Association of STAT4 polymorphisms with hepatitis B virus infection and clearance in Chinese Han population

Assessment of STAT4 Variants and Risk of Hepatocellular Carcinoma in Latin Americans and Europeans

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. The STAT4 rs7574865 genetic variant has been associated with an increased risk of developing HCC in Asian populations. However, this association has not been studied in Latin America and is poorly assessed in European populations. This case-control study investigated the association between STAT4 rs7574865 and HCC risk in these populations. We evaluated DNA samples from seven medical institutions across six Latin American countries and one Dutch institution in 1060 individuals (344 HCC and 716 controls). STAT4 rs7574865 SNP was genotyped using TaqMan-genotyping assay and analyzed using logistic regression. We found no significant association between the homozygous risk allele (G) of STAT4 and HCC development in either population, with odds ratios (OR) for GG versus TT of 0.85 (CI: 0.48-1.52, p = 0.58) and 0.81 (CI: 0.34-1.93, p = 0.67) for Latin Americans and Europeans respectively. No correlation was found between the risk allele and HCC based on underlying liver disease. However, we found that Latin Americans of European ancestry were more likely to carry the risk allele. Our results suggest that the STAT4 SNP rs7574865 does not influence the risk of developing HCC in Latin American or European populations, highlighting the importance of evaluating genetic risk factors in various ethnic groups and understanding the possible influence of ancestry on the genetic basis of disease.

The effects of the interactions of STAT4 rs7574865 with HBV mutations on the risk of hepatocellular carcinoma

Signal transducer and activator of transcription 4 (STAT4) is closely related to liver diseases and affects the processes of inflammation and carcinogenesis by regulating immune responses. A single-nucleotide polymorphism rs7574865 (T > G) in STAT4 has been reported to be associated with the risk of hepatocellular carcinoma (HCC). In addition, hepatitis B virus (HBV) mutations are crucial risk factors for HBV-induced HCC. However, the effects of the interactions of STAT4 rs7574865 with HBV mutations on the risk of HCC remain unknown. Rs7574865 was genotyped in 846 healthy controls (HCs), 968 chronic hepatitis B (CHB) subjects, 316 liver cirrhosis (LC) subjects and 1021 HCC subjects using Sequenom MassArray. HBV mutations were detected via direct sequencing. Multivariate logistic regression analysis was used to evaluate the effects of the interactions of STAT4 rs7574865 with HBV mutations on the risk of HCC. We found that the rs7574865 TT genotype was significantly associated with HBeAg seroconversion (TT vs. GG, p = 0.012; TT vs. GT, p = 0.033). The rs7574865 GG genotype was significantly associated with increased risks of CHB (p = 0.048), LC (p = 0.005) and HCC (p < 0.001). The interaction term between rs7574865 and HBV C1913A significantly increased the risk of progression from CHB to HCC (p = 0.038), while the interaction term between rs7574865 and HBV T1674C significantly increased the risk of progression from LC to HCC (p = 0.023). STAT4 rs7574865 is significantly associated with the risks of CHB, LC and HCC. The interactions of rs7574865 with HBV C1913A and T1674C mutations significantly increase the risk of HCC, which have the potential to identify HBV-infected individuals who tend to progress from CHB or LC to HCC.

Interferon and Hepatitis B: Current and Future Perspectives

Chronic hepatitis B virus (HBV) infection remains a major health burden worldwide for which there is still no effective curative treatment. Interferon (IFN) consists of a group of cytokines with antiviral activity and immunoregulatory and antitumor effects, that play crucial roles in both innate and adaptive immune responses. IFN-α and its pegylated form have been used for over thirty years to treat chronic hepatitis B (CHB) with advantages of finite treatment duration and sustained virologic response, however, the efficacy is limited and side effects are common. Here, we summarize the status and unique advantages of IFN therapy against CHB, review the mechanisms of IFN-α action and factors affecting IFN response, and discuss the possible improvement of IFN-based therapy and the rationale of combinations with other antiviral agents in seeking an HBV cure.

Immune Response-Related Genes - STAT4, IL8RA and CCR7 Polymorphisms in Lung Cancer: A Case-Control Study in China

Purpose

This study aimed to evaluate the associations between immune response-related genes – STAT4, IL8RA and CCR7 polymorphisms and risk of lung cancer.

Methods

Seven polymorphisms of STAT4, IL8RA and CCR7 were genotyped in 350 cases and 350 controls using a MassARRAY platform.

Results

The STAT4 rs1400656-G and rs7574865-T alleles may decrease the susceptibility to lung cancer (p_rs1400656= 0.020; p_rs7574865= 0.014); while IL8RA rs1008562-C and CCR7 rs3136685-T alleles may increase the risk of disease (p_rs1008562< 0.001; p_rs3136685= 0.018). The STAT4 rs1400656-GA and rs7574865-GT genotypes were determined as protective genotypes against lung cancer risk (p_rs1400656= 0.048; p_rs7574865= 0.042). However, IL8RA rs1008562-CG/GG and CCR7 rs3136685-TT genotypes were significantly associated with an elevated risk of disease (p_rs1008562< 0.0001; p_rs3136685= 0.020). Genetic model analysis revealed that STAT4 rs1400656 and rs7574865 were relate to a declining risk of disease under dominant and log-additive models (rs1400656: p_dominant = 0.014, p_log-additive= 0.016; rs7574865: p_dominant = 0.013, p_log-additive= 0.013). In contrast, IL8RA rs1008562 exhibited a strong correlation with an elevated risk of lung cancer under all three models (p_dominant < 0.0001, p_recessive = 0.011, p_log-additive< 0.0001). Moreover, CCR7 rs3136685 was correlated with an increased risk of disease under recessive and log-additive models (p_recessive = 0.007, p_log-additive= 0.019); and CCR7 rs17708087 was also identified as a risk factor in the dominant model (p = 0.038).

