methylnitronitrosoguanidine and Ovarian-Neoplasms

Breast cancer, cervical cancer, and ovarian cancer are three of the most commonly diagnosed malignancies in women, and more cancer prevention research is urgently needed.. Summary data of a large genome-wide association study of female cancers were derived from the UK biobank. We performed a transcriptome-wide association study and a gene set enrichment analysis to identify correlations between chemical exposure and aberrant expression, repression, or mutation of genes related to cancer using the Comparative Toxicogenomics Database.. We identified five chemicals (NSC668394, glafenine, methylnitronitrosoguanidine, fenofibrate, and methylparaben) that were associated with the incidence of both breast cancer and cervical cancer.. Using a transcriptome-wide association study and gene set enrichment analysis we identified environmental chemicals that are associated with an increased risk of breast cancer, cervical cancer, and ovarian cancer.

Topics: Breast Neoplasms; Environmental Exposure; Female; Fenofibrate; Gene Expression Profiling; Genome-Wide Association Study; Glafenine; Humans; Incidence; Methylnitronitrosoguanidine; Ovarian Neoplasms; Parabens; Phenols; Quinolones; Uterine Cervical Neoplasms

Poly(ADP-ribose) polymerase (PARP, EC 2.4.2.30) is a nuclear enzyme possibly involved in DNA base excision repair. The presence of single- or double-strand breaks in DNA stimulates this enzyme to covalently modify acceptor proteins with poly(ADP-ribose) in a reaction that uses NAD+ as substrate. To test the hypothesis that increased PARP activity could promote resistance towards DNA-damaging agents and gamma-radiation, we established stable rat cell transfectants that constitutively express human PARP. A number of subclones that showed different levels of PARP activity were isolated from two primary transfectants of different clonal origin. PARP activity was determined in permeabilized cells after maximal stimulation with a short, double-stranded oligonucleotide. Activity in different human PARP-expressing subclones was increased 1.6- to 3.1-fold compared with non-expressing subclones. In vivo labeling of poly(ADP-ribose) was performed in one of these subclones, revealing that the level of poly(ADP-ribose) accumulation after the same treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was four times higher in the human PARP-expressing subclone compared with both non-expressing transfected control cells and parental cells. Clonal survival assays revealed a sensitization upon treatment with gamma-radiation (up to 1.4-fold) or MNNG (up to 2.7-fold) of several subclones expressing human PARP; in some others survival was not changed. Survival after cisplatin (DDP) treatment remained essentially unchanged. A protective effect against DNA-damage was never observed. We conclude that human PARP overexpression in rodent cells leads to increased poly(ADP-ribosyl)ation capacity and does not promote survival after gamma-radiation or treatment with the DNA-damaging agents MNNG or DDP.

Topics: Adenosine Diphosphate Ribose; Animals; Cell Survival; Cisplatin; Female; Humans; Methylnitronitrosoguanidine; Ovarian Neoplasms; Poly(ADP-ribose) Polymerases; Rats; Transfection; Tumor Cells, Cultured

Selection of cells for resistance to cisplatin, a well-recognized mutagen, could result in mutations in genes involved in DNA mismatch repair and thereby to resistance to DNA-alkylating agents. Parental cells of the human ovarian adenocarcinoma cell line 2008 expressed hMLH1 when analyzed with immunoblot. One subline selected for resistance to cisplatin (2008/A) expressed no hMLH1, whereas another (2008/C13*5.25) expressed parental levels. Microsatellite instability was readily demonstrated in 2008/A cells but not in 2008 and in 2008/C13*5.25 cells. In addition, the 2008/A cells were 2-fold resistant to methyl-nitro-nitrosoguanidine and had a 65-fold elevated mutation rate at the HPRT locus as compared to 2008 cells, both of which are consistent with the loss of DNA mismatch repair in these cells. To determine whether the loss of DNA mismatch repair itself contributes to cisplatin resistance, studies were carried out in isogenic pairs of cell lines proficient or defective in this function. HCT116, a human colon cancer cell line deficient in hMLH1 function, was 2-fold resistant to cisplatin when compared to a subline complemented with chromosome 3 and expressing hMLH1. Similarly, the human endometrial cancer cell line HEC59, which expresses no hMSH2, was 2-fold resistant to cisplatin when compared to a subline complemented with chromosome 2 that expresses hMSH2. Therefore, the selection of cells for resistance to cisplatin can result in the loss of DNA mismatch repair, and loss of DNA mismatch repair in turn contributes to resistance to cisplatin.

