Event In Hepatocellular Carcinoma Research Articles

Transposable elements-mediated recruitment of KDM1A epigenetically silences HNF4A expression to promote hepatocellular carcinoma

Transposable elements (TEs) contribute to gene expression regulation by acting as cis-regulatory elements that attract transcription factors and epigenetic regulators. This research aims to explore the functional and clinical implications of transposable element-related molecular events in hepatocellular carcinoma, focusing on the mechanism through which liver-specific accessible TEs (liver-TEs) regulate adjacent gene expression. Our findings reveal that the expression of HNF4A is inversely regulated by proximate liver-TEs, which facilitates liver cancer cell proliferation. Mechanistically, liver-TEs are predominantly occupied by the histone demethylase, KDM1A. KDM1A negatively influences the methylation of histone H3 Lys4 (H3K4) of liver-TEs, resulting in the epigenetic silencing of HNF4A expression. The suppression of HNF4A mediated by KDM1A promotes liver cancer cell proliferation. In conclusion, this study uncovers a liver-TE/KDM1A/HNF4A regulatory axis that promotes liver cancer growth and highlights KDM1A as a promising therapeutic target. Our findings provide insight into the transposable element-related molecular mechanisms underlying liver cancer progression.

Suppression of A-to-I RNA-editing enzyme ADAR1 sensitizes hepatocellular carcinoma cells to oxidative stress through regulating Keap1/Nrf2 pathway

BackgroundA-to-I RNA editing is an abundant post-transcriptional modification event in hepatocellular carcinoma (HCC). Evidence suggests that adenosine deaminases acting on RNA 1 (ADAR1) correlates to oxidative stress that is a crucial factor of HCC pathogenesis. The present study investigated the effect of ADAR1 on survival and oxidative stress of HCC, and underlying mechanisms.MethodsADAR1 expression was measured in fifty HCC and normal tissues via real-time quantitative PCR, and immunohistochemistry. For stable knockdown or overexpression of ADAR1, adeno-associated virus vectors carrying sh-ADAR1 or ADAR1 overexpression were transfected into HepG2 and SMMC-7721 cells. Transfected cells were exposed to oxidative stress agonist tBHP or sorafenib Bay 43-9006. Cell proliferation, apoptosis, and oxidative stress were measured, and tumor xenograft experiment was implemented.ResultsADAR1 was up-regulated in HCC and correlated to unfavorable clinical outcomes. ADAR1 deficiency attenuated proliferation of HCC cells and tumor growth and enhanced apoptosis. Moreover, its loss facilitated intracellular ROS accumulation, and elevated Keap1 and lowered Nrf2 expression. Intracellular GSH content and SOD activity were decreased and MDA content was increased in the absence of ADAR1. The opposite results were observed when ADAR1 was overexpressed. The effects of tBHP and Bay 43–9006 on survival, apoptosis, intracellular ROS accumulation, and Keap1/Nrf2 pathway were further exacerbated by simultaneous inhibition of ADAR1.ConclusionsThe current study unveils that ADAR1 is required for survival and oxidative stress of HCC cells, and targeting ADAR1 may sensitize HCC cells to oxidative stress via modulating Keap1/Nrf2 pathway.

Knockdown of liver cancer cell-secreted exosomal PSMA5 controls macrophage polarization to restrain cancer progression by blocking JAK2/STAT3 signaling.

