[Effect of curcumin in combination with bortezomib on proliferation and apoptosis of human multiple myeloma cell line H929 and its mechanism].

This study was aimed to investigate the effect of curcumin in combination with bortezomib on the proliferation and apoptosis of human MM cell line H929 in vitro, and to explore its mechanisms. MTT assay was applied to detect the inhibitory effects of curcumin and bortezomib either alone or combined at different concentrations on H929 cells, and flow cytometry was employed to assay the apoptosis rate. In addition, RT-PCR was used to analyze the mRNA expression of gene BCL-2, BAX, cyclin D1. Immunofluorescence technique was performed to study the location changes of NF-κB P65 in different groups. The results showed that both curcumin and bortezomib inhibited the proliferation of MM cell line H929 in dose-dependent manner, and combination of these two drugs displayed synergistical effect. A much higher apoptosis rate was determined by flow cytometry in combinative groups than that in single or control group. And RT-PCR showed, as compared with curcumin or bortezomib group, there was mRNA expression decrease of BCL-2, cyclin D1 but increase of BAX in combined group. The expression of NF-κB P65 in nucleus was downregulated in either the curcumin or bortezomib group, however, distribution of NF-κB P65 in cytoplasm was observed in combined group. It is concluded that the combination of curcumin and bortezomib is much more effective for the inhibiting proliferation and promoting apoptosis of H929 cell line, which may function by inhibiting the transcription of NF-κB and apoptosis-related genes.