Apoptosis on U266 Cells Induced by Brucine by Death-Receptor Pathway

Multiple myeloma (MM) is an incurable hematological malignancy with high incidence in the elderly. The currently chemotherapeutic drugs show severe side effects, dose-limiting toxicity and development of resistance. The study in order to observe the Anti-proliferative of brucine which is a novel plant anti-cancer agents on multiple myeloma cell line-U266 and find the mechanism of apoptosis.

U266 cells was cultured in 90% RPMI-1640 medium supplemented with 10% fetal bovine serum (FBS), 100 IU/ml penicillin and 100 μg/ml streptomycin, and maintained in a humidified atmosphere with 5% CO₂ at 37°C. Cells (5×10⁴) were plated in the presence or absence of the brucine (0, 0.05, 0.1, 0.2, 0.4 mg/ml) in 96 well culture plates for 24–72 h. The anti-proliferative response of brucine was assessed by MTT assay. Nuclear morphology of the treated cells was observed using Fluorescence microscope. The mitochondrial membrane potential of treated cell were measured by flow cytometry. The expression change of caspase-3 was detected using RT-PCR.

The apoptotic effect of brucine show a dose and time dependent manner (p<0.05). The 50% inhibiting concentration of brucine was 0.16 mg/ml. Brucine treated cells show significant feature associated with apoptosis by Fluorescence microscope. The mitochondrial membrane potential using flow cytometry revealed no significant decline at different concentration. In addition, Brucine induced U266 cell apoptosis was caspase dependent, with caspase-3 activated by caspase-9 (p<0.05).

At 0.4mg/ml concentration range brucine can induce apoptosis in U266 cells. Brucine induces the apoptosis of U266 cell via death-receptor pathway.

No relevant conflicts of interest to declare.