Primary Hepatocellular Carcinoma Samples Research Articles

Distinct single-cell immune ecosystems distinguish true and de novo HBV-related hepatocellular carcinoma recurrences

ObjectiveRevealing the single-cell immune ecosystems in true versus de novo hepatocellular carcinoma (HCC) recurrences could help the optimal development of immunotherapies.DesignWe performed 5’and VDJ single-cell RNA-sequencing on 34 samples from...

Abstract 2106: Spatially resolved immune cell atlas of human liver cancer identifies the cellular interaction network underlying mucosal-associated invariant T (MAIT) cell dysfunction in hepatocellular carcinoma

Abstract Introduction: Hepatocellular Carcinoma (HCC) is considered a prototype of inflammation-derived cancer arising from chronic liver injury. The cellular composition of the HCC tumor immune microenvironment (TiME) has a major impact on cancer biology as the TiME can influence tumor initiation, progress, and response to therapy. Mucosal-associated invariant T (MAIT) cells can represent the most abundant T cell subtype in the human liver and have been found to be impaired in both number and function in liver cancer. These innate-like T cells are assigned crucial roles in regulating immunity and inflammation in the context of infection, albeit their role in HCC remains elusive. Methods: High-dimensional flow cytometry was used to analyze MAIT cell phenotypic changes in murine and human liver cancer. Highly multiplexed immunofluorescence microscopy was used to quantify immune cell infiltration in primary human HCC samples. We developed and validated a comprehensive 37-plex antibody panel for immunofluorescence imaging of human fresh frozen HCC samples. We applied co-detection by indexing (CODEX) technology to simultaneously profile in situ expression of 37 proteins at sub-cellular resolution in 15 HCC patient samples using whole slide scanning. Initial image analysis was performed using HALO quantitative image analysis software. Finally, we established an image analysis pipeline to quantify the MAIT cell interaction network at the HCC invasive front. Results: Profiling of human and murine HCC using flow cytometry and highly multiplexed CODEX imaging revealed substantial dysregulation/aberrant activation of MAITs in liver cancer. In situ phenotyping of 4,500,000 single cells (including 1,500,000 CD45+ immune cells) allowed for the quantification of 20 distinct immune cell phenotype clusters, differential analysis of activation markers and spatial features of each individual cell. CODEX imaging revealed detailed composition of the MAIT cell niche in human liver cancer tissue allowing for further distinct spatial analysis including infiltration and nearest-neighbor analysis. Importantly, flow cytometry data of paired samples correlated well with image-based immune phenotyping. Beyond that, whole slide imaging revealed spatial relationships and interactions within the MAIT cell hub localized in distinct tissue regions. Conclusion: Here, we demonstrate that spatially resolved, single-cell analysis of human liver cancer tissue allows for in-depth characterization of interacting immune cellular programs underlying MAIT cell dysfunction in HCC. Citation Format: Benjamin Ruf, Noemi Kedei, Matthias Bruhns, Sepideh Babaei, Bernd Heinrich, Varun Subramanyam, Chi Ma, Simon Wabitsch, Benjamin Green, Kylynda C. Bauer, Yuta Myojin, Jonathan Qi, Amran Nur, Justin McCallen, Layla Greten, William G. Telford, Merrill K. Stovroff, Kesha Oza, Jiman Kang, Alexander Kroemer, Manfred Claassen, Firouzeh Korangy, Tim F. Greten. Spatially resolved immune cell atlas of human liver cancer identifies the cellular interaction network underlying mucosal-associated invariant T (MAIT) cell dysfunction in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2106.

Bioenergetic Phenotyping of DEN-Induced Hepatocellular Carcinoma Reveals a Link Between Adenylate Kinase Isoform Expression and Reduced Complex I-Supported Respiration.

