ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of a novel retinoid CD437 and all-trans retinoic acid (ATRA) in inducing cell apoptosis and inhibiting the proliferation of human epidermoid carcinoma A431 cells and normal human epidermal keratinocytes.</p><p><b>METHODS</b>MTT assay was used to determine the inhibitory effects of CD437 and ATRA on the growth of A431 cells and normal human epidermal keratinocytes, and the cell morphological changes were observed microscopically. Flow cytometry was used to investigate the effect of CD437 and ATRA on the cell cycle and apoptosis.</p><p><b>RESULTS</b>CD437 was more effective than ATRA in inhibiting the proliferation of A431 cells and normal human epidermal keratinocytes. CD437 increased the percentage of sub-G1 populations in A431 cells and induced G1 arrest in normal human epidermal keratinocytes. ATRA appeared to be relatively ineffective for inducing apoptosis in A431 cells as compared to CD437. CD437 did not duce obvious apoptosis in normal human epidermal keratinocytes.</p><p><b>CONCLUSION</b>CD437 is more effective than ATRA in inhibiting the proliferation and inducing apoptosis in A431 cells and shows selective apoptosis-inducing effect against malignant keratinocytes, suggesting its potential in the prevention or treatment of cutaneous carcinoma.</p>