Alteration of retinoid X receptor a mRNA level after acitretin and/or narrow-band UVB treatment in normal human keratinocytes

Objective To investigate the alteration of retinoid X receptor α(RXRα) mRNA level in normal human keratinocytes after acitretin and/or NB-UVB irradiation treatment. Methods After a 12-hour incubation with 10^-7-10^-6 mol/L acitretin and/or following 50-100 mJ/cm² NB-UVB irradiation in normal human keratinocytes. RXRa mRNA expression was examined by reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR. Results The expression of RXRa mRNA was obviously decreased by NB-UVB irradiation, but not by acitretion single treatment. When combining acitretin treatment with NB-UVB irradiation, greater decreased RXRα mRNA expression was observed than that of single treatment. Conclusion Narrow-band UVB irradiation treatment can decrease RXRα mRNA expression, but not acitretin single treatment. Combining treatment with both can produce synergistic inhibition effects.