Identification of drivers from cancer genome diversity in hepatocellular carcinoma

Genetic screening of liver cancer: State of the art

Liver cancer, primarily hepatocellular carcinoma, remains a global health challenge with rising incidence and limited therapeutic options. Genetic factors play a pivotal role in the development and progression of liver cancer. This state-of-the-art paper provides a comprehensive review of the current landscape of genetic screening strategies for liver cancer. We discuss the genetic underpinnings of liver cancer, emphasizing the critical role of risk-associated genetic variants, somatic mutations, and epigenetic alterations. We also explore the intricate interplay between environmental factors and genetics, highlighting how genetic screening can aid in risk stratification and early detection via using liquid biopsy, and advancements in high-throughput sequencing technologies. By synthesizing the latest research findings, we aim to provide a comprehensive overview of the state-of-the-art genetic screening methods for liver cancer, shedding light on their potential to revolutionize early detection, risk assessment, and targeted therapies in the fight against this devastating disease.

Nanoquercetin and Extracellular Vesicles as Potential Anticancer Therapeutics in Hepatocellular Carcinoma

Despite world-class sophisticated technologies, robotics, artificial intelligence, and machine learning approaches, cancer-associated mortalities and morbidities have shown continuous increments posing a healthcare burden. Drug-based interventions were associated with systemic toxicities and several limitations. Natural bioactive compounds derived nanoformulations, especially nanoquercetin (nQ), are alternative options to overcome drug-associated limitations. Moreover, the EVs-based cargo targeted delivery of nQ can have enormous potential in treating hepatocellular carcinoma (HCC). EVs-based nQ delivery synergistically regulates and dysregulates several pathways, including NF-κB, p53, JAK/STAT, MAPK, Wnt/β-catenin, and PI3K/AKT, along with PBX3/ERK1/2/CDK2, and miRNAs intonation. Furthermore, discoveries on possible checkpoints of anticancer signaling pathways were studied, which might lead to the development of modified EVs infused with nQ for the development of innovative treatments for HCC. In this work, we abridged the control of such signaling systems using a synergetic strategy with EVs and nQ. The governing roles of extracellular vesicles controlling the expression of miRNAs were investigated, particularly in relation to HCC.

Hepatocellular carcinoma: molecular mechanism, targeted therapy, and biomarkers

Hepatocellular carcinoma (HCC) is a common malignancy and one of the leading causes of cancer-related death. The biological process of HCC is complex, with multiple factors leading to the broken of the balance of inactivation and activation of tumor suppressor genes and oncogenes, the abnormal activation of molecular signaling pathways, the differentiation of HCC cells, and the regulation of angiogenesis. Due to the insidious onset of HCC, at the time of first diagnosis, less than 30% of HCC patients are candidates for radical treatment. Systematic antitumor therapy is the hope for the treatment of patients with middle-advanced HCC. Despite the emergence of new systemic therapies, survival rates for advanced HCC patients remain low. The complex pathogenesis of HCC has inspired researchers to explore a variety of biomolecular targeted therapeutics targeting specific targets. Correct understanding of the molecular mechanism of HCC occurrence is key to seeking effective targeted therapy. Research on biomarkers for HCC treatment is also advancing. Here, we explore the molecular mechanism that are associated with HCC development, summarize targeted therapies for HCC, and discuss potential biomarkers that may drive therapies.

Mutational Landscape and Precision Medicine in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fourth most common malignancy worldwide and exhibits a universal burden as the incidence of the disease continues to rise. In addition to curative-intent therapies such as liver resection and transplantation, locoregional and systemic therapy options also exist. However, existing treatments carry a dismal prognosis, often plagued with high recurrence and mortality. For this reason, understanding the tumor microenvironment and mutational pathophysiology has become the center of investigation for disease control. The use of precision medicine and genetic analysis can supplement current treatment modalities to promote individualized management of HCC. In the search for personalized medicine, tools such as next-generation sequencing have been used to identify unique tumor mutations and improve targeted therapies. Furthermore, investigations are underway for specific HCC biomarkers to augment the diagnosis of malignancy, the prediction of whether the tumor environment is amenable to available therapies, the surveillance of treatment response, the monitoring for disease recurrence, and even the identification of novel therapeutic opportunities. Understanding the mutational landscape and biomarkers of the disease is imperative for tailored management of the malignancy. In this review, we summarize the molecular targets of HCC and discuss the current role of precision medicine in the treatment of HCC.

PORCN promotes hepatocellular carcinogenesis via Wnt/β-catenin-dependent manner

Background

Porcupine O-acyltransferase (PORCN), a membrane-bound O-acyltransferase, is crucial in Wnt ligand palmitoylation. However, the roles of PORCN in the development of hepatocellular carcinoma (HCC) remain unknown.

Methods

Western blot, real-time quantitative polymerase chain reaction (RT-qPCR) assays, and The Cancer Genome Atlas (TCGA) database were used to study the expression and prognostic values of PORCN in patients with HCC. Following this, Cell Counting Kit-8 (CCK-8), wound-healing tests, Transwell assay, and a xenograft mouse model were employed to examine the effect of PORCN on HCC cells. Finally, the underlying molecular mechanisms involved in cell proliferation and migration caused by PORCN were identified.

Results

The protein and messenger RNA (mRNA) levels of PORCN in HCC tissues were higher than those of adjacent normal tissues. The analysis of TCGA database indicated that patients with higher PORCN expression had a lower overall survival (OS) rate. Overexpression of PORCN could promote the proliferation and migration abilities of HCC cells both in vitro and in vivo. Gene set enrichment analysis (GSEA) showed that the effect of PORCN on the biological characteristics of HCC cells mainly centered on the Wnt-β-catenin signaling pathway. Mechanically, immunofluorescence staining and subcellular protein fraction assays showed that PORCN could induce epithelial-mesenchymal transition (EMT) by promoting the translocation of β-catenin from the cytoplasm to nucleus, ultimately promoting the progression of HCC.

Conclusions

The findings of this study suggest that PORCN can promote HCC cell proliferation and migration by stimulating the Wnt-β-catenin signaling pathway. Therefore, PORCN may be a promising therapeutic target for HCC.

Indocyanine green fluorescence patterns of hepatocellular carcinoma correlate with pathological and molecular features

BACKGROUND

Intraoperative Indocyanine Green Dye (ICG) routinely used in hepatobiliary surgery identifies different fluorescent patterns of hepatocellular carcinoma (HCC), a highly heterogeneous cancer. We aimed to correlate these patterns with gene mutations and extensive pathological features beyond the well-known tumor differentiation.

METHODS

Between February 2017 and December 2019, 21 HCC in 16 consecutive patients who underwent intraoperative ICG fluorescence imaging were included. Pathological review was performed by one pathologist blinded to fluorescence features. Random forest machine learning algorithm correlated pathological features of the tumor, peritumoral and non-tumoral liver, and gene mutations from a 28 gene-panel with rim and intra-lesion fluorescence.

RESULTS

Three HCC had negative intra-lesion and rim-like emission, 7 HCC had homogeneous pattern and 11 heterogeneous patterns in whom 3 with rim-like emission. Rim emission was associated with peritumoral vascular changes, lower differentiation and lower serum AFP level. Homogeneous intra-lesion fluorescence was associated with lower necrosis rate, thinner capsule, absence of peritumoral liver changes, and higher serum AFP level. Heterogeneous HCC without rim harbored lesser TP53 and ARID1A mutations.

