Variants identified by hepatocellular carcinoma and chronic hepatitis B virus infection susceptibility GWAS associated with survival in HBV-related hepatocellular carcinoma

Potentially functional genetic variants in ferroptosis-related CREB3 and GALNT14 genes predict survival of hepatitis B virus-related hepatocellular carcinoma

BACKGROUND

Ferroptosis is a known crucial player in the development of cancers. However, the effect of single nucleotide polymorphisms (SNPs) in ferroptosis-related genes on survival in hepatitis B virus (HBV)-related hepatocellular carcinoma (HBV-HCC) patients remains unknown.

METHODS

We used two-stage multivariable Cox proportional hazards regression analyses to estimate the associations between 48,774 SNPs in 480 ferroptosis-related genes and overall survival (OS) of 866 HBV-HCC patients.

RESULTS

We identified that two potentially functional SNPs (CREB3 rs10814274 C > T and GALNT14 rs17010547 T > C) were significantly independently associated with the OS of HBV-HCC patients (CT + TT verse CC, hazards ratio (HR) = 0.77, 95% confidence interval (CI) = 0.67-0.89, p < 0.001 for rs10814274 and TC + CC verse TT, HR = 0.66, 95% CI = 0.53-0.82, p < 0.001 for rs17010547, respectively). Additional joint assessment of protective genotypes of these two SNPs showed that patients with 1-2 protective genotypes had a significantly better OS compared with those carrying 0 protective genotypes (HR = 0.56, 95% CI = 0.45-0.70, p < 0.001). Moreover, the expression quantitative trait loci (eQTL) analysis revealed that the survival-associated SNP rs10814274 T allele was significantly correlated with reduced CREB3 transcript levels in both normal liver tissues and whole blood cells, while the GALNT14 rs17010547 C allele had a significant correlation with increased GALNT14 transcript levels in whole blood cells.

CONCLUSION

These results suggest that genetic variants of CREB3 and GALNT14 may affect the survival of HBV-HCC patients, likely via transcriptional regulation of respective genes. However, further studies are required to confirm these findings.

Mechanisms of DNA Methylation in Virus-Host Interaction in Hepatitis B Infection: Pathogenesis and Oncogenetic Properties

Hepatitis B virus (HBV), the well-studied oncovirus that contributes to the majority of hepatocellular carcinomas (HCC) worldwide, can cause a severe inflammatory microenvironment leading to genetic and epigenetic changes in hepatocyte clones. HBV replication contributes to the regulation of DNA methyltransferase gene expression, particularly by X protein (HBx), and subsequent methylation changes may lead to abnormal transcription activation of adjacent genes and genomic instability. Undoubtedly, the altered expression of these genes has been known to cause diverse aspects of infected hepatocytes, including apoptosis, proliferation, reactive oxygen species (ROS) accumulation, and immune responses. Additionally, pollutant-induced DNA methylation changes and aberrant methylation of imprinted genes in hepatocytes also complicate the process of tumorigenesis. Meanwhile, hepatocytes also contribute to epigenetic modification of the viral genome to affect HBV replication or viral protein production. Meanwhile, methylation levels of HBV integrants and surrounding host regions also play crucial roles in their ability to produce viral proteins in affected hepatocytes. Both host and viral changes can provide novel insights into tumorigenesis, individualized responses to therapeutic intervention, disease progress, and early diagnosis. As such, DNA methylation-mediated epigenetic silencing of cancer-related genes and viral replication is a compelling therapeutic goal to reduce morbidity and mortality from liver cancer caused by chronic HBV infection. In this review, we summarize the most recent research on aberrant DNA methylation associated with HBV infection, which is involved in HCC development, and provide an outlook on the future direction of the research.

The association of lncRNA SNPs and SNPs-environment interactions based on GWAS with HBV-related HCC risk and progression

Background

Long non‐coding RNA (lncRNA) plays an essential role in hepatitis B virus‐related hepatocellular carcinoma (HBV‐related HCC) occurrence and development. Single nucleotide polymorphism (SNP) may affect HBV‐related HCC susceptibility by altering the function of lncRNA. However, the relationship between lncRNA SNPs and HBV‐related HCC occurrence and development is still unclear.

