Predictive potential of IL-28B genetic testing for interferon based hepatitis C virus therapy in Pakistan: Current scenario and future perspective

In Pakistan which ranked second in terms of hepatitis C virus(HCV) infection, it is highly needed to have an established diagnostic test for antiviral therapy responseprediction. Interleukin 28B(IL-28B) genetic testing is widely used throughout the world for interferon based therapy prediction for HCV patients and is quite helpful not only for health care workers but also for the patients. There is a strong relationship between single nucleotide polymorphisms at or near the IL-28 B gene and the sustained virological response with pegylated interferon plus ribavirin treatment for chronic hepatitis C. Pakistan is a resource limited country, with very low per capita income and there is no proper social security(health insurance) system. The allocated health budget by the government is very low and is used on other health emergencies like polio virus and dengue virus infection. Therefore it is proposed that there should be a well established diagnostic test on the basis of IL-28 B which can predict the antiviral therapy response to strengthen health care set-up of Pakistan. This test once established will help in better management of HCV infected patients.

Clinical relevance of hepatitis B virus variants

The hepatitis B virus(HBV) is a global public health problem with more than 240 million people chronically infected worldwide, who are at risk for end-stage liver disease and hepatocellular carcinoma. There are an estimated 600000 deaths annually from complications of HBV-related liver disease. Antiviral therapy with nucleos/tide analogs(NA) targeting the HBV polymerase(P) can inhibit disease progression by long-term suppression of HBV replication. However, treatment may fail with first generation NA therapy due to the emergence of drugresistant mutants, as well as incomplete medication adherence. The HBV replicates via an error-prone reverse transcriptase leading to quasispecies. Due to overlapping open reading frames mutations within the HBV P can cause concomitant changes in the HBV surface gene(S) and vice versa. HBV quasispecies diversity is associated with response to antiviral therapy, disease severity and long-term clinical outcomes. Specific mutants have been associated with antiviral drug resistance, immune escape, liver fibrosis development and tumorgenesis. An understanding of HBV variants and their clinical relevance may be important for monitoring chronic hepatitis B disease progression and treatment response. In this review, we will discuss HBV molecular virology, mechanism of variant development, and their potential clinical impact.

Host nucleotide polymorphism in hepatitis B virusassociated hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is etiologically linked with hepatitis B virus(HBV) and is the leading cause of death amongst 80% of HBV patients. Among HBV affected patients, genetic factors are also involved in modifying the risk factors of HCC. However, the genetic factors that regulate progression to HCC still remain to be determined. In this review, we discuss several single nucleotide polymorphisms(SNPs) which were reportedly associated with increased or reduced risk of HCC occurrence in patients with chronic HBV infection such as cyclooxygenase(COX)-2 expression specifically at COX-2-1195G/A in Chinese, Turkish and Egyptian populations, tumor necrosis factor α and the three most commonly studied SNPs: PAT-/+, Lys939Gln(A33512C, rs2228001) and Ala499Val(C21151T, rs2228000). In genome-wide association studies, strong associations have also been found at loci 1p36.22, 11q22.3, 6p21(rs1419881, rs3997872, rs7453920 and rs7768538), 8p12(rs2275959 and rs37821974) and 22q11.21. The genes implicated in these studies include HLA-DQB2, HLA-DQA1, TCF19, HLA-C, UBE2L3, LTL, FDX1, MICA, UBE4 B and PG. The SNPs found to be associated with the above-mentioned genes still require validation in association studies in order to be considered good prognostic candidates for HCC. Screening of these polymorphisms is very beneficial in clinical experiments to stratify the higher or lower risk for HCC and may help in designing effective and efficient HCC surveillance programs for chronic HBV-infected patients if further genetic vulnerabilities are detected.

