Dianthin-EGF is an effective tumor targeted toxin in combination with saponins in a xenograft model for colon carcinoma.

Aims: The intention of this work was to lift saponin supported tumor targeted therapies onto the next level by using targeted toxins in nude mice xenotransplant models.

Materials & Methods: Combined application of dianthin coupled to EGF and saponin SO-1861 was tested in a xenograft model of colon carcinoma. In vitro cytotoxicity was tested in real-time in NIH3T3 cells (no human EGF receptor expression), HER14 and human colon carcinoma HCT116 (both EGF receptor overexpressing) cells. A xenograft model was established using HCT116 cells and tumor-bearing animals were treated with SO-1861 (30 µg/treatment) and dianthin coupled to EGF (0.35 µg/treatment). Tumor progression was monitored, using (18)F-2-fluor-2-desoxy-d-glucose, by small animal PET and by x-ray computed tomography.

Results: In vitro results demonstrated a high-receptor specificity and the in vivo experiment showed a progressive reduction of the tumor volume and glycolytic activity in the treated group (>95% reduction; p < 0.05).

Conclusion: This therapy has great advantage because of high specificity, low side effects and great effectiveness for future development in the treatment of colon cancer.