Antisense src Expression Inhibits U937 Human Leukemia Cell Proliferation in Conjunction with Reduction of c- myb Expression

Abstract

To elucidate the role of pp60 c- src in U937 human monoblastoid leukemia cell proliferation, recombinant plasmids containing the src gene or myb gene, which could produce antisense src or antisense myb RNA after dexamethasone treatment, were constructed and transfected into U937 cells (U937-ASRC, U937-AMYB). pp60 c- src synthesis in U937-ASRC was diminished by the third day after induction of antisense src RNA and the eel proliferation was reduced, furthermore, the amount of p75 c- myb was significantly decreased by the third day. p75 c- myb synthesis in U937-AMYB was diminished by the second day after induction of antisense myb RNA and the cell growth was significantly inhibited but the amount of pp60 c- src in U937-AMYB was not reduced. These results suggest that a decrease in the amount of pp60 c- src leads to an inhibition of p75 c- myb expression and subsequent reduction in the U937 cell proliferation.