sanare lab fenbendazole The antihelminthic drug fenbendazole, used to treat rodent pinworm infections, inhibits tumor growth in vitro. During an 8-wk facility treatment for Aspiculuris tetraptera pinworms at our institution, however, well established human lymphoma xenografts failed to grow in C.B-17/Icr-Prkdcscid/Crl (SCID) mice fed a diet containing fenbendazole and additional vitamins. The fenbendazole and vitamin concentrations in the vendor-supplied diet had decreased between order and shipment, and these reduced concentrations may have impaired the effects of the diet on cancer growth.
In cell culture, 2-h treatments with fenbendazole were not toxic to aerobic EMT6 monolayer cultures and produced no changes in the number of cells in cultures, even at concentrations approaching the limit of solubility. A 24-h fenbendazole treatment, on the other hand, significantly reduced both the clonogenicity of EMT6 cells and the yield-corrected surviving fractions of cultures (Figure 1).
To compare these in vitro data to in vivo tumorigenesis in BALB/cRw mice, the growth of unirradiated and irradiated EMT6 tumors was monitored. Tumor-bearing mice were randomized to receive three i.p. injections of fenbendazole, 10 Gy of x-rays alone, or a combination of fenbendazole and x-rays. Tumor growth was measured over time, and the results are shown in Table I. Time to four-fold volume data were rigorously compared among groups, and the data confirmed that fenbendazole had neither an effect on the growth of unirradiated tumors nor a synergistic effect with x-rays. We also analyzed irradiated tumor growth after three fenbendazole treatments and found that the results were consistent with the time to four-fold volume data in Table I.