Downregulation of TF Expression by ATRA and RARα Agonist AM580 in S-NB4: Inhibition of the Effect by RARα and RARβ Selective Antagonists
| Treatment . | TF Activity (% of control) . | Pv Control . |
|---|---|---|
| Untreated control | 100 ± 0 | |
| ATRA* | 51.3 ± 3.6 | .0001 |
| ATRA + anti-RARα | 80.1 ± 5.3 | .001 |
| ATRA + anti-RARβ | 59.4 ± 1 | .05 |
| ATRA + anti-RARα + anti-RARβ | 98 ± 1.6 | NS |
| AM580 (RARα agonist)* | 35.7 ± 2.6 | .0001 |
| AM580 + anti-RARα | 100 ± 2 | NS |
| AM580 + anti-RARβ | 31.7 ± 1 | .0001 |
| Treatment . | TF Activity (% of control) . | Pv Control . |
|---|---|---|
| Untreated control | 100 ± 0 | |
| ATRA* | 51.3 ± 3.6 | .0001 |
| ATRA + anti-RARα | 80.1 ± 5.3 | .001 |
| ATRA + anti-RARβ | 59.4 ± 1 | .05 |
| ATRA + anti-RARα + anti-RARβ | 98 ± 1.6 | NS |
| AM580 (RARα agonist)* | 35.7 ± 2.6 | .0001 |
| AM580 + anti-RARα | 100 ± 2 | NS |
| AM580 + anti-RARβ | 31.7 ± 1 | .0001 |
Cells were incubated with ATRA 10−8 mol/L or RARα agonist (AM580, 10−8 mol/L) for 96 hours in the presence of 10−6 mol/L retinoid receptor antagonists: anti-RARα (Ro 41-5253) or anti-RARβ (CD2665). TF activity was measured by a spectrophotometric assay for FXa. Results are expressed as percent of untreated control cells (=100%). Statistical analysis was done versus the untreated control by the paired Student's t-test.
Abbreviation: NS, not significant.
Comparison between the effects of the two agonists, by the unpaired Student's t-test, also showed that AM580 was significantly more potent than ATRA (P < .05) in reducing TF activity.