Methods

In the present study, based on HBV‐related HCC genome‐wide association studies, eight potentially functional SNPs from two lncRNAs were predicted using a set of bioinformatics strategies. In 643 HBV‐related HCC patients, 549 CHB carriers, and 553 HBV natural clearance subjects from Southern Chinese, we evaluated associations between SNPs and HBV‐related HCC occurrence or development with odds ratio (OR) and 95% confidence interval (CI) under credible genetic models.

Results

In HBV‐related HCC patients, rs9908998 was found to significantly increase the risk of lymphatic metastasis under recessive model (Adjusted OR = 1.95, 95% CI = 1.20–3.17). Lnc‐RP11‐150O12.3 rs2275959, rs1008547, and rs11776545 with cancer family history may show significant multiplicative and additive interactions on HBV‐related HCC susceptibility (all p_Adjusted < .05). The associations of rs2275959, rs1008547, and rs11776545 with distant metastasis of HBV‐related HCC patients were observed in additive model (Adjusted OR = 1.45, 95% CI = 1.06–1.97 for rs2275959; Adjusted OR = 1.45, 95% CI = 1.06–1.98 for rs1008547; Adjusted OR = 1.40, 95% CI = 1.03–1.91 for rs11776545).

Conclusion

Taken together, lnc‐ACACA‐1 rs9908998, lnc‐RP11‐150O12.3 rs2275959, rs1008547, and rs11776545 might be predictors for HBV‐related HCC risk or prognosis.

Crosslink among phosphatidylinositol-3 kinase/Akt, PTEN and STAT-5A signaling pathways post liposomal galactomannan hepatocellular carcinoma therapy

Liposomal drug-delivery systems (LDDs) provide a promising opportunity to precisely target organs, improve drug bioavailability and reduce systemic toxicity. On the other hand, PI₃K/Akt signaling pathways control various intracellular functions including apoptosis, invasion and cell growth. Hyper activation of PI3K and Akt is detected in some types of cancer that posses defect in PTEN. Tracking the crosstalk between PI3K/Akt, PTEN and STAT 5A signaling pathways, in cancer could result in identifying new therapeutic agents. The current study, identified an over view on PI3K/Akt, PTEN and STAT-5A networks, in addition to their biological roles in hepatocellular carcinoma (HCC). In the current study galactomannan was extracted from Caesalpinia gilliesii seeds then loaded in liposomes. Liposomes were prepared employing phosphatidyl choline and different concentrations of cholesterol. HCC was then induced in Wistar albino rats followed by liposomal galactomannan (700 ± 100 nm) treatment. Liver enzymes as well as antioxidants were assessed and PI3K/Akt, PTEN and STAT-5A gene expression were investigated. The prepared vesicles revealed entrapment efficiencies ranging from 23.55 to 69.17%, and negative zeta potential values. The optimum formulation revealed spherical morphology as well as diffusion controlled in vitro release pattern. Liposomal galactomannan elucidated a significant reduction in liver enzymes and MDA as well as PI3K/Akt, PTEN and STAT 5A gene expression. A significant elevation in GST and GSH were deduced. In conclusion, Liposomal galactomannan revealed a promising candidate for HCC therapy.

Interaction analysis of miR-1275/IGF2BP1/IGF2BP3 with the susceptibility to hepatocellular carcinoma

Aim: The aim of this study was to investigate the association of miR-1275 rs16759, IGF2BP1 rs11079850 and IGF2BP3 rs34414305 with hepatocellular carcinoma (HCC) risk. Materials & methods: Genotyping of the rs16759 and rs11079850 was performed using a Taqman assay and genotyping of the rs34414305 was performed using PCR. Relative expression of miR-1275, IGF2BP1 and IGF2BP3 was examined using quantitative PCR. Results: Comparison of the rs16759GG, CG/GG and CC genotype showed an increased risk of HCC. When comparing G with C allele, a significantly increased risk of HCC was also found. The rs16759, rs11079850 and rs34414305 had combined the interactive effects on the carcinogenesis of HCC. Moreover, the rs34414305 Del/ATT-Del/Del carriers displayed lower levels of IGF2BP3. Conclusion: The rs16759, rs11079850 and rs34414305 may singly and interactively contribute to carcinogenesis of HCC.

