Aurora kinase B is a predictive factor for the aggressive recurrence of hepatocellular carcinoma after curative hepatectomy

AURKB promotes tumorigenesis and carboplatin resistance by regulating the ERK pathway in neuroblastoma cells

BACKGROUND

Previous research has revealed that activation or aberrant expression of kinases can lead to tumorigenesis of various cancers, including neuroblastoma (NB). Suppression of kinase expression can reduce drug resistance. We explored the potential role and mechanism of the aurora kinase B (AURKB) gene in the acquisition of carboplatin resistance in NB.

METHODS

Immunohistochemistry (IHC) and qRT-PCR were used to explore the AURKB expression in NB patients. Subsequently, we structured Carboplatin-resistant NB cells. The potential biological functions of AURKB in carboplatin resistance were examined through knockdown of AURKB combined with CCK8, flow cytometry, immunohistochemistry, and western blot. Finally, overexpression of AURKB combined with ERK inhibitor (U0126) was carried out to explore the role of downstream signaling pathways.

RESULTS

Overexpression of AURKB was closely correlated to poor prognosis in NB patients. In vitro, knockdown of AURKB could lead to a decline in IC50 value and restrain the invasion and the expression of MRP1 and Ki67, while promotes apoptosis in carboplatin-resistant cells (IMR-32-R and SK-N-AS-R). Additionally, AURKB overexpression could potentiate the invasion and the expression of MRP1 and Ki67, while suppresses apoptosis in SK-N-AS-R and IMR-32-R, whereas ERK inhibitor U0126 could reverse the phenomenon caused by AURKB overexpression.

CONCLUSION

AURKB overexpression was strongly associated with poor prognosis and carboplatin resistant acquisition. Additionally, suppression of AURKB-ERK axis might be a potential therapy for carboplatin resistance in NB patients.

An in silico toxicogenomic approach in constructing the aflatoxin B1-mediated regulatory network of hub genes in hepatocellular carcinoma

Aflatoxin B1 (AFB1) can cause hepatocellular carcinoma (HCC) through a mutagenic mode of action but can also lead to global changes in gene expression; however, the AFB1 network of molecular pathways involved in HCC is not known. Here, we used toxicogenomic data from human liver cells exposed to AFB1 to infer the network of AFB1-responsive molecular pathways involved in HCC. The following computational tools: STRING, MCODE, cytoHubba, iRegulon, kinase enrichment tool KEA3, and DAVID were used to identify protein-protein interaction network, hub genes, transcription factors (TFs), upstream kinases, and biological processes (BPs). Predicted molecular events were validated with an external dataset, whereas the hub genes in HCC were validated using the UALCAN database. The results revealed an association between AFB1 and the hub genes involved in the cell cycle. We identified TFs that regulate the hub genes and linked them with upstream kinases including cyclin-dependent kinases, mitogen-activated protein kinase 1, and AKT. This approach enabled the construction of the AFB1-mediated regulatory network consisting of upstream kinases, TFs, hub genes, and BPs, thus revealing the signaling hierarchy and information flow that may contribute to AFB1-induced HCC. This could be a useful tool in predicting the molecular mechanisms involved in chemical-induced diseases when available toxicogenomic data exist.

Hepatitis C virus fitness can influence the extent of infection-mediated epigenetic modifications in the host cells

Introduction

Cellular epigenetic modifications occur in the course of viral infections. We previously documented that hepatitis C virus (HCV) infection of human hepatoma Huh-7.5 cells results in a core protein-mediated decrease of Aurora kinase B (AURKB) activity and phosphorylation of Serine 10 in histone H3 (H3Ser10ph) levels, with an affectation of inflammatory pathways. The possible role of HCV fitness in infection-derived cellular epigenetic modifications is not known.

Methods

Here we approach this question using HCV populations that display a 2.3-fold increase in general fitness (infectious progeny production), and up to 45-fold increase of the exponential phase of intracellular viral growth rate, relative to the parental HCV population.

Results

We show that infection resulted in a HCV fitness-dependent, average decrease of the levels of H3Ser10ph, AURKB, and histone H4 tri-methylated at Lysine 20 (H4K20m3) in the infected cell population. Remarkably, the decrease of H4K20m3, which is a hallmark of cellular transformation, was significant upon infection with high fitness HCV but not upon infection with basal fitness virus.

Discussion

Here we propose two mechanisms ─which are not mutually exclusive─ to explain the effect of high viral fitness: an early advance in the number of infected cells, or larger number of replicating RNA molecules per cell. The implications of introducing HCV fitness as an influence in virus-host interactions, and for the course of liver disease, are warranted. Emphasis is made in the possibility that HCV-mediated hepatocellular carcinoma may be favoured by prolonged HCV infection of a human liver, a situation in which viral fitness is likely to increase.

Exploring the mechanism of curcumin in the treatment of colon cancer based on network pharmacology and molecular docking

Objective: Curcumin is a plant polyphenol extracted from the Chinese herb turmeric. It was found that curcumin has good anti-cancer properties in a variety of cancers, but the exact mechanism is not clear. Based on the network pharmacology and molecular docking to deeply investigate the molecular mechanism of curcumin for the treatment of colon cancer, it provides a new research direction for the treatment of colon cancer. Methods: Curcumin-related targets were collected using PharmMapper, SwissTargetPrediction, Targetnet and SuperPred. Colon cancer related targets were obtained using OMIM, DisGeNET, GeneCards and GEO databases. Drug-disease intersection targets were obtained via Venny 2.1.0. GO and KEGG enrichment analysis of drug-disease common targets were performed using DAVID. Construct PPI network graphs of intersecting targets using STRING database as well as Cytoscape 3.9.0 and filter core targets. Molecular docking via AutoDockTools 1.5.7. The core targets were further analyzed by GEPIA, HPA, cBioPortal and TIMER databases. Results: A total of 73 potential targets of curcumin for the treatment of colon cancer were obtained. GO function enrichment analysis yielded 256 entries, including BP(Biological Progress):166, CC(celluar component):36 and MF(Molecular Function):54. The KEGG pathway enrichment analysis yielded 34 signaling pathways, mainly involved in Metabolic pathways, Nucleotide metabolism, Nitrogen metabolism, Drug metabolism - other enzymes, Pathways in cancer,PI3K-Akt signaling pathway, etc. CDK2, HSP90AA1, AURKB, CCNA2, TYMS, CHEK1, AURKA, DNMT1, TOP2A, and TK1 were identified as core targets by Cytoscape 3.9.0. Molecular docking results showed that the binding energies of curcumin to the core targets were all less than 0 kJ-mol-1, suggesting that curcumin binds spontaneously to the core targets. These results were further validated in terms of mRNA expression levels, protein expression levels and immune infiltration. Conclusion: Based on network pharmacology and molecular docking initially revealed that curcumin exerts its therapeutic effects on colon cancer with multi-target, multi-pathway. Curcumin may exert anticancer effects by binding to core targets. Curcumin may interfere with colon cancer cell proliferation and apoptosis by regulating signal transduction pathways such as PI3K-Akt signaling pathway,IL-17 signaling pathway, Cell cycle. This will deepen and enrich our understanding of the potential mechanism of curcumin against colon cancer and provide a theoretical basis for subsequent studies.

High expression of aurora kinase B predicts poor prognosis in hepatocellular carcinoma after curative surgery and its effects on the tumor microenvironment

BACKGROUND

Currently, the only broadly used biomarker for hepatocellular carcinoma (HCC), alpha fetoprotein (AFP), has multiple limitations and the need for novel biomarkers is urgent. Aurora kinase B (AURKB) is a key mitotic protein kinase which performs a critical function in cell cycle progression. Nonetheless, neither the function nor the mechanism of AURKB in HCC following curative surgery is fully grasped at this time. This study sought to evaluate the impact of AURKB on prognosis and the tumor immune microenvironment (TIME) in HCC.

METHODS

We evaluated both the expression profile of AURKB in HCC and its clinical value using online databases and clinical specimens. The prognostic value of AURKB was studied by Kaplan-Meier survival analysis, and the link between AURKB and tumor-infiltrating immune cells (TIICs) were analyzed.

RESULTS

We found the mRNA expression patterns of AURKB were remarkably upregulated in HCC in contrast with adjoining normal tissues (P<0.001). Upregulation of the AURKB protein in HCC was additionally verified by clinical samples. The expression of AURKB was substantially associated with Child-Pugh, microvascular invasion (MVI), Edmondson-Steiner grade, and tumor recurrence. Furthermore, patients diagnosed with HCC who had a low AURKB expression had a better. Our data suggested age [hazard ratio (HR): 1.34], alanine aminotransferase (ALT) (HR: 1.65), tumor size (HR: 1.99), mor number (HR: 1.60), MVI (HR: 1.93), grade (HR: 5.58), and AURKB expression (HR: 3.63) independently functioned as prognostic risk indicators for HCC (P<0.05). Importantly, we also found AURKB expression was inversely linked to resting natural killer (NK) cells, M2 macrophages, activated mast cells, and naive B cells, and positively linked to M0 macrophages, T follicular helper cells (Tfh), regulatory T cells (Treg), and resting myeloid dendritic cells. In addition, AURKB expression was also positively linked to the immune checkpoints of PDCD1, CD274, CTLA4, and LAG3. Finally, 1,696 DEGs were discovered, and were predominantly implicated in chromosome segregation, cell cycle, xenobiotic metabolic process, calcium signaling pathway, bile secretion, tyrosine metabolism, and DNA replication.

CONCLUSIONS

AURKB may be a potential prognostic biomarker for HCC after curative surgery, which correlates with MVI and the TIME in HCC.

Machine learning algorithm and deep neural networks identified a novel subtype in hepatocellular carcinoma

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Due to the lack of specific characteristics in the early stage of the disease, patients are usually diagnosed in the advanced stage of disease progression. OBJECTIVE: This study used machine learning algorithms to identify key genes in the progression of hepatocellular carcinoma and constructed a prediction model to predict the survival risk of HCC patients. METHODS: The transcriptome data and clinical information were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). The differential expression analysis and COX proportional-hazards model participated in the identification of survival-related genes. K-Means, Random forests, and LASSO regression are involved in identifying novel subtypes of HCC and screening key genes. The prediction model was constructed by deep neural networks (DNN), and Gene Set Enrichment Analysis (GSEA) reveals the metabolic pathways where key genes are located. RESULTS: Two subtypes were identified with significantly different survival rates (p< 0.0001, AUC = 0.720) and 17 key genes associated with the subtypes. The accuracy rate of the deep neural network prediction model is greater than 93.3%. The GSEA analysis found that the survival-related genes were significantly enriched in hallmark gene sets in the MSigDB database. CONCLUSIONS: In this study, we used machine learning algorithms to screen out 17 genes related to the survival risk of HCC patients, and trained a DNN model based on them to predict the survival risk of HCC patients. The genes that make up the model are all key genes that affect the formation and development of cancer.

Novel FLT3/AURK multikinase inhibitor is efficacious against sorafenib-refractory and sorafenib-resistant hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the sixth most common type of cancer and has a high mortality rate worldwide. Sorafenib is the only systemic treatment demonstrating a statistically significant but modest overall survival benefit. We previously have identified the aurora kinases (AURKs) and FMS-like tyrosine kinase 3 (FLT3) multikinase inhibitor DBPR114 exhibiting broad spectrum anti-tumor effects in both leukemia and solid tumors. The purpose of this study was to evaluate the therapeutic potential of DBPR114 in the treatment of advanced HCC.

Methods

Human HCC cell lines with histopathology/genetic background similar to human HCC tumors were used for in vitro and in vivo studies. Human umbilical vein endothelial cells (HUVEC) were used to evaluate the drug effect on endothelial tube formation. Western blotting, immunohistochemical staining, and mRNA sequencing were employed to investigate the mechanisms of drug action. Xenograft models of sorafenib-refractory and sorafenib-acquired resistant HCC were used to evaluate the tumor response to DBPR114.

Results

DBPR114 was active against HCC tumor cell proliferation independent of p53 alteration status and tumor grade in vitro. DBPR114-mediated growth inhibition in HCC cells was associated with apoptosis induction, cell cycle arrest, and polyploidy formation. Further analysis indicated that DBPR114 reduced the phosphorylation levels of AURKs and its substrate histone H3. Moreover, the levels of several active-state receptor tyrosine kinases were downregulated by DBPR114, verifying the mechanisms of DBPR114 action as a multikinase inhibitor in HCC cells. DBPR114 also exhibited anti-angiogenic effect, as demonstrated by inhibiting tumor formation in HUVEC cells. In vivo, DBPR114 induced statistically significant tumor growth inhibition compared with the vehicle control in multiple HCC tumor xenograft models. Histologic analysis revealed that the DBPR114 treatment reduced cell proliferation, and induced apoptotic cell death and multinucleated cell formation. Consistent with the histological findings, gene expression analysis revealed that DBPR114-modulated genes were mostly related to the G2/M checkpoint and mitotic spindle assembly. DBPR114 was efficacious against sorafenib-intrinsic and -acquired resistant HCC tumors. Notably, DBPR114 significantly delayed posttreatment tumor regrowth and prolonged survival compared with the regorafenib group.

Conclusion

Our results indicated that targeting AURK signaling could be a new effective molecular-targeted agent in the treatment of patients with HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-022-00788-0.

The Regulation of let-7c-5p on the Biological Characteristics of Lung Adenocarcinoma Cells by Targeting AURKB

To study the modulatory mechanism of let-7c-5p on the biological characteristics of lung adenocarcinoma (LUAD) cells by targeting AURKB. Differentially expressed genes (DEGs) were screened by bioinformatics analysis. CCK-8, colony formation, scratch healing, Transwell, and flow cytometry assays were employed to test biological functions of LUAD cells. Western Blot was undertaken to assay the protein level of AURKB, and qRT-PCR was undertaken to test AURKB mRNA and let-7c-5p expression. Dual-luciferase reporter gene method was applied to detect the interaction between AURKB and let-7c-5p. Let-7c-5p was much likely to target AURKB expression. Let-7c-5p was poorly expressed in LUAD cells and suppressed AURKB. Silencing AURKB or overexpressing let-7c-5p both could suppress proliferation, migration, and invasion and stimulate apoptosis, while overexpressing the two simultaneously could reverse such effect. Forced expression of let-7c-5p inhibited proliferation, migration, and invasion and accelerated apoptosis of LUAD cells by inhibiting AURKB, which may provide a new way to understand the malignant progression of LUAD.

Discovery of a novel Aurora B inhibitor GSK650394 with potent anticancer and anti-aspergillus fumigatus dual efficacies in vitro

Invasive fungal infections including Candidiasis and Aspergillosis are associated with considerable morbidity and mortality in immunocompromised individuals, such as cancer patients. Aurora B is a key mitotic kinase required for the cell division of eukaryotes from fungus to man. Here, we identified a novel Aurora B inhibitor GSK650394 that can inhibit the recombinant Aurora B from human and Aspergillus fumigatus, with IC₅₀ values of 5.68 and 1.29 µM, respectively. In HeLa and HepG2 cells, GSK650394 diminishes the endogenous Aurora B activity and causes cell cycle arrest in G2/M phase. Further cell-based assays demonstrate that GSK650394 efficiently suppresses the proliferation of both cancer cells and Aspergillus fumigatus. Finally, the molecular docking calculation and site-directed mutagenesis analyses reveal the molecular mechanism of Aurora B inhibition by GSK650394. Our work is expected to provide new insight into the combinational therapy of cancer and Aspergillus fumigatus infection.

Cytokinesis regulators as potential diagnostic and therapeutic biomarkers for human hepatocellular carcinoma

Cytokinesis, the final step of mitosis, is critical for maintaining the ploidy level of cells. Cytokinesis is a complex, highly regulated process and its failure can lead to genetic instability and apoptosis, contributing to the development of cancer. Human hepatocellular carcinoma is often accompanied by a high frequency of aneuploidy and the DNA ploidy pattern observed in human hepatocellular carcinoma results mostly from impairments in cytokinesis. Many key regulators of cytokinesis are abnormally expressed in human hepatocellular carcinoma, and their expression levels are often correlated with patient prognosis. Moreover, preclinical studies have demonstrated that the inhibition of key cytokinesis regulators can suppress the growth of human hepatocellular carcinoma. Here, we provide an overview of the current understanding of the signaling networks regulating cytokinesis, the key cytokinesis regulators involved in the initiation and development of human hepatocellular carcinoma, and their applications as potential diagnostic and therapeutic biomarkers.

