Development Of HBV-related Hepatocellular Carcinoma Research Articles

Insight into the mechanisms regulating liver cancer stem cells by hepatitis B virus X protein.

Hepatocellular carcinoma (HCC) is a heterogeneous disease with high recurrence and mortality. It is well known that a large proportion of HCCs are caused by hepatitis B virus (HBV) infection. In particular, the HBV X protein (HBX), a multifunctional molecule produced by the virus, plays a leading role in hepatocarcinogenesis. However, the molecular mechanisms underlying HBX-mediated HCC remain not fully elucidated. Recently, liver cancer stem cells (LCSCs), a unique heterogeneous subpopulation of the malignancy, have received particular attention owing to their close association with tumorigenesis. Especially, the modulation of LCSCs by HBX by upregulating CD133, CD44, EpCAM, and CD90 plays a significant role in HBV-related HCC development. More importantly, not only multiple signaling pathways, including Wnt/β-catenin signaling, transforming growth factor-β (TGF-β) signaling, phosphatidylinositol-3-kinase (PI-3K)/AKT signaling, and STAT3 signaling pathways, but also epigenetic regulation, such as DNA and histone methylation, and noncoding RNAs, including lncRNA and microRNA, are discovered to participate in regulating LCSCs mediated by HBX. Here, we summarized the mechanisms underlying different signaling pathways and epigenetic alterations that contribute to the modulation of HBX-induced LCSCs to facilitate hepatocarcinogenesis. Because LCSCs are important in hepatic carcinogenesis, understanding the regulatory factors controlled by HBX might open new avenues for HBV-associated liver cancer treatment.

HBV-related HCC development in mice is STAT3 dependent and indicates an oncogenic effect of HBx

Although most hepatocellular carcinoma (HCC) cases are driven by hepatitis and cirrhosis, a subset of patients with chronic hepatitis B develop HCC in the absence of advanced liver disease, indicating the oncogenic potential of hepatitis B virus (HBV). We investigated the role of HBV transcripts and proteins on HCC development in the absence of inflammation in HBV-transgenic mice. HBV-transgenic mice replicating HBV and expressing all HBV proteins from a single integrated 1.3-fold HBV genome in the presence or absence of wild-type HBx (HBV1.3/HBVxfs) were analyzed. Flow cytometry, molecular, histological and invitro analyses using human cell lines were performed. Hepatocyte-specific Stat3- and Socs3-knockout was analyzed in HBV1.3 mice. Approximately 38% of HBV1.3 mice developed liver tumors. Protein expression patterns, histology, and mutational landscape analyses indicated that tumors resembled human HCC. HBV1.3 mice showed no signs of active hepatitis, except STAT3 activation, up to the time point of HCC development. HBV-RNAs covering HBx sequence, 3.5-kb HBV RNA and HBx-protein were detected in HCC tissue. Interestingly, HBVxfs mice expressing all HBV proteins except a C-terminally truncated HBx (without the ability to bind DNA damage binding protein 1) showed reduced signs of DNA damage response and had a significantly reduced HCC incidence. Importantly, intercrossing HBV1.3 mice with a hepatocyte-specific STAT3-knockout abrogated HCC development. Expression of HBV-proteins is sufficient to cause HCC in the absence of detectable inflammation. This indicates the oncogenic potential of HBV and in particular HBx. In our model, HBV-driven HCC was STAT3 dependent. Our study highlights the immediate oncogenic potential of HBV, challenging the idea of a benign highly replicative phase of HBV infection and indicating the necessity for an HBV 'cure'. Although most HCC cases in patients with chronic HBV infection occur after a sequence of liver damage and fibrosis, a subset of patients develops HCC without any signs of advanced liver damage. We demonstrate that the expression of all viral transcripts in HBV-transgenic mice suffices to induce HCC development independent of inflammation and fibrosis. These data indicate the direct oncogenic effects of HBV and emphasize the idea of early antiviral treatment in the 'immune-tolerant' phase (HBeAg-positive chronic HBV infection).

Genome-wide functional integration identified MAZ-controlled RPS14 dysregulation in hepatocellular carcinoma.