Integrative analysis identifies genetic variant modulating MICA expression and altering susceptibility to persistent HBV infection

BACKGROUND & AIMS

Genome-wide association studies have identified multiple genetic signals associated with the risk of persistent hepatitis B virus (HBV) infection and HBV-related hepatocellular carcinoma. However, the majority of the associated variants may only be markers of functional variants and the underlying biological mechanisms remain elusive. We hypothesized that the functional variants with modulating transcription factor (TF) binding affinity in genome-wide association studies-identified loci may influence the risk of persistent HBV infection in Chinese people.

METHODS

A systematic bioinformatics approach was implemented to prioritize potential functional variants that may influence TF binding. A two-stage case-control study, including 1595 HBV-persistent carriers and 1590 subjects with HBV natural clearance, was conducted to examine the associations between candidate variants and susceptibility to persistent HBV infection. Biological assays were carried out to elucidate the underlying mechanism of the associated genetic variants.

RESULTS

Twelve candidate variants were identified, and rs2523454 G > A increased the risk of persistent HBV infection (dominant model: OR_combined  = 1.37, 95% CI = 1.19-1.58, P = 1.610 × 10^-5 ). Functional assays indicated that the rs2523454 A allele significantly decreased transcriptional activity compared to the G allele by influencing TF-binding affinity. In addition, expression quantitative trait loci analyses revealed that the A allele was associated with the reduced expression of MICA (P < 0.01).

CONCLUSIONS

Our findings suggest that the germline G > A variation at rs2523454 may influence TF-DNA interaction, downregulate the expression of MICA and play an important role in the development of persistent HBV infection in the Chinese population.

Association between HLA-DQA1/DRB1 polymorphism and development of hepatocellular carcinoma during entecavir treatment

BACKGROUND AND AIMS

It remains unclear whether there is an association between single-nucleotide polymorphisms (SNPs) and development of hepatocellular carcinoma (HCC) during entecavir (ETV) treatment in nucleos(t)ide analog-naïve patients with chronic hepatitis B virus infection. We investigated the risk factors for HCC, especially host factors, during ETV treatment.

METHODS

A total of 127 Japanese patients undergoing ETV treatment were enrolled in this study. Univariate and multivariate analyses for clinical factors, hepatic fibrosis markers, and SNPs associated with HCC development were analyzed.

RESULTS

A total of 10 patients developed HCC during the follow-up period (median duration, 3.3 years). The 3-, 5-, and 7-year cumulative rates of HCC development were 4.8%, 10.6%, and 13.6%, respectively. Liver fibrosis (cirrhosis; P = 0.0005), age (≥ 49 years; P = 0.0048), platelet count (≤ 115 × 10/mm³ ; P = 0.0007), α-fetoprotein (≥ 8.0 ng/mL; P = 0.030), type IV collagen (≥ 200 ng/mL; P = 0.043), fibrosis-4 index (≥ 4.14; P = 0.0006), and human leukocyte antigen (HLA)-DQA1/DRB1-SNP (AA genotype; P = 0.0092) were significantly associated with HCC development according to the log-rank test. In multivariate analysis, AA genotype in the HLA-DQA1/DRB1 gene (P = 0.013; hazard ratio 4.907; 95% confidence interval 1.407-17.113) and cirrhosis (P = 0.019; hazard ratio 4.789; 95% confidence interval 1.296-17.689) were significantly associated with HCC development.

CONCLUSIONS

Our findings suggested that patients with AA genotype in the HLA-DQA1/DRB1 gene or cirrhosis should be carefully followed up as a population potentially at higher risk of HCC during ETV treatment.

UBE2L3, a susceptibility gene that plays oncogenic role in hepatitis B-related hepatocellular carcinoma