Human genes involved in hepatitis B virus infection

Persistent hepatitis B virus(HBV)infection is a significant public health problem because it is a major cause of chronic liver disease,cirrhosis,and hepatocellular carcinoma(HCC).Roughly one-third of the world population has been infected with HBV and there are about350 million(5%-6%)persistent carriers.HBV causes80%of all liver cancer cases and is the second most important carcinogen,after smoking tobacco.There is an approximate 90%risk of becoming a persistent carrier following perinatal infection in infants born to e antigen positive carrier mothers and a 30%risk in pre-school children.Only 5%-10%of adults become persistent carriers following infection.Of individuals persistently infected with HBV,10%-30%will develop liver cirrhosis and HCC.These highly variable outcomes in both clearance rates and disease outcomes in persistently infected individuals cannot be fully explained by differences in immunological,viral or environmental factors.Thus,differences in host genetic factors may affect the natural history of hepatitis B.

Relationship between interleukin 18 polymorphisms and susceptibility to chronic hepatitis B virus infection

AIM: To identify the relationship between the tagging single nucleotide polymorphism sites (tagSNPs) of the Interleukin-18 (IL-18) gene and genetic susceptibility to chronic hepatitis B virus infection in Chinese patients. METHODS: Five hundred and one cases of chronic hepatitis B virus (HBV) infection and 301 HBV natural clearance controls were studied. Two tagSNPs in the IL-18 gene (rs1946518A/C and rs574424C/G) were genotyped by the Multiplex Snapshot technique. The genotype and allele frequencies were calculated and analyzed. RESULTS: In the genotypes of rs1946518, the AA type was present at a higher frequency in the patients compared to those in the controls. Odds ratio (OR) of the AA genotype for the comparison with that of the AC and the CC genotype was 1.537 (95% confidence intervals (CI): 1.116-2.218, P = 0.009 < 0.025). In phenotypes, the allele C at rs1946518 was of a significantly lower frequency in the patients with chronic hepatitis B than that in the controls (P = 0.017 < 0.025). OR of the allele A for the comparison with that of the allele C was 1.279 (95% CI: 1.045-1.567). As for the rs574424 genotypes, no significant difference in this genotype distribution or in this allele frequency between the patients and the control subjects was observed. No significant difference in the haplotype frequencies between the patients with chronic hepatitis B and HBV natural clearance individuals was displayed. CONCLUSION: The data suggest that genotype AA and the allele A of the IL-18 at position rs1946518 are closely associated with the resistance to chronic hepatitis B and may be the dangerous gene. However, no statistical association was found between polymorphisms of rs574424 for IL-18 and hepatitis B.

Differentially expressed genes in hepatocellular carcinoma induced by woodchuck hepatitis B virus in mice

INTRODUCTIONHepatocellular carcinoma(HCC)is one of the major causes of death in the word.The mechanism of carcinogenesis is unknown,although it is widely accepted that HBV and HCV are clsely related to liver cancer[1-5[1-5].Previously,a variety of studies have described the differences in gene expression which distinguished tumor from nontumor[6-11].Cloning of the genes,especially the genes associated with HBV and HCV,is still very important to account for the development of liver cancer.

No association between IRF3 polymorphism and susceptibility to hepatitis B virus infection in Chinese patients

AIM:To investigate the association between three tag single nucleotide polymorphisms (tagSNPs) in inter-feron regulatory factors (IRF3) and the genetic suscep-tibility to chronic hepatitis B virus (HBV) infection.METHODS:We performed a case-control study of 985 Chinese cases of chronic HBV infection and 294 self-limiting HBV-infected individuals as controls.Three tagSNPs in IRF3 (rs10415576,rs2304204,rs2304206) were genotyped with the Multiplex SNaPshot technique.The genotype and allele frequencies were calculatedand analyzed.RESULTS:The three SNPs showed no significant geno-type/allele associations with chronic HBV infection.Overall allele P values were:rs10415576,P=0.0908,odds ratio (OR) [95% confidence interval (CI)]=1.1798 (0.9740-1.4291);rs2304204,P=0.5959,OR (95% CI)=1.0597 (0.8552-1.3133);rs2304206,P=0.8372,OR (95% CI)=1.0250 (0.8097-1.2976).Overall genotype P values were:rs10415576,P=0.2106;rs2304204,P=0.8458;rs2304206,P=0.8315.There were no statisti-cally significant differences between patients with chron-ic HBV infection and controls.Haplotypes generated by these three SNPs were also not significantly different between the two groups.CONCLUSION:The three tagSNPs of IRF3 are not asso-ciated with HBV infection in the Han Chinese population.