Chronic infection with Hepatitis B virus (HBV) significantly increases the risk of hepatocellular carcinoma (HCC), particularly in Eastern Asia. However, only a subset of individuals with chronic HBV infection develop HCC, suggesting the role for genetic factors in HCC etiology. Despite genome-wide association studies (GWASs) identifying multiple single nucleotide polymorphisms (SNPs) associated with HBV-related HCC susceptibility, the underlying mechanisms and causal genetic polymorphisms remain largely unclear. To address this, we developed The Updated Integrative Functional Genomics Approach (TUIFGA), an methodology that combines data from transcription factor (TF) cistromics, ATAC-seq, DNAase-seq, and the 1000 Genomes Project to identify cancer susceptibility SNPs within TF-binding sites across human genome. Using TUIFGA, we discovered SNP rs13170300 which located in the TF MAZ binding motif of RPS14. The RPS14 rs13170300 was significantly associated with HCC risk in two case-control sets, with the T allele as the protective allele (Shandong discovery set: TT OR = 0.60, 95% CI = 0.49-0.74, P = 1.0 × 10-6; CT OR = 0.69, 95% CI = 0.55-0.86, P = 0.001; Jiangsu validation set: TT OR = 0.70, 95% CI = 0.56-0.87, P = 0.001; CT OR = 0.65, 95% CI = 0.53-0.82, P = 1.6 × 10-4). SNP rs13170300 affected MAZ binding in the RPS14 promoter, resulting in allele-specific changes in gene expression. RPS14 functions as a novel oncogene in HCC, specifically via activating the AKT signaling. Our findings present important insights into the functional genetics underlying HBV-related HCC development and may contribute to personalized approaches for cancer prevention and novel therapeutics.

The role of sex hormones and receptors in HBV infection and development of HBV-related HCC.

Gender disparity in hepatitis B virus (HBV)-related diseases has been extensively documented. Epidemiological studies consistently reported that males have a higher prevalence of HBV infection and incidence of hepatocellular carcinoma (HCC). Further investigations have revealed that sex hormone-related signal transductions play a significant role in gender disparity. Sex hormone axes showed significantly different responses to virus entry and replication. The sex hormones axes change the HBV-specific immune responses and antitumor immunity. Additionally, Sex hormone axes showed different effects on the development of HBV-related disease. But the role of sex hormones remains controversial, and researchers have not reached a consensus on the role of sex hormones and the use of hormone therapies in HCC treatment. In this review, we aim to summarize the experimental findings on sex hormones and provide a comprehensive understanding of their roles in the development of HCC and their implications for hormone-related HCC treatment.

HMMR alleviates endoplasmic reticulum stress by promoting autophagolysosomal activity during endoplasmic reticulum stress-driven hepatocellular carcinoma progression.

The mechanism of hepatitis B virus (HBV)-induced carcinogenesis remains an area of interest. The accumulation of hepatitis B surface antigen in the endoplasmic reticulum (ER) of hepatocytes stimulates persistent ER stress. Activity of the unfolded protein response (UPR) pathway of ER stress may play an important role in inflammatory cancer transformation. How the protective UPR pathway is hijacked by cells as a tool for malignant transformation in HBV-related hepatocellular carcinoma (HCC) is still unclear. Here, we aimed to define the key molecule hyaluronan-mediated motility receptor (HMMR) in this process and explore its role under ER stress in HCC development. An HBV-transgenic mouse model was used to characterize the pathological changes during the tumor progression. Proteomics and transcriptomics analyses were performed to identify the potential key molecule, screen the E3 ligase, and define the activation pathway. Quantitative real-time PCR and Western blotting were conducted to detect the expression of genes in tissues and cell lines. Luciferase reporter assay, chromatin immunoprecipitation, coimmunoprecipitation, immunoprecipitation, and immunofluorescence were employed to investigate the molecular mechanisms of HMMR under ER stress. Immunohistochemistry was used to clarify the expression patterns of HMMR and related molecules in human tissues. We found sustained activation of ER stress in the HBV-transgenic mouse model of hepatitis-fibrosis-HCC. HMMR was transcribed by c/EBP homologous protein (CHOP) and degraded by tripartite motif containing 29 (TRIM29) after ubiquitination under ER stress, which caused the inconsistent expression of mRNA and protein. Dynamic expression of TRIM29 in the HCC progression regulated the dynamic expression of HMMR. HMMR could alleviate ER stress by increasing autophagic lysosome activity. The negative correlation between HMMR and ER stress, positive correlation between HMMR and autophagy, and negative correlation between ER stress and autophagy were verified in human tissues. This study identified the complicated role of HMMR in autophagy and ER stress, that HMMR controls the intensity of ER stress by regulating autophagy in HCC progression, which could be a novel explanation for HBV-related carcinogenesis.

