[Biological implications of the inhibition of survivin by RNA interference in human androgen-independent prostate carcinoma with highly metastatic potential].
OBJECTIVE
To determine the expression level of survivin in androgen-independent prostate carcinoma, and to investigate the biological role of survivin in invasion and metastasis of androgen-independent prostate carcinoma.


METHODS
Highly metastatic prostatic cancer cell line PC-3M-1E8 was stably transfected with pSilencer plasmid targeting survivin expression by RNA interference. The biological effects were observed, including anchorage-independent growth, in vitro invasion by soft agar colony formation and Boyden chamber assay, and also in vivo tumorigenesis in nude mice. Cell cycle and apoptosis indices were evaluated by flow cytometry and Western blot analysis of bioactive fragments of caspase 3.


RESULTS
The expression of survivin in transfected PC-3M-1E8 cells was markedly depressed at both mRNA and protein levels (about 78% to 80%) as compared with control. The growth of tumor cells was retarded by anchorage-independent growth assay. The survivin transfectants formed smaller and fewer colonies (14.33 +/- 3.51) than the negative (52.33 +/- 6.81) and blank controls (54.00 +/- 6.00). Inhibition of survivin expression was correlated with enhanced apoptosis of tumor cells (percentages of apoptotic cells of the negative control, blank control and experimental groups were 5.88 +/- 0.99, 6.97 +/- 1.60, 16.40 +/- 1.95 respectively), along with an increased expression of activated caspase 3, and cell cycle inhibition at G(0)/G(1) phase (the relative number of cells at G(0)/G(1) phase were 43.65 +/- 3.44, 43.59 +/- 1.83 and 52.71 +/- 1.10, respectively). In addition, multinucleated giant cells were observed along with a marked inhibition of invasion as reflected by fewer penetrating cells by Boyden chamber assay (46.07 +/- 9.97, 47.87 +/- 9.58 and 38.67 +/- 6.59, respectively).


CONCLUSIONS
Survivin expression is high in androgen-independent prostate cancer cells and likely may be related to the apoptosis, growth and invasion of the tumor cells. Targeting the survivin pathway by RNA interference appears to be a promising approach for clinical treatment of androgen-independent prostate cancer.
Zhu
Xiang
X
Department of Pathology, Health Science Center, Peking University, Beijing 100083, China.
Ning
Jun-yu
JY
You
Jiang-feng
JF
Wang
Jie-liang
JL
Cui
Xiang-lin
XL
Fang
Wei-gang
WG
Zheng
Jie
J
D000728:Androgens / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000378:metabolism; D041681:NIH 3T3 Cells; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D034622:RNA Interference; D000077022:Survivin; D014162:Transfection; D014183:Transplantation, Heterologous
D000728:Androgens; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D000077022:Survivin; D049452:Green Fluorescent Proteins; D053148:Caspase 3