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

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

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

OBJECTIVE: To explore the correlation between histone H3-K9 methylation, DNA methylation and expression of carcinoma suppressor gene MGMT in laryngeal carcinoma Hep-2 cell line. METHOD: 5-Aza-dC was used to deal with Hep-2 cell cultured in vitro. ChIP, MSP and Realtime-PCR were used to detect H3-K9 methylation, DNA methylation, of MGMT gene promoter region and MGMT gene expression before and after treatment with drugs. RESULT: (1) In Hep-2 cell line, gene MGMT was characterized by DNA methylation and histone H3-K9 hypermethylation. (2) 5-Aza-dC was able to reduce H3-K9 methylation of MGMT gene histone in Hep-2 cell line, 5-Aza-dC was able to reverse DNA methylation of MGMT gene histone in Hep-2 cell line, 5-Aza-dC was able to upregulate the down-regulated gene expression of tumor suppressor genes MGMT. CONCLUSION Promoter methylation of cancer suppressor gene MGMT may induce the gene inactivity. DNA methylation may increase H3-K9 methylation. 5-Aza-dC can reduce H3-K9 methylation of tumor suppressor gene MGMT histone by reversing DNA methylation of tumor suppressor gene MGMT, and then the expression of tumor suppressor genes is increased and tumor development is inhibited.
Cell Line, Tumor ; DNA Methylation ; DNA Modification Methylases ; genetics ; metabolism ; DNA Repair Enzymes ; genetics ; metabolism ; Genes, Tumor Suppressor ; Histones ; metabolism ; Humans ; Laryngeal Neoplasms ; genetics ; metabolism ; pathology ; Tumor Suppressor Proteins ; genetics ; metabolism

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

To determine whether family history of cancer may be a risk factor for the mutator phenotype in colorectal cancer, we recruited 143 consecutive colorectal cancer patients with a family history of accompanying cancers not meeting the Amsterdam criteria. Microsatellite instability (MSI) at 5 markers, hMLH1-promoter methylation, and expression of mismatch repair (MMR) proteins (hMLH1, hMSH2, hMSH6, hMPS1, and hPMS2) were determined. Among the relatives of familial colorectal cancer patients, colorectal cancer was the most common tumor type. Of the proband colorectal cancers, 26 (18.2%) showed high-level MSI (MSI-H); 47 additional tumors with mutator phenotype (32.9%) were identified by hMLH1-promoter methylation and/or loss of MMR protein expression. Mutator phenotype was associated with right-sided colon cancer and the type of accompanying cancer. Family history, which was differentially quantified according to the degree of relatives and the type of accompanying cancers, effectively discriminated MSI-H from microsatellite stable (MSS) and low-level microsatellite instability (MSI-L) and mutator phenotypes. Our findings indicate that familial colorectal cancer may be associated with multiple occurrences of colorectal or accompanying cancers and that family history could be correlated with microsatellite instability.
Adaptor Proteins, Signal Transducing/genetics/metabolism ; Adenosine Triphosphatases/metabolism ; Adult ; Aged ; Aged, 80 and over ; Base Sequence ; Colorectal Neoplasms/*genetics/metabolism/pathology ; DNA Methylation ; DNA Mismatch Repair ; DNA Repair Enzymes/metabolism ; DNA, Neoplasm/genetics ; DNA-Binding Proteins/metabolism ; Female ; Humans ; Male ; *Microsatellite Instability ; Middle Aged ; MutS Homolog 2 Protein/metabolism ; Neoplasm Proteins/metabolism ; Nuclear Proteins/genetics/metabolism ; Phenotype ; Promoter Regions, Genetic ; Risk Factors

OBJECTIVETo investigate the expression of DNA mismatch repair (MMR) genes (MLH1, MSH2, MSH6 and PMS2) in endometrial adenocarcinoma (EC) of patients under 50 years and to explore the relationship between MMR expression and clinicopathological features including body mass index (BMI), histological grade and pathological stage of EC.

METHODSMMR gene expression was investigated by immunohistochemical S-P method in endometrial adenocarcinomas of patients under age of 50. The control groups included complexity atypical hyperplasia endometrium (CAHE), simple hyperplasia endometrium (SHE), normal endometrium (NE) of patients under age of 50 and EC of patients older than 65 years.

