Cancer study gives insight into biomarkers

CHICAGO, March 14 (UPI) -- A study showing that genistein, a soy compound, halts the spread of prostate cancer in mice provides a lesson about biomarkers, a U.S. researcher observes.

"This is really a lesson for researchers who depend on biomarker studies to test whether a treatment is working," Dr. Raymond Bergan, the study's senior researcher at Northwestern University, said in a statement. "They need to be aware that those biomarkers might be telling only half of the story."

The study, published in Cancer Research, found that feeding genistein to mice with aggressive human prostate cancer reduced the spread of cancer to the lungs by 96 percent. However, the mice expressed higher levels of genes that are involved in cancer cell migration, which at first might not make sense, Bergman said..

"What we think is happening here is that the cells we put in the mice normally like to move," he said. "When genistein restricted their ability to do so, they tried to compensate by producing more protein involved in migration. But genistein prevented those proteins from being activated."

In previous studies, researchers found genistein in prostate cancer cell cultures blocks activation of p38 MAP kinases -- molecules that activate proteins that loosen cancer cells from their tight hold within a tumor and push them to migrate, Bergman said.