INHIBITION OF THE G2 M TRANSITION OF THE CELL-CYCLE BY METHYL-2,5-DIHYDROXYCINNAMATE IN HUMAN LYMPHOID-CELLS/

Immortalized human lymphoid cells treated with Methyl-2,5-dihydroxycin namate (MDHC), a stable analog of erbstatin, inhibited the G2/M transi tion of the cell cycle. The MDHC inhibition of the cell cycle was obse rved at concentrations well below the IC50 for the inhibition of the E GF receptor and sufficiently below that reported to induce protein cro ss-linking. The effect of MDHC upon the cell cycle is relatively stabl e, since unlike erbstatin, inhibition of the G2/M transition was obser ved 32 hours following removal of the drug, PHA stimulated human perip heral blood mononuclear cells (PBMC) were much less sensitive to MDHC. This study shows that MDHC acts on cells lacking an EGF receptor and the target of MDHC is involved in promoting progression of the cell cy cle. (C) 1996 Academic Press, Inc.