ENHANCED EXPRESSION OF INITIATOR TRNA(MET) IN HUMAN GASTRIC AND COLORECTAL-CARCINOMA

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