OBJECTIVETo investigate the potential substitution effect of hOGG1 and hMTH1 on oxidative DNA damage, based on gene-deficient cell strains models.

METHODShOGG1 and hMTH1 gene deficient cell strains models were established by Human embryonic lung fibroblasts (HFL) cells. After HFL cells being exposed to 100 µmol/L H₂O₂ for 12 h, HPLC-EC detecting technique and RT-PCR method were adopted to analyze the genetic expression level of 8-oxo-dG (7, 8-dihydro-8-oxoguanine).

RESULTSThe gene-deficient cell strains models of hOGG1 and hMTH1 were obtained by infecting target cells with high titer of lentivirus. The mRNA expression level of hOGG1 was 0.09 ± 0.02, 91% lower than it in normal HFL cells, which was 1.00 ± 0.04. As the same, the mRNA expression level of hMTH1 (0.41 ± 0.04) also decreased by 60% compared with it in normal HFL cells (1.02 ± 0.06). After induced by 100 µmol/L H₂O₂ for 12 h, the genetic expression level of hMTH1 in hOGG1 gene-deficient cells (1.26 ± 0.18) increased 25% compared with it in control group (1.01 ± 0.07). Meanwhile, the genetic expression level of hOGG1 in hMTH1 gene-deficient cells (1.54 ± 0.25) also increased by 52%. The DNA 8-oxo-dG levels in hOGG1 gene-deficient cells (2.48 ± 0.54) was 3.1 times compared with it in the control group (0.80 ± 0.16), the difference showed statistical significance (P < 0.01). Whereas the 8-oxo-dG levels in hMTH1 gene-deficient cells (1.84 ± 0.46) was 2.3 times of it in the control group, the difference also showed statistical significance (P < 0.01).

CONCLUSIONBased on gene-deficient HFL cells models, a synergetic substitution effect on DNA damage and repair activity by both hOGG1 and hMTH1 were firstly discovered when induced by oxidation. The substitution effect of hOGG1 were stronger than that of hMTH1.

Cell Line ; DNA Damage ; DNA Glycosylases ; genetics ; DNA Repair ; DNA Repair Enzymes ; genetics ; Fibroblasts ; metabolism ; Humans ; Oxidative Stress ; genetics ; Phosphoric Monoester Hydrolases ; genetics

DNA Damage ; DNA Glycosylases ; genetics ; metabolism ; DNA Repair Enzymes ; genetics ; metabolism ; Humans ; Phosphoric Monoester Hydrolases ; genetics ; metabolism

OBJECTIVETo construct pEGFP-C1-T vector, an eukaryotic expression plasmid of hMTH1 gene antisense RNA.

METHODSThe conservative region of hMTH1 gene was amplified by RT-PCR after total RNA being extracted from human embryo lung fibroblast (HLF) and then cloned into pGEM-T vector. After the recombinant plasmid was certified by DNA sequencing, the conservative region of hMTH1 gene was inserted into pEGFP-C1 vector reversedly and pEGFP-C1-T vector was constructed. The efficiency of antisense inhibition was verified by Western blotting after cell transfection.

RESULTS423 bp fragment including conservative region of hMTH1 gene was obtained by RT-PCR. After cloned by pGEM-T vector and certified by DNA sequencing, pEGFP-C1-T vector was successfully constructed by means of recombinant DNA technology. Additionally pEGFP-C1-T vector could efficiently decrease hMTH1 protein level by 46%.

CONCLUSIONThe efficient expression vector of hMTH1 gene antisense RNA, pEGFP-C1-T has been constructed successfully.

DNA Repair Enzymes ; Genetic Vectors ; genetics ; Humans ; Phosphoric Monoester Hydrolases ; genetics ; Plasmids ; RNA, Antisense ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction

DNA Methylation ; DNA Modification Methylases ; genetics ; DNA Repair Enzymes ; genetics ; Humans ; Neoplasms ; genetics ; Prognosis ; Promoter Regions, Genetic ; Tumor Suppressor Proteins ; genetics

OBJECTIVETo study hMSH2 genetic polymorphism in southern Chinese Han population.

METHODSThe basic materials and blood samples from 163 southern Chinese were collected. The mutations of exon 6 and exon 7 of hMSH2 gene were investigated by PCR-SSCP, followed by DNA sequencing.

