CONCENTRATION-DEPENDENT EFFECTS OF 9-CIS RETINOIC ACID ON NEUROBLASTOMA-DIFFERENTIATION AND PROLIFERATION IN-VITRO

The observation that neuroblastoma cells differentiate in response to retinoic acid (RA) in vitro has led to clinical trials using either 13-cis or all-trans RA. Since 9-cis RA may also have important biological functions, we have compared the potential of RA isomers to induce differentiation and inhibit cell proliferation of SH SY 5Y neuroblastoma cells. 9-cis RA at high concentrations is better at inducing morphological differentiation than either all-trans or 13-cis RA and as effective at inhibiting proliferation. Hence, 9-cis RA or stable analogues may have important therapeutic potential in the treatment of neuroblastoma.