[Downregulation of HER2 by adenovirus-mediated RNA interference and its inhibitory effect on growth of SKBR3 breast cancer cell].
OBJECTIVE
To explore the possibility of RNA interference (RNAi)-based gene therapy against HER2-overexpressing tumors using adenovirus-mediated vector.


METHODS
A plasmid named pHER2-GFP containing HER2 and green fluorescent protein (GFP) fusion was constructed and cotransfected into CHO-K1 cells respectively with nine small interference RNA (siRNA)-expressing plasmids targeting different regions of HER2. The siRNA-expressing plasmids with best interference effect were screened out and then used to identify the gene silence effect in HER2-overexpressing SKBR3 breast cancer cells. Subsequently, the siRNA-expressing cassettes were subcloned into adenoviral vectors. Downregulation of HER2 by adenovirus-mediated RNAi and its effect on SKBR3 cell proliferation were identified again.


RESULTS
Two siRNA-expressing plasmids with best interference effect were screened out and HER2 was also efficiently downregulated in SKBR3 cells infected with the adenovirus containing these siRNA-expressing cassettes. Downregulation of HER2 resulted in the increase of cells in G1 phase and the induction of apoptosis. Furthermore, infection of adenovirus inhibited SKBR3 cell growth, which was confirmed by MTT and cell long-term proliferation assays.


CONCLUSIONS
The adenovirus-mediated RNAi could downregulate the HER2 expression efficiently and exert an inhibitory effect on growth of HER2-overexpressing breast cancer cell.
Cheng
Lian-sheng
LS
School of Life Science, University of Science and Technology of China, Anhui Province Key Laboratory of Molecular Medicine, Hefei 230027, China.
Zha
Zhao
Z
Xi
Jia-jia
JJ
Jiang
Bing
B
Liu
Jing
J
Yao
Xue-biao
XB
D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D006224:Cricetinae; D003412:Cricetulus; D015536:Down-Regulation; D015316:Genetic Therapy / Q000379:methods; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016133:Polymerase Chain Reaction; D034622:RNA Interference / Q000502:physiology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism*
D049452:Green Fluorescent Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases