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Letters to the Editor
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Figure 2. Induction of multiple myeloma (MM) cell apoptosis by reveromycin A (RM-A). (A) INA-6 and RPMI8226 MM cells were cultured for 24 hours (h) at pH 7.4 or 6.4 in the presence or absence of RM-A at 1 mM. Apoptotic cells were evaluated with annexin V and propidium iodide staining by flow cytometry. Distributions (%) of cells in each column are indicated. (B and C) INA-6 and RPMI8226 MM cells were cultured for 24 h at different pH values as indicated in the presence or absence of RM-A at 1 mM. The protein levels of cleaved caspase-8 and Sp1 (B) and cleaved caspase-9 (C) were analyzed by western blotting. β-actin was used as a protein loading control. (D) INA-6 cells were cultured for 24 h at the indicated pH values in the presence or absence of RM-A at 1 mM. Sp1 mRNA levels were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) (left). GAPDH served as an internal control. The caspase-8 inhibitor z- IETD-FMK at 100 mM was added together with RM-A as indicated. Sp1 and caspase 8 protein levels were analyzed by western blotting (right). β-actin was used as a protein loading control. (E) INA-6 and RPMI8226 MM cells were cultured for 24 h at pH 7.4 or 6.4 in the presence or absence of the Sp1 inhibitor terame- procol (TMP) at 50 mM. PIM2 and MYC protein levels were analyzed by western blotting. β-actin was used as a protein loading control. (F) INA-6 and RPMI8226 cells were cultured for 24 h at the indicated pH values in the presence or absence of RM-A at 1 mM. The protein levels of Sp1, PIM2 and MYC were analyzed by western blotting. β-actin was used as a protein loading control.
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haematologica | 2021; 106(4)