Hepatocellular carcinoma (HCC) is the most common form of liver cancer worldwide. Increasing evidence suggests that mitochondria play a central role in malignant metabolic reprogramming in HCC, which may promote disease progression. To comprehensively evaluate the mitochondrial phenotype present in HCC, we applied a recently developed diagnostic workflow that combines high-resolution respirometry, fluorometry, and mitochondrial-targeted nLC-MS/MS proteomics to cell culture (AML12 and Hepa 1-6 cells) and diethylnitrosamine (DEN)-induced mouse models of HCC. Across both model systems, CI-linked respiration was significantly decreased in HCC compared to nontumor, though this did not alter ATP production rates. Interestingly, CI-linked respiration was found to be restored in DEN-induced tumor mitochondria through acute in vitro treatment with P1, P5-di(adenosine-5′) pentaphosphate (Ap5A), a broad inhibitor of adenylate kinases. Mass spectrometry-based proteomics revealed that DEN-induced tumor mitochondria had increased expression of adenylate kinase isoform 4 (AK4), which may account for this response to Ap5A. Tumor mitochondria also displayed a reduced ability to retain calcium and generate membrane potential across a physiological span of ATP demand states compared to DEN-treated nontumor or saline-treated liver mitochondria. We validated these findings in flash-frozen human primary HCC samples, which similarly displayed a decrease in mitochondrial respiratory capacity that disproportionately affected CI. Our findings support the utility of mitochondrial phenotyping in identifying novel regulatory mechanisms governing cancer bioenergetics.

Loss of SIRT5 promotes bile acid-induced immunosuppressive microenvironment and hepatocarcinogenesis

The liver is a metabolically active organ and is also 'tolerogenic', exhibiting sophisticated mechanisms of immune regulation that prevent pathogen attacks and tumorigenesis. How metabolism impacts the tumor microenvironment (TME) in hepatocellular carcinoma (HCC) remains understudied. We investigated the role of the metabolic regulator SIRT5 in HCC development by conducting metabolomic analysis, gene expression profiling, flow cytometry and immunohistochemistry analyses in oncogene-induced HCC mouse models and human HCC samples. We show that SIRT5 is downregulated in human primary HCC samples and that Sirt5 deficiency in mice synergizes with oncogenes to increase bile acid (BA) production, via hypersuccinylation and increased BA biosynthesis in the peroxisomes of hepatocytes. BAs act as a signaling mediator to stimulate their nuclear receptor and promote M2-like macrophage polarization, creating an immunosuppressive TME that favors tumor-initiating cells (TICs). Accordingly, high serum levels of taurocholic acid correlate with low SIRT5 expression and increased M2-like tumor-associated macrophages (TAMs) in HCC patient samples. Finally, administration of cholestyramine, a BA sequestrant and FDA-approved medication for hyperlipemia, reverses the effect of Sirt5 deficiency in promoting M2-like polarized TAMs and liver tumor growth. This study uncovers a novel function of SIRT5 in orchestrating BA metabolism to prevent tumor immune evasion and suppress HCC development. Our results also suggest a potential strategy of using clinically proven BA sequestrants for the treatment of patients with HCC, especially those with decreased SIRT5 and abnormally high BAs. Hepatocellular caricinoma (HCC) development is closely linked to metabolic dysregulation and an altered tumor microenvironment. Herein, we show that loss of the metabolic regulator Sirt5 promotes hepatocarcinogenesis, which is associated with abnormally elevated bile acids and subsequently an immunosuppressive microenvironment that favors HCC development. Targeting this mechanism could be a promising clinical strategy for HCC.

Expression Status and Prognostic Significance of Gamma-Glutamyl Transpeptidase Family Genes in Hepatocellular Carcinoma.

