ANTISENSE SRC EXPRESSION INHIBITS PROLIFERATION AND ERYTHROPOIETIN-INDUCED ERYTHROID-DIFFERENTIATION OF K562 HUMAN LEUKEMIA-CELLS

We constructed a recombinant plasmid which expresses antisense src RNA in human cells and used it as a tool for investigating the role of pp 60(c-src) in proliferation and differentiation of K562 human leukemia cells. In erythropoietin (EPO)-responsive cells, EPO induces rapid tyr osine phosphorylation of several cellular proteins including EPO recep tor (EPOR) although EPOR has no tyrosine kinase domain. Here we show t hat antisense src RNA expression suppresses pp60(c-src) synthesis in t he recombinant plasmid-transfected K562 cells, reduces the proliferati on and inhibits hemoglobin synthesis and glycophorin A expression prom oted by EPO in K562 cells. These findings suggest that pp60(c-src) pla ys crucial roles in the proliferation and EPO-induced erythroid differ entiation of K562 cells. (C) 1994 Academic Press, Inc.