Two-dimensional membrane protein patterns of acute myeloid leukemia cells and mature myeloid cells after various ectolabeling procedures

Surface exposed membrane proteins of malignant cells may offer important clues about the differentiation stage of the cell or may contain proteins specific for the malignant state. We have studied the surface exposed membrane proteins of human acute myeloid leukemia cells employing the lactoperoxidase, periodate, or the neuraminidase/galactose oxidase ectolabeling procedures. One- dimensional membrane protein patterns were prepared from 20 patients, and from 19 patients, two-dimensional patterns were prepared according to OFarrell. No consistent differences in membrane proteins could be found between patients classified as M1, M2, M4, or M5 (FAB classification). A diagram of membrane proteins from acute myeloid leukemia cells subjected to two-dimensional electrophoresis could be composed from the results obtained. About 25 different membrane proteins can be indicated. Two-dimensional patterns, after the various ectolabeling procedures, were also prepared from mature myeloid cells, visualizing about 18 different membrane proteins. Comparison of these and the undifferentiated myeloid leukemia cell pattern reveals some maturation-linked or leukemia-associated differences. The most relevant proteins will be discussed, along with their association with a recently described “malignancy marker” with a molecular weight of 68,000 daltons.