Patterns of gene expression during plasmacytoid differentiation of chronic lymphocytic leukaemia cells

Abstract
Chronic lymphocytic leukaemia (CLL) cells may be induced to undergo plasmacytoid differentiation in vitro in response to 12-O-tetradecanoyl phorbol acetate (TPA). We show here that plasmacytoid differentiation and the accompanying accumulation of Cμ immunoglobulin mRNA are preceded by a rapid transient increase in the expression of the proto-oncogenes, c-myc and c-fos. In terminally differentiated cells the level of c-fos mRNA returned to the original basal level whilst c-myc expression remained appreciably higher than in undifferentiated CLL cells. These data support a possible role for c-fos and c-myc in the programmed chain of events that occur during terminal differentiation of B-lymphocytes