Next-generation des-r-carboxy prothrombin for immunohistochemical assessment of vascular invasion by hepatocellular carcinoma

Background

We have previously shown the value of next-generation des-r-carboxy prothrombin (NX-DCP) for predicting vascular invasion in hepatocellular carcinoma (HCC). Since conventional DCP is inaccurate under some conditions, this study aimed to assess whether NX-DCP immunohistochemical staining was related to vascular invasion in HCC.

Methods

Fifty-six patients scheduled to undergo resection for single HCC were divided into two groups, with and without pathological portal vein invasion. Immunohistochemical features of HCC and sites of vascular invasion were assessed using alpha-fetoprotein (AFP), conventional DCP, and NX-DCP.

Results

Pathological portal vein invasion was absent in 43 patients and present in 13 patients. Patient characteristics, pathological background of the liver parenchyma, and tumor-related factors did not differ significantly between the groups. There was no significant difference in the serum AFP level between the groups, whereas levels of conventional DCP (p < 0.0001) and NX-DCP (p < 0.0001) were significantly higher in the vascular invasion group. Immunohistochemical staining showed no significant difference in the staining rate of tumor (67.9% vs. 80.7%, p = 0.08), but NX-DCP stained significantly more at the sites of vascular invasion (15.4% vs. 46.2%, p = 0.01) than conventional DCP. No vascular invasion was stained by AFP.

Conclusions

NX-DCP offers better sensitivity for detecting sites of vascular invasion than AFP and conventional DCP.

Identification of diagnostic and prognostic biomarkers, and candidate targeted agents for hepatitis B virus-associated early stage hepatocellular carcinoma based on RNA-sequencing data

Primary liver cancer is a rapidly progressing neoplasm with high morbidity and mortality rates. The present study aimed to identify potential diagnostic and prognostic biomarkers, and candidate targeted agents for hepatitis B virus (HBV)-associated early stage hepatocellular carcinoma (HCC). The gene expression profiles were extracted from the Gene Expression Omnibus database. Differentially expressed genes (DEGs), hub genes and the enrichment of signaling pathways were filtered out via a high-throughput sequencing method. The association between hub genes and the effects of the abnormal expression of hub genes on the rate of genetic variation, overall survival (OS), relapse-free survival (RFS), progression-free survival (PFS) and disease-free survival (DSS) of patients with HCC, as well as pathological stage and grade, were analyzed using different databases. A total of 1,582 DEGs were identified. Gene Ontology analysis revealed that the DEGs were mainly involved in the ‘oxidation-reduction process’, ‘steroid metabolic process’, ‘metabolic process’ and ‘fatty acid beta-oxidation’. Enrichment analysis of Kyoto Encyclopedia of Genes and Genomes pathways revealed that the DEGs were mainly associated with ‘metabolic pathways’, ‘PPAR signaling pathway’, ‘fatty acid degradation’ and the ‘cell cycle’. A total of 8 hub genes were extracted. Additionally, the abnormal expression levels of hub genes were closely associated with the OS, RFS, PFS and DSS of patients, the pathological stage and the grade. Furthermore, abnormal expression levels of the 8 hub genes were found in >30% of all samples. Several small molecular compounds that may reverse the altered DEGs were identified based on Connectivity Map analysis, including phenoxybenzamine, GW-8510, resveratrol, 0175029-0000 and daunorubicin. In conclusion, the dysfunction of fat metabolic pathways, the cell cycle, oxidation-reduction processes and viral carcinogenesis may serve critical roles in the occurrence of HBV-associated early stage HCC. The identified 8 hub genes may act as robust biomarkers for diagnosis and prognosis. Some small molecular compounds may be promising targeted agents against HBV-associated early stage HCC.

Predictors for hepatocellular carcinoma recurrence after microwave ablation

Aim of the study

Microwave ablation (MWA) for treatment of hepatocellular carcinoma (HCC) is a new promising modality. The prognosis after treatment is mainly linked to the recurrence. We aimed to investigate the predictive value of α-fetoprotein (AFP) score and Aurora B kinase (AURKB) in HCC recurrence after MWA.

Material and methods

A cross-sectional study where 25 early-stage HCC patients (Barcelona Clinic Liver Cancer 0/A-B) were treated with MWA. Tumor biopsies were obtained just prior to MWA and assessed for WHO pathological grade and AURKB expression by immunohistochemistry. AFP score was calculated and a cut-off value of 2 classifies patients into high and low risk of recurrence. After achieving complete ablation, patients were followed every 3 months for 1 year by triphasic CT to detect recurrence.

Results

Child-Pugh classification has no significant impact on prognosis of HCC after MWA (χ² = 1.924, p = 0.165). Serum AFP level and AFP score can effectively predict the response to MWA among HCC patients (χ² = 6.451, ^MCp = 0.031) (χ² = 9.0, p = 0.003), respectively. AFP score was strongly associated with the pathological grade of the tumor (r = 0.467, p = 0.019). AURKB was over-expressed in tumoral more than non-tumoral specimens (p < 0.001). It was correlated with the size of the tumor, the number of tumor nodules and the pathological grade of the tumor (p < 0.05) but has no role in predicting recurrence after MWA (p = 0.869).

Conclusions

AFP score but not AURKB can predict the risk of recurrence of HCC after MWA.

AURKB promotes gastric cancer progression via activation of CCND1 expression

Aurora kinase B (AURKB) triggers the phosphorylation of serine 10 on histone H3 (H3S10ph), which is important for chromosome condensation and cytokinesis during mitosis in mammals. However, how exactly AURKB controls cell cycle and contributes to tumorigenesis as an oncoprotein under pathological conditions remains largely unknown. Here, we report that AURKB promotes gastric cancer cell proliferation in vitro and in vivo. Silencing AURKB expression inhibits gastric cell proliferation and arrests the cell cycle in G₂/M phase. We demonstrate that cyclin D1 (CCND1) is a direct downstream target of AURKB that plays a key role in gastric cancer cell proliferation. AURKB is able to activate the expression of CCND1 through mediating H3S10ph in the promoter of the CCND1 gene. Furthermore, we show that AZD1152, a specific inhibitor of AURKB, can suppress the expression of CCND1 in the gastric cancer cells and inhibit cell proliferation in vitro and in vivo. Importantly, we found that high AURKB and CCND1 expression levels are correlated with shorter overall survival of gastric cancer patients. This study demonstrates that AURKB promotes gastric tumorigenesis potentially through epigenetically activating CCND1 expression, suggesting AURKB as a promising therapeutic target in gastric cancer.

Overexpression of CDCA5, KIF4A, TPX2, and FOXM1 Coregulated Cell Cycle and Promoted Hepatocellular Carcinoma Development

This study aimed to identify key functional modules and genes in functional module involved in hepatocellular carcinoma (HCC) development. The microarray data set GSE54236 was obtained from Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between HCC, and normal samples were identified by Limma. DAVID was used to identify the gene ontology terms these genes enriched. The co-expression network was constructed based on Pearson correlation coefficient between gene expression values, and the functional modules these DEGs obviously enriched in were recognized through GraphWeb. Then, based on the genes related to the development of HCC, the DEGs interacting with HCC-associated genes were spotted. Finally, survival analysis and real-time quantitative polymerase chain reaction were performed. Totally, 427 upregulated (e.g., cell division cycle associated 5 [CDCA5], kinesin family member 4A [KIF4A], TPX2 microtubule nucleation factor [TPX2]) and 313 downregulated (e.g., metallothionein 1E [MT1E]) DEGs were identified in HCC. Besides, CDCA5, KIF4A, and TPX2 had interacting relationship and played important roles in HCC development by interrelating with HCC-related gene, forkhead box M1 (FOXM1). Furthermore, CDCA5, KIF4A, TPX2, and FOXM1 obviously enriched in cell cycle-related functional module, whereas MT1E enriched in mineral absorption module in Kyoto Encyclopedia of Genes and Genomes. CDCA5, KIF4A, and TPX2 expression were increased in HCC cells, and their high expressions were related to poor prognosis. Overexpression of CDCA5, KIF4A, TPX2, and FOXM1 coregulated cell cycle and thereby promoted the development of HCC. The finding provided potential targets for the study and treatment of HCC.

Development and validation of a TP53-associated immune prognostic model for hepatocellular carcinoma

BACKGROUND

TP53 mutation is the most common mutation in hepatocellular carcinoma (HCC), and it affects the progression and prognosis of HCC. We investigated how TP53 mutation regulates the HCC immunophenotype and thus affects the prognosis of HCC.