PurposeGamma-glutamyl transpeptidase (GGT) family genes play crucial roles in the formation and progression of several solid tumors. However, the expression patterns and the prognostic significance of GGT members in hepatocellular carcinoma (HCC) remain unknown. This study was designed to determine the expression profiles of GGT family members in HCC and validate the prognostic value of serum GGT protein in patients with HCC.MethodWe comprehensively searched public resources based on the LIHC dataset to determine the expression patterns, prognostic significance, DNA methylation status, immune infiltration, and biological pathways of GGT family genes in HCC. Subsequently, we validated the prognostic value of serum GGT protein in 85 patients with early-stage HCC subjected to curative hepatectomy from the Renmin Hospital of Wuhan University.ResultsExcept for GGT1, other GGT family members (GGT5, GGT6, and GGT7) were found to be differentially expressed in primary HCC samples (N = 371) and normal control tissues (N = 50). Furthermore, a positive relationship was not only observed between GGT1 and GGT5 (Spearman coefficient: 0.24, P = 5.143 × 10−6) but also between GGT5 and GGT6 (Spearman coefficient: 0.38, P = 1.24 × 10−13). The expression of GGT1, GGT5, and GGT7 was correlated with overall survival (OS), and GGT7 was associated with disease-free survival (DFS) in patients with HCC. Negative associations between DNA methylation and expression of mRNA were observed for GGT1 (Spearman coefficient: −0.38, P = 6.24e-14), GGT6 (Spearman coefficient: −0.29, P = 1.23e-8), and GGT7 (Spearman coefficient: −0.34, P=6.7e-11). GGT family genes were well correlated with the infiltration levels of immune cells in HCC, especially CD4+ T cells, macrophages, and dendritic cells. Finally, when validated with clinical data from the Renmin cohort, a high expression of serum GGT protein was identified as a strong prognostic element of unfavorable OS (HR = 3.114, P = 0.025), but not of DFS (HR = 1.198, P = 0.05) in patients with HCC subjected to curative hepatectomy.ConclusionTo our knowledge, this is the first comprehensive analysis of the expression patterns and clinical value of GGT family genes in patients with HCC. Our study laid the foundation for the clinical application of the GGT protein in the survival assessment of patients with HCC.

Urokinase plasminogen activator predicts poor prognosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and its prognosis remains dismal. Hence, it is important to identify the diagnostic and prognostic biomarkers for HCC. Urokinase plasminogen activator (uPA), an extracellular matrix (ECM)-degrading protease, plays a pivotal role in the invasion and metastasis of HCC. To confirm the clinical significance of uPA in HCC, we explored uPA expression in HCC in The Cancer Genome Atlas (TCGA) database. The expression level of uPA was further verified by quantitative reverse transcription polymerized chain reaction (qRT-PCR) in 133 pairs of primary HCC samples. A survival analysis was conducted with the Kaplan-Meier method in the HCC samples and TCGA database. Our results showed that uPA was overexpressed in HCC and was significantly associated with HCC tumor size (P=0.015), differentiation grade (P=0.028), and absence of tumor encapsulation (P=0.010). Patients with high uPA expression levels had a poor outcome (P=0.026). TCGA database analysis was also consistent with our experimental results. In conclusion, our findings revealed that uPA was overexpressed in HCC and was related to HCC malignant features including tumor size, differentiation grade and absence of tumor encapsulation. High uPA expression had a shorter survival time. It is a potential prognostic biomarker of HCC.

The Mutational and Transcriptional Landscapes of Hepatocarcinogenesis in a Rat Model.

SummaryHepatocellular carcinoma (HCC) initiation is characterized by stepwise accumulation of molecular alterations, during which the early events are largely unknown. Here, we presented a comprehensive genomic and transcriptomic landscape at stages of hepatitis, cirrhosis, and HCC by using a diethylnitrosamine-induced rat HCC model. We observed the early occurrence of gene instability and aberrant cancer associated signaling pathways in liver hepatitis. We further characterized the progressive molecular changes during hepatocarcinogenesis, wherein the intense rivalry between tumor-suppressive and oncogenic strengths occurred in cirrhosis stage. Despite the significant pathological difference, mutation signatures and expression landscape are highly similar between hepatitis and cirrhosis stages. Furthermore, we identified PI3K-Akt signaling pathway as a key pathway in the process of hepatocarcinogenesis through integrative analysis, and PIK3CD is a potential biomarker indicating HCC recurrence. The dynamic immune response during hepatocarcinogenesis, such as continuous decline of monocytes, suggests an immunological intervention strategy beyond chemoprevention for liver cancer.

Transcriptionally Active Androgen Receptor Splice Variants Promote Hepatocellular Carcinoma Progression

