WEDNESDAY, Sept. 27 (HealthDay News) -- A new class of iron chelators may be especially effective as therapeutic agents for cancers that have acquired the multi-drug-resistance phenotype, according to a study in cultured human cancer cells and in mice with human xenografts. The study was published online Sept. 26 in the Proceedings of the National Academy of Sciences Early Edition.
Since cancer cells have an increased requirement for iron compared with normal cells, Des R. Richardson, Ph.D., of the Children's Cancer Institute Australia for Medical Research in Sydney, and colleagues sought to evaluate the anti-tumor activity and iron chelation efficacy of a new class of iron chelators.
The most effective chelator -- called Dp44mT (di-2-pyridylketone-4,4,-dimethyl-3-thiosemicarbazone) -- inhibited growth of tumor cell lines resistant to chemotherapeutics like etoposide and vinblastine. Dp44mT also reduced the growth of melanoma xenografts in mice by 92 percent after seven weeks compared with control. The doses required for the anti-tumor effect were low enough to avoid systemic iron depletion.
"These results indicate that the novel iron chelators have potent and broad anti-tumor activity and can overcome resistance to established chemotherapeutics because of their unique mechanism of action," the authors conclude.