Virginia J. Evans

Comparison of methyl-labeled tRNA in a neoplastic cell line with a paired non-neoplastic control

Abstract A comparison has been made between methylation of tRNA in intact cells from a non-neoplastic mouse cell line and that from two related neoplastic mouse cell lines. By adding 3 H-methyl-methionine and 14 C-methyl-methionine to the growth medium, it was possible to separately label and then to simultaneously extract, isolate, and chromatograph the tRNA from neoplastic and non-neoplastic cells. Isotope ratios were calculated from reversed-phase chromatography profiles and a consistently reproducible variation in the ratio was seen through the region where the first tRNAs were eleuted, indicating chromatographic heterogeneity. Although this difference between tRNA methylation in non-neoplastic and that in neoplastic cells is small, the data are consistent with the view of Srinivasan and Borek that aberrant methylation may be a factor in neoplastic conversion.