Conclusion

These results widen the scope of knowledge about the association between STAT4, IL8RA and CCR7 polymorphisms and risk of lung cancer.

SNPs in the interleukin-12 signaling pathway are associated with breast cancer risk in Puerto Rican women

Interleukin-12 (IL-12) is a proinflammatory cytokine that links innate and adaptive immune responses against tumor cells. Single Nucleotide Polymorphisms (SNPs) in IL-12 genes have been associated with cancer risk. However, limited studies have assessed the role of IL-12 in breast cancer (BC) risk comprehensively, and these were done in European and Asian populations. Here, we evaluated the association of the IL-12 signaling pathway and BC risk in Puerto Rican women. A genetic association study was completed with 461 BC cases and 463 non-BC controls. By logistic regression, IL-12 signaling SNPs were associated with an increased BC risk, including rs2243123 (IL12A), rs3761041, rs401502 and rs404733 (IL12RB1), rs7849191 (JAK2), rs280500 (TYK2) and rs4274624 (STAT4). Conversely, other SNPs were associated with reduced BC risk including rs438421 (IL12RB1), rs6693065 (IL12RB2), rs10974947, and rs2274471 (JAK2), rs10168266 and rs925847 (STAT4), and rs2069718 (IFNG). Analyses based in hormone receptors such as estrogen (ER) and progesterone (PR) receptors also revealed protective (for SNPs rs3212227-IL12B; rs3024896 and rs3821236-STAT4) and predisposing (for rs2069705-IFNG SNP) BC associations. Haplotype analysis showed a decreased BC risk for IL12B and STAT4 SNPs, whereas increased risk for IL12RB1 SNPs. This study suggests a role of the IL-12 signaling axis and BC risk. SNPs in this pathway may alter IL-12 induced anti-tumor responses and modulate BC predisposition in a population-specific context. Functional studies will be necessary to confirm these findings, which potentially may benefit IL-12 related immunotherapeutic approaches towards BC.

Identification and characterization of SEC24D as a susceptibility gene for hepatitis B virus infection

Single nucleotide polymorphisms (SNPs) and genes associated with susceptibility to hepatitis B virus (HBV) infection that have been identified by genome-wide association studies explain only a limited portion of the known heritability, indicating more genetic variants remain to be discovered. In this study, we adopted a new research strategy to identify more susceptibility genes and variants for HBV infection. We first performed genetic association analysis of 300 sib-pairs and 3,087 case-control samples, which revealed that 36 SNPs located in 31 genes showed nominal associations with HBV infection in both samples. Of these genes, we selected SEC24D for further molecular analysis according to the following two main lines of evidence. First, a time course analysis of the expression profiles from HBV-infected primary human hepatocytes (PHH) demonstrated that SEC24D expression increased markedly as time passed after HBV infection (P = 4.0 × 10⁻⁴). Second, SNP rs76459466 in SEC24D was adversely associated with HBV risk (OR_meta = 0.82; P_meta = 0.002), which again indicated that SEC24D represents a novel susceptibility gene for HBV infection. Moreover, SEC24D appeared to be protective against HBV infection in vitro. Consistently, we found that SEC24D expression was significantly enhanced in non-infected liver tissues (P = 0.002). We conclude that SEC24D is a novel candidate gene linked to susceptibility to HBV infection.

Host Genetic Determinants of Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection is still a major health problem worldwide. Recently, a great number of genetic studies based on single nucleotide polymorphisms (SNPs) and genome-wide association studies have been performed to search for host determinants of the development of chronic HBV infection, clinical outcomes, therapeutic efficacy, and responses to hepatitis B vaccines, with a focus on human leukocyte antigens (HLA), cytokine genes, and toll-like receptors. In addition to SNPs, gene insertions/deletions and copy number variants are associated with infection. However, conflicting results have been obtained. In the present review, we summarize the current state of research on host genetic factors and chronic HBV infection, its clinical type, therapies, and hepatitis B vaccine responses and classify published results according to their reliability. The potential roles of host genetic determinants of chronic HBV infection identified in these studies and their clinical significance are discussed. In particular, HLAs were relevant for HBV infection and pathogenesis. Finally, we highlight the need for additional studies with large sample sizes, well-matched study designs, appropriate statistical methods, and validation in multiple populations to improve the treatment of HBV infection.

Human Genetic Determinants of Viral Diseases

Much progress has been made in the identification of specific human gene variants that contribute to enhanced susceptibility or resistance to viral diseases. Herein we review multiple discoveries made with genome-wide or candidate gene approaches that have revealed significant insights into virus-host interactions. Genetic factors that have been identified include genes encoding virus receptors, receptor-modifying enzymes, and a wide variety of innate and adaptive immunity-related proteins. We discuss a range of pathogenic viruses, including influenza virus, respiratory syncytial virus, human immunodeficiency virus, human T cell leukemia virus, human papilloma virus, hepatitis B and C viruses, herpes simplex virus, norovirus, rotavirus, parvovirus, and Epstein-Barr virus. Understanding the genetic underpinnings that affect infectious disease outcomes should allow tailored treatment and prevention approaches in the future.