Association of PNPLA3 SNP With the Development of HBV-related Hepatocellular Carcinoma.

Concomitant nonalcoholic fatty liver disease (NAFLD)/hepatic steatosis (HS) is suggested to increase the risk of hepatocellular carcinoma (HCC) in hepatitis virus B (HBV)-infected patients. Patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 gene single-nucleotide polymorphism (SNP) is well-known to be associated with the development of NAFLD/HS; however, it is still unclear whether this SNP is related to the development of HCC in HBV-infected patients. We investigated a total of 202 HBV-infected patients who received percutaneous liver biopsy, and simultaneously assessed biopsy-proven HS, insulin resistance, and the PNPLA3 SNP status. We further investigated the relationships of these factors with the development of HCC in HBV-infected patients. Most of the enrolled cases (196/202: 97.0%) were non-cirrhotic patients. One hundred seventy-three patients (85.6%) received antiviral therapy. A Kaplan-Meier analysis showed that the incidence of HCC development in patients with HS was higher than that in patients without HS (p<0.01). An increased homeostasis model assessment as an index of insulin resistance (HOMA-IR) value (≥1.6) was associated not only with the presence of HS (p<0.0001) but also with the development of HCC (p<0.01). The PNPLA3 rs738409 SNP was also associated with the presence of HS (p<0.01) and the development of HCC (p<0.05) in HBV-infected patients. In addition to HS and IR, PNPLA3 rs738409 SNP was suggested to be associated with the development of HCC in Japanese patients with HBV infection.

Hepatitis B virus X protein increases LASP1 SUMOylation to stabilize HER2 and facilitate hepatocarcinogenesis

The hepatitis B virus (HBV) X protein (HBX), a viral macromolecule, plays a vital role in the development of HBV-related hepatocellular carcinoma (HCC). Increased expression of HER2 is linked to HBV infection, and HBX is responsible for HER2 upregulation in HCC. Nevertheless, the underlying molecular mechanisms are not yet fully understood. In the study, we discovered that HBX promoted HER2 expression to facilitate the sensitization of the insulin signaling pathway and enhance the growth and migration of HCC cells. Mechanistically, the viral protein enhanced the stability of HER2 by preventing its ubiquitination-mediated proteasomal degradation through LASP1, which could bind to HER2. Furthermore, increased SUMOylation of LASP1 contributed to the upregulation of HER2 and the interaction of LASP1 with HER2. In addition, RANBP2 and RANGAP1 were found to interact with LASP1 and promote SUMOylation of LASP1 to upregulate HER2 expression in HBX-associated hepatoma cells. In summary, our work provides a novel insight into hepatocarcinogenesis mediated by HBX and estimates the detailed mechanisms related to the increase in HER2 regulated by the viral protein, which might help provide a theoretical basis for identifying novel targets for HBV-positive HCC treatment.

The significance of EphA2-regulated Wnt/β-catenin signal pathway in promoting the metastasis of HBV-related hepatocellular carcinoma.

Hepatitis B virus (HBV) infection is closely associated with the malignant progression of hepatocellular carcinoma (HCC). However, the mechanism involved in the HBV-related HCC development remains poorly understood. Hence, the aim of this study is to investigate the regulatory mechanism of EphA2-induced epithelial-mesenchymal transition (EMT) in the metastasis of HBV-related HCC cells. The expression level of EphA2 was determined in HBV-related human HCC cells. Then, the effects of EphA2 silencing on the EMT-associated proteins, the Wnt/β-catenin signal pathway and the metastatic potential of HBV-related HCC cells were evaluated. Finally, the inhibitory role of Entecavir (a potent antiviral drug for HBV) on EphA2-induced EMT was explored. The present study revealed that the EphA2 expression level was increased in HBV-related HCC cells compared with non-related HCC cells. Following EphA2 knockdown, the downregulation of Vimentin, β-catenin and p-GSK-3βSer9 expressions, the upregulation of E-cadherin expression, and the suppressed migration and invasion ability of HBV-related HCC cells were found. Additionally, Entecavir was proved to have a significant inhibitory effect on EphA2-induced EMT via attenuating the Wnt/β-catenin signal pathway. In this study, we found that EphA2-induced EMT was involved in the enhanced metastatic potential of HBV-related HCC cells through the activation of the Wnt/β-catenin signal pathway.

