Abstract

The aim of this project is to investigate the mechanisms by which genomic DNA-damage by mutagenic/carcinogenic chemicals inactivates cells (a combination of cell death and reproductive sterilization) and impairs population growth. In this project, study of the mechanisms of cytotoxic effects from damage to DNA are examined because much information is available about the chemical modification of this molecule and the effects of specific lesions on DNA replication and base mispairing (mutation). We will examine three monofunctional chemicals (MNNG, BPDE, and 4-NQO) that produce distinctly different and well-defined damage to DNA, damage that is repaired by different cellular processes and leads to cytotoxic responses of different magnitude. The effects of chemical damage on the dynamics of population growth will be studied in cultured fibroblastic cells from two species, man (NSFL 7010) and mouse (C3H 10T1/2), that appear to represent opposite ends of the spectrum of sensitivity to cytotoxicity from chemically-induced DNA damage. Three general categories of cellular response to DNA injury will be assessed (death, reproductive failure, and slowed or transiently blocked cycle transit) in response to varying chemical doses administered to cells at specific points in synchronous cycle transit. We hypothesize that two major consequences of DNA damage result in qualitively and quantitatively different cytotoxic responses by replication-dependent machanisms: a. prevention of complete replication of the genome is associated with high yields of dead and reproductively sterilized cells when damage is inflicted at any time during S phase and b. inaccurate replication of actively expressed housekeeping genes impairs cell viability by mutation of specific genes or by imparing gene expression and is maximally effective when damage occurs in early S phase. Dynamic changes in cell populations will be assessed with new methods employing flow cytometry and cell sorting, combined with classic techniques.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA024144-07
Application #
3166332
Study Section
Chemical Pathology Study Section (CPA)
Project Start
1978-08-01
Project End
1988-08-31
Budget Start
1985-09-01
Budget End
1986-08-31
Support Year
7
Fiscal Year
1985
Total Cost
Indirect Cost

  Institution

Name
University of North Carolina Chapel Hill
Department
Type
Schools of Medicine
DUNS #
078861598
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599

  Publications

Coleman, W B; Grisham, J W; Smith, G J (1994) Morphologic transformation of the C3H 10T1/2 cell line is accompanied by altered expression of the p53 tumor suppressor gene. Carcinogenesis 15:145-52
Coleman, W B; Throneburg, D B; Grisham, J W et al. (1994) Overexpression of c-K-ras, c-N-ras and transforming growth factor beta co-segregate with tumorigenicity in morphologically transformed C3H 10T1/2 cell lines. Carcinogenesis 15:1005-12
Smith, G J; Bell, W N; Grisham, J W (1993) Clonal analysis of the expression of multiple transformation phenotypes and tumorigenicity by morphologically transformed 10T1/2 cells. Cancer Res 53:500-8
Bakewell, W E; Smith, G J; Miller, B E et al. (1993) Confocal laser scanning immunofluorescence microscopy of the pulmonary surfactant system. Association of surfactant protein A with the nucleus of the alveolar type II cell. Lab Invest 68:566-76
Smith, G J; Bagnell, C R; Bakewell, W E et al. (1991) Application of confocal scanning laser microscopy in experimental pathology. J Electron Microsc Tech 18:38-49
Bakewell, W E; Viviano, C J; Dixon, D et al. (1991) Confocal laser scanning immunofluorescence microscopy of lamellar bodies and pulmonary surfactant protein A in isolated alveolar type II cells. Lab Invest 65:87-95
Dent, G A; Ayscue, L H; High, K A et al. (1989) Flow cytometric correlation of the c-myc oncoprotein and cell cycle kinetics of HL60 leukaemia during induced maturation with cytosine arabinoside and dimethylsulphoxide. Cell Tissue Kinet 22:1-11
Black, K A; McFarland, R D; Grisham, J W et al. (1989) S-phase block and cell death in human lymphoblasts exposed to benzo[a]pyrene diol epoxide or N-acetoxy-2-acetylaminofluorene. Toxicol Appl Pharmacol 97:463-72
Dent, G A; Leglise, M C; Pryzwansky, K B et al. (1989) Simultaneous paired analysis by flow cytometry of surface markers, cytoplasmic antigens, or oncogene expression with DNA content. Cytometry 10:192-8
Black, K A; McFarland, R D; Grisham, J W et al. (1989) Cell cycle perturbation and cell death after exposure of a human lymphoblastoid cell strain to N-methyl-N'-nitro-N-nitrosoguanidine. Am J Pathol 134:53-61

Showing the most recent 10 out of 12 publications