敲除H2-eb1基因建立的变应性鼻炎模型小鼠

背景:HLA-DRB1与变应性鼻炎发病发病有关,构建HLA-DRB1基因敲除动物模型,不仅为阐明变应性鼻炎发病机制、同时也为相关疾病发病机制的阐明提供了良好的途径,然而未查阅到利用H2-eb1基因敲除小鼠进行相关研究的报道。目的:构建HLA-DRB1基因敲除动物模型。方法:经杂合子小鼠近亲繁殖,获得纯合子、野生型和杂合子小鼠。经基因及蛋白鉴定确认,采用随机数字表法选取8周龄雌性野生型(H2-eb1+/+)小鼠12只和H2-eb1-/-小鼠12只,将12只H2-eb1+/+小鼠和12只H2-eb1-/-小鼠以卵清蛋白致敏激发,建立小鼠变应性鼻炎模型。将另12只H2-eb1+/+小鼠以PBS代替卵清蛋白激发作为对照。结果与结论:与对照小鼠相比,变应性鼻炎模型小鼠血清中卵清蛋白IgE、白细胞介素4水平明显升高,γ-干扰素水平明显降低;而与基因敲除野生型小鼠(H2-eb1+/+)相比,基因敲除H2-eb1-/-变应性鼻炎小鼠IgE、白细胞介素4水平较低,γ-干扰素水平较高。提示H2-eb1基因在变应性鼻炎的发病机制中的Th1/Th2失衡有重要调节作用。

Ku80 gene G-1401T promoter polymorphism and risk of gastric cancer

AIM:To evaluate the possible relationship between the Ku80 gene polymorphism and the risk of gastric cancer in China.METHODS:In this hospital-based case-control study of gastric cancer in Jiangsu Province,China,we investigated the association of the Ku80 G-1401T (rs828907) polymorphism with gastric cancer risk.A total of 241 patients with gastric cancer and 273 age-and sexmatched control subjects were genotyped and analyzed by polymerase chain reaction-restriction fragment length polymorphism.RESULTS:The frequencies of genotypes GG,GT and TT were 65.6%,22.8% and 11.6% in gastric cancer cases,respectively,and 75.8%,17.6% and 6.6% in controls,respectively.There were significant differences between gastric cancer and control groups in the distribution of their genotypes (P=0.03) and allelic frequencies (P=0.002) in the Ku80 promoter G-1401T polymorphism.CONCLUSION:The T allele of Ku80 G-1401T may be associated with the development of gastric cancer.

Function of nonstructural 5A protein of genotype 2a in replication and infection of HCV with gene substitution

AIM:To explore the function of Nonstructural 5A(NS5A) protein of genotype 2a(JFH1)in the replication and infection of hepatitis C virus(HCV).METHODS:Intergenotypic chimera FL-J6JFH/J4NS5A was constructed by inserting NS5A gene from 1b stain HC-J4 by the overlapping polymerase chain reaction (PCR)method and the restriction enzyme reaction.In vitro RNA transcripts of chimera,prototype J6JFH and negative control J6JFH1(GND)were prepared and transfected into Huh-7.5 cells with liposomes.Immunofluorescence assay(IFA),fluorescence quantitative PCR and infection assay were performed to determine the protein expression and gene replication in Huh-7.5 cells.RESULTS:The HCV RNA levels in FL-J6JFH/J4NS5A chimera RNA transfected cells were significantly lower than the wild type at any indicated time point(2.58 ±5.97×106 vs 4.27±1.72×104,P=0.032).The maximal level of HCV RNA in chimera was 5.6±1.8× 104 GE/μg RNA at day 34 after transfection,while the wild type reached a peak level at day 13 which was 126 folds higher(70.65±14.11×105 vs 0.56±0.90 ×105,P=0.028).HCV proteins could also be detected by IFA in chimera-transfected cells with an obviously low level.Infection assay showed that FL-J6JFH/J4NS5A chimera could produce infectious virus particles,ranging from 10±5 ffu/mL to 78.3±23.6 ffu/mL,while that of FL-J6JFH1 ranged from 5.8±1.5×102 ffu/mL to 2.5±1.4×104 ffu/mL.CONCLUSION:JFH1 NS5A might play an important role in the robust replication of J6JFH1.The establishment of FL-J6JFH/J4NS5A provided a useful platform for studying the function of other proteins of HCV.

A single nucleotide polymorphism in XRCC4 gene is associated with reduced colorectal cancer susceptibility in female

Objective： To investigate the association of XRCC4 polymorphic variants at G-1394T （rs6869366） with colorectal cancer susceptibility. Methods： In this hospital-based case-control study, the association of XRCC4 polymorphism with colorectal cancer risk in Chinese population was investigated. In total, 171 patients with colorectal cancer and 171 healthy individuals matched for age and gender were selected. The genomic DNAs of the patients and controls were extracted from peripheral blood and the 300 bp target DNA was amplified with Polymerase Chain Reaction. The products were then digested with restriction endonuclease HinclI, followed by agarose electrophoresis to identify the genotype. Results： We found a significant difference in the frequency of the XRCC4 G-1394T genotype between the colorectal cancer and control groups in female （1/127 vs 8/122, P〈0.05）. Those with G/T at XRCC4 G-1394T showed a decreased risk of colorectal cancer susceptibility compared with those with T/T （OR 0.113, 95%CI 0.014-0.932）. However, in overall population or in male, there was no significant difference of the distribution between the colorectal cancer and control groups. Conclusion： Our findings with decreased risk of colorectal cancer susceptibility suggested that the G allele of XRCC4 G-1394T were associated in female.

