Elevated expression of proto-oncogenes accompany enhanced induction of heat-shock genes after exposure of rat embryos in utero to ionizing irradiation

Journal Article · Sun Jan 01 00:00:00 EST 1989 · Teratogenesis, Carcinogenesis, and Mutagenesis; (USA)

DOI:https://doi.org/10.1002/tcm.1770090402· OSTI ID:5224224

Higo, H; Lee, J Y; Satow, Y; Higo, K ^[1]

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1. Hiroshima Univ. (Japan)

We have recently found that the effects of exposing rat embryos in utero to teratogens capable of producing cardiac anomalies were expressed later as enhanced induction of heat-shock proteins (hsp70 family) when embryonic hearts were cultured in vitro. However, it remained to be determined whether heat-shock proteins are induced in vivo after exposure to teratogens. The heat-shock response in some mammalian systems is known to be accompanied by elevated expression of proto-oncogenes. Using gene-specific DNA probes, we examined the levels of the expression (transcription) of heat-shock protein genes and two nuclear proto-oncogenes, c-fos and c-myc, in the embryos removed from irradiated pregnant mother rats 4 or 5 days after the irradiation. We found that the levels of expression in vivo of the hsp70 and c-myc genes in the irradiated embryos increased by approximately twofold as compared with those in the control. The expression in vivo of the c-fos gene was not detected in either the irradiated or non-irradiated embryos. After 0.5-hr incubation in vitro of the embryos, however, the expression of the c-fos gene in the irradiated embryos was highly enhanced whereas the control showed no changes. Although the exact functions of these gene products still remain obscure, the enhanced expression of hsp70 gene(s) and the nuclear proto-oncogenes observed in the present study may reflect repair of intracellular damages and/or regeneration of tissue by compensatory cell proliferation, processes that may disturb the normal program of organogenesis.

• OSTI ID: 5224224
• Journal Information: Teratogenesis, Carcinogenesis, and Mutagenesis; (USA), Vol. 9:4; ISSN 0270-3211
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
IONIZING RADIATIONS
TERATOGENESIS
ONCOGENES
RADIOINDUCTION
PROTEINS
GENES
DNA REPAIR
EMBRYOS
GENE REGULATION
HEAT
MESSENGER-RNA
RATS
TRANSCRIPTION
ANIMALS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
ENERGY
MAMMALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
RADIATIONS
RECOVERY
REPAIR
RNA
RODENTS
VERTEBRATES
560152* - Radiation Effects on Animals- Animals