Alterations in Specific Transfer Ribonucleic Acids in a Spectrum of Hepatomas

Tyrosyl-, histidyl-, asparaginyl-, and phenylalanyl-tRNAs from a spectrum of Morris hepatomas were compared to the same respective aminoacyl-tRNAs from normal rat liver by means of methylated albumin kieselguhr column chromatography. The tyrosyl-, histidyl-, and asparaginyl-tRNAs from hepatoma 3924A had altered elution profiles similar to those found earlier in Novikoff hepatoma. Hepatomas 9121, 9098, 3683F, and 5123C had altered phenyl-alanyl-tRNA profiles. Codon recognition properties of tyrosyl- tRNAs from Novikoff hepatoma, hepatomas 3924A and 9098, and normal rat liver were also examined. In the case of Novikoff hepatoma, the tyrosyl-tRNA was further fractionated on a DEAE-Sephadex A-50 column. All of the tyrosyl-tRNAs recognized the normal tyrosine codons UAU and UAC; the response to UAU was always greater than the response to UAC. None of the tyrosyl-tRNAs were bound by the chain terminator codons UAG or UAA. The biological and functional significance of these findings are discussed.