Previously, we identified UBE2L3 as a susceptibility gene for chronic hepatitis B virus (HBV) infection through genome-wide association study. Here, we analysed the association between genetic variants of UBE2L3 and the susceptibility to HBV-related hepatocellular carcinoma (HCC) and further explored its role in HCC. This case-control study included 1344 subjects who cleared HBV, 1560 HBV carriers and 1057 HBV-related HCC patients. Two single nucleotide polymorphisms (SNPs) were genotyped, including rs2266959 and rs4821116. Logistic regression analysis was performed to compute the odds ratio (OR) and 95% confidence interval (CI). We further analysed the expression of UBE2L3 and its association with pathological features based on The Cancer Genome Atlas (TCGA) data and our tissue microarray. Proliferation and migration assays were performed in hepatoma cell lines with or without UBE2L3 knockdown. Further RNA-seq analysis was performed to explore the underlying oncogenic mechanism. The variant genotypes of rs4821116 in UBE2L3 were associated with decreased risk for HCC and chronic HBV infection. Moreover, based on both TCGA and our tissue microarray data, higher levels of UBE2L3 expression were correlated with higher tumour grade, advanced tumour stage and poor survival. In vitro analysis revealed that UBE2L3 may promote hepatocyte proliferation and migration. RNA-seq analysis showed that UBE2L3 was inversely correlated with CDKN2B, a negative regulator of cell cycle, and CLDN1, loss of which may promote cancer metastasis. In conclusion, UBE2L3 may also be a susceptibility gene in HBV-related HCC, and it may promote HCC proliferation and migration by negatively regulating CDKN2B and CLDN1.

Genetic association of complement component 2 variants with chronic hepatitis B in a Korean population

BACKGROUND & AIMS

Numerous single nucleotide polymorphisms associated with an increased risk of liver diseases, chronic hepatitis B and chronic hepatitis B-related hepatocellular carcinoma have been identified. In this study, we scrutinized the genetic effects of C2 variants, which were conflicting in previous results, on the risk of chronic hepatitis B in a Korean population.

METHODS

We genotyped 22 common C2 genetic variants of 977 chronic hepatitis B cases including 302 chronic hepatitis B-related hepatocellular carcinoma cases and 785 population controls. Statistical analysis was performed to examine the effects of genotype on the risk of chronic hepatitis B and chronic hepatitis B-related hepatocellular carcinoma.

RESULTS

Logistic regression analyses showed that six C2 single nucleotide polymorphisms had significant associations with the risk of chronic hepatitis B and chronic hepatitis B-related hepatocellular carcinoma among the Korean subjects. Stepwise analysis revealed that causal markers (rs9267665 and rs10947223) were identified among the C2 variants (stepwise P = 3.32 × 10^-9 and 2.04 × 10^-5 respectively). In further conditional analysis with previous chronic hepatitis B-associated loci, these two single nucleotide polymorphisms were independently associated with the risk of chronic hepatitis B. In addition, we investigated the ability of genetic risk scores combining 12 multi-chronic hepatitis B loci to predict the risk of chronic hepatitis B. Individuals with higher genetic risk scores showed increased risk for chronic hepatitis B.

CONCLUSIONS

Our results suggested that the C2 gene might be a susceptibility locus for chronic hepatitis B in Korean populations. The cumulative genetic effects may contribute to future etiological explanations for chronic hepatitis B.

Human leukocyte antigen gene polymorphisms are associated with systemic inflammation in hepatitis B virus-related hepatocellular carcinoma

Background

Systemic inflammation (SI) is associated with tumor progression and overall survival (OS) in patients with hepatocellular carcinoma (HCC). The presence of some single nucleotide polymorphisms (SNPs) in the human leukocyte antigen (HLA) region can influence the prognosis of patients with hepatitis B virus (HBV)-related HCC, although the mechanism remains unknown. This study aimed to analyze the correlations between HLA gene polymorphisms and SI.

Patients and methods

This study included 330 patients with HCC. The clinical parameters were reviewed, and five SNPs, namely rs2647073, rs3997872, rs3077, rs7453920, and rs7768538, were genotyped using the MassARRAY system.

Results

The rs3997872, rs7453920, and rs7768538 genotypes were found to be significantly associated with OS (P<0.05). The rs7453920 genotype was significantly associated with the neutrophil/lymphocyte ratio (NLR; P=0.001), which was used as an SI index with a threshold determined by receiver operating characteristic analysis. An elevated NLR was also an independent predictor of OS according to univariate and multivariate analyses (P<0.001).

Conclusion

Our data show that HLA gene polymorphisms are associated with SI in patients with HBV-related HCC, and the absence of minor allele A (rs7453920) promotes SI and shortens OS.

