Scientists from the University of Chicago Medical Center have found molecular evidence that bioflavonoids, which are ordinarily considered quite beneficial, can cause breaks in DNA that could trigger the development of infant leukemias. Bioflavonoids are found at high levels in many foods, including soybeans, fruits, root vegetables and herbs, and are often ingested in high concentrations as dietary supplements.
The researchers found that 10 out of the 20 bioflavonoids tested caused breaks in one small region of a gene known as MLL, which is a key player in about 80 percent of infant leukemias. Some bioflavonoids were as active in causing DNA damage as the powerful anti-cancer drug etoposide (VP16), which has been tied to secondary leukemias -- cancers of the bone marrow that result from previous anti-cancer therapy.
"Although bioflavonoids may be beneficial in certain circumstances, our studies suggest that high dietary intake of bioflavonoids could cause DNA breaks in MLL and possibly in other partner genes," note the authors in the April 11 issue of the Proceedings of the National Academy of Sciences.
The DNA damage seen after exposure to either bioflavonoids or to anti-cancer drugs VP16 or doxorubicin (Dox) was identical, affecting one small region of the MLL gene. Although most adult leukemias involving MLL affect a different part of the gene, the breakpoints found in infant leukemias and secondary leukemias occur predominantly in the small region altered by the bioflavonoids.
"This strongly supports the notion that bioflavonoids could be a causative agent for infant and possibly childhood leukemias," continue the authors. "Maternal ingestion of bioflavonoids may induce MLL breaks and potentially translocation in utero," they conclude, "leading to infant and early childhood leukemias."
Infant leukemias are rare, affecting only about 37 out of every million children in the United States. Some researchers have argued th
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Contact: John Easton
jeaston@uchospitals.edu
773 702 6241
University of Chicago Medical Center
10-Apr-2000