Figure 3. 3E10 scFv localizes to tumor cell nuclei in vivo.

Immunodeficient mice bearing subcutaneous U87 human glioma xenografts were treated by intraperitoneal injection of control buffer or 3E10 scFv. Mice were sacrificed 4 or 24 hours after treatment, and tumors and select normal tissues were immunostained for the presence of 3E10 scFv. Brown nuclear stain indicates presence of 3E10 scFv, while blue nuclear stain is negative. (A) Four hours after treatment 3E10 scFv was detected in the nuclei of the U87 tumor cells but was not detected in tissues of major organs including heart, kidney, skeletal muscle, and liver. These results are consistent with preferential uptake of 3E10 scFv into tumors. (B) Twenty-four hours after treatment 3E10 scFv was still detectable in the tumors, demonstrating the stability of the uptake into tumor nuclei.