MCL-1 and BFL-1 are transcriptionally up-regulated in resistant cells. (A) OCI-Ly1, OCI-Ly1 R7, and OCI-LY1 R10 cells were treated with 20 μg/mL CHX for the time indicated. Cells were lysed immediately after treatment and subject to immunoblot analysis. These results are representative of 3 independent experiments. (B) Cells were cultured in the absence of ABT-737 for 2 weeks. RNA was isolated and MCL-1 fold change was analyzed by quantitative PCR. (C) Cells were cultured in the absence of ABT-737 for 2 weeks and then treated with DMSO or 250nM ABT-737 for 16 hours. RNA was isolated and MCL-1 fold change was analyzed by quantitative PCR. (D) OCI-Ly1 and OCI-Ly1 R10 cells were cultured in the absence of ABT-737 for 3 weeks. Cells were then treated with 20μM ZVAD.fmk for 45 minutes before treatment with 1μM ABT-737 for the time indicated. RNA was isolated and MCL-1 fold change was analyzed by quantitative PCR. (E) SU-DHL-4 and SU-DHL-4 R2 cells were cultured in the absence of ABT-737 for 3 weeks and treated and analyzed as in panel D. (F) RNA from panel E was used to assay BFL-1 fold change by quantitative PCR. Error bars in panels B through F indicate the SEM. RNA levels from the untreated parental cell lines were set to 1.