Fig. 1

MCL cell lines are either sensitive or resistant to etoposide treatment. a. Exponentially growing Granta519, JeKo1, MINO, NCEB1 and REC1 cells were seeded at 5 × 10⁴ cells/well in 96-well plates and treated with vehicle, as a control, or 1 μg/ml etoposide for 24–72 h (upper panel) or with various concentrations of etoposide (1–40 μg/ml) for 24 h (lower panel). The cell proliferation was analyzed using an MTS assay and calculated as the ratio of absorbance of etoposide-treated cells vs. vehicle-treated cells for each time point and concentration. The absorbance values at 492 nm were corrected by subtracting the average absorbance from the control wells containing “no cells”. The experiment was performed twice, each culture condition was done in triplicate. The comparison of sensitive (Granta519, MINO and JeKo1) and resistant (REC1, NCEB1) using the t-test was significant. *, p < 0.05. b. Left part, MCL cells were treated with vehicle or 4 μg/ml etoposide for 24 h, stained with an anti-APO2.7 PE-conjugated Ab and analyzed by flow cytometry. The experiment was performed twice (for NCEB1) or three times; at least 10,000 events were gated for each culture condition. Means ± SD of % of APO2.7+ cells are indicated in the histogram as well as the fold induction (FI) calculated as the ratio of % APO2.7+ in etoposide- vs. vehicle-treated cultures. Right part, whole cell proteins were extracted, 40 μg of proteins were loaded on gels, separated by SDS-PAGE, blotted onto nitrocellulose membranes, incubated with Abs anti-MCL1, anti-BCL2 or anti-β-actin (as a loading control). c. MCL cells were treated with 4 μg/ml etoposide for 24 h or vehicle, as a control, then stained with C₁₂FDG and analyzed by flow cytometry. At least 10,000 events were gated for each culture condition. The ratio mean of fluorescence intensity of vehicle vs. etoposide-treated cells is indicated on the figure