HBV-upregulated Lnc-HUR1 inhibits the apoptosis of liver cancer cells

Lnc-HUR1 is an HBV-related long non-coding RNA, which can promote the proliferation of hepatoma cells and the occurrence and development of liver cancer. In this study we explored the effect of lnc-HUR1 on the apoptosis of hepatocellular carcinoma cells by taking the approach of immunoblotting, quantitative real time PCR, luciferase reporter assay, chromatin immunoprecipitation (ChIP) and flow cytometry. We found that overexpression of lnc-HUR1 significantly reduced the activity of caspase3/7 and the cleavage of PARP-1, while knocking down of lnc-HUR1 significantly increased the activity of caspase3/7 and promoted the cleavage of PARP-1 in HepG2 cells treated with TGF-β, pentafluorouracil or staurosporine. Consistently, the data from Annexin-V/PI staining showed that overexpression of lnc-HUR1 inhibited apoptosis, while knockdown of lnc-HUR1 promoted apoptosis. Moreover, overexpression of lnc-HUR1 up-regulated the apoptosis inhibitor Bcl-2 and down-regulated the pro-apoptotic factor BAX at both RNA and protein levels. In the CCL4-induced acute liver injury mice model, the expression of Bcl-2 in the liver tissue of lnc-HUR1 transgenic mice was higher than that of the control mice. The data from ChIP assay indicated that lnc-HUR1 reduced the enrichment of p53 on Bcl-2 and BAX promoters. All these results indicated that lnc-HUR1 inhibited the apoptosis by promoting the expression of apoptosis inhibitor Bcl-2 and inhibiting the expression of apoptosis promoting factor BAX. Further studies showed that lnc-HUR1 regulated the transcription of Bcl-2 and BAX in HCT116 cells, but had no effect on the expression of Bcl-2 and BAX in HCT116 p53-/- cells, indicating that lnc-HUR1 regulates the transcription of Bcl-2 and BAX dependent upon the activity of p53. In conclusion, HBV upregulated lnc-HUR1 can inhibit the apoptosis of hepatoma cells. Lnc-HUR1 inhibits apoptosis by inhibiting the transcriptional activity of p53. These results suggest that lnc-HUR1 plays an important role in the occurrence and development of HBV-related hepatocellular carcinoma.

HBx and YAP expression could promote tumor development and progression in HBV-related hepatocellular carcinoma

BackgroundHepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) accounts for 10%–20% of the total HCC numbers. Its clinical features include the occurrence in the younger generation, large tumors, and poor prognosis. The contribution of hepatitis B virus X (HBx) protein in hepatocytes during activation of various oncogenic pathways has been reported. We aimed to assess the possible association between HBx and Yes-associated protein (YAP) expression in the liver tissue and the clinical features of HBV-related HCC. MethodsThe relationship between HBx and YAP expression was examined in vivo using HCC tumor and peritumor tissues (n = 55). The clinical information including tumor size, marker, and the prognosis was assessed with protein expressions. The in vitro gene expression analyses were conducted using HBx- and YAP-overexpressing HCC cell lines. ResultsAmong 19 cases of HBV-related, 17 cases of hepatitis C virus (HCV)-related, and 19 cases of nonviral-related HCC, the HBV-related tumor showed the largest size. The HBx-stained area in the tumor and peritumor tissue showed a significant correlation with tumor size and serum α-fetoprotein level. YAP expression was higher in HBV-related tumor tissue than in the peritumor tissue and HCV-related tumor. Additionally, HBx and YAP protein expressions are correlated and both expressions in the tumor contributed to the poor prognosis. An in vitro study demonstrated that HBx and YAP overexpression in the hepatocytes activate the various oncogenic signaling pathways. ConclusionsOur study demonstrated that YAP expression in the liver of HBV-infected patients might be the key factor in HBV-related HCC development and control of tumor-related features.