Tumor-associated macrophages, a major component of the tumor microenvironment, undergo polarization into M2 macrophages (M2), and thereby exert an immunosuppressive effect to induce cancer metastasis. This study strives to uncover a molecular mechanism underlying this event in hepatocellular carcinoma (HCC). Proteasome subunit alpha 5 (PSMA5) expression in liver hepatocellular carcinoma (LIHC) tissues and its association with LIHC patients were predicted using StarBase. PSMA5 level in human HCC cells was manipulated via transfection. Exosomes were isolated from HCC cells, and internalized into macrophages which were cocultured with HCC cells. Exosome internalization was observed after fluorescence labeling. HCC cell migration and invasion were evaluated by wound healing and Transwell assays. Xenograft assay was performed to investigate the role of PSMA5 in in vitro tumorigenesis. M2 polarization was assessed by enzyme-linked immunosorbent assay,quantitative reverse transcription polymerase chain reaction,and immunohistochemistry. PSMA5 expression in exosomes and Janus Kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) activation in macrophages and tumors were detected by Western blot analysis. High PSMA5 expression was observed in LIHC tissues and associated with compromised survival of LIHC patients. PSMA5 knockdown inhibited HCC cell migration and invasion. PSMA5 knockdown in HCC cells downregulated PSMA5 level in exosomes from these HCC cells. HCC cell-isolated exosomes were successfully internalized into macrophages, and facilitated M2 polarization and JAK2/STAT3 pathway activation. HCC cell-secreted exosomal PSMA5 knockdown inhibited the exosome-induced effect on macrophages, and attenuated the promotion induced by exosome-treated macrophages on HCC cell migration/invasion and tumorigenesis along with in vivo M2 polarization and JAK2/STAT3 pathway activation. HCC cell-secreted exosomal PSMA5 knockdown hinders M2 polarization to suppress cancer progression by restraining JAK2/STAT3 signaling.

DNA methylation-activated full-length EMX1 facilitates metastasis through EMX1-EGFR-ERK axis in hepatocellular carcinoma

Altered DNA methylation is a crucial epigenetic event in hepatocellular carcinoma (HCC) development and progression. Through methylation-transcriptomic analysis, we identified a set of sixty potential DNA methylation-based epidriver genes. In this set of genes, we focused on the hypermethylation of EMX1, which is frequently observed in hepatobiliary tumors. Despite of its frequent occurrence, the function of EMX1 remains largely unknown. By utilizing bisulfite-next-generation sequencing, we have detected EMX1 DNA hypermethylation on the gene body, which is positively correlated with EMX1 mRNA expression. Further analysis revealed that EMX1 mRNA terminal exon splicing in HCC generated two protein isoforms: EMX1 full length (EMX1-FL) and alternative terminal exon splicing isoform (EMX1-X1). Cellular functional assays demonstrated that gain-of-function EMX1-FL, but not EMX1-X1, induced HCC cells migration and invasion while silencing EMX1-FL inhibited HCC cells motility. This result was further validated by in vivo tumor metastasis models. Mechanistically, EMX1-FL bound to EGFR promoter, promoting EGFR transcription and activating EGFR-ERK signaling to trigger tumor metastasis. Therefore, EGFR may be a potential therapeutic target for EMX1-high expression HCC. Our work illuminated the crucial role of gene body hypermethylation-activated EMX1-FL in promoting tumorigenesis and metastasis in HCC. These findings pave the way for targeting the EMX1-EGFR axis in HCC tumorigenicity and metastasis.

S3993 Severe Gastric and Duodenal Ulceration with Bowel Perforation as Rare Immunotherapy Related Adverse Events in Hepatocellular Carcinoma: A Case Report

S3993 Severe Gastric and Duodenal Ulceration with Bowel Perforation as Rare Immunotherapy Related Adverse Events in Hepatocellular Carcinoma: A Case Report

Proteomics of adjacent-to-tumor samples uncovers clinically relevant biological events in hepatocellular carcinoma.

Normal adjacent tissues (NATs) of hepatocellular carcinoma (HCC) differ from healthy liver tissues and their heterogeneity may contain biological information associated with disease occurrence and clinical outcome that has yet to be fully evaluated at the proteomic level. This study provides a detailed description of the heterogeneity of NATs and the differences between NATs and healthy livers and revealed that molecular features of tumor subgroups in HCC were partially reflected in their respective NATs. Proteomic data classified HCC NATs into two subtypes (Subtypes 1 and 2), and Subtype 2 was associated with poor prognosis and high-risk recurrence. The pathway and immune features of these two subtypes were characterized. Proteomic differences between the two NAT subtypes and healthy liver tissues were further investigated using data-independent acquisition mass spectrometry, revealing the early molecular alterations associated with the progression from healthy livers to NATs. This study provides a high-quality resource for HCC researchers and clinicians and may significantly expand the knowledge of tumor NATs to eventually benefit clinical practice.

ALBI Grade Is a Predictive Factor of Lenvatinib Treatment Discontinuation due to Adverse Events in Hepatocellular Carcinoma.

