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TY - JOUR AU - Scher, Charles D. AU - Stone, Marilyn E. AU - Stiles, Charles D. PY - 1979 DA - 1979/10/01 TI - Platelet-derived growth factor prevents G0 growth arrest JO - Nature SP - 390 EP - 392 VL - 281 IS - 5730 AB - Baserga1 has summarised evidence that there are two growth states in which cells have a diploid content of DNA; G1—the interval between mitosis and S phase in exponentially growing cultures—and G0, a quiescent state entered only when conditions for growth are suboptimal. G0 can be distinguished from G1 by temporal measurements; for BALB/c 3T3 cells, the lag time between G0 and S phase is never shorter than 12 h (ref. 2), whereas in exponentially growing cells the mean lag time between mitosis and S (G1 by definition) lasts 5–6 h (ref. 3). G0 can also be distinguished from G1 by some biochemical parameters including G0- and G1-specific intracellular proteins4,5. SV40- or polyoma virus-transformed cells cannot enter G0 to become quiescent6–9. Serum induces the growth of BALB/c 3T3 cells in tissue culture. It sustains the growth of exponentially replicating populations, and causes density-inhibited cells to leave G0 and replicate10–12. Serum contains several sets of hormonal growth factors which have recently been defined2,13,14. One of these hormones, the platelet-derived growth factor (PDGF), is released into serum during the clotting process; PDGF is absent in platelet-poor plasma, the liquid portion of unclotted blood15–19. It promotes the growth of G0-arrested cells2,16 by stimulating cells to become ‘competent’ to enter the S phase2; plasma allows these competent cells to progress through G0/G1, synthesise DNA2,20 and divide13. We now show that PDGF has a second function. It prevents replicating cells from entering G0. SN - 1476-4687 UR - https://doi.org/10.1038/281390a0 DO - 10.1038/281390a0 ID - Scher1979 ER -