CONCLUSION

Tumoral and peri-tumoral fluorescence classification of HCC yielded a possible intraoperative pathological and molecular characterization. These preliminary observations could lead to intraoperative refinement in surgical strategy.

Advanced development of biomarkers for immunotherapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common liver cancer and one of the leading causes of cancer-related deaths in the world. Mono-immunotherapy and combination therapy with immune checkpoint inhibitors (ICIs) and multitargeted tyrosine kinase inhibitors (TKIs) or anti-vascular endothelial growth factor (anti-VEGF) inhibitors have become new standard therapies in advanced HCC (aHCC). However, the clinical benefit of these treatments is still limited. Thus, proper biomarkers which can predict treatment response to immunotherapy to maximize clinical benefit while sparing unnecessary toxicity are urgently needed. Contrary to other malignancies, up until now, no acknowledged biomarkers are available to predict resistance or response to immunotherapy for HCC patients. Furthermore, biomarkers, which are established in other cancer types, such as programmed death ligand 1 (PD-L1) expression and tumor mutational burden (TMB), have no stable predictive effect in HCC. Thus, plenty of research focusing on biomarkers for HCC is under exploration. In this review, we summarize the predictive and prognostic biomarkers as well as the potential predictive mechanism in order to guide future research direction for biomarker exploration and clinical treatment options in HCC.

Six Cell Cycle-related Genes Serve as Potential Prognostic Biomarkers and Correlated with Immune Infiltrates in Hepatocellular Carcinoma

Background: Cell cycle-related genes (CDK1, CDK5, CDC20, CCNA2, CCNB1, and CCNB2) play important roles in the regulation of mitotic cell cycle in eukaryotes. However, the correlation between cell cycle-related genes and tumor-infiltrating and prognosis of hepatocellular carcinoma (HCC) needs further investigation. Methods: Two public websites, Tumor Immune Estimate Resource (TIMER) and Oncomine, were used to assess the expression levels of cycle-related genes. We also analyzed the protein expression levels of six cell cycle-related genes using the HPA database. In addition, Kaplan-Meier plotter and Gene Expression Profiling Interactive Analysis (GEPIA) database were used to investigate the impact of cell cycle-related gene expression levels on the clinical prognosis of HCC. The correlation between cell cycle-related genes and cancer immune infiltrates was analyzed through TIMER site. Subsequently, GEPIA and TIMER database were used to assess the correlation between the expression of six cell cycle-related genes and polygenic markers in monocytes and macrophages, respectively. The cell cycle-related genes were also analyzed to find the associated genes with the highest alteration frequency, by the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) approaches of Metascape and String database, respectively. Results: The expression levels of cell cycle-related genes were up-regulated in tumor tissues compared with normal tissues. Subsequently, the expression of high cell cycle-related genes was positively correlated with poor overall survival (OS) and progression-free survival (PFS) in HCC, for CDK1 (OS: HR = 2.15, P = 1.1E-05 PFS: HR = 2.03, P = 2.3E-06), CDK5 (OS: HR = 1.85, P = 0.0035 PFS: HR = 1.26, P = 0.17), CDC20 (OS: HR = 2.49, P = 5.1E-07 PFS: HR = 1.77, P = 0.00012), CCNA2 (OS: HR = 1.92, P = 0.00018 PFS: HR = 1.96, P = 5.2E-06), CCNB1 (OS: HR = 2.34, P = 3.4E-05 PFS: HR = 1.97, P = 5.3E-06), and CCNB2 (OS: HR = 1.91, P = 0.0013 PFS: HR = 1.63, P = 0.0011), respectively. Furthermore, the transcription level of cell cycle-related genes was significantly correlated with immune infiltrating levels of CD4+ T and CD8+ T cells, neutrophils, macrophages, and dendritic cells (DCs) in HCC, respectively. Amongst them, the expression levels of CDK1, CDC20, CCNA2, CCNB1 and CCNB2 manifest strongly correlated with diverse immune marker sets in HCC. Conclusions: Our results demonstrated that cell cycle-related genes played key roles in the prognosis of HCC. Meanwhile, they were significantly correlated with immune infiltrating levels of CD4⁺ T cells, CD8⁺ T cells, neutrophils, macrophages and DCs in HCC, respectively. In addition, CDK1, CDC20, CCNA2, CCNB1 and CCNB2 expressions may be involved in the regulation of monocytes and tumor-associated macrophages (TAMs) in HCC, respectively. These findings strongly suggested that cell cycle-related genes could be used as novel biomarkers for exploring the prognosis and immune cells infiltration of HCC.

Identification and validation of a fatty acid metabolism-related lncRNA signature as a predictor for prognosis and immunotherapy in patients with liver cancer

Background

Fatty acid (FA) metabolism is considered the emerging cause of tumor development and metastasis, driving poor prognosis. Long non-coding RNAs (lncRNAs) are closely related to cancer progression and play important roles in FA metabolism. Thus, the discovery of FA metabolism-related lncRNA signatures to predict outcome and immunotherapy response is critical in improving the survival of patients with hepatocellular carcinoma (HCC).

Methods

FA metabolism scores and a FA metabolism-related lncRNA signature were constructed using a single-sample gene set enrichment analysis based on The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. “ConsensusClusterPlus” was used to screen molecular subtypes. Chi-squared test and Fisher’s exact test were applied to explore the relationship between clinical, genomic mutation characteristics and subtypes. Transcription factor (TF) activity scores, cellular distributions, immune cell infiltration, and immunotherapy response were employed to investigate the functions of FA metabolism-related lncRNA signatures. FA metabolism microarray and western blot were performed to detect the biological function of candidate lncRNAs.

Results

A total of 70 lncRNAs that highly correlated with FA metabolism scores in two cohorts were used to construct two distinct clusters. Patients in cluster 2 had lower FA metabolism scores and worse survival than those in cluster 1. Patients in cluster 2 exhibited a high frequency of DNA damage, gene mutations, oncogenic signaling such as epithelial-to-mesenchymal transition, and a high degree of immune cell infiltration. Moreover, the lncRNA signature could predict the effects of immunotherapy in patients with HCC. Furthermore, three lncRNAs (SNHG1, LINC00261, and SNHG7) were identified that were highly correlated with FA metabolism. Additionally, SNHG1 and SNHG7 were found to regulate various FA metabolism-related genes and ferroptosis-related genes in vitro experiments. GSEA analysis revealed that SNHG1 and SNHG7 promote fatty acid beta-oxidation. SNHG1 and SNHG7 silencing dramatically reduced lipid droplets in HCC cells. Many immune-infiltration genes and TFs were overexpressed in HCC tissues with SNHG1 and SNHG7 high expression.

Conclusions

A novel molecular model of FA metabolism-related lncRNAs was developed, which has significantly prognostic potential in HCC diagnosis and aids in clinical decision making.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10122-4.

A Novel Artificial Neural Network Prognostic Model Based on a Cancer-Associated Fibroblast Activation Score System in Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) ranks fourth as the most common cause of cancer-related death. It is vital to identify the mechanism of progression and predict the prognosis for patients with HCC. Previous studies have found that cancer-associated fibroblasts (CAFs) promote tumor proliferation and immune exclusion. However, the information about CAF-related genes is still elusive.