Relationship between interleukin-6 polymorphism and susceptibility to chronic hepatitis B virus infection

AIM:To identify the relationship between tag single nucleotide polymorphisms(tag SNPs) of interleukin-6(IL-6) gene and susceptibility to chronic hepatitis B virus(HBV) infection in a Han Chinese population.METHODS:We performed a case-control study of501 Chinese patients with chronic HBV infection and301 self-limiting HBV-infected individuals as controls.Genomic DNA was isolated from the whole blood of all subjects using phenol/chloroform with MaXtract highdensity tubes. Tag SNPs were identified using genotype data from the panel(Han Chinese in Beijing) of the phase II HapMap Project. Four tag SNPs in IL-6(rs17147230A/T,rs2066992G/T,rs2069837A/G and rs2069852A/G) were genotyped by the Multiplex Snapshot technique. The genotype and allele frequencies were calculated and analyzed.RESULTS:Five haplotypes were involved in the analysis,with frequencies higher than 0.03. One of the haplotypes,TTAA,was significantly different between the two groups. Overall haplotype P values were:ATAA,P = 0.605,OR(95%CI) = 1.056(0.860-1.297); TGAG,P = 0.385,OR(95%CI) = 1.179(0.813-1.709); TGGG,P = 0.549,OR(95%CI) = 1.087(0.827-1.429); TTAA,P = 0.004,OR(95%CI) = 0.655(0.491-0.873); TTAG,P = 0.266,OR(95%CI) = 1.272(0.832-1.944). However,the four SNPs showed no significant genotype/allele associations with susceptibility to chronic HBV infection. Overall allele P values were:rs17147230,P = 0.696,OR(95%CI) = 1.041(0.850-1.276); rs2066992,P = 0.460,OR(95%CI)= 1.090(0.868-1.369); rs2069837,P = 0.898,OR(95%CI) = 0.983(0.759-1.274); rs2069852,P = 0.165,OR(95%CI) = 0.859(0.693-1.064). Overall genotype P values were:rs17147230,P = 0.625; rs2066992,P= 0.500; rs2069837,P = 0.853; and rs2069852,P =0.380.CONCLUSION:The four tag SNPs of IL-6 gene may be associated with susceptibility to chronic HBV infection in the Han Chinese population.

Hepatitis B virus persistent infection-related single nucleotide polymorphisms in HLA regions are associated with viral load in hepatoma families

BACKGROUND Genome-wide association studies from Asia indicate that HLA-DP and HLA-DQ loci are important in persistent hepatitis B virus(HBV)infections.One of the key elements for HBV-related carcinogenesis is persistent viral replication and inflammation.AIM To examine genetic and nongenetic factors with persistent HBV infection and viral load in families with hepatocellular carcinoma(HCC).METHODS The HCC families included 301 hepatitis B surface antigen(HBsAg)carriers and 424 noncarriers born before the nationwide vaccination program was initiated in 1984.Five HBV-related single nucleotide polymorphisms(SNPs)—rs477515,rs9272105,rs9276370,rs7756516,and rs9277535—were genotyped.Factors associated with persistent HBV infection and viral load were analyzed by a generalized estimating equation.RESULTS In the first-stage persistent HBV study,all SNPs except rs9272105 were associated with persistent infection.A significantly higher area under the reciprocal operating characteristic curve for nongenetic factors vs genetic factors(P<0.001)suggests that the former play a major role in persistent HBV infection.In the second-stage viral load study,we added 8 HBsAg carriers born after 1984.The 309 HBsAg carriers were divided into low(n=162)and high viral load(n=147)groups with an HBV DNA cutoff of 105 cps/mL.Sex,relationship to the index case,rs477515,rs9272105,and rs7756516 were associated with viral load.Based on the receiver operating characteristic curve analysis,genetic and nongenetic factors affected viral load equally in the HCC family cohort(P=0.3117).CONCLUSION In these east Asian adults,the mechanism of persistent HBV infection-related SNPs was a prolonged viral replication phase.

