Neoplastic transformation of golden Syrian hamster embryo cells by /sup 3/H thymidine exposure

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6145636

Lin, S L

Incorporation of (methyl-/sup 3/H)thymidine, to cause specific nuclear/DNA damage, induces somatic mutation and neoplastic transformation. Normal diploid golden Syrian hamster embryo (GSHE) fibroblasts were exposed to (methyl-/sup 3/H)thymidine for 17 h, followed by a brief chase with deoxycytidine- and thymidine-containing growth medium. Analysis of cell killing curves suggested a multihit mechanism with D/sub q/ and D/sub 0/ equal to 0.01 ..mu..Ci/ml and 0.04 ..mu..Ci/ml respectively. Transformation studies demonstrate that expression of specific neoplastic phenotypes occurs at different post-treatment population doublings (PTPDs) beginning with morphological alteration (PTPD 3-4), followed by enhanced fibrinolytic activity (PTPD 11-16) and abilities to clone in medium containing 1% serum (PTPD 18-32) and soft agar (PTPD 25-32). All treated lines displayed tumorigenicity, when examined at PTPD 46, whereas control cultures did not. Incorporation of identical tritium doses using (5./sup 3/H) uridine did not significantly enhance somatic mutation or induce morphological transformation. It is concluded that the neoplastic transformation of GSHE fibroblasts by /sup 3/H-thymidine results specifically from DNA damage and that the transformation process reflects a gradual, rather than sudden, loss of growth control.

• OSTI ID: 6145636
• Country of Publication: United States
• Language: English

Related Subjects

550300 -- Cytology
560122* -- Radiation Effects on Cells-- Internal Source-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
AZINES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CONNECTIVE TISSUE CELLS
DNA
EMBRYONIC CELLS
FIBROBLASTS
HAMSTERS
HETEROCYCLIC COMPOUNDS
IN VITRO
LABELLED COMPOUNDS
MAMMALS
MUTATIONS
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ONCOGENIC TRANSFORMATIONS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENOTYPE
PYRIMIDINES
RADIATION EFFECTS
RADIOINDUCTION
RIBOSIDES
RODENTS
SOMATIC CELLS
SOMATIC MUTATIONS
SURVIVAL CURVES
THYMIDINE
TRITIUM COMPOUNDS
VERTEBRATES