[Berbamine induces apoptosis of multiple myeloma RPMI 8226 cells by activating GADD45/JNK pathway].

OBJECTIVE: To investigate the effect of berbamine (BBM) on multiple myeloma (MM) cell line RPMI 8226 and its mechanism. METHODS: MTT bioassay was used to examine the effect of berbamine on cell growth and IC(50) was calculated. Apoptosis was observed by flow cytometry (FCM) and DNA gelose electrophoresis. p53, p21, GADD45 mRNA were measured by RT-PCR. The alterations in p53, J NK, p-JNK and c-Jun proteins were detected by Western blot method. RESULT: The growth of RPMI 8226 cells was suppressed in a dose-dependent manner after treatment with BBM(P<0.05), and its IC(50) value was 3.83 microg/ml at 48 h. Both DNA ladder and FCM results showed that BBM induced apoptosis of RPMI 8226 cells with concomitant increase of activated p53, p21 and GADD45gamma mRNA. After treatment with BBM at 8 microg/ml for 24 h, the percentage of apoptotic cells increased from 1.07% to 24.84%. p-JNK and c-Jun proteins were activated. CONCLUSION: BBM can inhibit the growth of RPMI 8226 cells, which is associated with activation of GADD45/JNK signaling pathway and induction of cell apoptosis.