Topics: Adaptor Proteins, Signal Transducing; Adenocarcinoma; Base Sequence; Carcinogens; Carrier Proteins; Cisplatin; DNA Repair; DNA-Binding Proteins; DNA, Neoplasm; Drug Resistance, Neoplasm; Female; Humans; Hypoxanthine Phosphoribosyltransferase; Immunoblotting; Methylnitronitrosoguanidine; Molecular Sequence Data; Mutation; MutL Protein Homolog 1; MutS Homolog 2 Protein; Neoplasm Proteins; Nuclear Proteins; Ovarian Neoplasms; Proto-Oncogene Proteins; Tumor Cells, Cultured

The phenomenon of alkylation tolerance has been observed in cells that are deficient in some component of the DNA mismatch repair (MMR) system. An alkylation-induced cell cycle arrest had been reported previously in one MMR-proficient cell line, whereas a MMR-defective clone derived from this line escapes from this arrest. We examined human cancer cell lines to determine if the cell cycle arrest were dependent upon the MMR system. Growth characteristics and cell cycle analysis after MNNG treatment were ascertained in seven MMR-deficient and proficient cell lines, with and without confirmed mutations in hMLH1 or hMSH2 by an in vitro transcription/translation assay. MMR-proficient cells underwent growth arrest in the G2 phase of the cell cycle after the first S phase, whereas MMR-deficient cells escaped an initial G2 delay and resumed a normal growth pattern. In the HCT116 line corrected for defective MMR by chromosome 3 transfer, the G2 phase arrest lasted more than five days. In another MMR-proficient colon cancer cell line, SW480, cell death occurred five days after MNNG treatment. A competent MMR system appears to be necessary for G2 arrest or cell death after alkylation damage, and this cell cycle checkpoint may allow the cell to repair damaged DNA, or prevent the replication of mutated DNA by prohibiting clonal expansion.

Topics: Alkylating Agents; Carcinoma; Colonic Neoplasms; DNA Damage; DNA Repair; DNA-Binding Proteins; Female; G2 Phase; Humans; Methylnitronitrosoguanidine; Models, Genetic; MutS Homolog 2 Protein; Neoplasms; Ovarian Neoplasms; Proto-Oncogene Proteins; RNA, Messenger; Sequence Deletion; Stem Cells; Tumor Cells, Cultured

The effects of the poly(ADP-ribose) polymerase inhibitors 4-amino-1,8-naphthalimide (4-ANI), 6(5H)-phenanthridinone (PHD), 1,5-isoquinolinediol (IQD), 3-aminobenzamide (3-AB) or 4-hydroxyquinazoline (4-HYA) on the cytotoxicity of cisplatin were investigated. The human ovarian tumor cell lines SK-OV-3 and OAW 42 and the rat ovarian tumor cell line O-342 as well as its cisplatin (DDP)-resistant subline O-342/DDP were used. Cytotoxicity was determined with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. 1-Methyl-3-nitro-1-nitrosoguanidine (MNNG) plus its respective combinations with poly(ADP-ribose) polymerase inhibitors served as positive controls. In addition, the alkylating agents L-threitol-1,4-bismethanesulfonate (DHB) and 1,3-bis(2-chloroethyl)-1-nitrosourea (carmustine) as well as two other DNA-repair inhibitors caffeine and theophylline were included in the investigations. The cytotoxicity of cisplatin could not be increased by 4-ANI, PHD, IQD, 4-HYA or 3-AB in any cell line investigated, while it was increased by caffeine in lines O-342/DDP and SK-OV-3 as well as by theophylline in lines O-342/DDP, SK-OV-3 and OAW 42. The cytotoxicity of MNNG was increased by combination with 4-ANI, PHD, IQD, 4-HYA, 3-AB or theophylline for all lines except OAW42; in the latter line, only 4-ANI, PHD and IQD increased MNNG cytotoxicity. The cytotoxicity of DHB was increased by 4-ANI, PHD, 4-HYA, theophylline and caffeine in line O-342/DDP; by 4-HYA, theophylline and caffeine in line SK-OV-3; and by theophylline and caffeine in line OAW42. The cytotoxicity of carmustine was increased only by 3-AB in two lines (SK-OV-3 and OAW 42). Results are discussed with regard to different DNA-repair mechanisms.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Carmustine; Cell Survival; Cisplatin; DNA Damage; DNA Repair; Enzyme Inhibitors; Female; Humans; Methylnitronitrosoguanidine; Ovarian Neoplasms; Poly Adenosine Diphosphate Ribose; Rats; Tumor Cells, Cultured