Owing to the marked sexual dimorphism of hepatocellular carcinoma (HCC), sex hormone receptor signaling has been implicated in numerous aspects of liver cancer pathogenesis. We sought to reconcile the clear contribution of androgen receptor (AR) activity that has been established in preclinical models of HCC with the clinical failure of AR antagonists in patients with advanced HCC by evaluating potential resistance mechanisms to AR-targeted therapy. The AR locus was interrogated for resistance-causing genomic modifications using publicly available primary HCC datasets (1,019 samples). Analysis of HCC tumor and cell line RNA-seq data revealed enriched expression of constitutively active, treatment-refractory AR splice variants (AR-SV). HCC cell lines expressed C-terminal-truncated AR-SV; 28 primary HCC samples abundantly expressed AR-SV. Low molecular weight AR species were nuclear localized and constitutively active. Furthermore, AR/AR-SV signaling promoted AR-mediated HCC cell progression and conferred resistance to AR antagonists. Ligand-dependent and -independent AR signaling mediated HCC epithelial-to-mesenchymal transition by regulating the transcription factor SLUG. These data suggest that AR-SV expression in HCC drives HCC progression and resistance to traditional AR antagonists. Novel therapeutic approaches that successfully target AR-SVs may be therapeutically beneficial for HCC. SIGNIFICANCE: Treatment-refractory, constitutively active androgen receptor splice variants promote hepatocellular carcinoma progression by regulating the epithelial-to-mesenchymal transition pathway.

Regulation of hepatic glutamine metabolism by miR-122

ObjectiveIt is well established that the liver-specific miR-122, a bona fide tumor suppressor, plays a critical role in lipid homeostasis. However, its role, if any, in amino acid metabolism has not been explored. Since glutamine (Gln) is a critical energy and anaplerotic source for mammalian cells, we assessed Gln metabolism in control wild type (WT) mice and miR-122 knockout (KO) mice by stable isotope resolved metabolomics (SIRM) studies. MethodsSix-to eight-week-old WT and KO mice and 12- to 15-month-old liver tumor-bearing mice were injected with [U–13C5,15N2]-L-Gln, and polar metabolites from the liver tissues were analyzed by nuclear magnetic resonance (NMR) imaging and ion chromatography-mass spectrometry (IC-MS). Gln-metabolism was also assessed in a Gln-dependent hepatocellular carcinoma (HCC) cell line (EC4). Expressions of glutaminases (Gls and Gls2) were analyzed in mouse livers and human primary HCC samples. ResultsThe results showed that loss of miR-122 promoted glutaminolysis but suppressed gluconeogenesis in mouse livers as evident from the buildup of 13C- and/or 15N-Glu and decrease in glucose-6-phosphate (G6P) levels, respectively, in KO livers. Enhanced glutaminolysis is consistent with the upregulation of expressions of Gls (kidney-type glutaminase) and Slc1a5, a neutral amino acid transporter in KO livers. Both Gls and Slc1a5 were confirmed as direct miR-122 targets by the respective 3′-UTR-driven luciferase assays. Importantly, expressions of Gls and Slc1a5 as well as glutaminase activity were suppressed in a Gln-dependent HCC (EC4) cell line transfected with miR-122 mimic that resulted in decreased 13C-Gln, 13C-á-ketoglutarate, 13C-isocitrate, and 13C-citrate levels. In contrast, 13C-phosphoenolpyruvate and 13C-G6P levels were elevated in cells expressing ectopic miR-122, suggesting enhanced gluconeogenesis. Finally, The Cancer Genome Atlas—Liver Hepatocellular Carcinoma (TCGA-LIHC) database analysis showed that expression of GLS is negatively correlated with miR-122 in primary human HCCs, and the upregulation of GLS RNA is associated with higher tumor grade. More importantly, patients with higher expressions of GLS or SLC1A5 in tumors exhibited poor survival compared with those expressing lower levels of these proteins. ConclusionsCollectively, these results show that miR-122 modulates Gln metabolism both in vitro and in vivo, implicating the therapeutic potential of miR-122 in HCCs that exhibit relatively high GLS levels.

Genomic sequencing identifies WNK2 as a driver in hepatocellular carcinoma and a risk factor for early recurrence