Methods

The data were obtained from The Cancer Genome Atlas, International Cancer Genome Consortium, and Gene Expression Omnibus databases. On the basis of single-cell transcriptome and ligand–receptor interaction analysis, CAF-related genes were selected. By performing Cox regression and random forest, we filtered 12 CAF-related prognostic genes for the construction of the ANN model based on the CAF activation score (CAS). Then, functional, immune, mutational, and clinical analyses were performed.

Results

We constructed a novel ANN prognostic model based on 12 CAF-related prognostic genes. Cancer-related pathways were enriched, and higher activated cell crosstalk was identified in high-CAS samples. High immune activity was observed in high-CAS samples. We detected three differentially mutated genes (NBEA, RYR2, and FRAS1) between high- and low-CAS samples. In clinical analyses, we constructed a nomogram to predict the prognosis of patients with HCC. 5-Fluorouracil had higher sensitivity in high-CAS samples than in low-CAS samples. Moreover, some small-molecule drugs and the immune response were predicted.

Conclusion

We constructed a novel ANN model based on CAF-related genes. We revealed information about the ANN model through functional, mutational, immune, and clinical analyses.

Identification of a seven-gene signature predicting clinical outcome of liver cancer based on tumor mutational burden

The total number of somatic mutations may affect the prognosis of cancer, so we applied bioinformatics methods to investigate the association between the TMB (tumor mutational burden)-related differentially expressed genes (DEGs) and the prognosis of hepatocellular carcinoma (HCC). We calculated the TMB value of the patients with HCC in TCGA database and identified the differentially expressed genes between the high-TMB and low-TMB patients. We performed functional enrichment analysis and LASSO Cox regression analysis of the DEGs, and seven genes were screened to establish a risk score model. A nomogram based on the risk scores was drawn to assess the predictive outcomes compared to the actual outcomes. The expression level of the seven genes was verified in cancer cell lines. Moreover, we explored the difference in immune cells infiltration and immune checkpoints between the high-risk and low-risk groups. The results showed that the DEGs between the high-TMB and low-TMB patients were enriched in extracellular matrix organization. A seven-gene risk score model (PAGE1, CHGA, OGN, MMP7, TRIM55, MAGEA6, and MAGEA12) was established for predicting HCC prognosis. Patients with lower risk scores had longer survival time and lower mortality rate. The nomogram based on risk scores and TNM staging showed good performance and reliability in predicting the clinical outcomes. Significant differences in cell infiltration and checkpoints were found between the high-risk and low-risk groups. Our study demonstrated a seven-gene signature and a nomogram based on the risk score model to predict the prognosis of HCC. Some of the newly identified DEGs may be potential biomarkers or therapeutic targets.

A Prognostic Gene Signature for Hepatocellular Carcinoma

Hepatocellular carcinoma is the third most common cause of cancer-related deaths in China and immune-based therapy can improve patient outcomes. In this study, we investigated the relationship between immunity-associated genes and hepatocellular carcinoma from the prognostic perspective. The data downloaded from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) and the Gene Expression Omnibus (GEO) was screened for gene mutation frequency using the maftools package. Immunity-associated eight-gene signature with strong prognostic ability was constructed and proved as an independent predictor of the patient outcome in LIHC. Seven genes in the immune-related eight-gene signature were strongly associated with the infiltration of M0 macrophages, resting mast cells, and regulatory T cells. Our research may provide clinicians with a quantitative method to predict the prognosis of patients with liver cancer, which can assist in the selection of the optimal treatment plan.

Comprehensive Analysis of RAPGEF2 for Predicting Prognosis and Immunotherapy Response in Patients with Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is the sixth most common tumor worldwide. Additionally, deletion of RAPGEF2 plays a critical role in CNV and related to tumor immune microenvironment, whereas the prognostic potential of RAPGEF2 in HCC patient needs to be explored.

Methods

We looked for prognostic potential genes in HCC using a variety of R programs. Then, using the LASSO Cox regression, we thoroughly evaluated and integrated the RAPGEF2-related genes from TCGA database. Meanwhile, utilizing TCGA and ICGA databases, the link between RAPGEF2 and immunotherapy response in HCC was studied. In vivo, the effect of RAPGEF2 on tumor development and the capacity of natural killer (NK) cells to recruit were confirmed. To ascertain the connection between RAPGEF2-related genes and the prognosis of HCC, a prognostic model was created and validated.

Result

We demonstrated RAPGEF2 has a differential expression, and patients with deletion of RAPGEF2 gene get shorter survival in HCC. Additionally, the tissues without RAPGEF2 have a weaker ability to recruit the NK cells and response to immunotherapy. After that, we scoured the database for eight RAPGEF2-related genes linked with a better prognosis in HCC patients. Additionally, silencing RAPGEF2 accelerated tumor development in the HCC mouse model and decreased CD56+ NK cell recruitment in HCC tissues. TCGA database was used to classify patients into low- and high-risk categories based on the expression of related genes. Patients in the low-risk group had a significantly greater overall survival than those in the high-risk group (P < 0.001). Meanwhile, the low-risk group demonstrated connections with the NK cell and immunotherapy response. Finally, the prognostic nomogram showed a high sensitivity and specificity for predicting the survival of HCC patients at 1, 2, and 3 years.

Conclusion

The prognostic model based on RAPGEF2 and RAPGEF2-related genes showed an excellent predictive performance in terms of prognosis and immunotherapy response in HCC, therefore establishing a unique prognostic model for clinical assessment of HCC patients.

Characterization of diagnostic and prognostic significance of cell cycle-linked genes in hepatocellular carcinoma

Background

The high degree of heterogeneity of hepatocellular carcinoma (HCC) imposes a significant challenge to predict the prognosis. Currently, increasing evidence has indicated that cell cycle-linked genes are strongly linked to occurrence and progress of HCC. Herein, we purposed to create a prediction model on the basis of cell cycle-linked genes.

Methods

The transcriptome along with clinicopathological data abstracted from The Cancer Genome Atlas (TCGA) were used as a training cohort. Lasso regression analysis was employed to create a prediction model in TCGA cohort. The data of samples obtained from the International Cancer Genome Consortium (ICGC) data resource were applied in the verification of the model. A series of bioinformatics analyzed the relationship of the risk signature with overall survival (OS), biological function, and clinicopathological features.

Results

Six cell cycle-linked genes (PLK1, CDC20, HSP90AA1, CHEK1, HDAC1, and NDC80) were chosen to create the prognostic model, demonstrating a good prognostic capacity. Further analyses indicated that the model could independently assess the OS of HCC patients. A single-sample gene set enrichment analysis (ssGSEA) indicated that the risk signature was remarkably linked to immune status. Additionally, there was a remarkable association of the risk signature with TP53 mutation frequency, as well as immune checkpoint molecule expression levels.

Conclusions

We created a prediction model using six cell cycle-linked genes to predict HCC prognosis. The six genes are expected to be novel markers for HCC diagnosis, as well as treatment.

High-Mobility Group AT-Hook 1 Served as a Prognosis Biomarker and Associated with Immune Infiltrate in Hepatocellular Carcinoma

BACKGROUND

The protein high-mobility group AT-hook 1 (HMGA1) has been demonstrated that modulated cellular proliferation, invasion, and apoptosis with a poor prognosis in miscellaneous carcinomas. However, the mechanism of circumstantial carcinogenesis and association with the immune microenvironment of HMGA1 in hepatocellular carcinoma (HCC) had not been extensively explored.