Downregulation of miR-200a-3p induced by hepatitis B Virus X (HBx) Protein promotes cell proliferation and invasion in HBV-infection-associated hepatocarcinoma

BACKGROUND

Hepatitis B Virus X (HBx) Protein encoded by HBV is believed to be the major player in the process of HBV-induced oncogenesis. Ectopic expression of miR-200a-3p was reported to be associated with diverse tumorigenesis. This study aimed to better understand the role of miR-200a-3p and its correlation with HBx in HBV-induced hepatocellular carcinoma (HCC).

METHODS

In this report, we examined the gene expression using quantitative RT-PCR and protein expression using Western blotting analysis. Cells were transfected with miR-200a-3p mimics or empty vector, and HBx-carrying vector or empty vector. Cell viability was tested using CCK-8 assay. Wound healing assay was performed to assess cell migration while Transwell assay was performed to evaluate cell invasion.

RESULTS

miR-200a-3p was downregulated in HBV-positive tissue samples compared with HBV-negative tissue samples. This result was further confirmed with HBV-positive and - negative cell lines. HBx protein was overexpressed in HBV-positive cells where expression of miR-200a-3p was significantly suppressed. Increased cell viability, altered cell cycle progression, increased cell migration and invasion occurred in HBx-overexpressed cells compared to its controls. In forced expressed miR-200a-3p cells, cell viability, cell migration and invasion were significantly decreased, and cell cycle status was altered compared to its controls.

CONCLUSIONS

Taken together, pathogenetic function of HBx is negatively correlated with miR-200a-3p in HBV-cased HCC through regulating cell viability, cell cycle arrest, cell migration and cell invasion.

Hepatic inflammation-fibrosis-cancer axis in the rat hepatocellular carcinoma induced by diethylnitrosamine

PURPOSE

Hepatocellular carcinoma (HCC) cases are closely associated with chronic inflammation and fibrosis which is known as hepatic inflammation-fibrosis-cancer (IFC) axis. The aim of this study is to elucidate the development characteristics of the rat HCC model based on IFC axis.

METHODS

The diethylnitrosamine (DEN)-induced rat HCC, which presents a stepwise histopathological progression that is similar to human HCC, was used to analyze the features of the different stages (inflammation, fibrosis, cancer). Rats were injected DEN at a dose of 30 mg/kg body weight twice a week for 11 weeks and the animals were observed until week 20. Time series sera and organ samples from the DEN animal model were collected to evaluate the dynamic changes.

RESULTS

It was found that serum biochemical indicators (AST, ALT, ALP, TP, T-BIL, IL-6, TNF-α) from DEN-treated group were higher than that from control group. Fibrosis-related index in serum and live tissue were increased, respectively, from week 4 after DEN treatment. The expression of TGF-β1 and α-SMA in DEN-treated group was higher than that in control group. JAK2/STAT3 signaling was significantly up-regulated in DEN-treated group compared to that in control group. The histological examination confirmed that the hepatocarcinogenesis model was successfully established, and 100% of the animals in the DEN-exposed group developed liver tumors at 20 weeks. According to the pathological changes, the model characterized resulted in three stages: the inflammation stage (week 2-6), the fibrosis stage (week 8-12), and the HCC stage (week 14-20).

CONCLUSIONS

The results suggested that the HCC development was associated with IFC axis. The serial progression of hepatocarcinogenesis was according to the sequence of hepatic inflammation, fibrosis and then hepatic tumor.

Host genetic variants influencing the clinical course of hepatitis B virus infection

The clinical course of hepatitis B virus (HBV) infection greatly differs in individuals. Various viral, host, and environmental factors influence the natural history of HBV infection. Recent genome-wide association studies identified several host genetic factors influencing the clinical course of HBV infection. Genetic variations in HLA class II loci were significantly associated with susceptibility to persistent HBV infection. Other polymorphisms in or near the genes EHMT2, TCF19, and HLA-C, located near HLA class II loci, and UBE2L3 were also associated with persistent HBV infection. Meanwhile, polymorphisms in KIF1B, GRIK1, and STAT4 were associated with HBV-related hepatocellular carcinoma (HCC). Interestingly, HLA class II genetic variations were strongly associated with not only persistent HBV infection, but also disease progression and HBV-related HCC in chronic hepatitis B. Understanding the various genetic factors associated with the clinical course of HBV infection is essential for personalized treatment and surveillance of disease progression and HCC.