Insights into human immunodeficiency virus-hepatitis B virus co-infection in India

Shared routes of transmission lead to frequent human immunodeficiency virus(HIV)-hepatitis B virus(HBV) coinfection in a host which results in about 10% of HIV positive individuals to have chronic hepatitis B infection worldwide. In post-antiretroviral therapy era, liverdiseases have emerged as the leading cause of morbidity and mortality in HIV-infected individuals and HBV coinfection have become the major health issue among this population particularly from the regions with endemic HBV infection. In setting of HIV-HBV co-infection, HIV significantly impacts the natural history of HBV infection, its disease profile and the treatment outcome in negative manner. Moreover, the epidemiological pattern of HBV infection and the diversity in HBV genome(genotypic and phenotypic) are also varied in HIV co-infected subjects as compared to HBV mono-infected individuals. Several reports on the abovementioned issues are available from developed parts of the world as well as from sub-Saharan African countries. In contrast, most of these research areas remained unexplored in India despite having considerable burden of HIV and HBV infections. This review discusses present knowledge from the studies on HIV-HBV co-infection in India and relevant reports from different parts of the world. Issues needed for the future research relevant to HIV-HBV co-infection in India are also highlighted here, including a call for further investigations on this field of study.

Human leukocyte antigen-DP loci are associated with the persistent infection of hepatitis B virus in Chinese population

A genome-wide association study recently showed that genetic variants in human leukocyte antigen (HLA)-DP loci were strongly associated with a risk of persistent infection of hepatitis B virus (HBV) in Japanese and Thai individuals and variants in interleukin 28B (IL-28B) have been associated with responses to anti-hepatitis C virus (HCV) treatment. The aim of this study was to investigate whether the HLA-DP loci and IL-28B were associated with different outcomes of chronic HBV infection (CHB) in Chinese subjects. The rs9277535 near HLA-DPB1,rs3077 near HLA-DPA1, and rs12979860 near IL-28B were genotyped by direct sequencing in 185 CHB patients and 193 self-limited hepatitis B virus (SLHBV)-infected subjects who recovered from HBV infection. The rs9277535 near HLA-DPB1 was strongly associated with CHB (P=0.000 018 1, OR=1.905). This association was observed independent of HBV e antigen (HBeAg) status and HBV viral loads in HBeAg-positive CHB patients (P=0.000 4, OR=1.956), in HBeAg-negative CHB patients (P=0.000 9, OR=1.857), and in HBeAg-negative CHB individuals without detectable levels of HBV DNA in serum (P=0.001 1, OR=2.05). The rs3077 near HLA-DPA1 was associated with CHB (P=0.020 6, OR=0.686 5) and HBeAg-positive CHB infection status (P=0.014 3, OR=0.604 7). Meanwhile, a genetic variation of insertion-deletion (INDEL) polymorphism (rs361527, -/ATAAATGTTGA) near HLA-DPA1 was found to be associated with CHB (P=0.030 7, OR=0.702 8) and HBeAg-positive CHB infection status (P=0.023 3, OR=0.619). However,the rs12979860 genotype near IL-28B had no correlation with CHB. This study demonstrated that in the Han Chinese populations, HLA-DP loci, but not IL-28B, were associated with persistence of infection in different outcomes of HBV-infected patients; however, the mechanism needs to be further investigated.

Clinical, virologic and phylogenetic features of hepatitis B infection in Iranian patients

AIM： To characterize the clinical, serologic and virologic features of hepatitis B virus （HBV） infection in Iranian patients with different stages of liver disease.METHODS： Sixty two patients comprising of 12 inactive carriers, 30 chronic hepatitis patients, 13 patients with liver cirrhosis and 7 patients with hepatocellular carcinoma （HCC） were enrolled in the study. The HBV S, C and basal core promoter （BCP） regions were amplified and sequenced, and the clinical, serologic, phylogenetic and virologic characteristics were investigated.RESULTS： The study group consisted of 16 HBeAgpositive and 46 HBeAg-negative patients. Anti-HBepositive patients were older and had higher levels of ALT, ASL and bilirubin compared to HBeAg-positive patients. Phylogenetic analysis revealed that all patients were infected with genotype D （mostly ayw2）. The G1896A precore （PC） mutant was detected in 58.1% patients. HBeAg-negative patients showed a higher rate of PC mutant compared to HBeAg-positive patients （2,2 = 9.682, P = 0.003）. The majority of patients with HCC were HBeAg-negative and were infected with PC mutant variants. There was no significant difference in the occurrence of BCP mutation between the two groups, while the rate of BCP plus PC mutants was higher in HBeAg-negative patients （2,2 = 4.308, P = 0.04）. In the HBV S region, the genetic variability was low, and the marked substitution was P120T/S, with a rate of 9.7% （n = 6）.CONCLUSION： In conclusion, HBV/D is the predominant genotype in Iran, and the nucleotide variability in the BCP and PC regions may play a role in HBV disease outcome in HBeAg-negative patients.