METHODS

The gene expression, clinicopathological correlation, and prognosis analysis were performed in the data obtained from TCGA. The results were further validated by ICGC and GEO database and external validation cohort from Guangxi. The HMGA1 protein expression was further examined in the HPA database. Biological function analyses were conducted by GSEA, STRING database, and Coexpedia online tool. Using TIMER and CIBERSORT method, the relationship between immune infiltrate and HMGA1 was investigated.

RESULTS

In HCC, HMGA1 had much higher transcriptional and proteomic expression than in corresponding paraneoplastic tissue. Patients with high HMGA1 expression had a poor prognosis and unpromising clinicopathological features. High HMGA1 expression was closely related to the cell cycle, tumorigenesis, substance metabolism, and immune processes by regulating complex signaling pathways. Notably, HMGA1 may be associated with TP53 mutational carcinogenesis. Moreover, increased HMGA1 expression may lead to an increase in immune infiltration and a decrease in tumor purity in HCC. CIBERSORT analysis elucidated that the amount of B cell naive, B cell memory, T cells gamma delta, macrophages M2, and mast cell resting decreased when HMGA1 expression was high, whereas T cells follicular helper, macrophages M0, and Dendritic cells resting increased.

CONCLUSION

In conclusions, HMGA1 is a potent prognostic biomarker and a sign of immune infiltration in HCC, which may be a potential immunotherapy target for HCC.

Cooperation between liver-specific mutations of pten and tp53 genetically induces hepatocarcinogenesis in zebrafish

BACKGROUND

Liver cancer, mainly hepatocellular carcinoma, is one of the deadliest cancers worldwide and has a poor prognosis due to insufficient understanding of hepatocarcinogenesis. Previous studies have revealed that the mutations in PTEN and TP53 are the two most common genetic events in hepatocarcinogenesis. Here, we illustrated the crosstalk between aberrant Pten and Tp53 pathways during hepatocarcinogenesis in zebrafish.

METHODS

We used the CRISPR/Cas9 system to establish several transgenic zebrafish lines with single or double tissue-specific mutations of pten and tp53 to genetically induce liver tumorigenesis. Next, the morphological and histological determination were performed to investigate the roles of Pten and Tp53 signalling pathways in hepatocarcinogenesis in zebrafish.

RESULTS

We demonstrated that Pten loss alone induces hepatocarcinogenesis with only low efficiency, whereas single mutation of tp53 failed to induce tumour formation in liver tissue in zebrafish. Moreover, zebrafish with double mutations of pten and tp53 exhibits a much higher tumour incidence, higher-grade histology, and a shorter survival time than single-mutant zebrafish, indicating that these two signalling pathways play important roles in dynamic biological events critical for the initiation and progression of hepatocarcinogenesis in zebrafish. Further histological and pathological analyses showed significant similarity between the tumours generated from liver tissues of zebrafish and humans. Furthermore, the treatment with MK-2206, a specific Akt inhibitor, effectively suppressed hepatocarcinogenesis in zebrafish.

CONCLUSION

Our findings will offer a preclinical animal model for genetically investigating hepatocarcinogenesis and provide a useful platform for high-throughput anticancer drug screening.

MicroRNA-129-5p promotes proliferation and metastasis of hepatocellular carcinoma by regulating the BMP2 gene

Hepatocellular carcinoma (HCC) is a malignant tumor that poses a serious threat to human health. Due to its occult onset and rapid development, HCC is a challenge to diagnose early and effectively treat, and thus patients with HCC often have an unfavorable prognosis. MicroRNA (miR)-129 and its target gene play an important role in the regulation of various diseases. Therefore, the aim of the present study was to investigate the role and mechanism of action for miR-129-5p in the development of HCC. Quantitative results of clinical samples analyzed using reverse transcription-quantitative PCR suggested that miR-129-5p had a significantly lower expression level in tumoral tissues compared with corresponding peritumoral tissues. Overexpression of miR-129-5p in HCC cells was performed using a transfection technique, followed by MTT, Transwell, invasion and wound healing assays to detect the effect of miR-129-5p on the cell cytotoxicity and metastasis of liver cancer in vitro. The downstream target gene of miR-129-5p, bone morphogenetic protein 2 (BMP2), was determined using a luciferase reporter assay. Overexpression of miR-129-5p played a vital role in decreasing cytotoxicity and promoting metastasis of HCC, which may be attributed to its inhibitory effect on the expression of its target gene, BMP2. In clinical samples, miR-129-5p expression levels were found to be negatively correlated with BMP2 and closely associated with HCC metastasis and infiltration. Collectively, the results suggested that miR-129-5p may contribute to proliferation and metastasis of HCC through its target gene, BMP2, and thus may be a potential novel therapeutic target for the treatment of HCC.

Novel Molecular Subtypes Associated With 5mC Methylation and Their Role in Hepatocellular Carcinoma Immunotherapy

Background

5-methylcytosine (5mC) has been reported in the prognosis of a variety of cancers, however, its role in hepatocellular carcinoma (HCC) has not been investigated yet. This study aimed at identifying the molecular subtypes associated with 5mC and establishing a relevant score to predict its prognosis in HCC.

Methods

Somatic gene mutation data and gene expression data were retrieved from The Cancer Genome Atlas database. Molecular subtypes were identified by unsupervised clustering based on the expression of 5mC regulators, and the molecular features of each subtype were investigated by survival, mutation, gene set variation, and immune cell infiltration analyses. Next, we performed a differentially expressed analysis based on the new subtypes and selected the overlapping genes for further analysis. We undertook univariate Cox analysis to analyze these genes and constructed a prognostic model by lasso regression analysis. Meanwhile, survival and gene set enrichment analyses were used to explore the prognosis and the relevant pathways, respectively. The LIRI cohort from the International Cancer Genome Consortium database was used as a reference to validate the 5mC subtypes and 5mC score.

Results

Twenty-one types of 5mC regulators were employed in this study, and three 5mC-associated molecular subtypes were identified. These three subtypes presented significant differences in prognosis, immune cell infiltration, immune checkpoint inhibitors, signaling pathways, and mutational features. Compared with cluster 3, cluster 2 exhibited significantly increased expression of PD-L1, TIM3, Galectin9, CTLA4, and CD80, while PD-L1, TIM3, and CD80 were higher in cluster 2 than in cluster 1. Furthermore, a 5mC-related score, composed of seven genes (SGPP2, SALL4, B3GNT7, ROR1, MYBL2, SLC7A1, and CAND2), was proven to be significantly associated with prognosis. The established subtypes and scores were thus successfully verified by the validated cohort.

Conclusion

To the best of our knowledge, this is the first study to identify a novel molecular subtype based on 5mC regulators. The identification of the 5mC-associated subtype may help reveal the potential relation between 5mC and immunity and provide novel insights for the development of individualized therapy for HCC.

Metallophosphoesterase 1, a novel candidate gene in hepatocellular carcinoma malignancy and recurrence

BACKGROUND

There is an unmet need to identify novel mechanism-based prognostic genes associated with hepatocellular carcinoma (HCC) recurrence that can predict patient outcomes and provide therapeutic targets. This study aims to identify potential novel driver genes and mutations in HCC.