METHODS

We investigated TP53 mutation status and RNA expression in different populations and platforms and developed an immune prognostic model (IPM) based on immune-related genes that were differentially expressed between TP53^WT and TP53^MUT HCC samples. Then, the influence of the IPM on the immune microenvironment in HCC was comprehensively analysed.

FINDINGS

TP53 mutation resulted in the downregulation of the immune response in HCC. Thirty-seven of the 312 immune response-related genes were differentially expressed based on TP53 mutation status. An IPM was established and validated based on 865 patients with HCC to differentiate patients with a low or high risk of poor survival. A nomogram was also established for clinical application. Functional enrichment analysis showed that the humoral immune response and immune system diseases pathway represented the major function and pathway, respectively, related to the IPM genes. Moreover, we found that the patients in the high-risk group had higher fractions of T cells follicular helper, T cells regulatory (Tregs) and macrophages M0 and presented higher expression of CTLA-4, PD-1 and TIM-3 than the low-risk group.

INTERPRETATION

TP53 mutation is strongly related to the immune microenvironment in HCC. Our IPM, which is sensitive to TP53 mutation status, may have important implications for identifying subgroups of HCC patients with low or high risk of unfavourable survival. FUND: This work was supported by the International Science and Technology Cooperation Projects (2016YFE0107100), the Capital Special Research Project for Health Development (2014-2-4012), the Beijing Natural Science Foundation (L172055 and 7192158), the National Ten Thousand Talent Program, the Fundamental Research Funds for the Central Universities (3332018032), and the CAMS Innovation Fund for Medical Science (CIFMS) (2017-I2M-4-003 and 2018-I2M-3-001).

Targeting epigenetics for cancer therapy

Cancer can be identified as a chaotic cell state, which breaks the rules that govern growth and reproduction, with main characteristics such as uncontrolled division, invading other tissues, usurping resources, and eventually killing its host. It was once believed that cancer is caused by a progressive series of genetic aberrations, and certain mutations of genes, including oncogenes and tumor suppressor genes, have been identified as the cause of cancer. However, piling evidence suggests that epigenetic modifications working in concert with genetic mechanisms to regulate transcriptional activity are dysregulated in many diseases, including cancer. Cancer epigenetics explain a wide range of heritable changes in gene expression, which do not come from any alteration in DNA sequences. Aberrant DNA methylation, histone modifications, and expression of long non-coding RNAs (lncRNAs) are key epigenetic mechanisms associated with tumor initiation, cancer progression, and metastasis. Within the past decade, cancer epigenetics have enabled us to develop novel biomarkers and therapeutic target for many types of cancers. In this review, we will summarize the major epigenetic changes involved in cancer biology along with clinical and preclinical results developed as novel cancer therapeutics.

Identification of genes and pathways, including the CXCL2 axis, altered by DNA methylation in hepatocellular carcinoma

PURPOSE

Recent genetic studies have suggested that tumor suppressor genes are often silenced during carcinogenesis via epigenetic modification caused by methylation of promoter CpG islands. Here, we characterized genes inactivated by DNA methylation in human hepatocellular carcinoma (HCC) to identify the genes and pathways involved in DNA methylation in hepatocellular carcinoma.

METHODS

Eight HCC-derived cell lines were treated with a DNA demethylating agent, 5-aza-2'-deoxycytidine. Additionally, 100 pairs of primary HCC and adjacent non-cancerous tissues as well as 15 normal liver tissues were analyzed by comprehensive gene expression analysis using microarrays. Moreover, gene set enrichment analysis identified the major molecular pathways associated with DNA methylation. Validation of gene expression and DNA methylation status was performed by real-time PCR after bisulfite modification.

RESULTS

We showed that CXCL2, an immune-related chemokine, expression was significantly downregulated in tumor tissues and also significantly upregulated by DAC treatment in cell lines. Furthermore, we observed a statistically significant difference in methylation status between normal liver tissues and tumor tissues (P < 0.05). In addition, tumors with higher CXCL2 expression included significantly more numbers of multiple tumors than the lower expression group.

CONCLUSIONS

We identified CXCL2, an immune-related chemokine, decreased in hepatocellular carcinoma and the regulation mechanism may be controlled by methylation. Further studies should be warranted to examine if and to what extent the gene is actually suppressed by methylation and if there is a possibility that the CXCL2 axis plays a role for diagnosis and treatment of hepatocellular carcinoma.

Butein suppresses hepatocellular carcinoma growth via modulating Aurora B kinase activity

Aurora B is aberrantly expressed in various tumors and shown to be a promising target for cancer therapy. Butein, a chalcone isolated from Rhus cerniciflua, has demonstrated antitumor activities in different cancers. In this study, we aimed to validate whether Aurora B kinase was the direct target of butein to exhibit its potency in hepatocellular carcinoma (HCC). Comparing with the normal cell line and tissue, Aurora B was overexpressed in all tested HCC cells and the majority of tumor tissue. Knocking down of Aurora B with shRNA substantially inhibited HCC cell proliferation, colony formation and delayed tumor growth in nude mice. Except computer docking, a series of kinase assays revealed butein directly interacted with Aurora B and inhibited its kinase activity. Along with the decrease of Aurora B and histone H3 phosphorylation, HCC cells were induced G2/M cell cycle arrest and subjected to cell apoptosis. Butein-mediated antitumor activities were substantially impaired in Aurora B knockdown cells, suggesting Aurora B was an important target of butein in HCC. Oral administration of butein substantially restrained HCC xenograft growth and the expressions of Ki67 and phosphor-histone H3 were significantly decreased in butein-treated tissue. To the best of our knowledge, our studies revealed that Aurora B was the direct target of butein in HCC.

Targeting high Aurora kinases expression as an innovative therapy for hepatocellular carcinoma

The Aurora kinases A and B control tumorigenesis by inhibiting apoptosis and promoting proliferation and metastasis, however, it remains unknown whether Aurora A and B overexpressed concomitantly and its clinical significance in hepatocellular carcinoma (HCC). Here, we obsearved Aurora A and B tended to overexpress parallelly on protein level (r = 0.8679, P < 0.0001) and their co-overexpression (Aurora A^HB^H), associated with the worst prognosis, was an independent predictor for the survival. Importantly, with the lower IC50 and stronger anti-tumor effect than selective inhibitors, SNS-314, the pan-inhibitor of Aurora kinases, which induced YAP (Yes-associated protein) reduction and resulted in P21 accumulation, significantly promoted the polyploidy (> 4N) formation and apoptosis in HCC. High YAP expression (YAP^H) was associated with Aurora A^HB^H, and appeared to be an independent predictor for survival, but P21 not. Moreover, silencing YAP also induced P21 accumulation, and knockdown P21, which enhanced YAP accumulation and weakened the SNS-314-induced YAP reduction, impaired SNS-314-induced apoptosis. Therefore, P21 enhanced the apoptotic effect of SNS-314 in HCC. Taken together, our findings indicated Aurora kinases/YAP/P21 was an oncogenic signaling axis in HCC, and revealed targeting Aurora A^HB^H induced apoptosis by YAP suppression. Our results also provided a solid evidence for SNS-314 as a potential targeted therapy, and a proof-of-concept evidence for a possible combined therapy of SNS-314 plus Hippo pathway inhibitors on HCC.

Targeting hepatocarcinogenesis model in C56BL6 mice with pan-aurora kinase inhibitor Danusertib

Background: To elucidate the expression of Aurora kinases (AURK) and the anticancer effects of pan-aurora kinase inhibitor Danusertib in hepatocarcinogenesis model in C56Bl6 mice.

Methods: Thirty mice C56Bl6 were randomly divided into Group A or control, Group B animals who underwent experimental hepatocarcinogenesis with diethylnitrosamine (DEN), and Group C animals with DEN-induced hepatocarcinogenenesis that treated with pan-aurora kinase inhibitor Danusertib. Primary antibodies for immunochistochemistry (IHC) included rabbit antibodies against Ki-67, DKK1, INCENP, cleaved caspase-3, NF-κB p65, c-Jun, β-catenin. Hepatocyte growth factor receptor (C-MET/HGFR) and Bcl-2 antagonist of cell death (BAD) serum levels were determined using a quantitative sandwich enzyme immunoassay technique.

Results: Inhibition of AURK reduced the number of DEN-induced liver tumours. Apoptosis and proliferation was very low in both DEN-induced and anti- AURK groups respectively. The hepatocellular adenoma cells of DEN-treated mice uniformly had ample nuclear INCENP whereas in anti- AURK markedly decreased. Expression of β-catenin, NF-kB and c-Jun did not differ in liver tumors of both AURK -depleted and non-depleted mice.

