Enhanced expression of initiator TRNA(Met) in human gastric and colorectal carcinoma

Transfer RNA isoaccepting species are differentially expressed at different times during development, differentiation, growth, aging, and carcinogenesis processes. It has been suggested that alterations in tRNA patterns might be mechanistically important in modulating gene expression during the various physiological/pathological cellular stages. As part of a study to investigate the possible mechanisms by which alterations of translational machinery can start and/or sustain carcinogenic cell proliferation, in this communication we report analysis of tRNA distribution in two gastro-intestinal human tumors. The qualitative and quantitative data obtained for cellular tRNA distribution put into evidence a shift in the tRNA population with increased level of initiator tRNA(Met) in the malignant tissues. This observation confirms previous data obtained on experimental carcinogenesis models and suggests the possibility of specific involvement of tRNA changes in protein synthesis initiation during tumorigenesis.