RESULTSFragments of 250 bp including exon 6 and fragments of 323 bp including exon 7 of hMSH2 gene were amplified by multiple PCR. The allele frequencies of C18, A82 and B39 type mutations were 0.0184, 0.0031, 0.0031, respectively. The gene frequencies and gene type frequencies of three polymorphism sites in normal population accorded with Hardy-Weinberg equilibrium (P>0.05). The heterozygosity of C18 type mutation (0.0361) was the highest.

CONCLUSIONThere were three polymorphism sites in exon 7 of hMSH2 gene in southern Chinese Han population, among which the genotype frequency of C18 type was the highest, suggesting that C18 type mutation be a useful genetic mark.

Asian Continental Ancestry Group ; genetics ; Base Pair Mismatch ; DNA Ligase ATP ; DNA Ligases ; genetics ; DNA Mismatch Repair ; genetics ; physiology ; DNA Repair Enzymes ; genetics ; Exons ; genetics ; Female ; Humans ; Male ; Microsatellite Repeats ; genetics ; Middle Aged ; Polymorphism, Genetic

OBJECTIVETo investigate the association between ERCC6 gene polymorphisms and peripheral blood lymphocyte DNA damage among the workers in coking plant.

METHODSBy cluster sampling, 379 coke oven workers having worked for 8 hours were included in the exposure group, 398 coke oven workers having rested for more than 16 hours were included in the recovery group, and 398 workers having never been exposed to polycyclic aromatic hydrocarbons (PAHs) in the same plant were included in the control group. Lymphocytes were separated from their peripheral venous blood, and single cell gel electrophoresis was used to evaluate DNA damage; TaqMan-MGB probes were used to analyze ERCC6 gene polymorphisms. PHASE 2.0.2 genetic analysis software was used to calculate the haplotypes.

RESULTSThe Olive tail moment (OTM) of lymphocytes in the exposure group was significantly higher than those in the recovery group and control group (-0.86±0.70 vs -1.14±0.68 and -1.13±0.65, P < 0.05). In the exposure group, for workers ≥37 years old, the OTM of lymphocytes in workers carrying CG+GG genotype at rs3793784 locus of ERCC6 gene was significantly lower than that in workers carrying CC genotype (P < 0.05); the OTM of lymphocytes in workers <37years old carrying CC genotype at rs3793784 locus of ERCC6 gene was significantly lower than that in workers ≥37 years old carrying CC genotype (P < 0.05); the OTMof lymphocytes in workers <37 years old carrying CG+GG genotype at rs3793784 locus of ERCC6 gene was significantly higher than that in workers ≥37 years old carrying CG+GG genotype (P < 0.05). For patients with internal exposure, in the 1-hydroxypyrene >4.36 ümol/L group, the OTM of lymphocytes in workers carrying AG+GG genotype was significantly higher than that in workers carrying AA genotype (P < 0.05).

CONCLUSIONDifferent genotypes of ERCC6 gene rs3793784 in peripheral blood lymphocytes of coke oven workers exposed to PAHs have different functions at different ages, suggesting that genotype may interact with age in population exposed to PAHs.

Adult ; Coke ; DNA Damage ; DNA Helicases ; genetics ; DNA Repair Enzymes ; genetics ; Genotype ; Humans ; Lymphocytes ; Middle Aged ; Occupational Exposure ; adverse effects ; Poly-ADP-Ribose Binding Proteins ; Polymorphism, Single Nucleotide

OBJECTIVETo investigate the association of polymorphisms of nucleotide excision repair genes and chromosomal damage in peripheral blood lymphocytes among coke-oven workers.

METHODSThe genotypes of ERCC1 C19007T, ERCC2 C22541A, ERCC2 G23591A, ERCC2 A35931C, ERCC4 T30028C, ERCC5 G3507C and ERCC6 A3368G among 140 coke-oven workers and 66 non-coke-oven controls were determined by PCR-PFLP methods. Chromosomal damage was detected by cytokinesis-block micronucleus (CBMN) assay.

RESULTSMultivariate analysis of covariance revealed that in coke-oven workers, the ERCC1 19007 CC genotype exhibited significantly higher CBMN frequency [(1.05 +/- 0.68)%] than did the CT [(0.81 +/- 0.66)%] (P = 0.01) or TT [(0.66 +/- 0.37)%] (P = 0.05) or CT + TT genotypes [(0.75 +/- 0.63)%] (P = 0.004). For the ERCC6 A3368G polymorphism, AA genotype exhibited significantly higher CBMN frequency [(1.00 +/- 0.69)%] than did the AG [(0.67 +/- 0.42)%] (P = 0.05) or AG + GG genotypes [(0.66 +/- 0.41)%] (P = 0.02). Stratification analysis found the significant association between the two polymorphisms, ERCC1 C19007T and ERCC6 A3368G, and the CBMN frequencies were most pronounced in older workers. In addition, for the polymorphism of ERCC2 G23591A, GA carriers had significantly higher CBMN frequencies [(1.40 +/- 0.63)%] than those GG carriers [(0.98 +/- 0.59)%] (P = 0.01) in older workers.

