The sequence complexities of nuclear of RNAs from 2-acetylaminofluorene-induced rat
hepatomas and host cirrhotic livers were compared in
RNA-driven and host cirrhotic livers were compared in
RNA-driven hybridization experiments using iodinated single-copy
DNa as a probe. Normal liver nuclei
RNA hybridized to 10.0 +/- 0.3+ (mean +/- S.D.) of the
DNA, indicating an RNA sequence complexity of 3.8 x 10(8)
nucleotides. Although nuclear RNAs from cirrhotic livers displayed a greater variation between animals, the mean values for percent
DNA hybridized (9.5 +/- 2.0%) and RNA sequence complexity (3.6 x 10(8)
nucleotides) for 5 cirrhotic livers examined did not differ significantly from normal. Analysis of nuclear RNAs from 10
tumors, 8 of which were classified as moderately to well differentiated histologically, revealed a level of hybridization (9.5 +/- 1.8%) and a mean value of RNA sequence complexity (3.6 x 10(8)
nucleotides) that were almost identical with those for normal liver. Variation in the complexity amont
tumors was slightly less than that among cirrhotic liver RNAs. These results suggest that while growth characteristics, biochemical properties, and physiology are known to vary between
hepatomas and normal or cirrhotic liver tissue, there is no substantial or consistent difference in the RNA sequence complexity of chemically-induced
hepatoma cells compared with normal or chemically-induced cirrhotic liver.