Different gene expression for ribosomal RNA of AH-130 tumor and embryonic and adult rat liver

Abstract

The nucleotides of 45-S ribosomal precursor RNA in the nucleoli of a number of tumors comprise less adenylic, and more cytidylic acid than those of normal rat liver. The base ratios of cytoplasmic mature ribosomal RNA in tumors are rather similar to those in normal rat liver, but the 32P distribution in oligonucleotides of ribosomal RNA of these tissues differs appreciably. The isotope content of dinucleotides of RNA of tumors was higher, and that of pentanucleotides was lower than in RNA of normal liver. Analyses of digestion products of ribosomal RNA of these tissues suggested that the primary structure of ribosomal RNA of tumors might differ from that of rat liver. Furthermore, the 32P distribution in the isoplithic peaks of ribosomal RNA of tumor cells were similar to that of 14-day-old embryonic liver. These results suggested that gene expression for ribosomal RNA may differ in adult liver and less differentiated tissues.