Prostaglandins E1 and E2 interact with prostaglandin F2alpha to regulate initiation of DNA replication and cell division in swiss 3T3 cells.

Abstract
Prostaglandin (PG)E1 or PGE2 added at 2-1,000 ng/ml to quiescent cultures of Swiss 3T3 cells synergistically enhanced the rate of initiation of DNA replication stimulated by PGF2.alpha. alone or with insulin. Neither PGD2 nor PGF1.alpha. had any effect with PGF2.alpha.. An increse in the rate of entry into S phase also occurred when PGE1 or PGE2 was added 8 or 15 h after addition of PGF2.alpha.. Adding PGE2 and PGE2 together with PGF2.alpha. did not further enhance the synergistic effect observed with PGE1 or PGE2 separately. The synergistic effect was also observed in stimulation of 2-deoxyglucose uptake but not in early changes of intracellular levels of cAMP. These results may be relevant in understanding the control of fibroblastic proliferation in wound healing and may provide an alternative mechanism for oncogenic transformation.