RXRα mRNA expression is associated with cell proliferation and cell cycle regulation in Hep3B cell

Retinoids are well-characterized differentiation and anti-proliferation agents. The functional role of retinoid x receptor alpha (RXRα) in cell proliferation and cell cycle regulation is not well understood. Using human Hep3B cell line, we showed that the mRNA level of RXRα was closely associated with cell growth. RXRα mRNA expression elevated along with the proliferation of Hep3B cells. This association was most evident in RXRα and was also noted with retinoic acid (RA) receptor α (RARα), but not found in other RARs and RXRs. The expression of RXRα and cyclin A mRNA was co-regulated when Hep3B cells were cultured in serum-free medium. The mRNA levels of RXRα and cyclin A appeared to be highest in G1/S phase in Hep3B cells treated by aphidicolin. Taken together, our data suggest that RXRα may be actively involved in cell proliferation and cell cycle regulation in Hep3B cells.