人类白细胞抗原HLA-A基因多态性与HBV携带的相关性研究

目的探讨人类白细胞抗原(human leukocyte antigen,HLA)基因多态性与乙型肝炎病毒(HBV)感染的相关性。方法收集云南省昆明市延安医院健康体检者静脉血样本501例,采用酶联免疫吸附试验(ELISA)检测HBV二对半,根据HBV二对半检测结果分为HBV携带组和既往感染组以及健康对照组3组,用序列特异性引物聚合酶链反应(polymerase chain reaction with sequence specific primers,PCR-SSP)基因分型技术检测HLA-A抗原的基因型,将HBV携带组和健康对照组以及HBV既往感染组和健康对照组的HLA-A基因多态性的分布频率进行比较。采用SPSS17.0软件进行数据统计分析。结果健康对照组HLA-A2阳性数占比47.49%,等位基因频率数占比31.29%;健康对照组基因分布频率总体与中华骨髓库发布的中国常见及确认的HLA-A等位基因表一致。HBV携带组HLA-A2阳性数占比63.04%,等位基因频率数占比42.23%,携带者的HLA-A2阳性率和等位基因频率差异有统计学意义(P<0.05);HBV既往感染组HLA-A2阳性数占比56.14%,等位基因频率数占比35.97%,既往感染组的HLA-A2阳性率和等位基因频率差异无统计学意义(P>0.05)。结论HLA-A2基因可能是慢性乙型肝炎HBV携带者的易感基因。

2D-QSAR Studies on Anthranilic Acid Derivatives: A Novel Class of Allosteric Inhibitors of Hepatitis C NS5B Polymerase

Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic function approximation （GFA） method of variable selection was used to generate the model. Highly statistically significant model with r^2 = 0.966 and r^2cv = 0.951 was obtained when the number of descriptors in the equation was set to 5. High r^2pred value of 0.884 indicates the good predictive power of the best model. Spatial descriptors of radius of gyration （RadOfGration）, molecular volume （Vm）, length of molecule in the z dimension （Shadow-Zlength）, thermodynamic descriptors of the octanol/water partition coefficient （LogP） and molecular refractivity index （MR） showed enormous contributions to HCV NS5B polymerase inhibition. The validation of the model was done by leave-one-out （LOO） test, randomization tests and external test set prediction. The model gives insight on indispensable structural requirements for the activity and can be used to design more potent analogs against HCV NSSB polymerase.

Conservation and variability of hepatitis B core at different chronic hepatitis stages