Chemical shift assignments of a fusion protein comprising the C-terminal-deleted hepatitis B virus X protein BH3-like motif peptide and Bcl-xL

Chronic hepatitis B virus (HBV) infection is a major risk factor for the development of liver diseases including fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). HBV has the multifunctional protein, HBV X protein (HBx, 154 residues), which plays key roles in HBV replication and liver disease development. Interaction of HBx through its BH3-like motif with the anti-apoptotic protein Bcl-xL leads to HBV replication and induction of apoptosis, resulting in HCC development. Our previous nuclear magnetic resonance (NMR) study revealed that the HBx BH3-like motif peptide (residues 101-136) binds to the common BH3-binding groove of Bcl-xL. Importantly, a C-terminal-truncated HBx, e.g., residues 1-120 of HBx, is strongly associated with the increased risk of HBV-related HCC development. However, the interaction mode between the C-terminal-truncated HBx and Bcl-xL remains unclear. To elucidate this interaction mode, the C-terminal-deleted HBx BH3-like motif peptide (residues 101-120) was used as a model peptide in this study. To facilitate the NMR analysis, we prepared a fusion protein of HBx (101-120) and Bcl-xL connected with five repeats of the glycine-serine dipeptide as a linker. Here, we report the 1H, 13C, and 15N resonance assignments of the fusion protein. This is the first step for the elucidation of the pathogenesis of liver diseases caused by the interaction between the C-terminal-truncated HBx and Bcl-xL.

The HBV Specially-Related Long Noncoding RNA HBV-SRL Involved in the Pathogenesis of Hepatocellular Carcinoma.

Hepatitis B virus (HBV) is one of the major risk factors for HCC (hepatocellular carcinoma) occurrence with a diverse role in the pathogenesis of HCC. More works need to be performed to elucidate a more thorough understanding of the molecular mechanisms involving in HBV-induced HCC, although some mechanisms such as genome integration have been reported. In the present study, aberrantly expressed lncRNAs were identified between HCC tumor tissues with or without HBV infection. Among these molecules, HBV specially-related long noncoding RNA (HBV-SRL) was further found to correlate with poor prognosis and a shorter overall survival time in HCC patients with HBV infection. Additionally, HBV-SRL was found function as oncogene by upregulating the NF-κB2 expression. These data suggest that HBV infection altered gene expression pattern in liver cells which contributed to HBV-related HCC development, and HBV-SRL may serve as a new molecular marker or potential therapeutic target of HBV-related HCC.

LncRNA MAPKAPK5_AS1 facilitates cell proliferation in hepatitis B virus -related hepatocellular carcinoma

AbstractWe explored the biological role of long non-coding RNA (lncRNA) MAPKAPK5_AS1 (MAAS) and the mechanism of its differential expression in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Differentially expressed lncRNAs in HBV-related HCC were determined using bioinformatics analysis. Gain-of-function experiments were conducted to evaluate the effect of MAAS on cell proliferation. A xenograft model was established for in vivo experiments. Dual-luciferase reporter assays, chromatin immunoprecipitation, co-immunoprecipitation, and methylated RNA immunoprecipitation were performed to elucidate the underlying molecular mechanisms. MAAS was upregulated in HBV-related HCC cancerous tissues and its high expression was closely related to the poor survival probability of patients. Functional assays revealed that MAAS overexpression facilitated the proliferation of HBV+HCC cells in vitro and in vivo. Mechanistically, MAAS promoted the MYC proto-oncogene (c-Myc)-induced transcriptional activation of cyclin-dependent kinase 4 (CDK4), CDK6, and S-phase kinase associated protein 2 via stabilizing c-Myc protein, thereby facilitating G1/S transition. The latter contributed to the paradoxical proliferation of HBV+HCC cells. Although MAAS was upregulated in HBV-related HCC cancerous tissues, it was highly expressed in M2 macrophages, a major phenotype of tumor-associated macrophages in HBV-related HCC, instead of in HBV+HCC cells. HBeAg, an HBV-associated antigen, further elevated the MAAS level in M2 macrophages by enhancing the methyltransferase-like 3-mediated N6-methyladenosine modification of MAAS. The increased MAAS in the M2 macrophages was then transferred to HBV+HCC cells through the M2 macrophage-derived exosomes, promoting cell proliferation. Our findings show that HBV+HCC cell-secreted HBeAg upregulates MAAS expression in M2 macrophages by affecting its m6A modification. The upregulated MAAS is then transferred to HBV+HCC cells via exosomes, facilitating the proliferation of HBV+HCC cells by targeting c-Myc.The present study reveals that the hepatitis-B (HBV) antigen HBeAg found in HBV+HCC upregulates long non-coding RNA MAPKAPK5_AS1 (MAAS) expression in M2 macrophages by affecting its m6A modification. MAAS is transferred to HBV+HCC cells via exosomes, which in turn facilitates their proliferation. This is a novel role for MAAS and further elucidates the mechanism of HBeAg-induced HBV-related HCC development.

