[Effects of small interfering RNA magnetic nanoparticles combination with external magnetic fields on survivin gene expression of bladder cancer cells and apoptosis].
OBJECTIVE
To investigate the effects of the small interfering RNA plasmid-dextran magnetic nanoparticles (siRNA-DMN) combination with external magnetic fields on silencing survivin gene expression of bladder cancer cells and apoptosis when DMN used as gene carrier to transfer siRNA-survivin recombinant plasmid in vivo.


METHODS
The siRNA-survivin recombinant plasmid specific targeted survivin was synthesized in previous experiment. DMN were prepared by chemical coprecipitation method and used as gene carrier. The siRNA-DMN were constructed by static electricity of polylysine and transferred into human bladder cancer BIU-87 cells with the help of external magnetic fields. The growth inhibiting rate (IR) of BIU-87 cells was observed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide's test and the apoptosis index (AI) was detected by transferase-mediated dUTP nick end labeling method. The relatively transcription levels of survivin mRNA and protein expression were respectively detected by semi-quantitive reverse transcription polymerase chain reaction and Western Blotting techniques.


RESULTS
The diameter, effective diameter and saturation magnetization of DMN-siRNA were about 10 - 12 nm, 94.8 nm and 0.19 emu/g, respectively. The IR (39.60%) and AI (28.72%), the relative expression of survivin mRNA and protein of siRNA-DMN combination with external magnetic fields on BIU-87 cells were significantly higher and lower than those in the control group and single siRNA-DMN group, respectively (P < 0.05).


CONCLUSIONS
The siRNA-survivin plasmid-DMN combination with external magnetic fields could effectively inhibit survivin expression and induce BIU-87 cells apoptosis which provided experimental basis for the magnetic targeting gene therapy of bladder tumor.
Cao
Zheng-guo
ZG
Department of Urology, Anhui Provincial Hospital, Anhui Medical College, Hefei 230001, China.
Zhu
Yu-ping
YP
Zhou
Si-wei
SW
Liu
Ji-hong
JH
Qi
Lin
L
Zhu
Ming
M
Ye
Zhang-qun
ZQ
D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D004574:Electromagnetic Fields; D015972:Gene Expression Regulation, Neoplastic; D005822:Genetic Vectors; D005936:Glucans; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000235:genetics*; D053758:Nanoparticles; D009363:Neoplasm Proteins / Q000235:genetics*; D010957:Plasmids; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000494:pharmacology*; D000077022:Survivin; D014162:Transfection / Q000379:methods; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*
C107489:BIRC5 protein, human; D005936:Glucans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000077022:Survivin