Figure 3.

Intratumoral administration of EGFR antisense plasmid DNA has antitumor efficacy. One million SCCHN cells (1483) were injected subcutaneously into six athymic nude mice on both flanks. EGFR sense plasmid DNA (■) or antisense plasmid DNA (▲) (25 μg/tumor) was administered daily into the left and right tumor respectively. Tumors were measured twice a week. The graph depicts growth of the tumors over the treatment period. B: EGFR antisense gene therapy reduces SCCHN xenograft cell proliferation. SCCHN tumors treated with either EGFR antisense or sense gene therapy were paraffin-embedded and examined for proliferation using Ki-67 staining. Positive cells demonstrated by the dark brown nuclear staining were counted under 400X magnification in 10 separate fields. There was a significant difference between tumors treated with EGFR antisense oligonucleotides compared to the control (p= 0.0001). Error bars indicate ± SEM.