Viral Genotypes and Associated Risk Factors of Hepatocellular Carcinoma in India

Objective This study aims to investigate the etiological relationship among hepatitis B virus （HBV）, hepatitis C virus （HCV）, and alcohol as risk factors in a cohort of hepatocellular carcinoma （HCC） patients from India. The clinical and biochemical profiles and tumor characteristics in the HCC cases were also evaluated. Methods A total of 357 consecutive cases of HCC fulfilling the diagnostic criteria from the Barcelona-2000 EASL conference were included in the study. The blood samples were evaluated for serological evidence of HBV and HCV infection, viral load, and genotypes using serological tests, reverse transcription-polymerase chain reaction, and restriction fragment length polymorphism. Results The male/female ratio for the HCC cases was 5.87：1. Majority of the HCC patients （33.9%） were 50 to 59 years of age, with a mean age of 4±13.23 years. More than half the cases （60.8%） had underlying cirrhosis at presentation. Among the HCC patients, 68.9% were HBV related, 21.3% were HCV related, 18.8%, were alcoholic, and 18.2% were of cryptogenic origin. The presence of any marker positive for HBV increased the risk for developing HCC by almost 27 times [OR： 27.33; （12.87-60.0）]. An increased risk of 10.6 times was observed for HCC development for cases positive for ally HCV marker [OR： 10.55; （3.13-42.73）]. Heavy alcohol consumption along with HCV RNA positivity in cirrhotic patients was found to be a risk for developing HCC by 3 folds ]OR： 3.17; （0.37-70.71）]. Conclusions Patients of chronic HBV infection followed by chronic HCV infection were at higher risk of developing HCC in India. Chronic alcohol consumption was found to be a risk factor in cirrhotic cases only when it was associated with HCV RNA positivity. Most of the patients had a large tumor size （〉5 cm） with multiple liver nodules, indicating an advanced stage of the disease thus making curative therapies difficult.

Infrequent microsatellite instability mutator phenotype in Chinese hepatocellular carcinomas

Objective: In order to elucidate the molecular mechanisms that might be responsible for hepatocarcinogenesis, we examined microsatellite instability (MSI), mismatch repair gene hMLH1 mutation and methylation in hepatocellular carcinoma. Methods: Fifty-two cases of surgically resected sporadic hepatocellular carcinoma (HCC) were studied. hMLH1 mutation was examined by two-dimensional electrophoresis and DNA sequencing; hMLH1 methylation was determined by methylation-specific PCR(MSP); and MSI at BAT26 was analyzed by PCR-based methods. Results: MSI at BAT26 was found in 3 of 52 cases (5.8%) of the tumors analyzed. No hMLH1 mutation or hypermethylation was found in these 52 cancerous tissues. No correlation existed between MSI and clinico-pathological characteristics of the patients. Conclusion: Our results suggest that MSI at BAT26 is rarely associated with carcinogenesis of chinese HCC. The genesis of sporadic HCC may occur in an alternative pathway that is probably different from MSI pathway.

Relationship of large multifunctional proteasome 7 gene polymorphism with susceptibility to type 1 diabetes mellitus and DR3 gene

Objective To study the relationship of the large multifunctional proteasome 7 (LMP7) gene polymorphism with susceptibility to type 1 diabetes mellitus (DM-1) and the DR3 gene in south Chinese Han population.Methods LMP7 genotypes and the DR3 gene were identified in 71 DM-1 patients and 86 healthy persons (as controls) by polymerase chain reaction-restriction fragment length polymorphism. DM-1 patients and controls were divided into DR3-positive and DR3-negative subjects. The frequencies of LMP7 genotypes and alleles were compared between DM-1 patients and controls respectively in the random subjects and in the DR3-matched subjects. Furthermore, DM-1 patients were divided into 3 groups according to the age of diabetic onset: group A≤14 years, group B 15-30 years, group C≥31 years.Results In the random subjects, the frequency of LMP7-B/B was lower (39% vs 58%, P<0.05) and that of LMP7-B/A was higher (54% vs 31%, P<0.01) in DM-1 patients than that in controls. In DR3-positive subjects, the frequencies of LMP7 genotypes and alleles showed no differences between DM-1 patients and controls. In DR3-negative subjects, the frequency of LMP7-B/B was decreased (40% vs 61%) and that of LMP7-B/A was increased (55% vs 28%, P<0.01) in DM-1 patients. The frequencies of LMP7 genotypes and alleles showed no significant differences among different ages of diabetic onset.Conclusions LMP7-B/B may be the protective genotype, and LMP7-B/A may be the susceptible genotype of DM-1, and this may not be affected by the DR3 gene. Persons with LMP7-B/B may have a decreased risk, and those with LMP7-B/A have an increased risk suffering from DM-1. The LMP7 gene may not be associated with the age of diabetic onset.