Reconstitution of B-cell–specific gene expression by ATRA/ATO in cHL cell lines. (A) Stimulation of CD19, CD79a, and CD79b transcription by ATRA in L1236 (left) and L428 (right) cell lines detected by firefly luciferase reporter activity (top) and RQ-PCR (bottom). The luciferase signal was normalized to the cell number measured via calcein-generated fluorescence. Cells were treated with ATRA at 10 μM for 48 hours or left untreated (UT). (B) As in panel A, but treated with ATO at 10 μM for 48 hours. (C) CD19 and CD20 transcript levels in response to ATO in L1236 (left) and L428 (right) cell lines (as in panel B), detected by RQ-PCR. (D) Immunoblot analysis of CD20 protein expression in cHL cell lines as in panel B. α-Tubulin serves as a loading control. (E) Expression of B-cell–related transcription factor transcripts (left) and Hodgkin-typical transcripts (right) after ATO treatment in L1236 cells (as in panel B). (F) Expression of transcripts in L1236 cells as in E, but in response to ATRA (10 µM for 48 hours). Data are presented as mean ± SD; *P < .05.