Conclusions: Depletion of AURK reduced the number of DEN-induced hepatic tumours. However, their size did not differ significantly between the groups.

CHK2 overexpression and mislocalisation within mitotic structures enhances chromosomal instability and hepatocellular carcinoma progression

OBJECTIVE

Chromosomal instability (CIN) is the most common form of genomic instability, which promotes hepatocellular carcinoma (HCC) progression by enhancing tumour heterogeneity, drug resistance and immunity escape. CIN per se is an important factor of DNA damage, sustaining structural chromosome abnormalities but the underlying mechanisms are unknown.

DESIGN

DNA damage response protein checkpoint kinase 2 (Chk2) expression was evaluated in an animal model of diethylnitrosamine-induced HCC characterised by DNA damage and elevated mitotic errors. Chk2 was also determined in two discrete cohorts of human HCC specimens. To assess the functional role of Chk2, gain on and loss-of-function, mutagenesis, karyotyping and immunofluorescence/live imaging were performed by using HCT116, Huh7 and human hepatocytes immortalised with hTERT gene (HuS).

RESULTS

We demonstrate that mitotic errors during HCC tumorigenesis cause lagging chromosomes/DNA damage and activation of Chk2. Overexpression/phosphorylation and mislocalisation within the mitotic spindle of Chk2 contributes to induce lagging chromosomes. Lagging chromosomes and mitotic activity are reversed by knockdown of Chk2. Furthermore, upregulated Chk2 maintains mitotic activity interacting with Aurora B kinase for chromosome condensation and cytokinesis. The forkhead-associated domain of Chk2 is required for Chk2 mislocalisation to mitotic structures. In addition, retinoblastoma protein phosphorylation contributes to defective mitoses. A cohort and independent validation cohort show a strong cytoplasm to nuclear Chk2 translocation in a subset of patients with HCC.

CONCLUSIONS

The study reveals a new mechanistic insight in the coinvolvement of Chk2 in HCC progression. These findings propose Chk2 as a putative biomarker to detect CIN in HCC providing a valuable support for clinical/therapeutical management of patients.

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

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

Aurora kinases: novel therapy targets in cancers

Aurora kinases, a family of serine/threonine kinases, consisting of Aurora A (AURKA), Aurora B (AURKB) and Aurora C (AURKC), are essential kinases for cell division via regulating mitosis especially the process of chromosomal segregation. Besides regulating mitosis, Aurora kinases have been implicated in regulating meiosis. The deletion of Aurora kinases could lead to failure of cell division and impair the embryonic development. Overexpression or gene amplification of Aurora kinases has been clarified in a number of cancers. And a growing number of studies have demonstrated that inhibition of Aurora kinases could potentiate the effect of chemotherapies. For the past decades, a series of Aurora kinases inhibitors (AKIs) developed effectively repress the progression and growth of many cancers both in vivo and in vitro, suggesting that Aurora kinases could be a novel therapeutic target. In this review, we'll first briefly present the structure, localization and physiological functions of Aurora kinases in mitosis, then describe the oncogenic role of Aurora kinases in tumorigenesis, we shall finally discuss the outcomes of AKIs combination with conventional therapy.

Upregulate KIF4A Enhances Proliferation, Invasion of Hepatocellular Carcinoma and Indicates poor prognosis Across Human Cancer Types

Hepatocellular carcinoma (HCC) is one of the most aggressive and heterogeneous cancers worldwide. Herein, we demonstrate KIF4A (Chromosome-associated kinesin KIF4A) as a potential biomarker, is up-regulated in most samples of HCC. The expression level of KIF4A in tumor tissue is significantly associated with the survival time, and a significant correlation between KIF4A expression and clinical information stage, metastasis and tumor dimension was observed. We further measured the proliferation and migration ability of two HCC cell lines, HCC-LM3 and PLC/PRF/5, following KIF4A-siRNA transfection. Knocking down of KIF4A significantly reduced migration and proliferation ability. Moreover, we also measured the proliferation and migration ability of two HCC cell lines through KIF4A overexpression, and found that KIF4A overexpression could enhance migration and proliferation ability, indicating that KIF4A exhibits oncogenic effects. Besides, study based on TCGA cohorts also reveals high KIF4A mRNA expression are significantly associated with shorter overall survival in multiple cancer types. Gene sets enrichment analysis exhibited that cell cycle related pathways and p53 signaling pathways to be top altered pathways of in KIF4A-high expression group in HCC, suggesting the potential role of KIF4A in mediating tumor initiation and progression. In summary, our work identified KIF4A as a potential predictive and prognostic marker for hepatocellular carcinoma.

Epigenetics in cancer: Fundamentals and Beyond

Activation of oncogenes or the deactivation of tumor suppressor genes has long been established as the fundamental mechanism leading towards carcinogenesis. Although this age old axiom is vastly accurate, thorough study over the last 15years has given us unprecedented information on the involvement of epigenetic in cancer. Various biochemical pathways that are essential towards tumorigenesis are regulated by the epigenetic phenomenons like remodeling of nucleosome by histone modifications, DNA methylation and miRNA mediated targeting of various genes. Moreover the presence of mutations in the genes controlling the epigenetic players has further strengthened the association of epigenetics in cancer. This merger has opened up newer avenues for targeted anti-cancer drug therapy with numerous pharmaceutical industries focusing on expanding their research and development pipeline with epigenetic drugs. The information provided here elaborates the elementary phenomena of the various epigenetic regulators and discusses their alteration associated with the development of cancer. We also highlight the recent developments in epigenetic drugs combining preclinical and clinical data to signify this evolving field in cancer research.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

HERC5 is a prognostic biomarker for post-liver transplant recurrent human hepatocellular carcinoma

BACKGROUND AND AIMS

Orthotopic liver transplantation (OLT) can be an effective treatment option for certain patients with early stage hepatocellular carcinoma (HCC) meeting Milan, UCSF, or Hangzhou criteria. However, HCC recurrence rates post-OLT range from 20 to 40 %, with limited follow-up options. Elucidating genetic drivers common to primary and post-OLT recurrent tumors may further our understanding and help identify predictive biomarkers of recurrence-both to ultimately help manage clinical decisions for patients undergoing OLT.

METHODS

Whole exome and RNA sequencing in matched primary and recurrent tumors, normal adjacent tissues, and blood from four Chinese HCC patients was conducted. SiRNA knockdown and both qRT-PCR and Western assays were performed on PLCPRF5, SNU449 and HEPG2 cell lines; immunohistochemistry and RNA Sequencing were conducted on the primary tumors of Chinese HCC patients who experienced tumor recurrence post-OLT (n = 9) or did not experience tumor recurrence (n = 12).

RESULTS

In three independent HCC studies of patients undergoing transplantation (n = 21) or surgical resection (n = 242, n = 44) of primary tumors (total n = 307), HERC5 mRNA under-expression correlated with shorter: time to tumor recurrence (p = 0.007 and 0.02) and overall survival (p = 0.0063 and 0.023), even after adjustment for relevant clinical variables. HERC5 loss drives CCL20 mRNA and protein over-expression and associates with regulatory T cell infiltration as measured by FOXP3 expression. Further, matched primary and recurrent tumors from the 4 HCC patients indicated clonal selection advantage of Wnt signaling activation and CDKN2A inactivation.

CONCLUSIONS

HERC5 plays a crucial role in HCC immune evasion and has clinical relevance as a reproducible prognostic marker for risk of tumor recurrence and survival in patients.

New Auroras on the Roles of the Chromosomal Passenger Complex in Cytokinesis: Implications for Cancer Therapies

The chromosomal passenger complex (CPC), composed of a kinase component, Aurora B, the scaffolding subunit inner centromeric protein, Borealin, and Survivin, is a key regulator of cell division. It controls multiple events, from chromosome condensation in prophase to the final separation or abscission of the two daughter cells. The essential functions of the CPC during metaphase, however, have always hindered an accurate study of its role during cytokinesis. The recent development of small molecule inhibitors against Aurora B and the use of elegant technologies such as chemical genetics have offered new approaches to study the functions of the CPC at the end of cell division. Here, we review the recent findings about the roles of the CPC in controlling the assembly of the cleavage furrow, central spindle, and midbody. We will also discuss the crucial function of this complex in controlling abscission timing in order to prevent abscission when lagging chromatin is present at the cleavage site, thereby avoiding the formation of genetically abnormal daughter cells. Finally, we offer our perspective on how to exploit the potential therapeutic applications of inhibiting CPC activity during cytokinesis in cancer cells.

