<i>RARα</i> and <i>RARß</i> antagonist (A) and <i>RXR</i>γ knockdown (B) studies.

<p>A, Application (+) of ER50891, a specific RARα antagonist or LE 135, a selectively RARß antagonist for 24 h disclosed the involvement of both RAR subtypes in RA/BMP-4 mediated apoptosis induction in WERI-Rb1 cells. B, WERI-Rb1 cells with a <i>RXR</i>γ knockdown (sh RXRγ) and non-silencing controls were treated for 24 h with RA or a combination of RA and BMP-4 in the presence (+) or absence (-) of a RARα antagonist (ER 50891) and a RARß antagonist (LE 135). Values are means from 3 independent assays ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001 statistical differences calculated by one way Annova and Newman-Keuls Post test.