Effects of all-trans retinoic acid on proliferation of human aorta smooth muscle cells

The primary cultured human aorta smooth muscle cells (SMCs) were characterized and the effects of all-trans retinoic acid (atRA) on these cells were analysed. It is found that atRA could slow down the growth rate of SMCs, and decrease the expression levels of cyclinD1, CDK4, c-myc at 39%, 38% and 43.6% respectively, while atRA had no effects on the expression of alpha-actin which is specific for SMCs. Results demonstrated that atRA inhibited cell growth of SMCs but did not induce cell differentiation. These effects may be due to the decreased translation levels of cyclinD1, CDK4 and transcription level of c-myc. The fact that atRA inhibited SMCs proliferation may become one of the theoretic basis for the clinical use of atRA in the treatment of SMCs proliferative diseases such as atherosclerosis.