HBV HBx-Downregulated lncRNA LINC01010 Attenuates Cell Proliferation by Interacting with Vimentin.

Hepatitis B virus (HBV) infection is closely related to hepatocellular carcinoma (HCC) development. To investigate the mechanism of HBV causing HCC, we previously analyzed the transcription of the HBV-transgenic cell line HepG2-4D14 and parental HepG2 cells and identified a subset of long noncoding RNAs (lncRNAs) differentially expressed between them. In this study, we focus on lncRNA LINC01010, as it is significantly downregulated in HepG2-4D14 cells and in liver tissues of HCC patients, and positively correlated with survival. We found that HBV-encoded HBx can reduce the transcription of LINC01010. Functional analysis showed that the overexpression of LINC01010 inhibits proliferation, migration and invasion of HepG2 cells while the knockdown of LINC01010 promotes these processes. By taking the approach of RNA immunoprecipitation (RIP) and mass spectrometry, we identified that LINC01010 can interact with vimentin. Further studies demonstrated that LINC01010 negatively affects the vimentin network extension and causes more rapid subunit exchange and lower stability of vimentin filaments. In addition, LINC01010 can reduce the amount of insoluble vimentin within cells, which suggests that LINC01010 interfers with vimentin polymerization. These data indicate that LINC01010 can inhibit the assembly of vimentin filament. Thus, we revealed that HBV HBx-downregulated LINC01010, which suppresses cell proliferation and migration by negatively regulating the formation of vimentin filament. Taken together, LINC01010 is a potential tumor suppressor that may restrain HBV-related HCC development.

Circ_0027089 regulates NACC1 by targeting miR-136-5p to aggravate the development of hepatitis B virus-related hepatocellular carcinoma.

Hepatitis B virus (HBV) infection is the main trigger of hepatocellular carcinoma (HCC). Circular RNA plays an indispensable role in cancer development, and this study aimed to disclose the function and mechanism of circ_0027089 in HBV-related HCC. The expression levels of circ_0027089, miR-136-5p and nucleus accumbens associated protein 1 (NACC1) mRNA were measured by quantitative real-time PCR, and the protein level of NACC1 was detected by western blot. For functional analyses, cell proliferation was assessed by cell counting kit-8 assay and colony formation assay. Cell apoptosis and cell cycle were detected by flow cytometry assay, and cell apoptosis was also assessed by caspase 3/7 activity. The capacities of migration and invasion were evaluated by wound healing assay and transwell assay, respectively. The predicted relationship between miR-136-5p and circ_0027089 or NACC1 was validated by dual-luciferase reporter assay and RNA binding protein immunoprecipitation assay. Animal experiments were performed in nude mice to explore the role of circ_0027089 in vivo. Circ_0027089 expression and NACC1 expression were elevated, while miR-136-5p expression was decreased in HBV-related HCC tissues and cells. In function, circ_0027089 knockdown inhibited HepG2.2.15 and HepAD38 (tet-off) cell proliferation, migration and invasion but induced cell cycle arrest and apoptosis, while circ_0027089 overexpression played the reversed effects. For mechanism exploration, miR-136-5p was a target of circ_0027089, and miR-136-5p deficiency could reverse the role of circ_0027089 knockdown. Circ_0027089 functioned as an oncogene to promote the development of HBV-related HCC by regulating NACC1 via competitively targeting miR-136-5p.