Aurora B Overexpression Causes Aneuploidy and p21Cip1 Repression during Tumor Development

Aurora kinase B, one of the three members of the mammalian Aurora kinase family, is the catalytic component of the chromosomal passenger complex, an essential regulator of chromosome segregation in mitosis. Aurora B is overexpressed in human tumors although whether this kinase may function as an oncogene in vivo is not established. Here, we report a new mouse model in which expression of the endogenous Aurkb locus can be induced in vitro and in vivo. Overexpression of Aurora B in cultured cells induces defective chromosome segregation and aneuploidy. Long-term overexpression of Aurora B in vivo results in aneuploidy and the development of multiple spontaneous tumors in adult mice, including a high incidence of lymphomas. Overexpression of Aurora B also results in a reduced DNA damage response and decreased levels of the p53 target p21(Cip1) in vitro and in vivo, in line with an inverse correlation between Aurora B and p21(Cip1) expression in human leukemias. Thus, overexpression of Aurora B may contribute to tumor formation not only by inducing chromosomal instability but also by suppressing the function of the cell cycle inhibitor p21(Cip1).

High proliferation index, as determined by immunohistochemical expression of Aurora kinase B and geminin, indicates poor prognosis in neuroblastomas

Expression profile analysis of cell cycle biomarkers provides a powerful index of the proliferative state of tumors, which is linked to disease aggressiveness. We investigated the impact of the biomarkers of S-G2-M phases of cell cycle, Aurora kinase B (AURKB) and geminin (GMNN), on disease progression in neuroblastomas. The expression of AURKB and GMNN was studied by immunostaining 84 neuroblastomas. A proliferation index (PI) was obtained on scanned immunostained slides using image analysis software. The median PI was 8.5 % for AURKB- and 16.8 % for GMNN-stained slides with a high correlation between the two (r s = 0.72, P < 0.001). The PI for both markers was significantly higher in neuroblastomas from patients with unfavorable clinical (high-risk group, advanced stage, age ≥18 months at presentation, primary abdominal compared to extra-abdominal sites), biological (MYCN amplification, 1p deletion, 17q gain), and pathological (undifferentiated or poorly differentiated status, high mitosis-karyorrhexis index, [MKI], unfavorable histology) factors. Using Cox regression models, a higher-than-median AURKB and GMNN PI was associated with a significantly shorter overall survival (OS) and event-free survival (EFS) in univariable analysis. In multivariable analysis, a high AURKB PI was associated with significantly shorter OS and EFS, independent of MYCN amplification, and significantly shorter EFS, independent of MKI. High GMNN PI was also associated with significantly shorter OS and EFS after adjusting for MYCN amplification but failed to reach statistical significance after adjusting for MKI. Our study shows that in neuroblastomas, AURKB- or GMNN-based PI provides valuable prognostic information and high PI indicates aggressive disease.

Novel Aurora/vascular endothelial growth factor receptor dual kinase inhibitor as treatment for hepatocellular carcinoma

We previously identified Aurora B kinase as the only independent factor predictive of the aggressive recurrence of hepatocellular carcinoma (HCC). In this preclinical study, JNJ-28841072, a novel Aurora/vascular endothelial growth factor receptor dual kinase inhibitor, was evaluated for treatment of HCC. In vitro and in vivo effects of JNJ-28841072 were analyzed using human HCC cell cultures and xenograft models. An orthotopic liver xenograft model was used for the pharmacobiological effects on Aurora kinase and vascularization in hepatic tumors. JNJ-28841072 suppressed in vitro phosphorylation of histone H3 with induction of cell polyploidy and death in a dose-dependent manner (IC₅₀ = 0.8–1.2 μM). In s.c. human HCC xenografts, remarkable inhibition of tumor growth was observed after JNJ-28841072 treatment (P = 0.0005). In orthotopic liver xenografts, the treatment with JNJ-28841072 significantly suppressed in vivo phosphorylation of histone H3 (P = 0.0008), vessel formation (P = 0.018), normoxic area (P = 0.0001), and hepatoma growth (P = 0.038). Our preclinical studies indicate that JNJ-28841072 is a promising novel therapeutic approach for the treatment of HCC. It might be worthy of evaluation in further studies.

The immune system in hepatocellular carcinoma and potential new immunotherapeutic strategies

BACKGROUND

Hepatocellular carcinoma is a major health problem worldwide and the third most common cause of cancer-related death. HCC treatment decisions are complex and dependent upon tumor staging. Several molecular targeted agents have been evaluated in clinical trials in advanced HCC. Despite of only modest objective response rates according to the Response Evaluation Criteria in Solid Tumors, several studies showed encouraging results in terms of prolongation of the time to progression, disease stabilization, and survival. Cellular immunotherapy would improve the immune state and has potential in enhancing the therapeutic outcome for HCC patients.

MATERIALS AND METHODS

A search of the literature was made using cancer literature, the PubMed, Scopus, and Web of Science (WOS) database for the following keywords: "hepatocellular carcinoma," "molecular hepatocarcinogenesis," "targeted therapy," "molecular immunological targets," "tumour-associated antigens," "Tregs," "MDSCs," "immunotherapy."

DISCUSSION AND CONCLUSION

Treatment strategies combining blockade of immunoregulatory cell types such as Tregs and MDSCs and of inhibitory receptors, with vaccine-induced activation of TAA-specific T cells, may be necessary to achieve the most effective therapeutic antitumour activity in HCC. In the future, new therapeutic options will be represented by a blend of immunotherapy-like vaccines and T-cell modulators, supplemented by molecularly targeted inhibitors of tumor signaling pathways.

HCA519/TPX2: a potential T-cell tumor-associated antigen for human hepatocellular carcinoma

Background

Immunotherapy for human hepatocellular cancer (HCC) is slowly making progress towards treating these fatal cancers. The identification of new antigens can improve this approach. We describe a possible new antigen, hepatocellular carcinoma‐associated antigen‐519/targeting protein for Xklp‐2 (HCA519/TPX2), for HCC that might be beneficial for T‐cell specific HCC immunotherapy.

Methods

HCC was studied for the expression for 15 tumor‐associated antigens considered useful for immunotherapy within three HCC cell lines (HepG2, Hep3B, and PLC/PRF/5), lymphocytes, non‐cancerous livers, and clinical HCC. The expression of tumor antigenic precursor proteins (TAPPs) messenger RNA was first screened by reverse transcriptase quantitative real‐time polymerase chain reaction.

Results

Four antigens (alpha fetoprotein, aspartyl/asparaginyl β­hydroxylase, glypican­3 and HCA519/TPX2) proved to be the best expressed TAPPs within the HCC specimens by molecular analyses. HCA519/TPX2 was detected by intracellular cell flow cytometry within HCC cell lines by using a specific antibody towards this TAPP. This antibody also detected the protein within primary HCCs. We synthesized two HCA519/TPX2 peptides (HCA519_464–472 and HCA519_351–359) which can bind to human leukocyte antigen (HLA)‐A*0201. Dendritic cells pulsed with these peptides stimulated cytolytic T lymphocytes (CTLs). These killer T‐cells lysed HLA‐A*0201+ T2 cells exogenously loaded with the correct specific peptide. The CTLs killed HepG2 (HLA‐A2+ and HCA519+), but not the Hep3B and PLC/PRF/5 cell lines, which are HCA519+ but HLA‐A2‐negative. In silico analysis reveals that HCA519/TPX2 has the inherent ability to bind to a very wide variety of HLA antigens.

Conclusion

HCA519/TPX2 is a viable immunotarget that should be further investigated within HCC patients.

Microtubule-targeting agents in oncology and therapeutic potential in hepatocellular carcinoma

In mammalian cells, microtubules are present both in interphase and dividing cells. In the latter, microtubules forming the mitotic spindle are highly dynamic and exquisitely sensitive to therapeutic inhibitors. Developed to alter microtubule function, microtubule-binding agents have been proven to be highly active as an anticancer treatment. Significant development of microtubule-binding agents has taken place in recent years, with newer anti-tubulin agents now showing novel properties of enhanced tumor specificity, reduced neurotoxicity, and insensitivity to chemoresistance mechanisms. Hepatocellular carcinoma remains one of the most difficult cancers to treat, with chemotherapies being relatively ineffective. There is now evidence to suggest that microtubule-binding agents may be effective in the treatment of hepatocellular carcinoma, especially when used in combination with mammalian target of rapamycin inhibitors. Preclinical models have suggested that the latter may be able to overcome resistance to microtubule binding agents. In this review article, recent developments of novel microtubule binding agents and their relevance to the treatment of hepatocellular carcinoma will be discussed.