Humans show heterogeneous susceptibility to cancer development, suggesting the involvement of various genetic backgrounds in control of the production of endogenous carcinogens, the metabolism of carcinogens, the repair of DNA damage, cell proliferation and defence mechanisms including immune reactions. Gastric cancer is the major cancer in Japan. However, little is known about the genes linked with its development. In 1967, we found that N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induced gastric cancers in Wistar rats. Subsequently the Buffalo strain of rats was reported to be resistant to MNNG stomach carcinogenesis, while ACI rats were very sensitive. In a carcinogenesis study using F1 and F2 rats, we suggested that this trait of MNNG stomach carcinogenesis-resistance was regulated by a single autosomal dominant allele. The O6-methylguanine adduct levels in gastric mucosa induced by MNNG were the same in Buffalo and ACI rats, but cell proliferation induced by MNNG was much higher in ACI than Buffalo animals. Chromosome mapping of the gene responsible for susceptibility to MNNG-induced carcinogenesis is now in progress and its identification will hopefully give us clues to the involvement of genetic traits in susceptibility to gastric cancer in humans. In addition, the genetic background of susceptibility to breast cancer is also being studied. In Japan, about 5% of all cases of breast cancer are familial. We have studied BRCA1, the breast cancer susceptibility gene, as a determinant of susceptibility to breast cancer by linkage analyses in 11 families, but our results indicate that BRCA1 may not be important for development of familial breast cancer in Japanese.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; BRCA1 Protein; Breast Neoplasms; Female; Gastric Mucosa; Genetic Predisposition to Disease; Humans; Japan; Lod Score; Methylnitronitrosoguanidine; Middle Aged; Neoplasm Proteins; Neoplasms; Ovarian Neoplasms; Polymorphism, Genetic; Rats; Rats, Inbred ACI; Rats, Inbred BUF; Rats, Wistar; Species Specificity; Stomach Neoplasms; Transcription Factors

We have cloned malignant cells carrying specific antigens associated with ovarian cancer (OVC) and malignant lymphoma (ML) from BS-SHI-4M cells, a line derived from a 1-methyl-3-nitro-1-nitrosoguanidine-treated B-lymphoblastoid cell line isolated from a patient with Bloom syndrome. Since BS-SHI-4M cells react with sera from various individual cancer patients at relatively low frequencies (2-9%), as detected by an indirect immunofluorescence technique, cell clones that specifically react with sera from patients with OVC and ML were separated by the "panning" method in which polystyrene dishes were coated with sera from OVC and ML patients and cells with the corresponding antigens bound to the dishes. Subsequent cloning by limiting dilution provided cell clones highly enriched for OVC- and ML-associated antigens. Karyotype analyses revealed that cell clones with OVC and ML antigens had common marker chromosomes, der(14)t(14;14) (p11;q11),t(6;?)(p25;?) and t(9;?)(q34;?), besides t(17;?) (q25;?) found in the OVC-antigen-positive clones and t(5;?) (p13;?),t(7;?)(q36;?) found in the ML-antigen-positive clones. Interestingly, in cell clones with a strong OVC antigen response, the distal part of the Y chromosome (Yq11) was missing in 100% of the cells. Therefore the cell line BS-SHI-4M appears to be a reservoir of cell clones each of which carries a specific tumor antigen and thus provides a potential tool for rapid serological diagnosis of cancer.

Topics: Antigens, Neoplasm; Bloom Syndrome; Cell Line; Chromobox Protein Homolog 5; Clone Cells; DNA, Neoplasm; Female; Genetic Markers; Humans; Karyotyping; Lymphoma; Methylnitronitrosoguanidine; Ovarian Neoplasms