brucine and Multiple-Myeloma

The aim of this study was to investigate the mechanism of the apoptotic effect of brucine on human multiple myeloma (MM) cells. U266 cells (5x104) were plated in the presence or absence of brucine (0, 0.05, 0.1, 0.2 and 0.4 mg/ml) in 96‑well culture plates for 24‑72 h. The anti-proliferative response to brucine was assessed by MTT assay. Analysis of the cell cycle of U266 cells treated with or without brucine was performed using flow cytometry. The expression change of c-Jun following treatment with brucine or brucine plus the c-Jun N-terminal kinase (JNK)-specific inhibitor SP600125 was detected using RT-PCR. Brucine appeared to have an effect on apoptosis in a dose- and time‑dependent manner. Cell cycle analysis using flow cytometry revealed the accumulation of cells at the sub-G0/G1 phase. The apoptotic rates were 4.137, 10.55, 12.31, 27.67 and 29.67% (0, 0.05, 0.1, 0.2, 0.4 mg/ml brucine, respectively; P<0.01). The gray scale values were 0.7961 ± 0.007 and 0.4683 ± 0.003 (mRNA expression of c-Jun of U266 cells with or without SP600125, respectively). Concentrations of ≤ 0.4 mg/ml brucine induced apoptosis in U266 cells. Thus, brucine‑induced apoptosis in U266 cells occurs via the JNK signaling pathway and phosphorylation of c-Jun.

Topics: Adjuvants, Immunologic; Anthracenes; Apoptosis; Caspase 3; Cell Line, Tumor; G1 Phase Cell Cycle Checkpoints; Humans; JNK Mitogen-Activated Protein Kinases; Multiple Myeloma; Phosphorylation; Signal Transduction; Strychnine

The aim of this study was to explore the effects of brucine on bone metabolism in multiple myeloma (MM) and to compare brucine and bortezomib regarding the effects on MM in vitro. The half maximal inhibitory concentration (IC50) values of brucine and bortezomib in the MM cell line U266 were detected by MTT assay. In addition, the expression of alkaline phosphatase (ALP), osteocalcin (OC), osteoprotegerin (OPG) and osteoprotegerin ligand (also termed receptor activator of nuclear factor κB ligand) (RANKL) at mRNA levels were measured by RT-PCR. IC50 of bortezomib in the U266 cell line at 48 h was 22.4 nmol/l, and that of brucine was 0.16 nmol/l. Compared with osteoblasts incubated with MM cell supernatant alone, the mRNA levels of ALP, OC and OPG in osteoblasts co-treated with brucine and MM cell supernatant were higher (p<0.05), while the mRNA expression of RANKL was lower, and the ranges of the changes were all larger than those of the group treated with bortezomib (P<0.05). Brucine exerts effects on bone metabolism in multiple myeloma through the regulation of osteoclasts by osteoblasts.

Topics: Alkaline Phosphatase; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Bone and Bones; Boronic Acids; Bortezomib; Cell Differentiation; Cell Line, Tumor; Culture Media; Humans; Inhibitory Concentration 50; Multiple Myeloma; Osteoblasts; Osteocalcin; Osteoclasts; Osteoprotegerin; Polymerase Chain Reaction; Pyrazines; RANK Ligand; RNA, Messenger; RNA, Neoplasm; Stem Cells; Strychnine

This study was aimed to explore the influence of brucine on the early differentiation of osteoblasts and the metabolic pathway of osteoclast in multiple myeloma (MM) and to compare the effects of brucine and bortezomib on MM. The half inhibitory concentration (IC(50)) of brucine and bortezomib on MM cell line U266 was determined by MTT method; the mRNA levels of alkaline phosphatase (ALP), osteocalcin (OC), osteoprotegerin (OPG) and osteoprotegerin ligand (RANKL) were detected by RT-PCR after the supernatant of cultured U266 cells was added into the culture system for inducing the differentiation of osteoblast line MC3T3-E1 and culturing. The results showed that the IC(50)of bortezomib and brucine on U266 cells for 48 hours were 22.4 nmol/L and 0.16 mg/ml respectively. As compared with osteoblasts treated by supernatant of cultured MM cells alone, the mRNA levels of ALP, OC and OPG in osteoblasts treated by brucine combined with supernatant of cultured MM cells were enhanced (p < 0.05), while the RANKL mRNA level was lowered (p < 0.05), moreover the enhanced and lowered degree also was large (p < 0.05). It is concluded that the influence of brucine on metabolism of osteoblasts and osteoclasts in MM may be realized through the regulation of osteoclasts by osteoblasts. The therapeutic efficacy of brucine on MM is superior to bortezomib.

Topics: Animals; Cell Line; Cell Line, Tumor; Humans; Inhibitory Concentration 50; Mice; Multiple Myeloma; Osteoblasts; Osteoclasts; Strychnine

Multiple myeloma (MM) is an incurable hematological malignancy with high incidence in the elderly. The currently used chemotherapeutic drugs show severe side effects, dose-limiting toxicity and development of resistance. In search of novel plant derived anti-cancer agents, Strychnos nux-vomica L. (SN) root extract was screened using the human MM-cell line, RPMI 8226. SN-extract exhibited anti-proliferative activity in a dose and time dependent manner. The morphological assessment of SN-extract treated cells showed significant features associated with apoptosis. Cell cycle analysis using flow cytometry of cells stained with propidium iodide revealed accumulation of cells at sub-G(0)/G(1) phase. In addition, disruption of mitochondrial membrane potential and subsequent leakage of mitochondrial cytochrome c was observed in SN-extract treated myeloma cells. The anti-proliferative and cytotoxic activity could be due to the alkaloids strychnine and brucine, which have been identified by LC-mass spectral analysis of the SN-extract in comparison to the reference standards analyzed under identical conditions.

Topics: Antineoplastic Agents, Phytogenic; Cell Cycle; Cell Line, Tumor; Cell Nucleus; Cell Proliferation; Cell Survival; Cytochromes c; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Flow Cytometry; Humans; Membrane Potential, Mitochondrial; Mitochondria; Multiple Myeloma; Plant Extracts; Plant Roots; Strychnine; Strychnos nux-vomica