Germline Variants and Genetic Interactions of Several EMT Regulatory Genes Increase the Risk of HBV-Related Hepatocellular Carcinoma.

Epithelial-mesenchymal transition (EMT) plays an important role in the development of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). We hypothesized that germline variants in the major EMT regulatory genes (SNAIL1, ZEB1, ZEB2, TWIST1) may influence the development of HBV-related HCC. We included 421 cases of HBsAg-positive patients with HCC, 1371 cases of HBsAg-positive subjects without HCC [patients with chronic hepatitis B (CHB) or liver cirrhosis (LC)] and 618 cases of healthy controls in the case-control study. Genotype, allele, and haplotype associations in the major EMT regulatory genes were tested. Environment-gene and gene-gene interactions were analysed using the non-parametric model-free multifactor dimensionality reduction (MDR) method. The SNAIL1rs4647958T>C was associated with a significantly increased risk of both HCC (CT+CC vs. TT: OR=1.559; 95% confidence interval [CI], 1.073-2.264; P=0.020) and CHB+LC (CT+CC vs. TT: OR=1.509; 95% CI, 1.145-1.988; P=0.003). Carriers of the TWIST1rs2285681G>C (genotypes CT+CC) had an increased risk of HCC (CG+CC vs. GG: OR=1.407; 95% CI, 1.065-1.858; P=0.016). The ZEB2rs3806475T>C was associated with significantly increased risk of both HCC (P recessive =0.001) and CHB+LC (P recessive<0.001). The CG haplotype of the rs4647958/rs1543442 haplotype block was associated with significant differences between healthy subjects and HCC patients (P=0.0347). Meanwhile, the CT haplotype of the rs2285681/rs2285682 haplotype block was associated with significant differences between CHB+LC and HCC patients (P=0.0123). In MDR analysis, the combination of TWIST1rs2285681, ZEB2rs3806475, SNAIL1rs4647958 exhibited the most significant association with CHB+LC and Health control in the three-locus model. Our results suggest significant single-gene associations and environment-gene/gene-gene interactions of EMT-related genes with HBV-related HCC.

MiR-3 Encoded by Hepatitis B Virus Downregulates PTEN Protein Expression and Promotes Cell Proliferation.

PurposeChronic hepatitis B virus (HBV) infection is a key determinant of hepatocellular carcinoma (HCC). However, the mechanism by which HBV contributes to the development of HCC remains to be further explored. HBV-encoded miR-3 (HBV-miR-3) is a newly discovered microRNA that can affect the replication of HBV, but its influence on host genes is unclear. The tumor suppressor phosphatase and tensin homolog (PTEN) is expressed at low levels in most cancer cells. How HBV-miR-3 acts on PTEN to induce tumorigenesis has not been clarified.Materials and MethodsPTEN protein expression was evaluated in HBV-miR-3-transfected cells and HBV-related liver cancer and paracancerous tissues. A luciferase reporter assay was employed to identify the HBV-miR-3 binding site on the 3ʹ-untranslated region (3ʹ-UTR) of PTEN. Cell apoptosis was assessed by flow cytometry. Cell proliferation was evaluated by colony formation assays. Transwell assays were used to detect cancer cell invasion.ResultsHBV-miR-3 was identified only in HBV-replicating HCC cells and HBV-infected patients. HBV-miR-3 expression in liver cancer tissues was higher than that in paracancerous tissues, and the corresponding PTEN expression was significantly decreased. Wild-type HBV-miR-3 bound to the 3ʹ-UTR of PTEN and downregulated its protein expression in a dose-dependent manner. Moreover, the inhibition of HBV-miR-3 rescued PTEN protein expression. Furthermore, HBV-miR-3 reduced liver cancer cell apoptosis, enhanced cell invasion, and promoted cell proliferation.ConclusionHBV-miR-3 binds to the 3ʹ-UTR of PTEN mRNA and downregulates PTEN protein expression, thereby reducing cell apoptosis and enhancing cell invasion and proliferation. These results indicate that HBV-miR-3 contributes to the development of HBV-related HCC and may be a therapeutic target for this cancer.

Screening and Identification of Potential Biomarkers in Hepatitis B Virus-Related Hepatocellular Carcinoma by Bioinformatics Analysis.

