of EIF5A2 in HCC cells largely enhanced the binding of c-Myc on the promoter of miR-29b and downregulation of miR-29b by EIF5A2 was dependent on c-Myc. Our findings, collectively, reveal that EIF5A2 contributes to the maintenance of CD133+ HCC cells via the c-Myc/miR-29b axis. Stem Cells 2018;36:180-191.

Transporter Expression in Noncancerous and Cancerous Liver Tissue from Donors with Hepatocellular Carcinoma and Chronic Hepatitis C Infection Quantified by LC-MS/MS Proteomics.

Protein expression of major hepatobiliary drug transporters (NTCP, OATPs, OCT1, BSEP, BCRP, MATE1, MRPs, and P-gp) in cancerous (C, n = 8) and adjacent noncancerous (NC, n = 33) liver tissues obtained from patients with chronic hepatitis C with hepatocellular carcinoma (HCV-HCC) were quantified by LC-MS/MS proteomics. Herein, we compare our results with our previous data from noninfected, noncirrhotic (control, n = 36) and HCV-cirrhotic (n = 30) livers. The amount of membrane protein yielded from NC and C HCV-HCC tissues decreased (31%, 67%) relative to control livers. In comparison with control livers, with the exception of NTCP, MRP2, and MATE1, transporter expression decreased in NC (38%-76%) and C (56%-96%) HCV-HCC tissues. In NC HCV-HCC tissues, NTCP expression increased (113%), MATE1 expression decreased (58%), and MRP2 expression was unchanged relative to control livers. In C HCV-HCC tissues, NTCP and MRP2 expression decreased (63%, 56%) and MATE1 expression was unchanged relative to control livers. Compared with HCV-cirrhotic livers, aside from NTCP, OCT1, BSEP, and MRP2, transporter expression decreased in NC (41%-71%) and C (54%-89%) HCV-HCC tissues. In NC HCV-HCC tissues, NTCP and MRP2 expression increased (362%, 142%), whereas OCT1 and BSEP expression was unchanged. In C HCV-HCC tissues, OCT1 and BSEP expression decreased (90%, 80%) relative to HCV-cirrhotic livers, whereas NTCP and MRP2 expression was unchanged. Expression of OATP2B1, BSEP, MRP2, and MRP3 decreased (56%-72%) in C HCV-HCC tissues in comparison with matched NC tissues (n = 8), but the expression of other transporters was unchanged. These data will be helpful in the future to predict transporter-mediated hepatocellular drug concentrations in patients with HCV-HCC.

NK3 homeobox 1 (NKX3.1) up-regulates forkhead box O1 expression in hepatocellular carcinoma and thereby suppresses tumor proliferation and invasion

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related mortality in China, and the molecular mechanism of uncontrolled HCC progression remains to be explored. NK3 homeobox 1 (NKX3.1), an androgen-regulated prostate-specific transcription factor, suppresses tumors in prostate cancer, but its role in HCC is unknown, especially in hepatocellular carcinoma. In the present study, the differential expression analyses in HCC tissues and matched adjacent noncancerous liver tissues revealed that NKX3.1 is frequently down-regulated in human primary HCC tissues compared with matched adjacent noncancerous liver tissues. We also noted that NKX3.1 significantly inhibits proliferation and mobility of HCC cells both in vitro and in vivo Furthermore, NKX3.1 overexpression resulted in cell cycle arrest at the G1/S phase via direct binding to the promoter of forkhead box O1 (FOXO1) and up-regulation of expression. Of note, FOXO1 silencing in NKX3.1-overexpressing cells reversed the inhibitory effects of NKX3.1 on HCC cell proliferation and invasion. Consistently, both FOXO1 and NKX3.1 were down-regulated in human HCC tissues, and their expression was significantly and positively correlated with each other. These results suggest that NKX3.1 functions as a tumor suppressor in HCC cells through directly up-regulating FOXO1 expression.

Sporadic PCDH18 somatic mutations in EpCAM-positive hepatocellular carcinoma

BackgroundThe 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.MethodsTwo 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.ResultsWhole 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.ConclusionsOur 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.

TRIM31 is upregulated in hepatocellular carcinoma and promotes disease progression by inducing ubiquitination of TSC1–TSC2 complex

Tripartite motif (TRIM) 31 is a member of the tripartite motif-containing protein family, and TRIM family proteins are involved in a broad range of biological and pathological processes. However, the role of TRIM31 in hepatocellular carcinoma (HCC) progression is not known. Here we demonstrated that TRIM31 expression was significantly upregulated in liver cancer tissues compared with paired distal non-cancerous liver tissues from HCC patients, and its overexpression was significantly correlated with advanced disease status. Both gain and loss of function assay verified that TRIM31 promoted the malignant behaviors of HCC cells through overactivation of mammalian target of rapamycin complex1 (mTORC1) pathway. We further demonstrated that TRIM31 exerted its oncogenic effect by directly interacting with the tuberous sclerosis complex (TSC) 1 and TSC2 complex, the upstream suppressor of mTORC1 pathway, and promoting the E3 ligase-mediated K48-linked ubiquitination and degradation of this complex. In conclusion, this study demonstrated TRIM31 could promote HCC progression by targeting TSC1-TSC2 complex for degradation and further overactivating mTORC1 pathway. Thus, it revealed a novel molecular mechanism of HCC progression and indicated a potential therapeutic strategy against HCC by targeting TRIM31.

Clinical significance of lncRNA-ATB expression in human hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a worldwide health problem and it is important to understand the mechanistic roles of the biomolecules involved in its pathogenesis. Long non-coding RNAs (lncRNAs) are frequently and aberrantly expressed in various human cancers and are known to play a role in cancer pathogenesis. The aim of this study was to analyze the expression of lncRNA-ATB in HCC and investigate the implications for prognoses.In total, 100 samples of HCC tissues and their corresponding, adjacent, non-cancerous liver tissues were collected. Total RNAs were extracted and the expression levels of lncRNA-ATB were measured by qRT-PCR. The association of lncRNA expression with clinicopathological features and patient survival were then analyzed.LncRNA-ATB was significantly upregulated in HCC tissues compared with the levels in corresponding non-cancerous tissues. Expression of lncRNA-ATB was significantly associated with portal vein thrombosis, intrahepatic or extrahepatic metastases, mUICC stage, and the BCLC stage. Large tumors (> 5 cm, HR = 3.851, 95% CI = 1.431–10.364, p = 0.008) and higher lncRNA-ATB expression (HR = 4.158, 95% CI = 1.226–14.107, p = 0.022) were the significant prognostic factors for overall survival.With this novel evidence of the involvement of lncRNA-ATB in HCC pathogenesis and clinical features, lncRNA-ATB can be concluded to have potential as a biomarker for the prognosis of HCC and as a targeted therapy for afflicted patients.