INCREMENT OF THE CYCLIN-D1 MESSENGER-RNA LEVEL IN TPA-TREATED 3 HUMAN MYELOID-LEUKEMIA CELL-LINES - HEL, CMK AND HL-60 CELLS

To study the involvement of cyclins in cell-cycle progression, changes of mRNA levels for three G1 cyclins (cyclin C, D1 and E) and cyclin A were studied in a leukemia cell line, HEL cells, before and after incubation with 12-O-tetradecanoylphorbol-13-acetate (TPA). Unexpectedly, the cyclin D1 mRNA level markedly increased in the HEL cells when the cells were growth-arrested by TPA, while the amounts of cyclin E and A mRNAs decreased to an almost undetectable level in HEL cells after incubation with TPA. The similar marked increment of the cyclin D1 mRNA level was observed in other leukemia cell lines, CMK and HL-60 cells, after incubation with TPA. The cyclic C mRNA was not detected in HEL cells before and after incubation with TPA. © 1993 Academic Press, Inc.