Early recurrence of hepatocellular carcinoma (HCC) after curative resection is common. However, the association between genetic mechanisms and early HCC recurrence, especially in Chinese patients, remains largely unknown. We performed whole-genome sequencing (49 cases), whole-exome sequencing (18 cases), and deep targeted sequencing (115 cases) on 182 primary HCC samples. Focusing on WNK2, we used Sanger sequencing and qPCR to evaluate all the coding exons and copy numbers of that gene in an additional 554 HCC samples. We also explored the functional effect and mechanism of WNK2 on tumor growth and metastasis. We identified 5 genes (WNK2, RUNX1T1, CTNNB1, TSC1, and TP53) harboring somatic mutations that correlated with early tumor recurrence after curative resection in 182 primary HCC samples. Focusing on WNK2, the overall somatic mutation and copy number loss occurred in 5.3% (39/736) and 27.2% (200/736), respectively, of the total 736 HCC samples. Both types of variation were associated with lower WNK2 protein levels, higher rates of early tumor recurrence, and shorter overall survival. Biofunctional investigations revealed a tumor-suppressor role of WNK2: its inactivation led to ERK1/2 signaling activation in HCC cells, tumor-associated macrophage infiltration, and tumor growth and metastasis. Our results delineate genomic events that characterize Chinese HCCs and identify WNK2 as a driver of early HCC recurrence after curative resection. We applied next-generation sequencing and conducted an in-depth genomic analysis of hepatocellular carcinomas from a Chinese patient cohort. The results delineate the genomic events that characterize hepatocellular carcinomas in Chinese patients and identify WNK2 as a driver associated with early tumor recurrence after curative resection.

Clinical Significance of TRMT6 in Hepatocellular Carcinoma: A Bioinformatics-Based Study.

BackgroundThe purpose of this study was to investigate the correlation between TRMT6 mRNA expression levels and clinicopathological features in primary HCC patients and to evaluate their prognostic value.Material/MethodsThe clinical information and the mRNA sequencing data of the patients with primary hepatocellular carcinoma (HCC) were extracted from The Cancer Genome Atlas (TCGA) Liver Cancer database. The correlation between the clinicopathological features and the expression of TRMT6 was analyzed by t test and chi-square test. The overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method and Cox regression models. Gene set enrichment analysis (GSEA) was used to explore the potential mechanisms of TRMT6 dysregulation in primary HCC patients.ResultsCompared to normal tissues, TRMT6 was significantly upregulated in primary HCC tissues. Kaplan-Meier survival curves revealed that higher TRMT6 expression was associated with reduced RFS (p=0.0146) and OS (p=0.0224) in HCC patients. Moreover, multivariable Cox regression analysis indicated that TRMT6 upregulation independently predicted poor RFS (HR: 1.871, 95% CI: 1.204, 2.905, p=0.005) and OS (HR: 2.176, 95% CI: 1.234, 3.836, p=0.007). Gene Set Enrichment Analysis (GSEA) indicated that primary HCC samples in the TRMT6 high expression group were enriched for the G2M checkpoint, spermatogenesis, and MYC target genes.ConclusionsTRMT6 was upregulated in HCC tissues, and higher TRMT6 expression levels was correlated with reduced OS and RFS in patients with primary HCC. TRMT6 might be a promising prognostic biomarker for poor clinical outcomes in primary HCC patients.

Role of Allelic Imbalance in Predicting Hepatocellular Carcinoma (HCC) Recurrence Risk After Liver Transplant

BackgroundOne of the most controversial problems for liver transplantation in patients affected by hepatocellular carcinoma (HCC) remains the lack of an oncologic staging system to predict cancer recurrence after liver transplantation (LT). We analyzed allelic imbalance (AI) in 19 microsatellites, and assessed the post-LT HCC recurrence risk.Material/MethodsSeventy-one patients were included; 18 had tumor recurrence within 5 years post-transplant. Molecular analysis was done in the primary HCC and peripheral blood samples: a total of 19 microsatellites was used to assess AI. Specific AI was evaluated when outside of range value between 0.66 and 1.5. Based on data in the literature, we grouped the 19 microsatellites into 4 panels. We calculated the fractional allelic imbalance (FAI) to make comparisons between different panels including different subsets of microsatellites.ResultsWe report that AI was associated with HCC recurrence in 3 main loci (D3S2303, D9S251, and D9S254). Tumor recurrence was associated only with 2 specific panels with 9 microsatellites previously reported to be associated with high risk for HCC recurrence. Our data show that fractional allelic imbalance (FAI) index has good negative ability to predict HCC recurrence (Panel 2: negative predictive value of 95%).ConclusionsAI analysis could have prognostic value in risk management of HCC recurrence after LT, especially for early recurrence.

