Global gene expression profiling in cultured cells is strongly influenced by treatment with siRNA-cationic liposome complexes.
OBJECTIVE
The purpose of this study is to determine if the treatment with siRNA-lipoplexes significantly influences on global gene expression in the treated cells.


METHODS
We investigated global gene expression in a HT1080 cell line by a cDNA microarray. We also evaluated the effect of lipofection on global gene expression by determining the change of the expression of an exogenous gene, green fluorescence protein (GFP), and also determined treatment-related cytotoxicity.


RESULTS
Treatment of the cells with either siRNA-lipoplexes or cationic liposomes altered the expression of approximately 2,500 genes. When lipoplexes containing non-specific siRNAs were used, GFP expression was enhanced. In this case the effect was independent on the dose and type of siRNA in the formulation. By contrast, when lipoplexes containing a specific siRNA against GFP was used, GFP expression was markedly diminished. These results clearly indicate that an efficient reduction of a targeted gene expression by a specific siRNA is accompanied by a significant alteration of the expression of numerous non-targeted genes. In addition, treatment-related cytotoxicity increased with siRNA- and cationic lipid-doses, but was not dependent on siRNA type.


CONCLUSIONS
Non-specific effects of siRNA-lipoplexes may either enhance, attenuate or even fully mask the desired outcomes of siRNA-based biochemical studies and therapies.
Tagami
Tatsuaki
T
Department of Pharmacokinetics and Biopharmaceutics, Subdivision of Biopharmaceutical Sciences, Institute of Health Biosciences, The University of Tokushima, 1-78-1 Sho-machi, Tokushima 770-8505, Japan.
Hirose
Kiyomi
K
Barichello
Jose Mario
JM
Ishida
Tatsuhiro
T
Kiwada
Hiroshi
H
D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D020869:Gene Expression Profiling; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D008081:Liposomes; D020411:Oligonucleotide Array Sequence Analysis; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000494:pharmacology
D008081:Liposomes; D034741:RNA, Small Interfering; D049452:Green Fluorescent Proteins