RalA signaling pathway as a therapeutic target in hepatocellular carcinoma (HCC)

Ral (Ras like) leads an important proto-oncogenic signaling pathway down-stream of Ras. In this work, RalA was found to be significantly overactivated in hepatocellular carcinoma (HCC) cells and tissues as compared to non-malignant samples. Other elements of RalA pathway such as RalBP1 and RalGDS were also expressed at higher levels in malignant samples. Inhibition of RalA by gene-specific silencing caused a robust decrease in the viability and invasiveness of HCC cells. Additionally, the use of geranyl-geranyl transferase inhibitor (GGTI, an inhibitor of Ral activation) and Aurora kinase inhibitor II resulted in a significant decrease in the proliferation of HCC cells. Furthermore, RalA activation was found to be at a higher level of activation in HCC stem cells that express CD133. Transgenic mouse model for HCC (FXR-Knockout) also revealed an elevated level of RalA-GTP in the liver tumors as compared to background animals. Finally, subcutaneous mouse model for HCC confirmed effectiveness of inhibition of aurora kinase/RalA pathway in reducing the tumorigenesis of HCC cells in vivo. In conclusion, RalA overactivation is an important determinant of malignant phenotype in differentiated and stem cells of HCC and can be considered as a target for therapeutic intervention.

Prognostic biomarkers for prediction of recurrence of hepatocellular carcinoma: Current status and future prospects

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death worldwide, with region specific etiologies. Despite improvements made in the diagnosis of HCC, the prognosis of HCC patients remains poor due to the high recurrence rate of HCC. There is an urgent need for development of prognostic biomarkers to predict the risk of recurrence in HCC patients after “curative” treatment. Such stratification may aid in patient management and development of personalized medicine for HCC treatment. Omics based studies facilitate the study of global changes in biomolecules in a disease in a high throughput manner, and hence are well poised to understand the complex changes which led to HCC recurrence. The quantitative nature of data obtained from omics based studies allow for development of prognostic biomarkers based on changes in gene, protein and metabolite expression. In this review, we surveyed the application of transcriptomics, proteomics and metabolomics in the study of HCC recurrence. We summarised the data in the literature from these three fields of studies that claimed to be prognostic for HCC recurrence. We critiqued on the limitations of each area of research and the challenges faced in translating the research results for clinical application in predicting HCC recurrence.

Application of microRNA and mRNA expression profiling on prognostic biomarker discovery for hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most highly malignant and lethal cancers of the world. Its pathogenesis has been reported to be multi-factorial, and the molecular carcinogenesis of HCC can not be attributed to just a few individual genes. Based on the microRNA and mRNA expression profiling of normal liver tissues, pericancerous hepatocellular tissues and hepatocellular carcinoma tissues, we attempted to find prognosis related gene sets for HCC patients.

Results

We identified differentially expressed genes (DEG) from three comparisons: Cancer/Normal, Cancer/Pericancerous and Pericancerous/Normal. GSEA (gene set enrichment analysis) were performed. Based on the enriched gene sets of GO terms, pathways and transcription factor targets, it was found that the genome instability and cell proliferation increased while the metabolism and differentiation decreased in HCC tissues. The expression profile of DEGs in each enriched gene set was used to correlate to the postoperative survival time of HCC patients. Nine gene sets were found to prognostic correlation. Furthermore, after substituting DEG-targeting-microRNA for DEG members of each gene set, two gene sets with the microRNA expression profiles were obtained that had prognostic potential.

Conclusions

The malignancy of HCC could be represented by gene sets, and pericancerous liver exhibits important characteristics of liver cancer. The expression level of gene sets not only in HCC but also in the pericancerous liver showed potential for prognosis implying an option for HCC prognosis at an early stage. Additionally, the gene-targeting-microRNA expression profiles also showed prognostic potential, demonstrating that the multi-factorial molecular pathogenesis of HCC is contributed by various genes and microRNAs.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-S1-S13) contains supplementary material, which is available to authorized users.

Post-transplant endothelial progenitor cell mobilization via CXCL10/CXCR3 signaling promotes liver tumor growth

BACKGROUND & AIMS

Patients with hepatocellular carcinoma (HCC) receiving living donor liver transplantation appear to possess significantly higher tumor recurrence than the recipients receiving deceased donor liver transplantation. The underlying mechanism for HCC recurrence after transplantation remains unclear. Here, we aim to investigate the impact of small-for-size liver graft injury on HCC recurrence after transplantation.

METHODS

The correlation between tumor recurrence, liver graft injury, CXCL10 expression and endothelial progenitor cell (EPC) mobilization was studied in 115 liver transplant recipients and rat orthotopic liver transplantation (OLT) models. The direct role of CXCL10/CXCR3 signaling on EPC mobilization was investigated in CXCL10(-/-) mice and CXCR3(-/-) mice. The role of EPCs on tumor growth and angiogenesis was further investigated in an orthotopic liver tumor model.

RESULTS

Clinically, patients with small-for-size liver grafts (<60% of standard liver weight, SLW) had significantly higher HCC recurrence (p=0.04), accompanied by more circulating EPCs and higher early-phase intragraft and plasma CXCL10 levels, than the recipients with large grafts (≥60% of SLW), which were further validated in rat OLT models. Circulatory EPC mobilization was reduced after liver injury both in CXCL10(-/-) mice and CXCR3(-/-) mice in comparison to wild-type controls. CXCL10 recruited EPCs in dose-dependent and CXCR3-dependent manners in vitro. Early-phase EPC/CXCL10 injection enhanced orthotopic liver tumor growth, angiogenesis and metastasis in nude mice.

CONCLUSIONS

Post-transplant enhanced CXCL10/CXCR3 signaling in small-for-size liver grafts directly induced EPC mobilization, differentiation and neovessel formation, which further promotes tumor growth. Targeting CXCL10/CXCR3 signaling may attenuate early-phase liver graft injury and prevent late-phase tumor recurrence/metastasis after transplantation.

Cytoskeleton-associated protein 2 is a potential predictive marker for risk of early and extensive recurrence of hepatocellular carcinoma after operative resection

BACKGROUND

De principe transplantation is an attractive strategy for the treatment of patients with hepatocellular carcinoma (HCC). The most important issue for this strategy is how to predict the risk of early and extensive recurrence. The present study aimed to identify a molecule associated with early and extensive recurrence of HCC after resection.

METHODS

Differentially expressed genes were screened by DNA microarray analysis with the use of 12 HCC samples from patients who had different clinical courses based on the timing and extent of recurrence after operative resection. Furthermore, the obtained results were validated in 60 independent samples by quantitative real-time reverse transcription-polymerase chain reaction. Immunohistochemistry was performed to assess gene expression at the protein level.

RESULTS

Microarray analysis and quantitative reverse transcription-polymerase chain reaction revealed cytoskeleton-associated protein 2 (CKAP2) as a candidate gene associated with early and extensive recurrence of HCC after resection. This observation was confirmed through examination of independent set samples, in which patients with greater-level CKAP2 mRNA expression exhibited shorter recurrence-free survival. Immunohistochemistry showed CKAP2 protein expression was associated with early (≤3 years) and extensive recurrence (beyond Milan criteria) after operative resection.

CONCLUSION

Immunohistochemical CKAP2 expression might be a potential biologic marker for identifying HCC patients at risk of early and extensive recurrence after operative resection.

VX680 suppresses the growth of HepG2 cells and enhances the chemosensitivity to cisplatin

VX680 is an Aurora A inhibitor. It has been reported to inhibit the growth of the HepG2 cell line in several studies. However, whether it enhances chemosensitivity to cisplatin remains unclear. In this study, the synergistic effect of VX680 and cisplatin on the proliferation of HepG2 cells was determined by MTT assay. The changes in cell apoptosis were detected by flow cytometry. Aurora A, Bcl-2 and p53 protein levels were analyzed by western blotting. This study demonstrated that VX680, cisplatin and a combination of the two inhibit the growth of HepG2 cells in a dose- and time-dependent manner. A synergistic effect was observed with the combined therapy. Moreover, the inhibitory effect of VX680 was positively correlated with the expression of Aurora A. The rate of apoptosis in the combined group was significantly higher compared with that of the VX680 and cisplatin groups. In addition, VX680 and cisplatin increased the expression of the p53 protein. Cisplatin reduced the expression of Bcl-2 protein, while VX680 did not. In the combined group, the expression of Bcl-2 and p53 changed significantly compared with the single drug group and control group. This study suggests that Aurora A may represent a valid target in hepatocellular carcinoma. We also demonstrated that the Aurora A inhibitor VX680 has a synergistic effect with cisplatin.