Lenvatinib is a multiple-tyrosine kinase inhibitor used to treat hepatocellular carcinoma (HCC), and its systematic concentration varies according to liver function. The albumin-bilirubin (ALBI) grade is a novel indicator for predicting liver function in patients with hepatic disease. This study aimed to investigate the relationship between ALBI grade and HCC patients' lenvatinib treatment duration. This is a retrospective cohort study of patients with HCC and Child-Pugh A treated with lenvatinib between April 2018 and December 2019. The baseline liver function was determined using the ALBI grade. The primary outcome was discontinuation owing to adverse events. The risk factors for discontinuation owing to adverse effects were analyzed using logistic regression. This investigation included 48 HCC patients. Patients with ALBI grade 2 had a significantly shorter time of discontinuation due to adverse events than those with grade 1 (p=0.036). However, the time of treatment failure did not differ between the groups. Multiple logistic regression analysis showed that ALBI grade 2 and non-use of antihypertensive drugs were independent factors for discontinuation due to adverse events [odds ratio (OR)=14.1, 95% confidence interval (CI)=1.46-135, p=0.022 and OR=5.48, 95% CI=1.13-23.9, p=0.024, respectively]. The ALBI grades may be useful in predicting adverse events caused by lenvatinib in patients with HCC and Child-Pugh A.

N4BP3 promotes angiogenesis in hepatocellular carcinoma by binding with KAT2B.

Although angiogenesis is a critical event in hepatocellular carcinoma (HCC), and this process provides the tumor with sufficient oxygen and nutrients, the precise molecular mechanism by which it occurs is not fully understood. NEDD4 binding protein 3 (N4BP3) was identified in this study as a novel pro‐angiogenic factor in HCC cell lines and tissues. We discovered that N4BP3 was significantly expressed in HCC and that its level of expression was positively correlated with the density of tumor microvessels in HCC tissues. Cell biology experiments have shown that N4BP3 knockdown in HCC cells significantly inhibits the formation of complete tubular structures by HUVECs in vitro and HCC angiogenesis in vivo. In HCC cells, overexpression of N4BP3 has the opposite effects. Further cell and molecular biology experiments have revealed that N4BP3 interacts with KAT2B (lysine acetyltransferase 2B), increasing signal transducer and activator of transcription 3 (STAT3) expression by regulating the distribution of acetyl‐histone H3 (Lys27) (H3K27ac) in its promoter region. This, in addition, regulates the activity of the STAT3 signaling pathway, which promotes the proliferation of microvessels in HCC and accelerates the malignant process of the tumor. In vivo experiments in nude mice have confirmed our findings, and also suggested that N4BP3 could be a potential target for the treatment of HCC in combination with sorafenib.

Abstract No. 558 Risk factors for adverse events following yttrium-90 radiation segmentectomy for hepatocellular carcinoma

To identify rates and risk factors for adverse events in hepatocellular carcinoma (HCC) patients treated with yttrium-90 (Y-90) radiation segmentectomy (RS) with glass microspheres (TheraSphere, Boston Scientific, Marlborough, MA)

Jianpi Huayu Decoction enhances the effect of sorafenib and alleviates adverse events in hepatocellular carcinoma by remodeling the gut microbiota

BackgroundThere is an urgent need for effective treatment for advanced hepatocellular carcinoma (HCC). Sorafenib, a multi-kinase inhibitor, is the first-line treatment for advanced HCC, which has a modest efficacy due to severe adverse effects (AEs), acquired resistance, and others. Jianpi Huayu Decoction (JHD) is a traditional Chinese medicine formulation, effective as an alternative and complementary therapy of HCC. Combined sorafenib with JHD is a potential approach to overcome sorafenib resistance. MethodsEffect and AEs of clinical-dose sorafenib combined JHD were evaluated in a subcutaneous model. Diarrhea, the most frequently reported AEs, was evaluated by diarrhea score. Illumina NovaSeq analyzed the gut microbiota (GM) composition of the mice. ResultsJHD administration enhanced anti-tumor response to sorafenib and prevented the occurrence of sorafenib-induced diarrhea and body weight loss. Proinflammatory GM Helicobacter positively correlated with sorafenib treatment while anti-inflammatory GM, Muribaculum, Fusicatenibacter, and Dorea positively correlated with JHD treatment. In addition, JHD decreased the infiltration of inflammatory cells and downregulated signaling of interleukin 6/signal transducer and activator of the transcription-3 pathway. ConclusionsOur finding suggested that JHD with microbiota modulation properties could significantly potentiate sorafenib and provide a promising treatment for advanced HCC.

