Cd++ inhibits EGF induced DNA synthesis but not EGF induced myc mRNA accumulation in serum starved NRK-49F cells.
Cd++ inhibits EGF-induced 3H-thymidine incorporation in serum deprived NRK-49F cells in a dose dependent pattern. The underlying mechanisms for this inhibition are largely unknown. EGF-induced myc mRNA accumulation in NRK-49F cells and the effects of Cd++ on this response were examined under conditions that result in partial or complete inhibition of EGF-induced DNA synthesis. It was found that doses of Cd++ that inhibit EGF-induced DNA synthesis do not inhibit EGF-induced protein synthesis and myc mRNA accumulation. Cd++ doses of 0.5 microM and 1 microM were found actually to increase EGF-induced myc mRNA accumulation and amino acid incorporation. These results show that the effect of Cd++ on EGF-induced DNA synthesis is not due to inhibition of entrance into G1, but rather that Cd++ acts on events subsequent to myc accumulation; that is, events associated with either G1 progression, entry into S or DNA synthesis.
Tang
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N
Department of Zoology, Iowa State University, Ames 50011.
Clapper
J A
JA
Enger
M D
MD
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D002104:Cadmium / Q000494:pharmacology*; D002453:Cell Cycle; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis*; D004815:Epidermal Growth Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D016259:Genes, myc; D008938:Mitosis; D012333:RNA, Messenger / Q000096:biosynthesis*; D013936:Thymidine / Q000378:metabolism
D000596:Amino Acids; D012333:RNA, Messenger; D002104:Cadmium; D004815:Epidermal Growth Factor; D004247:DNA; D013936:Thymidine