Figure 1.

Compound 147 reduces secretion of ALLC from AL patient–derived ALMC-2 cells. (A) Representative immunoblot and quantification of ALLC in conditioned media prepared on ALMC-2 cells treated for 18 hours with vehicle (Veh) or 147 (10 µM). Error bars show standard error of the mean (SEM) for 4 independent experiments. (B) Representative nonreducing (−DTT) and reducing (+DTT) immunoblots of conditioned media prepared on ALMC-2 cells treated for 18 hours with Veh or 147 (10 µM). Fully assembled IgGs, oxidized LC dimers, oxidized LC monomers, and reduced LC monomers are indicated. (C) Quantification of nonreducing immunoblots as shown in panel B showing the relative recovery of oxidized LC monomers, oxidized LC dimers, and fully assembled IgGs. Error bars show SEM for 3 or 4 independent experiments. (D) Graph showing the fraction of ALLC secreted from ALMC-2 cells treated with Veh or 147 (10 µM) for 18 hours and then treated with cycloheximide (CHX; 50 µg/mL) at 0, 3, or 6 hours. ALLC in conditioned media and lysates were measured by ELISA. The experimental protocol is shown above. Fraction secreted was calculated as follows: fraction secreted = ALLC in media at t = 3 or 6 hours/ALLC in the lysate at t = 0 hours. Error bars show SEM for 5 replicates. (E) Graph showing the fraction of ALLC remaining from ALMC-2 cells treated for 18 hours with Veh or 147 (10 µM) and then treated with CHX (50 µg/mL), as in panel D. ALLC in conditioned media and lysates were measured by ELISA. Fraction of ALLC remaining was calculated as follows: fraction of ALLC remaining = (ALLC in media t = 6 hours + ALLC in lysate at t = 6 hours)/ALLC in lysate at t = 0 hours. Error bars show SEM for 5 replicates. *P < .05, **P < .01 (paired Student t test); ***P < .005 vs Veh (unpaired Student t test). n.s., not significant.