BACKGROUND Since it is currently not possible to eradicate hepatitis B virus(HBV)infection with existing treatments,research continues to uncover new therapeutic strategies.HBV core protein,encoded by the HBV core gene(HBC),intervenes in both structural and functional processes,and is a key protein in the HBV life cycle.For this reason,both the protein and the gene could be valuable targets for new therapeutic and diagnostic strategies.Moreover,alterations in the protein sequence could serve as potential markers of disease progression.AIM To detect,by next-generation sequencing,HBC hyper-conserved regions that could potentially be prognostic factors and targets for new therapies.METHODS Thirty-eight of 45 patients with chronic HBV initially selected were included and grouped according to liver disease stage[chronic hepatitis B infection without liver damage(CHB,n=16),liver cirrhosis(LC,n=5),and hepatocellular carcinoma(HCC,n=17)].HBV DNA was extracted from patients’plasma.A region between nucleotide(nt)1863 and 2483,which includes HBC,was amplified and analyzed by next-generation sequencing(Illumina Mi Seq platform).Sequences were genotyped by distance-based discriminant analysis.General and intergroup nt and amino acid(aa)conservation was determined by sliding window analysis.The presence of nt insertion and deletions and/or aa substitutions in the different groups was determined by aligning the sequences with genotype-specific consensus sequences.RESULTS Three nt(nt 1900-1929,2249-2284,2364-2398)and 2 aa(aa 117-120,159-167)hyper-conserved regions were shared by all the clinical groups.All groups showed a similar pattern of conservation,except for five nt regions(nt 1946-1992,2060-2095,2145-2175,2230-2250,2270-2293)and one aa region(aa 140-160),where CHB and LC,respectively,were less conserved(P<0.05).Some group-specific conserved regions were also observed at both nt(2306-2334 in CHB and 1935-1976 and 2402-2435 in LC)and aa(between aa 98-103 in CHB and 28-30 and 51-54 in LC)levels.No differences in insertion and deletions frequencies were observed.An aa substitution(P79 Q)was observed in the HCC group with a median(interquartile range)frequency of 15.82(0-78.88)vs 0(0-0)in the other groups(P<0.05 vs CHB group).CONCLUSION The differentially conserved HBC and HBV core protein regions and the P79 Q substitution could be involved in disease progression.The hyper-conserved regions detected could be targets for future therapeutic and diagnostic strategies.

Genetic and epigenetic alterations in hepatitis B virus-associated hepatocellular carcinoma

Hepatitis B virus(HBV) is a major cause of hepatocellular carcinoma(HCC). Its chronic infection can lead to chronic liver inflammation and the accumulation of genetic alterations to result in the oncogenic transformation of hepatocytes. HBV can also sensitize hepatocytes to oncogenic transformation by causing genetic and epigenetic changes of the host chromosomes. HBV DNA can insert into host chromosomes and recent large-scale whole-genome sequencing studies revealed recurrent HBV DNA integrations sites that may play important roles in the initiation of hepatocellular carcinogenesis. HBV can also cause epigenetic changes by altering the methylation status of cellular DNA, the post-translational modification of histones, and the expression of micro RNAs. These changes can also lead to the eventual hepatocellular transformation. These recent findings on the genetic and epigenetic alterations of the host chromosomes induced by HBV opened a new avenue for the development of novel diagnosis and treatments for HBV-induced HCC.

Interactions of chemical carcinogens and genetic variation in hepatocellular carcinoma

In the etiology of hepatocellular carcinoma (HCC), in addition to hepatitis B virus and hepatitis C virus infections, chemical carcinogens also play important roles. For example, aflatoxin B 1 (AFB 1 ) epoxide reacts with guanine in DNA and can lead to genetic changes. In HCC, the tumor suppressor gene p53 codon 249 mutation is associated with AFB 1 exposure and mutations in the K -ras oncogene are related to vinyl chloride exposure. Numerous genetic alterations accumulate during the process of hepatocarcinogenesis. Chemical carcinogen DNA-adduct formation is the basis for these genetic changes and also a molecular marker which reflects exposure level and biological effects. Metabolism of chemical carcinogens, including their activation and detoxification, also plays a key role in chemical hepatocarcinogenesis. Cytochrome p450 enzymes, N -acetyltransferases and glutathione S -transferases are involved in activating and detoxifying chemical carcinogens. These enzymes are polymorphic and genetic variation influences biological response to chemical carcinogens. This genetic variation has been postulated to influence the variability in risk for HCC observed both within and across populations. Ongoing studies seek to fully understand the mechanisms by which genetic variation in response to chemical carcinogens impacts on HCC risk.

