Combination of active and inactive siRNA targeting the mitotic kinesin Eg5 impairs silencing efficiency in several cancer cell lines.
Gene silencing by RNA interference (RNAi) has proven to be a powerful tool for investigating gene function in mammalian cells. Combination of several short interfering RNA (siRNA) targeting the same gene is commonly used to improve RNA interference. However, in contrary to the well-described mechanism of RNAi, efficiency of single siRNA compared to pool remains poorly documented. We addressed this issue using several active and inactive siRNA targeting Eg5, a kinesin-related motor involved in mitotic spindle assembly. These siRNA, used alone or in combination, were tested for their silencing efficiency in several cancer cell lines. Here we show that presence of inactive Eg5 siRNA in a pool dramatically decreases knockdown efficacy in a cell line- and dose-dependent manner. Lack of inhibition by unrelated siRNA suggests that a competition may occur during siRNA incorporation into RNA-induced silencing complexes (RISCs) along with the target mRNA. Altogether, our results, which need to be confirmed with additional inactive siRNA, indicate that combination of siRNA may not increase but instead decrease silencing efficiency.
Formstecher
Etienne
E
Hybrigenics SA, 75014 Paris, France.
Reverdy
Celine
C
Cholay
Mickael
M
Planquette
Cecile
C
Trouplin
Virginie
V
Lehrmann
Heike
H
Aresta
Sandra
S
Calabrese
Alessandra
A
Arar
Khalil
K
Daviet
Laurent
L
Colland
Frederic
F
D001483:Base Sequence; D045744:Cell Line, Tumor; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D016547:Kinesins / Q000037:antagonists & inhibitors* / Q000235:genetics*; D008938:Mitosis / Q000187:drug effects / Q000235:genetics; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology*; D014162:Transfection
D018076:DNA, Complementary; C470243:KIF11 protein, human; D034741:RNA, Small Interfering; D016547:Kinesins