Two-dimensional gel electrophoresis of major cytosolic proteins derived from spleen mononuclear cells of normal and leukemic rats.

Proteins from leukemic spleen cells derived from a F344 rat transplant model were investigated by 2D gel electrophoresis. The cell line was maintained in vivo by serial transplant of mononuclear spleen cells from leukemic donors into syngeneic recipients. Cytosolic proteins from mononuclear cells (MNC) were isolated from spleens of normal and leukemic rats and separated by electrophoresis. Replicate data from silver-stained gels for each preparation were compiled into Master Images using image analysis algorithms in order to characterize the normal and leukemic protein profiles. Comparative analysis showed a total of 458 proteins that were reproducibly detected in normal MNC, while almost twice the number of proteins (828) were found in leukemic MNC, suggestive of the more mitotically active tumor cells. Profile analysis showed that normal and leukemic preparations shared 228 common proteins, with 600 proteins observed only in leukemic MNC, and 230 proteins found only in normal MNC. Differences in protein patterns between normal and leukemic MNC in rats probably reflects a shift in spleen leukocyte populations and a relative induction of gene expression in leukemic MNC as compared to the normal MNC.