Fig. 4.
A. In cell culture tests, anti-Grm1 siRNA, but not anti-GFP control siRNA, constructs introduced into iBMK-Grm1 cells permitted doxycycline-inducible knockdown of Grm1 at the protein level as assessed by immunoblots. Grm1 expression as percentage of control, by densitometry.
B. In vivo inhibition of tumor development by anti-Grm1 siRNA. Mice bearing allografted tumors developing from W2- and D3-Grm1-siGrm1 cells from Fig. 4a were treated with doxycycline (0.1% w/v in drinking water) to induce siRNA expression to knockdown levels of Grm1. Results indicated sustained expression of Grm1 is necessary to maintain W2- and D3-Grm1 tumor progression (respectively P < 0.05 and P < 0.001, t test, n=20). No significant differences in tumor growth were observed between doxycycline treated and untreated W2- and D3-Grm1-siGFP (control siRNA) mice.