Global analysis of DNA methylation in hepatocellular carcinoma via a whole-genome bisulfite sequencing approach

Alterations in DNA methylation patterns are considered early events in hepatocellular carcinoma (HCC). However, their mechanism and significance remain to be elucidated. We studied the genome-wide DNA methylation landscape of HCC by applying whole-genome bisulfite sequencing (WGBS) techonlogy. Overall, HCC exhibits a genome-wide hypomethylation pattern. After further annotation, we obtained 590 differentially hypermethylated genes (hyper-DMGs) and 977 differentially hypomethylated genes (hypo-DMGs) from three groups. Hyper-DMGs were mainly involved in ascorbate and alternate metabolism pathways, while hypo-DMGs were mainly involved in focal adhesion. By integrating the DMGs with HCC-related differentially expressed genes (DEGs) and DMGs from the TCGA database, we constructed prognostic model based on thirteen aberrantly methylated DEGs, and verified our prognostic model in GSE14520 dataset. This study compares the patterns of global epigenomic DNA methylation during the development of HCC, focusing on the role of DNA methylation in the early occurrence and development of HCC, providing a direction for future research on its epigenetic mechanism.

Single-cell RNA sequencing reveals the mechanism of sonodynamic therapy combined with a RAS inhibitor in the setting of hepatocellular carcinoma

BackgroundRas activation is a frequent event in hepatocellular carcinoma (HCC). Combining a RAS inhibitor with traditional clinical therapeutics might be hampered by a variety of side effects, thus hindering further clinical translation. Herein, we report on integrating an IR820 nanocapsule-augmented sonodynamic therapy (SDT) with the RAS inhibitor farnesyl-thiosalicylic acid (FTS). Using cellular and tumor models, we demonstrate that combined nanocapsule-augmented SDT with FTS induces an anti-tumor effect, which not only inhibits tumor progression, and enables fluorescence imaging. To dissect the mechanism of a combined tumoricidal therapeutic strategy, we investigated the scRNA-seq transcriptional profiles of an HCC xenograft following treatment.ResultsIntegrative single-cell analysis identified several clusters that defined many corresponding differentially expressed genes, which provided a global view of cellular heterogeneity in HCC after combined SDT/FTS treatment. We conclude that the combination treatment suppressed HCC, and did so by inhibiting endothelial cells and a modulated immunity. Moreover, hepatic stellate secretes hepatocyte growth factor, which plays a key role in treating SDT combined FTS. By contrast, enrichment analysis estimated the functional roles of differentially expressed genes. The Gene Ontology terms “cadherin binding” and “cell adhesion molecule binding” and KEGG pathway “pathway in cancer” were significantly enriched by differentially expressed genes after combined SDT/FTS therapy.ConclusionsThus, some undefined mechanisms were revealed by scRNA-seq analysis. This report provides a novel proof-of-concept for combinatorial HCC-targeted therapeutics that is based on a non-invasive anti-tumor therapeutic strategy and a RAS inhibitor.

TBX3 functions as a tumor suppressor downstream of activated CTNNB1 mutants during hepatocarcinogenesis