METHODS

Single nucleotide variations (SNVs) contributing to HCC recurrence were identified using whole-exome sequencing of 5 DNA samples extracted from a single HCC patient with HBV-induced cirrhosis. SNVs were verified in primary HCC (n = 87), recurrent HCC (n = 34), and benign liver disease with cirrhosis tissues (n = 43). A candidate gene was identified, and its association and function in HCC development and recurrence were examined.

RESULTS

177 SNVs were identified and 70 SNVs were verified. A MPPE1 missense mutation on chr18_11897016 was the most frequent mutation (16.5%) in primary and recurrent HCC tissues, occurring with a higher frequency in recurrent HCC than primary HCC or benign liver tumor tissues. The MPPE1 mutation was significantly associated with HCC recurrence (P = .003), TNM stage (P = .002), and Child-Pugh classification (P = .039), and was an independent risk factor for HCC recurrence (HR = 1.969; 95%CI = 1.043-3.714, P = .037). Analysis of publically available data deposited in the GEO and TCGA showed MPPE1 expression levels were significantly increased in HCC tumor samples compared to adjacent nontumor tissues. The knockdown of MPPE1 in HCC cell lines significantly inhibited cell proliferation, migration and invasion, induced cell cycle arrest and apoptosis in vitro, and inhibited xenograft tumor growth in nude mice in vivo (P < .05).

CONCLUSIONS

MPPE1 is a novel gene associated with HCC malignancy and recurrence.

The perplexity of targeting genetic alterations in hepatocellular carcinoma

Genetic heterogeneity is a well-recognized feature of hepatocellular carcinoma (HCC). The coexistence of multiple genetic alterations in the same HCC nodule contributes to explain why gene-targeted therapy has largely failed. Targeting of early genetic alterations could theoretically be a more effective therapeutic strategy preventing HCC. However, the failure of most targeted therapies has raised much perplexity regarding the role of genetic alterations in driving cancer as the main paradigm. Here, we discuss the methodological and conceptual limitations of targeting genetic alterations and their products that may explain the limited success of the novel mechanism-based drugs in the treatment of HCC. In light of these limitations and despite the era of the so-called "precision medicine," prevention and early diagnosis of conditions predisposing to HCC remain the gold standard approach to prevent the development of this type of cancer. Finally, a paradigm shift to a more systemic approach to cancer is required to find optimal therapeutic solutions to treat this disease.

Random-forest algorithm based biomarkers in predicting prognosis in the patients with hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) one of the most common digestive system tumors, threatens the tens of thousands of people with high morbidity and mortality world widely. The purpose of our study was to investigate the related genes of HCC and discover their potential abilities to predict the prognosis of the patients.

Methods

We obtained RNA sequencing data of HCC from The Cancer Genome Atlas (TCGA) database and performed analysis on protein coding genes. Differentially expressed genes (DEGs) were selected. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were conducted to discover biological functions of DEGs. Protein and protein interaction (PPI) was performed to investigate hub genes. In addition, a method of supervised machine learning, recursive feature elimination (RFE) based on random forest (RF) classifier, was used to screen for significant biomarkers. And the basic experiment was conducted by lab, we constructe a clinical patients’ database, and obtained the data and results of immunohistochemistry.

Results

We identified five biomarkers with significantly high expression to predict survival risk of the HCC patients. These prognostic biomarkers included SPC25, NUF2, MCM2, BLM and AURKA. We also defined a risk score model with these biomarkers to identify the patients who is in high risk. In our single-center experiment, 95 pairs of clinical samples were used to explore the expression levels of NUF2 and BLM in HCC. Immunohistochemical staining results showed that NUF2 and BLM were significantly up-regulated in immunohistochemical staining. High expression levels of NUF2 and BLM indicated poor prognosis.

Conclusion

Our investigation provided novel prognostic biomarkers and model in HCC and aimed to improve the understanding of HCC. In the results obtained, we also conducted a part of experiments to verify the theory described earlier, The experimental results did verify our theory.

Whole-exome mutational landscape of metastasis in patient-derived hepatocellular carcinoma cells

In order to explore the genomic basis for liver cancer metastasis, whole-exome sequencing (WES) was performed on patient-derived hepatocellular carcinoma (HCC) cell lines with differential metastatic potentials and analyzed their clonal evolution relationships. An evolutionary tree based on genomic single nucleotide polymorphism (SNP) was constructed in MegaX software. The WES data showed that the average percentage of heterogeneous mutations in each HCC cell lines was 16.55% (range, 15.38%–18.17%). C: G > T: A and T: A > C: G somatic transitions were the two most frequent substitutions. In these metastatic HCC cell lines, non-silent gene mutations were found in 21.88% of known driver genes and 10 classical signaling pathways. The protein interaction network was constructed by STRING, and hub genes were found in the shared trunk mutation genes and the heterogeneous branch mutations respectively. In cBioPortal database, some of the selected hub genes were found to be associated with poor overall survival (OS) of HCC patients. Among the mutated HCC driver genes, a novel KEAP1 mutation with a homozygous frameshift truncation at the c-terminal Nrf2 binding region was detected and verified in MHCC97-H and HCC97LM3 cells. In conclusion, WES data demonstrate that HCC cell lines from tumor biopsy specimens of the same patient have obtained different metastatic potentials through repeated selection in rodents in vivo, and they do indeed have a genetic relationship at the genomic level.

Prognostic values of immune scores and immune microenvironment-related genes for hepatocellular carcinoma

It is crucial to grasp the characteristics of tumour immune microenvironment to improve effects of immunotherapy. In this study, the immune and stromal scores of 371 cases were calculated for quantitative analysis of immune and stromal cell infiltration in the tumour microenvironment of hepatocellular carcinoma (HCC). The weighted gene co-expression network analysis and protein–protein interaction network were analysed to identify immune microenvironment-related genes. The results showed that patients with high immune scores had a higher 4-year recurrence-free rate. TP53, CTNNB1, and AXIN1 mutations significantly varied with immune scores. In immune score-related modules analysis, Kyoto encyclopaedia of genes and genomes pathways and gene ontology terms were closely related to immune processes, tumorigenesis, and metastasis. Twelve new immune microenvironment-related genes were identified and had significantly positive correlations with seven immune checkpoint genes. In prognostic analysis, eleven immune microenvironment-related genes exhibited high expression, nine of which were validated in the GSE62232 dataset and were significantly associated with a good prognosis. Our findings suggest that calculating immune score and stromal score could help to determine tumour purity and immune cell infiltration in the tumour microenvironment. Nine immune microenvironment-related genes identified in this study had potential as prognostic markers for HCC.