The role of Aurora B expression in non-tumor liver tissues of patients with hepatocellular carcinoma

BACKGROUND

Aurora B is a serine-threonine kinase and chromosomal passenger protein involved in the control of chromosome assembly and segregation during mitosis. Aberrant expression of Aurora B has been reported in some tumors, including lung and hepatocellular carcinoma (HCC). We investigated the role of Aurora B expression in both HCC and matched adjacent non-tumor tissue.

METHODS

Sixty-three patients with HCC who underwent hepatic resection were enrolled in this study. Aurora B expression in tumor and non-tumor tissue was examined by use of quantitative reverse transcription-polymerase chain reaction. The patients were divided into high and low gene expression groups by median value, and clinicopathological data were compared between the two groups.

RESULTS

Aurora B expression was significantly higher in tumor tissue than in non-cancerous tissue (P < 0.001). Disease-free survival was not significantly different between groups with high and low expression in the tumor tissues. For non-tumor tissues, disease-free survival of the low-expression group was significantly better than that of the high-expression group (P < 0.05). The gene expression level of Aurora B correlated with results from liver function tests, for example prothrombin time.

CONCLUSION

Aurora B expression in non-cancerous tissues may be a prognostic factor for HCC.

Contrast-enhanced intraoperative ultrasonography for vascular imaging of hepatocellular carcinoma: clinical and biological significance

Abnormal tumor vascularity is one of the typical features of hepatocellular carcinoma (HCC). In this study, the significance of contrast-enhanced intraoperative ultrasonography (CEIOUS) images of HCC vasculature was evaluated by clinicopathological and gene expression analyses. We enrolled 82 patients who underwent curative hepatic resection for HCC with CEIOUS. Clinicopathological and gene expression analyses were performed according to CEIOUS vasculature patterns. CEIOUS images of HCC vasculatures were classified as reticular HCC or thunderbolt HCC. Thunderbolt HCC was significantly correlated with higher alpha-fetoprotein levels, tumor size, histological differentiation, portal vein invasion, and tumor-node-metastasis stage, and these patients demonstrated a significantly poorer prognosis for both recurrence-free survival (P = 0.0193) and overall survival (P = 0.0362) compared with patients who had reticular HCC. Gene expression analysis revealed that a rereplication inhibitor geminin was significantly overexpressed in thunderbolt HCCs (P = 0.00326). In vitro knockdown of geminin gene reduced significantly the proliferation of human HCC cells. Immunohistochemical analysis confirmed overexpression of geminin protein in thunderbolt HCC (P < 0.0001). Multivariate analysis revealed geminin expression to be an independent factor in predicting poor survival in HCC patients (P = 0.0170).

CONCLUSION

CEIOUS vascular patterns were distinctly identifiable by gene expression profiling associated with cellular proliferation of HCC and were significantly related to HCC progression and poor prognosis. These findings might be clinically useful as a determinant factor in the postoperative treatment of HCC.

Canine osteosarcoma cells exhibit resistance to aurora kinase inhibitors

We evaluated the effect of Aurora kinase inhibitors AZD1152 and VX680 on canine osteosarcoma cells. Cytotoxicity was seen in all four cell lines; however, half-maximal inhibitory concentrations were significantly higher than in human leukaemia and canine lymphoma cells. AZD1152 reduced Aurora kinase B phosphorylation, indicating resistance was not because of failure of target recognition. Efflux mediated by ABCB1 and ABCG2 transporters is one known mechanism of resistance against these drugs and verapamil enhanced AZD1152-induced apoptosis; however, these transporters were only expressed by a small percentage of cells in each line and the effects of verapamil were modest, suggesting other mechanisms contribute to resistance. Our results indicate that canine osteosarcoma cells are resistant to Aurora kinase inhibitors and suggest that these compounds are unlikely to be useful as single agents for this disease. Further investigation of these resistance mechanisms and the potential utility of Aurora kinase inhibitors in multi-agent protocols is warranted.

Molecular targeted therapies in hepatocellular carcinoma

In vivo tumor progression requires the supply of oxygen and nutrition by neovasculature. Hepatocellular carcinoma (HCC) is one of the typical tumors with neovascularization, and the dramatic alteration in the arterial vascularity may lead to acquisition of the potential for vascular invasiveness and metastasis. In 2008, phase III clinical trials revealed anti-angiogenic agent "sorafenib" as the first drug that demonstrated an improved overall survival in patients with advanced HCC. A new era of HCC treatment had arrived, but there has been limited further improvement in survival benefits. This review summarizes molecular targeted therapy with a focus on angiogenesis, growth signals, and mitotic abnormalities, as well as the promising concepts of "cancer stemness" and "synthetic lethality" for the strategy of targeted therapy.

Villin 1 is a predictive factor for the recurrence of high serum alpha-fetoprotein-associated hepatocellular carcinoma after hepatectomy

The prognostic assessment of patients with hepatocellular carcinoma (HCC) after resection is an important clinical issue. The present study investigated those genes associated with high serum alpha-fetoprotein (AFP), and their clinical significance, including prognosis and recurrence after hepatectomy. Based on gene expression analysis of 110 training HCC cases, 20 genes whose mRNA expression levels were significantly upregulated and 50 genes that were downregulated correlated with high serum AFP-associated HCC patients. Gene expression profiles of Villin1 (Vil1) were obtained in high serum AFP-associated HCC tumor tissues. In the present analysis, only VIL1 was significantly correlated with the recurrence of HCC. The results were validated independently using Taqman gene expression assays and immunostaining analysis. Results showed that the upregulation of VIL1 mRNA was also correlated with high serum PIVKAII, vascular invasion (P < 0.05), poor differentiation, an advanced cancer stage (P < 0.01) and recurrence-free survival (P = 0.017). The upregulation of VIL1 mRNA was observed more frequently in the early recurrence patients as compared to the late recurrence patients. Cox regression univariate and multivariate analyses indicated that high serum AFP levels (overall survival, HR 1.675, P = 0.002; FRS, HR 1.359, P = 0.039) and Vil1 protein expression (overall survival, HR 0.253, P = 0.009; FRS, HR 0.401, P = 0.041) were independent, unfavorable prognostic factors for overall and recurrence-free survival of patients. We demonstrated that the VIL1 gene is a potential candidate molecular marker for high serum AFP-associated HCC and a predictive candidate for the postoperative recurrence and poorer prognosis of HCC.

Relationship of increased aurora kinase A gene copy number, prognosis and response to chemotherapy in patients with metastatic colorectal cancer

BACKGROUND

Increased Aurora kinase A gene copy number (AURKA-CN) has been reported in metastatic colorectal cancer (mCRC), with unknown relationship to clinical outcome. We correlated increased AURKA-CN in mCRC tumours with KRAS mutation status, overall and progression-free survival (OS, PFS).

METHODS

Sixty-one mCRC tumours were analysed for AURKA-CN using q-PCR, and KRAS mutation status by direct sequencing. Expression of AURKA protein was analysed by immunohistochemistry. Cox-proportional hazard method, Kaplan-Meier curves and log-rank statistics were used to estimate and compare the hazard ratios and median survival between the groups.

RESULTS

In all, 68% of tumour exhibited high AURKA-CN, and 29% had a KRAS mutation, without correlation between the two. Patients with high AURKA-CN tumours had longer median OS (48.6 vs 18.8 months, P=0.01), with stronger trend among KRAS wild-type tumours (median OS not reached vs 18.8 months, P=0.003). Progression-free survival was longer on first-line or second-line chemotherapy among patients with KRAS wild-type and high vs low AURKA-CN (first: 17.6 vs 5.13 months, P=0.04; second: 10.4 vs 5.1 months, P=0.01). AURKA-CN level did not affect outcomes among patients with KRAS mutant tumours.

CONCLUSION

Increased AURKA-CN is common in mCRC tumours and is associated with longer OS and longer PFS during chemotherapy, particularly in KRAS wild-type tumours.