Gain of function (GOF) mutations in the CTNNB1 gene are one of the most frequent genetic events in hepatocellular carcinoma (HCC). T-box transcription factor 3 (TBX3) is a liver-specific target of the Wnt/β-catenin pathway and thought to be an oncogene mediating activated β-catenin-driven HCC formation. We evaluated the expression pattern of TBX3 in human HCC specimens. Tbx3 was conditionally knocked out in murine HCC models by hydrodynamic tail vein injection of Cre together with c-Met and ΔN90-β-catenin (c-Met/β-catenin) in Tbx3flox/flox mice. TBX3 was overexpressed in human HCC cell lines to investigate the functions of TBX3 invitro. A bimodal expression pattern of TBX3 in human HCC samples was detected: high expression of TBX3 in GOF CTNNB1 HCC and downregulation of TBX3 in non-CTNNB1 mutant tumors. High expression of TBX3 was associated with increased differentiation and decreased expression signatures of tumor growth. Using Tbx3flox/flox mice, we found that ablation of Tbx3 significantly accelerates c-Met/β-catenin-driven HCC formation. Moreover, Tbx3(-) HCC demonstrated increased YAP/TAZ activity. The accelerated tumor growth induced by loss of TBX3 in c-Met/β-catenin mouse HCC was successfully prevented by overexpression of LATS2, which inhibited YAP/TAZ activity. In human HCC cell lines, overexpression of TBX3 inhibited HCC cell growth as well as YAP/TAZ activation. A negative correlation between TBX3 and YAP/TAZ target genes was observed in human HCC samples. Mechanistically, phospholipase D1 (PLD1), a known positive regulator of YAP/TAZ, was identified as a novel transcriptional target repressed by TBX3. Our study suggests that TBX3 is induced by GOF CTNNB1 mutants and suppresses HCC growth by inactivating PLD1, thus leading to the inhibition of YAP/TAZ oncogenes. TBX3 is a liver-specific target of the Wnt/β-catenin pathway and thought to be an oncogene in promoting liver cancer development. Herein, we demonstrate that TBX3 is in fact a tumor suppressor gene that restricts liver tumor growth. Strategies which increase TBX3 expression and/or activities may be effective for HCC treatment.

Distinct functions of transforming growth factor-\u03b2 signaling in c-MYC driven hepatocellular carcinoma initiation and progression

Dysregulation of transforming growth factor-beta (TGFβ) signaling has been implicated in liver carcinogenesis with both tumor promoting and inhibiting activities. Activation of the c-MYC protooncogene is another critical genetic event in hepatocellular carcinoma (HCC). However, the precise functional crosstalk between c-MYC and TGFβ signaling pathways remains unclear. In the present investigation, we investigated the expression of TGFβ signaling in c-MYC amplified human HCC samples as well as the mechanisms whereby TGFβ modulates c-Myc driven hepatocarcinogenesis during initiation and progression. We found that several TGFβ target genes are overexpressed in human HCCs with c-MYC amplification. In vivo, activation of TGFβ1 impaired c-Myc murine HCC initiation, whereas inhibition of TGFβ pathway accelerated this process. In contrast, overexpression of TGFβ1 enhanced c-Myc HCC progression by promoting tumor cell metastasis. Mechanistically, activation of TGFβ promoted tumor microenvironment reprogramming rather than inducing epithelial-to-mesenchymal transition during HCC progression. Moreover, we identified PMEPA1 as a potential TGFβ1 target. Altogether, our data underline the divergent roles of TGFβ signaling during c-MYC induced HCC initiation and progression.

Jianpi Huayu Decoction Enhances the Effect of Sorafenib and Alleviates Adverse Events in Hepatocellular Carcinoma by Remodeling the Gut Microbiota

Jianpi Huayu Decoction Enhances the Effect of Sorafenib and Alleviates Adverse Events in Hepatocellular Carcinoma by Remodeling the Gut Microbiota

Telomere length is key to hepatocellular carcinoma diversity and telomerase addiction is an actionable therapeutic target

