INCREASED MESSENGER-RNA EXPRESSION OF PHOSPHOLIPASE-D (PLD) ISOZYMES DURING GRANULOCYTIC DIFFERENTIATION OF HL60 CELLS

In response to dibutyryl cyclic AMP (dbcAMP) and all-trans retinoic ac id (ATRA), HL60 cells differentiate into granulocyte-like cells. Membr ane-associated phospholipase D (PLD) activity in response to guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) or phorbol myristate acetate (PMA) was upregulated by these treatments. Reverse transcriptase-polym erase chain reaction (RT-PCR) analyses revealed that both hPLD1a and h PLD1b mRNAs were expressed in HL60 cells and that their expression lev els increased during differentiation. hPLD2 mRNA levels rose dramatica lly during differentiation. These results suggest that the PLD genes u ndergo changes in transcriptional regulation during granulocytic diffe rentiation of HL60 cells. (C) 1998 Elsevier Science B.V.