Theoretical mechanisms for synthesis of carcinogen-induced embryonic proteins. I. Alpha-fetoprotein induction by ethionine.
The neoplastic cellular phenotype expresses many embryonic features. These features are believed to occur by derepression of embryonic genes during the carcinogenic process. A specific case is the ability of ethionine, a hepatocarcinogen, to induce an embryonic protein known as alpha-fetoprotein. A mechanism is proposed for this derepression process along with supporting evidence. It is hypothesized that the repressor protein for the alpha-fetoprotein gene must be modified (methylated) before it is functional and if for any reason this does not occur, alpha-fetoprotein will be produced. This simple theory can explain a variety of states of the liver cell in which alpha-fetoprotein is expressed namely i) fetal, ii) ethionine-treated, iii) neoplastic, and iv) tyrosinemic liver cells.
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000196:embryology / Q000378:metabolism; D004032:Diet; D005001:Ethionine / Q000494:pharmacology*; D005333:Fetus / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008113:Liver Neoplasms / Q000196:embryology / Q000378:metabolism; D008715:Methionine / Q000494:pharmacology; D051381:Rats; D000509:alpha-Fetoproteins / Q000096:biosynthesis*
D000509:alpha-Fetoproteins; D008715:Methionine; D005001:Ethionine