Figure 4.

IV administered E. coli specifically colonizes tumors in mice. Subcutaneous LLC tumors were induced in MF1 nu/nu mice and bacteria administered upon tumor development (12–14 days; average tumor volume 100 mm³). For intravenous administration, each animal received 10⁶ cells injected directly into the lateral tail vein. (a) Recovery from subcutaneous tumor tissue (bars, y axis) and bacterial lux expression in vivo in live mice (black circles, z axis and images). Time scale (x axis) is time in days after bacterial administration. Increase in bacterial numbers and lux gene expression specifically in tumors was observed over time. (b) There was no detectable luminescence in organs of treated animals LLC, Lewis lung carcinoma.