By Will Boggs, MD NEW YORK (Reuters Health) –
A vitamin D formulation, combined with antibodies against a cancer-associated protein, targets breast cancer cells in mice and inhibits tumor growth, according to a report in the International Journal of Cancer. Specifically, researchers found that the vitamin D formulation, D5, combined with antibodies against the Her-2 protein, killed Her-2-positive breast cancer cells in both laboratory experiments and in mice. Vitamins and other natural products that inhibit the growth of cancer cells in the laboratory could be developed to prevent or treat various types of cancer, Dr. Rajeshwari R. Mehta from University of Illinois at Chicago told Reuters Health. "Targeted delivery of micronutrients will be safe and nontoxic."
Mehta and colleagues previously showed that D5 had potent anticancer effects on breast cancer cells in laboratory experiments. Here they examined the possible therapeutic potential of targeted delivery of D5 to Her-2-overexpressing breast cancer cells implanted in mice. The D5-Her-2 compound inhibited the growth of breast carcinoma cells in the test tube, and also significantly reduced the average tumor volumes in female mice that were transplanted with these breast carcinoma cells, the report indicates. Tumor volumes were similar to those seen in mice that received dietary D5 supplement and smaller than those seen in mice treated with Her-2 antibody alone.
D5 alone, administered directly into the abdominal cavity, did not reduce tumor volumes, the researchers note. "We are currently testing whether Herceptin, a humanized Her-2 antibody, (combined with) D5 is more effective than either agent given alone," Mehta said. "Once we find promising results in experimental animals, the next step will be to study its toxicity." This approach could be used for any cancer, the researcher noted. This "immunoconjugate therapy" might also be useful in reducing drug-associated toxicity, Mehta added. "We can use reduced dose and still could get optimum effect without compromising safety."
SOURCE: International Journal of Cancer, March 1, 2004. Via Yahoo! news.