Hepatocellular carcinoma (HCC) is one of the most lethal cancers globally. Hepatitis B virus (HBV) infection might cause chronic hepatitis and cirrhosis, leading to HCC. To screen prognostic genes and therapeutic targets for HCC by bioinformatics analysis and determine the mechanisms underlying HBV-related HCC, three high-throughput RNA-seq based raw datasets, namely GSE25599, GSE77509, and GSE94660, were obtained from the Gene Expression Omnibus database, and one RNA-seq raw dataset was acquired from The Cancer Genome Atlas (TCGA). Overall, 103 genes were up-regulated and 127 were down-regulated. A protein–protein interaction (PPI) network was established using Cytoscape software, and 12 pivotal genes were selected as hub genes. The 230 differentially expressed genes and 12 hub genes were subjected to functional and pathway enrichment analyses, and the results suggested that cell cycle, nuclear division, mitotic nuclear division, oocyte meiosis, retinol metabolism, and p53 signaling-related pathways play important roles in HBV-related HCC progression. Further, among the 12 hub genes, kinesin family member 11 (KIF11), TPX2 microtubule nucleation factor (TPX2), kinesin family member 20A (KIF20A), and cyclin B2 (CCNB2) were identified as independent prognostic genes by survival analysis and univariate and multivariate Cox regression analysis. These four genes showed higher expression levels in HCC than in normal tissue samples, as identified upon analyses with Oncomine. In addition, in comparison with normal tissues, the expression levels of KIF11, TPX2, KIF20A, and CCNB2 were higher in HBV-related HCC than in HCV-related HCC tissues. In conclusion, our results suggest that KIF11, TPX2, KIF20A, and CCNB2 might be involved in the carcinogenesis and development of HBV-related HCC. They can thus be used as independent prognostic genes and novel biomarkers for the diagnosis of HBV-related HCC and development of pertinent therapeutic strategies.

Downregulation of GSK3β and Upregulation of URG7 in Hepatitis B-Related Hepatocellular Carcinoma

: Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC). The exact molecular contributors to the development of HBV-related HCC are not yet completely understood. Recent studies demonstrated that the deregulation of the Wnt pathway is highly associated with the development of HCC. Besides, HBV is known to have roles in the deregulation of this pathway. The present study evaluated the molecular aspects of the Wnt pathway in HBV-related HCC in liver tissue samples. Viral characterization was done by identifying the HBx mutations and the assessment of intrahepatic viral load. The expression of Wnt pathway genes was assessed using real-time PCR and methylation-specific PCR. The intrahepatic viral load was significantly higher in tumor samples than in normal tissues (P = 0.0008). Aberrant expression was observed in Wnt-1, Wnt-7a, FZD2, FZD7, β-catenin, URG7, c-Myc, SFRP5, and GSK3β, among which Wnt1, FZD2, SFRP5, Gsk3β, and URG7 were associated with HBV. HBx mutations at positions I88, L116, and I127 + F132 were associated with the decreased expression of GSK3β and overexpression of URG7 and Wnt1. Alterations in the expression level of β-catenin, as well as some mutants of HBx, were correlated with the level of c-Myc. HBV-related HCC seems to be mostly coordinated with epigenetic behaviors of HBx, such a multi-functional peptide with suppressing/trans-activating functions.

Vagaries of the Host Response in the Development of Hepatitis B-related Hepatocellular Carcinoma: A Case Series

The hepatitis B virus (HBV) is one of the leading causes of hepatocellular carcinoma (HCC) worldwide. In the endemic region, the infection is commonly spread through vertical transmission in which mother and child possess genetically identical viral genotypes in the setting of similar host genomes. Despite these genetic similarities, clinical outcomes from chronic hepatitis B (CHB) can vary widely, ranging from lifelong asymptomatic infection to terminal HCC. Presented here are the longitudinal observations over multiple decades of three family clusters, including monozygotic twins with non-discordant HCC, that demonstrate the heterogeneity of HBV-related outcomes. These findings emphasize the important need to untangle the role of genetic and non-genetic host factors in the development of HBV-related HCC, as well as highlight the novel research avenues that can clarify the contributions of such factors in HBV-related HCC.