[Inhibitory effect of silencing STAT3 gene with short hairpin RNA mediated by polyamidoamine dendrimers on growth of prostate cancer].
OBJECTIVE
To investigate the possibility of using generation 5 polyamidoamine dendrimers (G5-PAMAM-D) as gene vector for eukaryotic expression plasmid of siRNA in prostate carcinoma in vitro and vivo.


METHODS
Firstly, eukaryotic expression vector of siRNA pSilencing 4.1-EGFP-shRNA, specific for enhanced green fluorescent protein (EGFP), pSilencing 4.1-STAT3-shRNA for signal transducers and activators of transcription 3 (STAT3) was constructed. pEGFP-C1 and pSilencing 4.1-EGFP-shRNA were cotransfected into prostate cancer cells PC-3 and 22Rv1 with G5-PAPAM-D as vector, and to observe silencing of EGFP. Next, pSilencing 4.1-STAT3-shRNA was transfected into PC-3 and 22Rv1 cells by G5-PAPAM-D, Western blotting and apoptosis staining was used to detect silencing of STAT3 and growth inhibition. Thirdly, BALB/C mice subcutaneous tumor model was made with PC-3 cells. Polyplex of G5-PAMAM-D and pSilencing 4.1-STAT3-shRNA was injected intratumorally. The tumor volume was measured and recorded.


RESULTS
Fluorescence detection and Western blotting analysis demonstrated that G5-PAMAM-D was able to deliver Silencing 4.1-EGFP-shRNA and pSilencing 4.1-STAT3-shRNA into the two prostate cancer cell lines, and shRNA was expressed to induce silence of EGFP and STAT3. MTT results showed that proliferation of prostate cancer cells was suppressed by G5-PAMAM-D/pSilencing 4.1-STAT3-shRNA and induced apoptosis of PC-3 cells in vitro. Human prostate cancer in mice was successfully formed by inoculation of PC-3 cells into male BABL/C mice. In G5-PAMAM-D/pSilencing 4.1-STAT3-shRNA treated group, the tumor volume was shrank remarkably at 9 days after treatment and tumor growth was retarded compared with control groups.


CONCLUSIONS
GS-PAMAM-D nanoparticles can be used to deliver plasmid vector expressing shRNA into prostate cancer cells effectively in vitro and vivo. It appears to be a promising gene vector for RNA interference therapy in prostate cancer.
Zhao
Wei-ming
WM
Second Hospital of Tianjin Medical University, Tianjin Institute of Urology, Tianjin 300211, China.
Xiu
You-Cheng
YC
Xu
Yong
Y
Wang
Yan-ming
YM
Cheng
Zhao-kang
ZK
Yu
Qi
Q
Kong
De-ling
DL
D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D050091:Dendrimers; D020868:Gene Silencing; D005822:Genetic Vectors; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D053758:Nanoparticles; D009368:Neoplasm Transplantation; D010957:Plasmids; D011073:Polyamines / Q000737:chemistry; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D034741:RNA, Small Interfering / Q000235:genetics*; D050796:STAT3 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D047368:Tumor Burden
D050091:Dendrimers; C104700:PAMAM Starburst; D011073:Polyamines; D034741:RNA, Small Interfering; D050796:STAT3 Transcription Factor