[Effect of human recombinant PDCD5 protein on cell apoptosis of multiple myeloma KM3 cells induced by dexamethasone and its mechanism].
OBJECTIVE
To observe the effect of programmed cell death 5 (PDCD5) protein on the apoptosis of multiple myeloma KM3 cells induced by dexamethasone and to understand its mechanism.


METHODS
The human recombinant PDCD5 (rhPDCD5) protein was added (alone of different concentrations or associated with dexamethasone) into KM3 cells. Cultured together for certain time, the cells were collected for the following experiments: (1)The effect of rhPDCD5 protein and dexamethasone on the apoptotic rate of KM3 cells was determined by flowcytometry (FCM) analysis after the cells were stained by Annexin V-FITC & PI (propidium iodide). (2)Caspase-3 activity of KM3 cells was evaluated by Western blot. (3)The expression of survivin protein in KM3 cells was detected by immunocytochemistry.


RESULTS
The apoptotic rate of KM3 cells and the activity of caspase-3 increased significantly, and that treated with rhPDCD5 protein and dexamethasone was higher than that treated with rhPDCD5 protein only. The expression of survivin protein in the rhPDCD5 with dexemethas group was down-regulated, and with the concentration of rhPDCD5 and dexamethasone increasing, the changes was more obviously.


CONCLUSIONS
PDCD5 protein can induce the apoptosis of KM3 cells, and accelerate the apoptosis of KM3 cells induced by dexamethasone. PDCD5 protein may reduce the expression of survivin protein and increase activation of caspase-3 to play its role in promoting apoptosis.
Liu
Jing
J
Department of Hematology, Third Xiangya Hospital, Central South University, Changsha 410013, China. jingliu0318@yahoo.com.cn
Li
Xin
X
Gui
Rong
R
Jiang
Tiebin
T
Wang
Erhua
E
D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000494:pharmacology*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D003907:Dexamethasone / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism; D009101:Multiple Myeloma / Q000473:pathology*; D009363:Neoplasm Proteins / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000494:pharmacology; D000077022:Survivin
D051017:Apoptosis Regulatory Proteins; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D009363:Neoplasm Proteins; C117283:PDCD5 protein, human; D011994:Recombinant Proteins; D000077022:Survivin; D003907:Dexamethasone; C505407:CASP3 protein, human; D053148:Caspase 3