RESULTSTwenty seven of 40 EC (67.5%) lost at least one MMR protein expression. Loss of at least one MMR protein expression was seen in 5/15 cases of CAHE, 1/13 SHE and 1/11 NE, respectively (P < 0.01). The rates of loss of expression of MLH1, MSH2, MSH and PMS2 proteins in EC were 52.5%, 12.5%, 35.0%, and 30.0%, respectively. The difference between MLH1 and MSH6 expression among the four groups were significant (P < 0.05), but the expression of MSH2 showed no significant difference among the groups (P = 0.295). The expression of MMR protein had no relationship with histological grade and pathological stage, although loss of MSH6 was more frequently seen in patients of higher BMI.

CONCLUSIONSAbnormal expression of MMR proteins is correlated with the development of EC from complex atypical hyperplasia. With the exception of the correlation of MSH6 expression with higher BMI, the expression of MMR proteins in EC has no significant relationship with histological grade and pathological stage.

Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma ; genetics ; metabolism ; pathology ; Adenosine Triphosphatases ; metabolism ; Adult ; Body Mass Index ; DNA Mismatch Repair ; DNA Repair Enzymes ; metabolism ; DNA-Binding Proteins ; metabolism ; Endometrial Neoplasms ; genetics ; metabolism ; pathology ; Female ; Humans ; Immunohistochemistry ; Middle Aged ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Neoplasm Grading ; Neoplasm Staging ; Nuclear Proteins ; 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

OBJECTIVETo observe the effects of Dujieqing Oral Liquid (DJQ) on the promoter methylation of the O6-methylguanine-DNA methyltransferase (MGMT) gene in the plasma DNA samples from middle-and-late stage tumor patients receiving chemotherapy.

METHODSRecruited 60 patients were randomly assigned to the treatment group (treated by conventional chemotherapy combined DJQ, 20 mL each time, three times daily) and the control group (treated by chemotherapy alone), 30 in each group. The therapeutic course was 8 weeks. The promoter methylation of the MGMT gene in the plasma DNA samples form middle-and-late stage tumor patients receiving chemotherapy was detected before and after treatment using nested methylation-specific polymerase chain reaction (MSP). Meanwhile, the peripheral hemogram was detected. The clinical efficacy and toxic/adverse reactions were assessed using Karnofsky performance scale (KPS).

RESULTSResults of the promoter methylation of MGMT genes showed that methylation rate was 20.00% in the treatment group and 46.67% in the control group (P<0.05). Compared with before treatment, the KPS was significantly improved in the treatment group after treatment, while it significantly decreased in the control group after treatment (both P<0.05). There was statistical difference in the KPS between the two groups after treatment (P<0.01). The toxic/adverse reactions were milder in the treatment group than in the control group (P<0.01).

CONCLUSIONSDJQ showed efficiency synergism and toxicity reducing effects, but with no effect on the hematopoietic function of the bone marrow. MGMT gene was indicated as DJQ's target point for efficiency synergism and toxicity reducing. The efficiency synergism and toxicity reducing effects were achieved by regulating the activities of MGMT gene.

Adult ; Aged ; DNA Methylation ; DNA Modification Methylases ; genetics ; DNA Repair Enzymes ; genetics ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Humans ; Male ; Middle Aged ; Neoplasm Staging ; Neoplasms ; genetics ; metabolism ; pathology ; Promoter Regions, Genetic ; Tumor Suppressor Proteins ; genetics

Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma, Clear Cell ; genetics ; metabolism ; pathology ; surgery ; Adenosine Triphosphatases ; metabolism ; Age Factors ; Carcinoma, Endometrioid ; genetics ; metabolism ; pathology ; surgery ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; metabolism ; pathology ; surgery ; Cystadenocarcinoma, Serous ; genetics ; metabolism ; pathology ; surgery ; DNA Mismatch Repair ; DNA Repair Enzymes ; metabolism ; DNA-Binding Proteins ; metabolism ; Endometrial Neoplasms ; genetics ; metabolism ; pathology ; surgery ; Female ; Humans ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Neoplasms, Multiple Primary ; genetics ; metabolism ; pathology ; surgery ; Nuclear Proteins ; metabolism