HNSCC cells were inoculated either subcutaneously or intradermally and were randomized either after tumors were well-established (23 days, 6–8 mm, UMSCC-11A) or after palpable tumors were observed (5days, 3–4 mm, FaDu). Nanocapsules containing anti-CK2α/α′ ODN were administered at 10 μ/kg every three days. (A) Left panel: UM-SCC 11A tumor bearing mice were treated i.p. with three doses of anti-CK2α/α′ ODN (n=4), while control animals (n=5) received equivalent dosing with diluent or nanoencapsulated anti-GAPDH ODN. Tumor dimensions were measured by caliper and reported at day 7. The second left panel: FaDu tumor bearing mice were treated i.v. with two doses of anti-CK2α/α′ ODN (n=6) 48 hours apart; tumor size was reported at day 7 compared with diluent controls (n=8). * indicates statistical significance p<0.05, and ** indicates p<0.01. (B) IHC was performed using UM-SCC 11A tumors harvested on day 7 after anti-CK2α/α′ ODN treatment and compared with controls. Photomicrographs were taken by light microscopy at 400× magnification.