Aquaporin 9 inhibits growth and metastasis of hepatocellular carcinoma cells via Wnt/β-catenin pathway

Hepatocellular carcinoma (HCC) is the most common type of liver cancer worldwide, and it is the second leading cause of cancer-related mortality. Aquaporin 9 (AQP9) is an essential aquaporin in the liver and located in the basolateral membrane of hepatocytes, but its roles on HCC has not been completely elucidated. This study investigated the regulatory functions of AQP9 in the pathogenesis of HCC. The expression levels of AQP9 were significantly down-regulated in HCC tissues and cells, which was also correlated with tumor size and number, TNM stage, five-year survival rate, lymphatic and distal metastasis within the patients. Furthermore, overexpressed AQP9 suppressed the proliferation, migration and invasion of HCC cells. The levels of PCNA, E-cad, N-cad, α-SMA, DVL2, GSK-3β, cyclinD1 and β-catenin in HCC cells were reduced by overexpressed AQP9, while cell apoptosis was remarkably enhanced. Additionally, following the treatment with Wnt/β-catenin signaling inhibitor (XAV939), the proliferative activity of HCC cells was significantly inhibited; PCNA and EMT-related markers were down-regulated; migration and invasion of cells were notably suppressed; cell apoptotic rate was decreased. Vice versa, after the cells were treated with Wnt/β-catenin inducer (SKL2001), the effects caused by overexpressed AQP9 were abrogated. In vivo studies indicated that tumor volume and weight were remarkably decreased in AQP9 overexpression group, where the levels of Wnt/β-catenin signaling- and EMT-associated molecules were also reduced. Taken together, our results suggested that overexpressed AQP9 could inhibit growth and metastasis of HCC cells via Wnt/β-catenin pathway. AQP9 may be a promising therapeutic target for the treatment of patients with HCC.

Systemic Management for Advanced Hepatocellular Carcinoma: A Review of the Molecular Pathways of Carcinogenesis, Current and Emerging Therapies, and Novel Treatment Strategies

Hepatocellular carcinoma (HCC) arises from a number of cirrhosis-related and non-cirrhosis-related exposures and is one of the leading causes of cancer-related deaths worldwide. Achieving a durable cure currently relies on either resection or transplantation, but since most patients will be diagnosed with inoperable disease, there is great interest in achieving more effective systemic therapies. At a molecular level, HCC is heterogeneous, but initial treatment strategies, including the use of multi-targeted tyrosine kinase inhibitors and checkpoint inhibitors, have been fairly homogenous, depending on general host factors and overall tumor burden rather than specific molecular signatures. Over the past 2 decades, however, there has been significant success in identifying key molecular targets, including driver mutations involving the telomerase reverse transcriptase, p53, and beta-catenin genes, and significant work is now being devoted to translating these discoveries into the development of robust and well-tolerated targeted therapies. Furthermore, multi-modal therapies have also begun to emerge, harnessing possible synergism amongst a variety of different treatment classes. As the findings of these landmark trials become available over the next several years, the landscape of the systemic management of advanced HCC will change significantly.

Global Epidemiology, Prevention, and Management of Hepatocellular Carcinoma

The incidence rate of hepatocellular carcinoma (HCC) is rising. It is one of the most common cancers worldwide and accounts for substantial morbidity and mortality. Chronic hepatitis B virus (HBV) infection, chronic hepatitis C virus (HCV) infection, and nonalcoholic fatty liver disease (NAFLD) are the most important etiologies of HCC, and effective screening and management strategies are crucial to reduce the HCC risk. For HBV, which accounts for the majority of HCC cases, most infections were acquired via perinatal and early horizontal transmission. Universal vaccination of newborns has led to a decline in HCC incidence compared with the pre-vaccination era. Effective antiviral therapies with nucleos(t)ide analogues or pegylated interferon reduced the incidence of HCC. For HCV, the emergence of effective direct-acting antiviral (DAA) agents has substantially improved cure rates; therefore all patients with HCV should be considered for DAA treatment. The most important obstacle in eliminating HCV is access to therapy. For NAFLD, the global incidence is increasing rapidly, thus its impact on HCC incidence may be explosive. Progression to HCC in NAFLD happens particularly in those with nonalcoholic steatohepatitis (NASH) and exacerbated by metabolic syndrome, or PNPLA3 gene polymorphism. Lifestyle changes are imperative while drug therapy has yet to demonstrate substantive protective effects on HCC prevention. For management of HCC, early diagnosis via imaging surveillance among persons with HCC risk factors remains the most important strategy to identify early-stage disease appropriate for resection or transplantation.

The correlation analysis of miRNAs and target genes in metastasis of cervical squamous cell carcinoma

Aim: This study was intended to identify the metastasis-related miRNAs and target genes in cervical squamous cell carcinoma. Materials & methods: The mRNA and miRNA next-generation sequencing data were downloaded. Differential expression analysis was carried out, followed by target gene prediction of differentially expressed miRNAs. The biological function of differentially expressed genes was performed. Validation was carried out by survival analysis and qRT-PCR. Results: N4BP3 were associated with the survival time of patients. Hsa-mir-451 and hsa-mir-486 were related to tumor differentiation stage. Validated expression of hsa-mir-24–2, hsa-mir-582, NOTCH1, PIP4K2B, DIP2B and IGFBP5 was consistent with the bioinformatics analysis. Conclusion: Alterations of miRNAs and target genes may be useful in understanding the metastasis mechanisms of cervical squamous cell carcinoma.

HAfTs are novel lncRNA transcripts from aflatoxin exposure

The transcriptome can reveal insights into precancer biology. We recently conducted RNA-Seq analysis on liver RNA from male rats exposed to the carcinogen, aflatoxin B1 (AFB1), for 90 days prior to liver tumor onset. Among >1,000 differentially expressed transcripts, several novel, unannotated Cufflinks-assembled transcripts, or HAfTs (Hepatic Aflatoxin Transcripts) were found. We hypothesized PCR-cloning and RACE (rapid amplification of cDNA ends) could further HAfT identification. Sanger data was obtained for 6 transcripts by PCR and 16 transcripts by 5’- and 3’-RACE. BLAST alignments showed, with two exceptions, HAfT transcripts were lncRNAs, >200nt without apparent long open reading frames. Six rat HAfT transcripts were classified as ‘novel’ without RefSeq annotation. Sequence alignment and genomic synteny showed each rat lncRNA had a homologous locus in the mouse genome and over half had homologous loci in the human genome, including at least two loci (and possibly three others) that were previously unannotated. While HAfT functions are not yet clear, coregulatory roles may be possible from their adjacent orientation to known coding genes with altered expression that include 8 HAfT-gene pairs. For example, a unique rat HAfT, homologous to Pvt1, was adjacent to known genes controlling cell proliferation. Additionally, PCR and RACE Sanger sequencing showed many alternative splice variants and refinements of exon sequences compared to Cufflinks assembled transcripts and gene prediction algorithms. Presence of multiple splice variants and short tandem repeats found in some HAfTs may be consequential for secondary structure, transcriptional regulation, and function. In summary, we report novel, differentially expressed lncRNAs after exposure to the genotoxicant, AFB1, prior to neoplastic lesions. Complete cloning and sequencing of such transcripts could pave the way for a new set of sensitive and early prediction markers for chemical hepatocarcinogens.

