Suppression of Protein Levels but not mRNA using siRNA

[gandalfthegrey]

Hi everyone,
I have suppression at the protein levels but not at the RNA level!

I created stable cell lines with siRNA which were under drug selection. I have seen almost a 90% reduction in protein levels, however there is no or little change at the mRNA / RNA levels.

What is going on?

I have repeated the western blots several times to confirm.

Has anyone encountered a similar problem?
please help

[Jon Moulton]

It sounds like your siRNA might not be completely complementary to the target mRNA for which you are assaying the corresponding protein. Translation inhibition is the usual miRNA effect, and generally accompanies siRNA knockdowns as inhibition of translation from off-target genes.

Short interfering RNAs can induce unexpected and divergent changes in the levels of untargeted proteins in mammalian cells. Scacheri PC, Rozenblatt-Rosen O, Caplen NJ, Wolfsberg TG, Umayam L, Lee JC, Hughes CM, Shanmugam KS, Bhattacharjee A, Meyerson M, Collins FS. Proc Natl Acad Sci U S A. 2004 Feb 17;101(7):1892-7. Epub 2004 Feb 09.