OBJECTIVE: To investigate the in vitro effects of fludarabine on apoptosis and gene expression profile in human multiple myeloma (MM) cells. METHODS: Cell growth was measured by a MTT assay. Cells apoptosis was evaluated by flow cytometry. The activation of caspase cascade was determined by Western blot analysis. The expression profile of apoptosis-related genes in human MM cells was detected by cDNA expression array system. RESULTS: The growth of RPMI8226 and KM3 cells was suppressed by fludarabine treatment in a dose and time-dependent manner. After treatment with fludarabine for 24 h, the IC(50) for RPMI8226 cells was 2.13 µg/ml, and 0.36 µg/ml for KM3 cells. Apoptotic cells of RPMI8226 and KM3 increased in a dose- dependent manner after exposure to fludarabine for 24 h. Western blot analysis showed the activation of caspase-3 and PARP in the MM cells treated with fludarabine. The cDNA expression array showed that multiple pathways were involved in the apoptosis induced by fludarabine. Among 97 apoptosis-related genes, 25 genes were differently expressed and 13 expressions were up-regulated in fludarabine treated group, involving in Bcl-2 pro-apoptotic gene, tumor necrosis factor (TNF) and its receptor superfamily gene, and caspase recruitment domain family, 12 genes expression down-regulated, including Bcl-2 antiapoptotic gene, TNF superfamily and its receptor related factor gene and apoptosis inhibitor protein family. CONCLUSION: Fludarabine can significantly inhibit MM cell growth and induce apoptosis in vitro. The multiple pathways may be involved for the apoptosis in MM cells.
OBJECTIVE: To investigate the in vitro effects of fludarabine on apoptosis and gene expression profile in humanmultiple myeloma (MM) cells. METHODS: Cell growth was measured by a MTT assay. Cells apoptosis was evaluated by flow cytometry. The activation of caspase cascade was determined by Western blot analysis. The expression profile of apoptosis-related genes in human MM cells was detected by cDNA expression array system. RESULTS: The growth of RPMI8226 and KM3 cells was suppressed by fludarabine treatment in a dose and time-dependent manner. After treatment with fludarabine for 24 h, the IC(50) for RPMI8226 cells was 2.13 µg/ml, and 0.36 µg/ml for KM3 cells. Apoptotic cells of RPMI8226 and KM3 increased in a dose- dependent manner after exposure to fludarabine for 24 h. Western blot analysis showed the activation of caspase-3 and PARP in the MM cells treated with fludarabine. The cDNA expression array showed that multiple pathways were involved in the apoptosis induced by fludarabine. Among 97 apoptosis-related genes, 25 genes were differently expressed and 13 expressions were up-regulated in fludarabine treated group, involving in Bcl-2 pro-apoptotic gene, tumor necrosis factor (TNF) and its receptor superfamily gene, and caspase recruitment domain family, 12 genes expression down-regulated, including Bcl-2 antiapoptotic gene, TNF superfamily and its receptor related factor gene and apoptosis inhibitor protein family. CONCLUSION:Fludarabine can significantly inhibit MM cell growth and induce apoptosis in vitro. The multiple pathways may be involved for the apoptosis in MM cells.