The biology of Hepatocellular carcinoma: implications for genomic and immune therapies

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, is a leading cause of cancer-related death worldwide. It is highly refractory to most systemic therapies. Recently, significant progress has been made in uncovering genomic alterations in HCC, including potentially targetable aberrations. The most common molecular anomalies in this malignancy are mutations in the TERT promoter, TP53, CTNNB1, AXIN1, ARID1A, CDKN2A and CCND1 genes. PTEN loss at the protein level is also frequent. Genomic portfolios stratify by risk factors as follows: (i) CTNNB1 with alcoholic cirrhosis; and (ii) TP53 with hepatitis B virus-induced cirrhosis. Activating mutations in CTNNB1 and inactivating mutations in AXIN1 both activate WNT signaling. Alterations in this pathway, as well as in TP53 and the cell cycle machinery, and in the PI3K/Akt/mTor axis (the latter activated in the presence of PTEN loss), as well as aberrant angiogenesis and epigenetic anomalies, appear to be major events in HCC. Many of these abnormalities may be pharmacologically tractable. Immunotherapy with checkpoint inhibitors is also emerging as an important treatment option. Indeed, 82% of patients express PD-L1 (immunohistochemistry) and response rates to anti-PD-1 treatment are about 19%, and include about 5% complete remissions as well as durable benefit in some patients. Biomarker-matched trials are still limited in this disease, and many of the genomic alterations in HCC remain challenging to target. Future studies may require combination regimens that include both immunotherapies and molecularly matched targeted treatments.

Precision medicine for hepatocellular carcinoma: driver mutations and targeted therapy

Hepatocellular carcinoma (HCC) is the third most frequent cause of tumor-related mortality and there are an estimated approximately 850,000 new cases annually. Most HCC patients are diagnosed at middle or advanced stage, losing the opportunity of surgery. The development of HCC is promoted by accumulated diverse genetic mutations, which confer selective growth advantages to tumor cells and are called "driver mutations". The discovery of driver mutations provides a novel precision medicine strategy for late stage HCC, called targeted therapy. In this review, we summarized currently discovered driver mutations and corresponding signaling pathways, made an overview of identification methods of driver mutations and genes, and classified targeted drugs for HCC. The knowledge of mutational landscape deepen our understanding of carcinogenesis and promise future precision medicine for HCC patients.

Hepatocellular carcinoma in non-alcoholic steatohepatitis: Current knowledge and implications for management

With the prevalence of hepatitis C virus expected to decline, the proportion of hepatocellular carcinoma (HCC) related to non-alcoholic steatohepatitis (NASH) is anticipated to increase exponentially due to the growing epidemic of obesity and diabetes. The annual incidence rate of developing HCC in patients with NASH-related cirrhosis is not clearly understood with rates ranging from 2.6%-12.8%. While multiple new mechanisms have been implicated in the development of HCC in NASH; further prospective long-term studies are needed to validate these findings. Recent evidence has shown a significant proportion of patients with non-alcoholic fatty liver disease and NASH progress to HCC in the absence of cirrhosis. Liver resection and transplantation represent curative therapeutic options in select NASH-related HCC patients but have placed a significant burden to our healthcare resources and utilization. Currently NASH-related HCC is the fastest growing indication for liver transplant in HCC candidates. Increased efforts to implement effective screening and preventative strategies, particularly in non-cirrhotic NASH patients, are needed to reduce the future impact imposed by NASH-related HCC.

Using a biologically annotated library to analyze the anticancer mechanism of serine palmitoyl transferase (SPT) inhibitors

Mechanistic understanding is crucial to anticancer drug discovery. Here, we reveal that inhibition of serine palmitoyl transferase (SPT), the rate-limiting enzyme in sphingolipid synthesis, induced death in a lung cancer cell line via a necrosis-dependent pathway. To elucidate the mechanism of cell death induced by SPT inhibition, a biologically annotated library of diverse compounds was screened with an SPT inhibitor. This analysis identified suppressors of SPT inhibitor-mediated cell death. Further analysis using hit compounds from this screening revealed that SPT inhibitors induce COX-2 expression, leading to necrosis-dependent cell death. SPT inhibitors might therefore represent novel candidates for cancer therapy via necrosis pathway regulation. Our data illustrate that compound combination screening of biologically annotated libraries could be used for mechanistic elucidation.

Relationship between RUNX1 and AXIN1 in ER-negative versus ER-positive Breast Cancer

RUNX1 plays opposing roles in breast cancer: a tumor suppressor in estrogen receptor-positive (ER⁺) disease and an oncogenic role in ER-negative (ER^-) tumors. Potentially mediating the former, we have recently reported that RUNX1 prevents estrogen-driven suppression of the mRNA encoding the tumor suppressor AXIN1. Accordingly, AXIN1 protein expression was diminished upon RUNX1 silencing in ER⁺ breast cancer cells and was positively correlated with AXIN1 protein expression across tumors with high levels of ER. Here we report the surprising observation that RUNX1 and AXIN1 proteins are strongly correlated in ER^- tumors as well. However, this correlation is not attributable to regulation of AXIN1 by RUNX1 or vice versa. The unexpected correlation between RUNX1, playing an oncogenic role in ER^- breast cancer, and AXIN1, a well-established tumor suppressor hub, may be related to a high ratio between the expression of variant 2 and variant 1 (v2/v1) of AXIN1 in ER^- compared with ER⁺ breast cancer. Although both isoforms are similarly regulated by RUNX1 in estrogen-stimulated ER⁺ breast cancer cells, the higher v2/v1 ratio in ER^- disease is expected to weaken the tumor suppressor activity of AXIN1 in these tumors.

Meta-analysis of CYP2E1 polymorphisms in liver carcinogenesis

BACKGROUND

The CYP2E1 protein is a monooxygenase with certain polymorphisms linked to liver cancer. However, results from individual studies remain controversial.

AIMS

To evaluate CYP2E1 polymorphisms in liver carcinogenesis through meta-analysis.

METHODS

All studies about CYP2E1 polymorphisms and liver cancer were retrieved from seven major databases. Original data from each study were pooled and re-analyzed.

RESULTS

Total of 16 articles with 4862 cases were selected, including 1820 cases of liver cancer and 3042 cases of controls. The c1 allelic frequency in the cases and controls was 83.3% and 85.3%, respectively. Five genetic variations were compared: dominant c1c2/c2c2 vs. c1/c1 (OR=0.987 (0.853, 1.141)), homozygous c2c2 vs. c1c1 (OR=0.767 (0.526, 1.119)), heterozygous c1c2 vs. c1c1 (OR=1.005 (0.854, 1.182)), recessive c2c2 vs. c1c2/c2c2 (OR=0.771 (0.530, 1.122)), and different alleles c2 vs. c1 (OR=0.947 (0.828, 1.082)). Pooled data were further analyzed based on ethnicity, control sources, and HWE (Hardy-Weinberg equilibrium). These results from stratified groups were similar to that of nonstratified groups.

CONCLUSIONS

Our meta-analysis results suggest that there is no evidence for a major role of CYP2E1 polymorphism in liver carcinogenesis, but do not rule out the possibility in certain cases.

Genetic alterations in hepatocellular carcinoma: An update

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Although recent advances in therapeutic approaches for treating HCC have improved the prognoses of patients with HCC, this cancer is still associated with a poor survival rate mainly due to late diagnosis. Therefore, a diagnosis must be made sufficiently early to perform curative and effective treatments. There is a need for a deeper understanding of the molecular mechanisms underlying the initiation and progression of HCC because these mechanisms are critical for making early diagnoses and developing novel therapeutic strategies. Over the past decade, much progress has been made in elucidating the molecular mechanisms underlying hepatocarcinogenesis. In particular, recent advances in next-generation sequencing technologies have revealed numerous genetic alterations, including recurrently mutated genes and dysregulated signaling pathways in HCC. A better understanding of the genetic alterations in HCC could contribute to identifying potential driver mutations and discovering novel therapeutic targets in the future. In this article, we summarize the current advances in research on the genetic alterations, including genomic instability, single-nucleotide polymorphisms, somatic mutations and deregulated signaling pathways, implicated in the initiation and progression of HCC. We also attempt to elucidate some of the genetic mechanisms that contribute to making early diagnoses of and developing molecularly targeted therapies for HCC.