CONCLUSIONSOur results suggested that polymorphisms of ERCC1 C19007T, ERCC6 A3368G and ERCC2 G23591A were associated with the CBMN frequencies in coke-oven workers.

Adult ; Alcohol Drinking ; Coke ; Comet Assay ; DNA Damage ; DNA Repair ; genetics ; DNA Repair Enzymes ; genetics ; Dihydroxydihydrobenzopyrenes ; urine ; Extraction and Processing Industry ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; Genotype ; Humans ; Lymphocytes ; Male ; Micronucleus Tests ; Middle Aged ; Occupational Exposure ; analysis ; Polymorphism, Genetic ; Smoking

OBJECTIVETo explore the molecular biological mechanism of acupuncture and moxibustion for relieving myelosuppression and increasing white blood cells.

METHODSTwo hundred and twenty-four clean male Kunming mice were randomly divided into a control group, a model group, an acupuncture group and a moxibustion group, 56 mice in each group. The model of myelosuppression was made with Cyclophosphamide. In the acupuncture group and the moxibustion group, acupoints "Dazhui" (GV 14), "Geshu" (BL 17), "Shenshu" (BL 23) and "Zusanli" (ST 36) were used for treatment with acupuncture and moxibustion, respectively, while, in the control group and the model group, there were no treatment carried out except catching and fixing. The changes of bone marrow cell DNA pol beta and XPD between the 2nd and 7th day were examined with immunohistochemical method.

RESULTSAcupuncture and moxibustion markedly up-regulated the expression of bone marrow cell DNA pol beta and XPD, and promoted the base excision repair and nucleotide excision repair, which leads to the relieving Cyclophosphamide-induced myelosuppression and increasing the number of white blood cells.

CONCLUSIONFor acupuncture and moxibustion, one of the bone major mechanisms in relieving post-chemotherapy myelosuppression, protecting hemopoietic function and increasing the white blood cells is that it can promote the repair of the bone marrow cell DNA excision and protect hemopoietic cells from injury by chemical drugs.

Acupuncture Therapy ; Animals ; Bone Marrow Cells ; enzymology ; Cyclophosphamide ; pharmacology ; DNA Damage ; drug effects ; DNA Repair ; DNA Repair Enzymes ; genetics ; metabolism ; Gene Expression ; drug effects ; Male ; Mice ; Moxibustion ; Random Allocation

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adenosine Triphosphatases ; genetics ; metabolism ; DNA Mismatch Repair ; DNA Repair Enzymes ; genetics ; metabolism ; DNA-Binding Proteins ; genetics ; metabolism ; Endometrial Neoplasms ; etiology ; genetics ; metabolism ; pathology ; Female ; Genetic Predisposition to Disease ; Humans ; Lynch Syndrome II ; complications ; genetics ; metabolism ; pathology ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; genetics ; metabolism ; Mutation ; Nuclear Proteins ; genetics ; metabolism

Lentiviral vectors were powerful gene delivery tools for gene therapy. We developed a new lentiviral vector pBobi-MIL that constitutively expressed O6-methylguanine-DNAmethyltransferase (MGMT) and Luciferase, linked by the internal ribosomal entry site (IRES), to realize drug tolerance and real time monitoring in vivo. All results from RT-PCR, drug treating clones forming, immunofluorometric assay and chemiluminescence detection showed that cells infected by recombinant lentivirus L-MIL simultaneously expressed these two genes. This lays the foundation for the further research in gene therapy and can also help identify lentivirus titer.
DNA Modification Methylases ; biosynthesis ; genetics ; DNA Repair Enzymes ; biosynthesis ; genetics ; Drug Resistance ; genetics ; Genetic Therapy ; methods ; Genetic Vectors ; genetics ; Humans ; Lentivirus ; genetics ; metabolism ; Luciferases ; biosynthesis ; genetics ; Tumor Suppressor Proteins ; biosynthesis ; genetics