Telomerase activation is the earliest event in hepatocellular carcinoma (HCC) development. Thus, we aimed to elucidate the role of telomere length maintenance during liver carcinogenesis. Telomere length was measured in the tumor and non-tumor liver tissues of 1,502 patients (978 with HCC) and integrated with TERT alterations and expression, as well as clinical and molecular (analyzed by genome, exome, targeted and/or RNA-sequencing) features of HCC. The preclinical efficacy of anti-TERT antisense oligonucleotides (ASO) was assessed in vitro in 26 cell lines and in vivo in a xenograft mouse model. Aging, liver fibrosis, male sex and excessive alcohol consumption were independent determinants of liver telomere attrition. HCC that developed in livers with long telomeres frequently had wild-type TERT with progenitor features and BAP1 mutations. In contrast, HCC that developed on livers with short telomeres were enriched in the non-proliferative HCC class and frequently had somatic TERT promoter mutations. In HCCs, telomere length is stabilized in a narrow biological range around 5.7 kb, similar to non-tumor livers, by various mechanisms that activate TERT expression. Long telomeres are characteristic of very aggressive HCCs, associated with the G3 transcriptomic subclass, TP53 alterations and poor prognosis. In HCC cell lines, TERT silencing with ASO was efficient in highly proliferative and poorly differentiated cells. Treatment for 3 to 16 weeks induced cell proliferation arrest in 12 cell lines through telomere shortening, DNA damage and activation of apoptosis. The therapeutic effect was also obtained in a xenograft mouse model. Telomere maintenance in HCC carcinogenesis is diverse, and is associated with tumor progression and aggressiveness. The efficacy of anti-TERT ASO treatment in cell lines revealed the oncogenic addiction to TERT in HCC, providing a preclinical rationale for anti-TERT ASO treatment in HCC clinical trials. Telomeres are repeated DNA sequences that protect chromosomes and naturally shorten in most adult cells because of the inactivation of the TERT gene, coding for the telomerase enzyme. Here we show that telomere attrition in the liver, modulated by aging, sex, fibrosis and alcohol, associates with specific clinical and molecular features of hepatocellular carcinoma, the most frequent primary liver cancer. We also show that liver cancer is dependent on TERT reactivation and telomere maintenance, which could be targeted through a novel therapeutic approach called antisense oligonucleotides.

MiR-17-5p and miR-20a-5p suppress postoperative metastasis of hepatocellular carcinoma via blocking HGF/ERBB3-NF-κB positive feedback loop.

Dysregulation of microRNA (miRNA) is a frequent event in hepatocellular carcinoma (HCC), but little is known whether it is a bystander or an actual player on residual HCC metastasis during liver microenvironment remodeling initiated by hepatectomy.Methods: The differently expressed miRNAs and mRNAs were identified from RNA-seq data. Western blot, qRT-PCR, fluorescence in situ hybridization, immunofluorescence and immunohistochemical were used to detect the expression of miRNA and mRNA in cell lines and patient tissues. The biological functions were investigated in vitro and in vivo. Chromatin immunoprecipitation, proximity ligation and luciferase reporter assay were used to explore the specific binding of target genes. The expression of HGF/ERBB3 signaling was detected by Western blot.Results: In this study, HGF induced by hepatectomy was shown to promote metastasis of residual HCC cells. miR-17-5p and miR-20a-5p were confirmed to play inhibitory roles on HCC metastasis. And ERBB3 was found to be the common target of miR-17-5p and miR-20a-5p. HCC cells with lower levels of miR-17-5p and miR-20a-5p or higher level of ERBB3 were often more sensitive to response HGF stimuli and to facilitate metastatic colonization both in vitro and in vivo experimental systems. Furthermore, HGF reinforced ERBB3 expression by NF-κB transcriptional activity in a positive feedback loop. Of particular importance, HCC patients with lower levels of miR-17-5p and miR-20a-5p or higher level of ERBB3 had significantly shorter OS and PFS survivals after surgical resection.Conclusion: miR-17-5p and miR-20a-5p could suppress postoperative metastasis of hepatocellular carcinoma via blocking HGF/ERBB3-NF-κB positive feedback loop and offer a new probable strategy for metastasis prevention after HCC resection.

Comprehensive Bioinformatics Analysis of Key Methyltransferases and Demethylases for Histone Lysines in Hepatocellular Carcinoma.

Background & Aims:Methylation of lysines on histones, controlled by various methyltransferases and demethylases, is an important component of epigenetic modifications, and abnormal regulation of such enzymes serves as common events in hepatocellular carcinoma. We determined to identify important methyltransferases and demethylases that might regulate the development of hepatocellular carcinoma by bioinformatics.Methods:The Oncomine and UALCAN databases were used to retrieve mRNA expression levels of histone lysine methyltransferases and demethylases in hepatocellular carcinoma. Data analyses of genetic alterations, mainly mutations and copy number alterations, were performed on the cBioportal platform. Protein-protein interactions were established in the STRING database.Results:mRNA expression of 8 genes correlated with clinical staging and grading, whereas 4 genes indicated a role in the prognosis, all co-expressed with SEDB1 and WHSC1. Genetically, 12 genes showing an alteration rate higher than 5% were identified, and only 3 were indicative of prognosis. Copy number gains in ASH1L, SETDB1, and KDM5B might partially contribute to the upregulation of their mRNA expression. The close relationship of mutations in MLL2/MLL3 with driver gene mutations in hepatocellular carcinoma provided a rationale for further investigation.Conclusions:We identified 11 methyltransferases and demethylases for major histone lysines that might be promising research targets in the pathogenesis, development, and prediction of prognosis in hepatocellular carcinoma using bioinformatics.