Cooperative antiproliferative effect of coordinated ectopic expression of DLC1 tumor suppressor protein and silencing of MYC oncogene expression in liver cancer cells: Therapeutic implications

Human hepatocellular carcinoma (HCC) is one of the most common types of cancer and has a very poor prognosis; thus, the development of effective therapies for the treatment of advanced HCC is of high clinical priority. In the present study, the anti-oncogenic effect of combined knockdown of c-Myc expression and ectopic restoration of deleted in liver cancer 1 (DLC1) expression was investigated in human liver cancer cells. Expression of c-Myc in human HCC cells was knocked down by stable transfection with a Myc-specific short hairpin (sh) RNA vector. DLC1 expression in Huh7 cells was restored by adenovirus transduction, and the effects of DLC1 expression and c-Myc knockdown on Ras homolog gene family, member A (RhoA) levels, cell proliferation, soft agar colony formation and cell invasion were measured. Downregulation of c-Myc or re-expression of DLC1 led to a marked reduction in RhoA levels, which was associated with decreases in cell proliferation, soft agar colony formation and invasiveness; this inhibitory effect was augmented with a combination of DLC1 transduction and c-Myc suppression. To determine whether liver cell-specific delivery of DLC1 was able to enhance the inhibitory effect of c-Myc knockdown on tumor growth in vivo, DLC1 vector DNA complexed with galactosylated polyethylene glycol-linear polyethyleneimine was administered by tail vein injection to mice bearing subcutaneous xenografts of Huh7 cells transfected with shMyc or control shRNA. A cooperative inhibitory effect of DLC1 expression and c-Myc knockdown on the growth of Huh7-derived tumors was observed, suggesting that targeted liver cell delivery of DLC1 and c-Myc shRNA may serve as a possible gene therapy modality for the treatment of human HCC.

Statin Use and Survival with Early-Stage Hepatocellular Carcinoma

BACKGROUND

Limited clinical and epidemiologic data suggest that statins may improve the outcomes of hepatocellular carcinoma (HCC), which has poor prognosis.

METHODS

We identified 1,036 stage I or II HCC patients, diagnosed between 2007 and 2009, through the linked Surveillance, Epidemiology, and End Results (SEER) Program and Medicare claims database. Of these, 363 patients were using statin either at the time of their HCC diagnosis or afterwards. We conducted multivariable Cox regression analysis to estimate the time-dependent effect of statin on survival. The analysis included age, sex, resection, transarterial chemoembolization, transplantation, cirrhosis, cardiovascular disease, diabetes, dyslipidemia, and hepatitis B and C.

RESULTS

Over a median follow-up time of 21 months, 584 HCC patients died. Statin users had a longer median survival compared with nonusers: 23.9 versus 18.9 months (P = 0.047). However, after accounting for immortal time bias and confounding, statin use was not associated with survival (HR, 0.98; 95% confidence interval, 0.80-1.20). The associations did not vary by hepatitis C or intensity of statin use.

CONCLUSION

Statin treatment after HCC diagnosis was not associated with survival in elderly patients with stage I/II disease.

IMPACT

Our study of nationally representative elderly patients with stage I or II HCC in the United States shows that statin treatment does not improve survival with liver cancer. Cancer Epidemiol Biomarkers Prev; 25(4); 686-92. ©2016 AACR.

Genetic and epigenetic aspects of initiation and progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary cancer of the liver that is predominant in developing countries and is responsible for nearly 600000 deaths each year worldwide. Similar to many other tumors, the development of HCC must be understood as a multistep process involving the accumulation of genetic and epigenetic alterations in regulatory genes, leading to the activation of oncogenes and the inactivation or loss of tumor suppressor genes. Extensive research over the past decade has identified a number of molecular biomarkers, including aberrant expression of HCC-related genes and microRNAs. The challenge facing HCC research and clinical care at this time is to address the heterogeneity and complexity of these genetic and epigenetic alterations and to use this information to direct rational diagnosis and treatment strategies. The multikinase inhibitor sorafenib was the first molecularly targeted drug for HCC to show some extent of survival benefits in patients with advanced tumors. Although the results obtained using sorafenib support the importance of molecular therapies in the treatment of HCC, there is still room for improvement. In addition, no molecular markers for drug sensitivity, recurrence and prognosis are currently clinically available. In this review, we provide an overview of recently published articles addressing HCC-related genes and microRNAs to update what is currently known regarding genetic and epigenetic aspects of the pathogenesis of HCC and propose novel promising candidates for use as diagnostic and therapeutic targets in HCC.

Challenges of deciphering gastric cancer heterogeneity

Gastric cancer is in decline in most developed countries; however, it still accounts for a notable fraction of global mortality and morbidity related to cancer. High-throughput methods are rapidly changing our view and understanding of the molecular basis of gastric carcinogenesis. Today, it is widely accepted that the molecular complexity and heterogeneity, both inter- and intra-tumour, of gastric adenocarcinomas present significant obstacles in elucidating specific biomarkers for early detection of the disease. Although genome-wide sequencing and gene expression studies have revealed the intricate nature of the molecular changes that occur in tumour landscapes, the collected data and results are complex and sometimes contradictory. Several aberrant molecules have already been tested in clinical trials, although their diagnostic and prognostic utilities have not been confirmed thus far. The gold standard for the detection of sporadic gastric cancer is still the gastric endoscopy, which is considered invasive. In addition, genome-wide association studies have confirmed that genetic variations are important contributors to increased cancer risk and could participate in the initiation of malignant transformation. This hypothesis could in part explain the late onset of sporadic gastric cancers. The elaborate interplay of polymorphic low penetrance genes and lifestyle and environmental risk factors requires additional research to decipher their relative impacts on tumorigenesis. The purpose of this article is to present details of the molecular heterogeneity of sporadic gastric cancers at the DNA, RNA, and proteome levels and to discuss issues relevant to the translation of basic research data to clinically valuable tools. The focus of this work is the identification of relevant molecular changes that could be detected non-invasively.

Comparative transcriptome analysis reveals that the extracellular matrix receptor interaction contributes to the venous metastases of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of liver cancer in the world. Portal vein tumor thrombus (PVTT) is one of the most serious complications of HCC and is strongly correlated with a poor prognosis for HCC patients. However, the detailed mechanism of PVTT development remains to be explored. In this study, we present a large-scale transcriptome analysis, by RNA sequencing, of 11 patients diagnosed with HCC with PVTT. The dysregulated genes between HCC and PVTT suggested that the extracellular matrix receptor interaction was correlated with the venous metastases of HCC. Among all of the recurrent alternative splicing events, we identified exon 6 skipping of RPS24, which is likely to be a cancer driver. We also identified five common fusion genes between HCC and its corresponding PVTT samples, including ARID1A-GPATCH3, MDM1-NUP107, PTGES3-RARG, PRLR-TERT, and C9orf3-TMC1. All of these findings broaden our knowledge of PVTT development and may also contribute to the diagnosis and treatment of HCC patients with PVTT.