Sequence complexity of nuclear RNA from 2-acetylaminofluorene-induced rat hepatomas and host cirrhotic liver

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.