HBV感染DLBCL患者的分子机制及预后研究

近年来乙型肝炎病毒(hepatitis B virus,HBV)感染者患弥漫大B细胞淋巴瘤(diffuse large B cell lymphoma,DLBCL)的概率呈上升趋势,且其病因复杂,治疗棘手,因此受到国内外学者的广泛关注。本文在回顾分析国内外学者研究的基础上,进一步探讨了HBV感染致DLBCL发生、发展的机制及相关患者的临床预后情况,最终发现在基因组、转录组层面,HBV可能主要通过诱导BCL6、FOXO1、ZFP36L1等基因的改变,以及通过HBV的X蛋白激活各种调控基因,从而诱导淋巴细胞克隆性增生,最终形成淋巴瘤;而针对患者的临床预后评估,主要通过分析比较患者发病年龄、性别、脏器受累情况、国际预后指数(IPI)、乳酸脱氢酶(lactate dehydrogenase,LDH)水平、增殖指数(Ki-67)、bcl-2、bcl-6、炎症指标等因素,旨在为DLBCL的临床诊治及基础研究提出理论依据。

958例乙型肝炎患者HBV前C/BCP区变异检测及其意义分析

目的检测不同病情乙型肝炎患者HBV前C/BCP区的变异特点并分析变异的意义。方法采用巢式PCR方法扩增399例轻中度慢性乙型肝炎、211例重度慢性乙型肝炎和348例慢性重型乙型肝炎患者的HBV前C/BCP区序列,PCR产物纯化后直接测序。分析10个热点变异位点及其插入/缺失变异情况,并进行统计学分析,比较这些变异对病情进展的影响。结果随着病情的加重,T1753、A1762、G1764、C1766、T1768、G1862、G1896、G1899等8个位点变异频率显著增加(P<0.01),其中5个位点的变异发生率呈现出轻中度慢性乙型肝炎<重度慢性乙型肝炎<慢性重型乙型肝炎的阶梯式上升特点。3组患者未检出突变的比率分别为27.82%、7.58%和2.01%,呈现阶梯式下降特点。此外,前C/BCP区多联变异和插入/缺失突变的发生率在病情加重时也明显增加(P<0.01),其中三联变异率依次为轻中度慢性乙型肝炎35.34%、重度慢性乙型肝炎53.56%、慢性重型乙型肝炎67.82%。结论乙型肝炎患者HBV前C/BCP区多个位点变异与慢性乙型肝炎的重症化进程相关,对乙型肝炎重症化发生机制的研究及其临床预警分析有积极意义。

HBx蛋白羧基端缺失对肝癌细胞生物学行为的影响

背景与目的:肝癌组织内普遍存在着截短表达的HBx蛋白,这种蛋白可能与肝癌的发生有关,本研究探讨截短表达的HBx蛋白和野生型HBx对人肝癌细胞Huh7生物学行为的影响。方法:脂质体法介导HBx突变体和野生型HBx重组体转染HBV(-)的Huh7细胞。PCR方法扩增Neo基因检测质粒DNA片段插入。通过MTT、平板克隆形成实验、流式细胞仪和裸鼠成瘤实验检测稳定转染细胞的生物学活性。结果:HBx3′-20和HBx3′-40组细胞生长速度较HBx3′-30组明显增快(P<0.05);HBx3′-20组[(17.34±2.77)%]和HBx3′-40组[(18.36±2.61)%]克隆形成率明显较HBx3′-30组[(7.31±1.44)%]和pcDNA3组[(6.87±2.38)%]高(P<0.05)。细胞周期检测结果显示,对比于野生型HBx组,HBx3′-20组和HBx3′-40组蛋白的表达能加速Huh7细胞由G0/G1期到S期的进程[S期:(36.96±1.82)%vs.(46.20±3.23)%,(53.99±4.02)%,P<0.05],相反,HBx3′-10和HBx3′-30组则出现G1期阻滞,而HBx组与pcDNA3空载体组间[(38.60±1.15)%]在S期无明显变化。裸鼠成瘤实验显示,HBx3′-40组[(3.19±0.34)cm3]成瘤体积明显大于HBx3′-30组[(1.58±0.27)cm3]、HBx组[(1.75±0.15)cm3]和pcDNA3组[(1.67±0.12)cm3],各组瘤重存在显著性差异(P<0.01)。结论:对比野生型HBx组,HBx3′-20和HBx3′-40对Huh7细胞的生长具有明显促增殖作用,HBx3′-30组显示出抑制作用。HBx通过缺失突变修饰其生物学功能,在原发性肝癌发生、发展过程中起着重要作用。