Effects of 25-hydroxycholesterol , cholesterol , and isoprenoid derivatives on the G1 progression in Swiss 3T3 cells .

Larsson O ; Zetterberg A

J Cell Physiol 129 : 94-102 ( 1986)

Abstract
The effect of inhibition of 3-Hydroxy-3-methylglutaryl Coenzyme A reductase ( HMG CoA reductase ) on cell cycle progression in proliferating T3 cells was studied . It was found that short transient exposures to the HMG CoA reductase inhibitor 25-hydroxycholesterol temporarily blocked the cell cycle traverse in the postmitotic half of G1 ( G1pm ) , whereas cells in the subsequent cell cycle phases were unaffected . The kinetics of the cell cycle delay , induced by 25-hydroxycholesterol , resembled the kinetics of the delay induced by serum depletion , which also inhibited the activity of HMG CoA reductase . In contrast to the case of serum depletion , platelet derived growth factor ( PDGF ) , which efficiently prevented the decrease of HMG CoA reductase in serum-free medium , was not capable of preventing the growth inhibitory effect following treatment by 25-hydroxycholesterol . However , cholesterol and two isoprenoids , dolichol and coenzyme Q , were effective in this respect . In addition , dolichol counteracted the cell cycle delay following short periods of serum starvation .