147 - Glyoxalase 2 correlates with redox signaling and enhances survival outcome in patients with hepatocellular carcinoma

Glyoxalase 2 (Glo2), the second of two enzymes in the glyoxalase system, protects against cellular damage by detoxification of methylglyoxal which is involved in oxidative stress and mitochondrial dysfunction. However, the role of Glo2 in Hepatocellular carcinoma (HCC) progression and survival outcome remains unclear. Here, we investigated the expression of Glo2 in HCC and normal tissues, as well as identified the correlation of Glo2 with the clinicopathological, recurrence risk, patient survival, and other genes related to redox signaling and oxidative stress. Clinical information and gene expression data were retrieved from The Cancer Genome Atlas and Gene Expression Omnibus, comprising of 648 patients. We found that Glo2 was significantly decreased in primary HCC samples relative to pair-matched normal tissues (p-value

MicroRNA-214-3p inhibits proliferation and cell cycle progression by targeting MELK in hepatocellular carcinoma and correlates cancer prognosis

BackgroundMicroRNAs are considered as potential regulators in various biological pathways and contribute to the diagnosis and prognosis of cancers. MicroRNA-214-3p (miR-214-3p) was proved to be correlated with various cancers in recent studies. However, the biological functions of miR-214-3p in hepatocellular carcinoma (HCC) and its association with the prognosis of HCC after liver transplantation are still unevaluated. Here we intended to elucidate the functional implication of miR-214-3p in regulation of cell proliferation and apoptosis and its potential prediction of clinical prognosis of HCC patients.MethodsExpressions of miR-214-3p in 98 HCC patients and three HCC cell lines were detected by quantitative reverse transcription PCR (qRT-PCR) to explore the association of miR-214-3p expression and clinicopathological characteristics. The effects of miR-214-3p on cell proliferation and apoptosis were examined by proliferation and flow cytometry assay, respectively. The direct target gene of miR-214-3p was also detected by luciferase reporter assay.ResultsThe effects of miR-214-3p on cell proliferation and apoptosis were examined by proliferation and flow cytometry assay, respectively. The direct target gene of miR-214-3p was also detected by luciferase reporter assay. The results showed that miR-214-3p expression was downregulated in primary HCC samples compared with normal liver tissues, and was decreased in HCC recurrence species compared with non-recurrence controls (P = 0.001). Low miR-214-3p level was associated with poor overall survival (OS) (Log rank P = 0.003) and recurrence-free survival (RFS) (Log rank P = 0.007). Moreover, miR-214-3p precursor transfection resulted in decreased cell proliferation, cell cycle arrest at G1 phase, and enhanced cell apoptosis in HepG2 and HUH-7 cells. Further investigation showed that miR-214-3p could regulate its target gene maternal embryonic leucine zipper kinase (MELK) by directly binding to MELK-3′-UTR.ConclusionsmiR-214-3p suppresses HCC progression by directly down-regulating MELK expression, indicating a potential therapeutic target for the treatment and prognosis of HCC patients.

TNFAIP8 interacts with LATS1 and promotes aggressiveness through regulation of Hippo pathway in hepatocellular carcinoma.

Although TNFAIP8 overexpression has been implicated in several human cancers, its clinical significance and biological function in hepatocellular carcinoma (HCC) remains unknown. Our study demonstrated that TNFAIP8 overexpression in primary HCC samples correlated with TNM stage, recurrence, poor prognosis and served as an independent favorable prognostic factor. We further showed that TNFAIP8 upregulated cell proliferation, migration, invasion and xenograft tumor growth of HCC cells. In addition, TNFAIP8 overexpression inhibited YAP phosphorylation, increased its nuclear localization and stabilization, leading to upregulation of cyclin proteins, CTGF and cell proliferation. We also found that TNFAIP8 could interact with LATS1 and decreased its phosphorylation. Depletion of LATS1 and YAP by siRNA blocked the biological effects of TNFAIP8. Collectively, the present study provides a novel finding that TNFAIP8 promotes HCC progression through LATS1-YAP signaling pathway. TNFAIP8 may serve as a candidate biomarker for poor prognosis and a target for new therapies.