Systematic analysis and prediction model construction of alternative splicing events in hepatocellular carcinoma: a study on the basis of large-scale spliceseq data from The Cancer Genome Atlas.

Growing evidence showed that alternative splicing (AS) event is significantly related to tumor occurrence and progress. This study was performed to make a systematic analysis of AS events and constructed a robust prediction model of hepatocellular carcinoma (HCC). The clinical information and the genes expression profile data of 335 HCC patients were collected from The Cancer Genome Atlas (TCGA). Information of seven types AS events were collected from the TCGA SpliceSeq database. Overall survival (OS) related AS events and splicing factors (SFs) were identified using univariate Cox regression analysis. The corresponding genes of OS-related AS events were sent for gene network analysis and functional enrichment analysis. Optimal OS-related AS events were selected by LASSO regression to construct prediction model using multivariate Cox regression analysis. Prognostic value of the prediction models were assessed by receiver operating characteristic (ROC) curve and KaplanMeir survival analysis. The relationship between the Percent Spliced In (PSI) value of OS-related AS events and SFs expression were analyzed using Spearman correlation analysis. And the regulation network was generated by Cytoscape. A total of 34,163 AS events were identified, which consist of 3,482 OS-related AS events. UBB, UBE2D3, SF3A1 were the hub genes in the gene network of the top 800 OS-related AS events. The area under the curve (AUC) of the final prediction model based on seven types OS-related AS events was 0.878, 0.843, 0.821 in 1, 3, 5 years, respectively. Upon multivariate analysis, risk score (All) served as the risk factor to independently predict OS for HCC patients. SFs HNRNPH3 and HNRNPL were overexpressed in tumor samples and were signifcantly associated with the OS of HCC patients. The regulation network showed prominent correlation between the expression of SFs and OS-related AS events in HCC patients. The final prediction model performs well in predicting the prognosis of HCC patients. And the findings in this study improve our understanding of the association between AS events and HCC.

Wnt status-dependent oncogenic role of BCL9 and BCL9L in hepatocellular carcinoma

BackgroundActivation of Wnt/β-catenin pathway is a frequent event in hepatocellular carcinoma and is associated with enhanced cell survival and proliferation. Therefore, targeting this signaling pathway is discussed as an attractive therapeutic approach for HCC treatment. BCL9 and BCL9L, two homologous coactivators of the β-catenin transcription factor complex, have not yet been comprehensively characterized in HCC. We aimed to elucidate the roles of BCL9 and BCL9L, especially regarding Wnt/β-catenin signaling and their prognostic value in HCC.MethodsExpression of BCL9/BCL9L was determined in HCC cell lines (HLE, HLF, Huh7, HepG2, Hep3B, and Huh6) and normal liver cell lines (THLE-2 and THLE-3). To analyze proliferation and apoptosis, BCL9 and/or BCL9L were knocked down in Wnt-inactive HLE and Wnt-active HepG2 and Huh6 cells using siRNA. Subsequently, Wnt reporter assays were performed in HepG2 and Huh6 cells. BCL9 and BCL9L expression, clinicopathological and survival data of public HCC datasets were analyzed, taking the Wnt signaling status into account.ResultsKnockdown of BCL9L, but not of BCL9, reduced Wnt signaling activity. Knockdown of BCL9 and/or BCL9L reduced cell viability and increased apoptosis of Wnt-inactive HCC cells, but had no effect in Wnt-active cells. Expression of BCL9 and BCL9L was upregulated in human HCC and increased with progressing dedifferentiation. For BCL9L, higher expression was observed in tumors of larger size. Overexpression of BCL9 and BCL9L correlated with poor overall survival, especially in HCC without activated Wnt signaling.ConclusionOncogenic BCL9 proteins represent promising targets for cancer therapy and inhibiting them may be particularly beneficial in Wnt-inactive HCCs.Graphic abstract