Imatinib Induces Apoptosis of Myeloma Cells by Inhibiting c-Kit Signaling Transduction.

Objective To evaluate the mechanism and influence of Imatinib on myeloma cells which express c-Kit receptor.

Methods KM3 cells were treated with Imatinib for indicated time and indicated concentration and cell growth index were evaluated by XTT assay. Cell cycle were examined by flow cytometry. Apoptosis were assessed by Annexin V/PI. c-Kit and phosphate c-Kit were examined by Western blot.

Results Imatinib inhibited proliferation of KM3 cells in a concentration more than 0.25μmol/L, induced a progressive decline in S phase cell fraction and an increase in G0/G1 cells. Annexin V/PI staining and DNA ladder indicated that Imatinib had a substantial effect on apoptosis of KM3 cells in a dose-dependent manner and induced pro-caspase-3 and PARP to cleave. Imatinib treatment inhibited expression of c-Kit and provoked a decreased of IL-6 induced c-Kit phosphorylation.

Conclusion Imatinib inhibites KM3 myeloma cells proliferation and induces apoptosis of KM3 myeloma cells by inhibiting c-Kit signaling transduction.