Biochemical changes induced by tumors at distant sites: altered transfer RNA profiles in livers of mice bearing plasmacytomas.

Tumor growth is known to have systemic effects upon the host's metabolism. We report here for the first time that histologically normal livers of mice bearing subcutaneous plasmacytomas contain chromatographic peaks of asparaginyl-, aspartyl-, histidinyl-, and tyrosinyl-transfer RNAs not found in significant amounts in normal livers. Lysyl-, prolyl-, seryl-, threonyl-, tryptophanyl-, and valyl-transfer RNAs, from normal tissues, but these tRNAs are not altered in livers of tumor bearing mice. This suggests that distant tumor growth causes a derangement in one of the liver enzymes that normally modify transfer RNA after transcription.