Expression of Maternal Embryonic Leucine Zipper Kinase (MELK) Correlates to Malignant Potentials in Hepatocellular Carcinoma

Maternal embryonic leucine zipper kinase (MELK) is categorized as a member of AMP-activated protein kinase families. Various MELK-associated cellular and biological processes affect multiple stages of tumorigenesis. The aim of the present study was to clarify the relationship between MELK expression and hepatocellular carcinoma (HCC) clinicopathological features. In thirty conserved frozen primary HCC and non-HCC samples MELK mRNA expression was examined by quantitative real-time polymerase chain reaction (PCR). HCC tissues exhibited significantly higher expression levels compared to non-cancerous tissues. MELK expression had a statistically parallel correlation between tumor diameter and protein induced by vitamin K absence or antagonist II (PIVKA-II). The overall survival (OS) and recurrence-free survival (RFS) of the low MELK mRNA expression group was significantly longer than that of the high MELK mRNA expression group. MELK expression in HCC is extremely intense compared to its expression reported in other types of cancer. MELK could be a promising effective tumor marker of HCC and further consideration is needed.

Abstract 2354: Cancer vaccine development for hepatocellular carcinoma - HEPAVAC

Abstract The HEPAVAC Consortium aims to develop a highly innovative, novel cancer vaccine approach for hepatocellular carcinoma (HCC). The international project consortium consists of 9 European Partners from academia and the biotech industry with complementary and substantial expertise in developing immunotherapeutic strategies to treat cancer. The project has started in September 2013 and is supported by the European Commission's 7th Framework Program (www.hepavac.eu). HCC/normal adjacent tissue matched samples have been collected for HLA immunopeptidome analysis. 17 HCC samples from HLA-A*02+ patients and 15 samples from HLA-A*24+ patients have been analysed by mass spectrometry (LC-MS/MS). RNA-expression profiles have been established for 12 HCC samples. HLA-presentation/expression of peptides and mRNA on primary HCC samples are compared to >140 normal tissue samples from relevant organs (including heart, brain, lung, kidney, liver, nerve, skin etc.) from Immatics’ database. A total of 9051 HLA-A*02-restricted different tumor-associated peptides (TUMAPs) have been identified from HLA-A*02+ samples, while a total of 3286 different HLA-A*24-restricted TUMAPs have been identified from HLA-A*24+ samples. Of these, 33 HLA-A*02+ TUMAPS and 33 HLA-A*24+ TUMAPs have been validated, including peptide synthesis, immunogenicity testing and pharmaceutical evaluation. Most promising TUMAP candidates show selective expression only in HCC samples and no expression in normal tissues. In parallel, more than 6600 HLA-DR TUMAPs have been identified in Hep3B cells transfected with CIITA as well as an average of 1500 HLA-DR TUMAPs have been identified in HCC samples. A total of 16 newly identified HCC-specific epitopes have been selected for the HEPAVAC vaccine cocktail and are currently synthesized according to GMP standard. Of these, 7 are restricted to HLA- class I A*02; 5 HLA-A*24 and 4 HLA class II. In parallel, preclinical studies assessing the formulation and combination of the immunological RNA-based adjuvant (RNAdjuvant®) with peptide cocktails are underway. A multi Center phase I/II clinical trial in early HCC patients is predicted to start in July 2016. Citation Format: Sarah Kutscher, Roberto Accolla, Yuk T. Ma, Regina Heidenreich, Francesco Izzo, Alfred Koenigsrainer, Markus Loeffler, Phillip Mueller, Andrea Mayer, Hans-Georg Rammensee, Bruno Sangro, Sven Francque, Danila Valmori, Toni Weinschenk, Harpreet Singh-Jasuja, Luigi Buonaguro. Cancer vaccine development for hepatocellular carcinoma - HEPAVAC. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2354.

NUPR1, a new target in liver cancer: implication in controlling cell growth, migration, invasion and sorafenib resistance.

