Oncolytic adenovirus mediated Survivin knockdown by RNA interference suppresses human colorectal carcinoma growth in vitro and in vivo.
BACKGROUND
Colorectal cancer is a one of the most common alimentary malignancies. Survivin has been proved by many studies to be an ideal target for cancer gene therapy because of its strong anti-apoptotic effect. The reduction of Survivin expression by means of chemically synthesized small interfering RNA or small hairpin RNA expressed from plasmid and resulted growth inhibition of cancer cells had been proved by many studies including ours, but the transfection efficiency was not encouraging. So for the first time we constructed the Survivin shRNA into an oncolytic adenovirus, tested its effects on colorectal cancer cell lines and nude mice xenograft model.


METHODS
In this study, we constructed an oncolytic adenovirus with a Survivin targeted small hairpin RNA and a reporter gene (ZD55-Sur-EGFP). The expression of Survivin mRNA and protein were analyzed by RT-PCR and western blot. The cell growth and apoptosis were tested by in vitro cytopathic assay, MTT assay and flow cytometry respectively. The effect of the constructed virus on xenograft model was evaluated by tumor volume and western blot analysis.


RESULTS
ZD55-Sur-EGFP replicated in cancer cells specifically, reduced the expression of Survivin mRNA and protein expression effectively (P < 0.0001), induced cancer cell apoptosis and inhibited SW480 cell growth both in vitro and in vivo significantly.


CONCLUSIONS
We conclude Survivin RNA interference combining with oncolytic adenovirus virotherapy to be a promising treatment for colorectal cancer.
Shen
Wei
W
Department of General Surgery, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, PR China. toby_shenwei@hotmail.com
Wang
Chun-Yi
CY
Wang
Xue-Hu
XH
Fu
Zhong-Xue
ZX
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000235:genetics / Q000517:prevention & control* / Q000821:virology; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D051034:Inhibitor of Apoptosis Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D008869:Microtubule-Associated Proteins / Q000502:physiology*; D050130:Oncolytic Virotherapy; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077022:Survivin
C107489:BIRC5 protein, human; C117749:Birc5 protein, mouse; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D000077022:Survivin; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins