Heterogeneity of enzyme-altered foci in rat liver.
Enzyme-altered foci (EAF) in liver are assumed to be precursor lesions for tumors in this organ. Results obtained with selected hepatocarcinogens which produce lesions of differing phenotype and growth behavior indicate that not the total number of enzyme-altered cells but rather the proliferation of individual cell clones is of major importance for additional changes leading to malignancy. Analyses including multiple marker enzymes demonstrate a relationship between foci phenotype and proliferation. The inducibility of certain downregulated enzymes in EAF indirectly suggests disturbances in the expression of regulatory genes such as proto-oncogenes. Data on Ha-ras and c-myc proto-oncogene expression in EAF are presented.
Schwarz
M
M
German Cancer Research Center, Institute of Biochemistry, Heidelberg.
Buchmann
A
A
Schulte
M
M
Pearson
D
D
Kunz
W
W
D000251:Adenosine Triphosphatases / Q000172:deficiency*; D000818:Animals; D002273:Carcinogens / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D005819:Genetic Markers; D008658:Inactivation, Metabolic; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000201:enzymology* / Q000235:genetics; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D011230:Precancerous Conditions / Q000139:chemically induced / Q000201:enzymology* / Q000235:genetics; D012333:RNA, Messenger / Q000302:isolation & purification; D012334:RNA, Neoplasm / Q000302:isolation & purification; D051381:Rats; D011919:Rats, Inbred Strains
D002273:Carcinogens; D004273:DNA, Neoplasm; D005819:Genetic Markers; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D003577:Cytochrome P-450 Enzyme System; D000251:Adenosine Triphosphatases