Sorafenib, an oral multikinase inhibitor, is the only approved agent for the treatment of advanced hepatocellular carcinoma (HCC). However, its benefits are modest, and as its mechanisms of action remain elusive, a better understanding of its anticancer effects is needed. Based on our previous study results, we investigated here the implication of the nuclear protein 1 (NUPR1) in HCC and its role in sorafenib treatment. NUPR1 is a stress-inducible protein that is overexpressed in various malignancies, but its role in HCC is not yet fully understood. We found that NUPR1 expression was significantly higher in primary human HCC samples than in the normal liver. Knockdown of NUPR1 significantly increased cell sensitivity to sorafenib and inhibited the cell growth, migration and invasion of HCC cells, both in vitro and in vivo. Moreover, NUPR1 silencing influenced the expression of RELB and IER3 genes. Unsurprisingly, RELB and IER3 knockdown also inhibited HCC cell viability, growth and migration. Using gene expression profiling of HCC cells following stable NUPR1 knockdown, we found that genes functionally involved in cell death and survival, cellular response to therapies, lipid metabolism, cell growth and proliferation, molecular transport and cellular movement were mostly suppressed. Network analysis of dynamic gene expression identified NF-κB and ERK as downregulated gene nodes, and several HCC-related oncogenes were also suppressed. We identified Runt-related transcription factor 2 (RUNX2) gene as a NUPR1-regulated gene and demonstrated that RUNX2 gene silencing inhibits HCC cell viability, growth, migration and increased cell sensitivity to sorafenib. We propose that the NUPR1/RELB/IER3/RUNX2 pathway has a pivotal role in hepatocarcinogenesis. The identification of the NUPR1/RELB/IER3/RUNX2 pathway as a potential therapeutic target may contribute to the development of new treatment strategies for HCC management.

Hepatocellular carcinoma: thyroid hormone promotes tumorigenicity through inducing cancer stem-like cell self-renewal.

Cancer stem-like cells (CSCs) play a key role in maintaining the aggressiveness of hepatocellular carcinoma (HCC), but the cell-biological regulation of CSCs is unclear. In the study, we report that thyroid hormone (TH) promotes cell self-renewal in HCC cells. TH also increases the percentage of CD90 + HCC cells and promotes drug resistance of HCC cells. By analyzing primary human HCC samples, we found that TRα transcript level is significantly elevated in primary liver cancer and portal vein metastatic tumor, compared to that of adjacent normal liver tissue. Knocking down TRα not only inhibits HCC self-renewal in vitro but also suppresses HCC tumor growth in vivo. Interestingly, treatment of TH leads to activation of NF-κB, which is required for the function of TH on inducing HCC cell self-renewal. We also found TRα and p65 cooperatively drive the expression of BMI1 by co-binding to the promoter region of BMI1 gene. In summary, our study uncovers a novel function of TH signaling in regulating the CSCs of HCC, and these findings might be useful for developing novel therapies by targeting TH function in HCC cells.

Expression of early growth response 2 in hepatocellular carcinoma and its effect on proliferation of HepG2 cells

Objective To investigate the expression and biologic function of early growth response 2 (EGR2) in hepatocellular carcinoma (HCC). Methods RNAseqV2 data sets of 50 pairs of HCC tissues (T) and their paired adjacent non-cancerous tissues (N) were downloaded from the cancer genome atlas (TCGA) website to analyze the expression of EGR2. Meanwhile, real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) was performed to compare the expression of EGR2 between HCC samples (T) and their paired adjacent non-cancerous tissues (N) from a same patient. The stable cell lines overexpressing EGR2 were established, and the expression of EGR2 protein was confirmed by Western blotting. The effect of overexpression of EGR2 on HCC cell proliferation was analyzed by MTT assay and colony formation assay. Western blotting and FQ-PCR were employed to analyze the protein and RNA levels of Cyclin D1 in EGR2 overexpressing- and vector control-HCC cells. Results The results from TCGA database analysis showed that the relative mRNA expression of EGR2 (89.95±16.04) in HCC tissues was obviously lower than that (440.59±60.60) in adjacent non-cancerous tissues (P<0.05). The mRNA expression level of EGR2 was down-regulated in primary HCC samples as compared with their paired adjacent non-cancerous tissues. MTT assay showed that ectopic expression of EGR2 decreased the growth of HepG2 cells as compared with vector-control cells (P<0.05). Our data from colony formation assay also showed that the EGR2 over-expressing cells exhibited fewer colonies (86.00±5.51) than control cells (177.00±8.18). Furthermore, over-expression of EGR2 decreased the expression levels of Cyclin D1 in HCC cells. Conclusion EGR2 is down-regulated in HCC. Moreover, EGR2 inhibits the proliferation of HCC cells partly through regulation of Cyclin D1. Key words: Carcinoma, hepatocellular; Early growth response 2; Proliferation; Cyclin D1