"We also found many changes in the DNA damage pathway genes," Ittmann said. These genes reduce the negative effects of DNA changes on cells - either by correcting the DNA or prompting cell death. "This implies that there may be different kinds of DNA damaging stimuli going on in the stroma as well as cancer cells," said Ittmann. "DNA damage could be related to mutations in the stroma."

The researchers also found changes in growth factor pathways, including those for fibroblast growth factor and transforming growth factor beta as well as pathways linked to the growth and maintenance of stem cells, said Ittmann.

While many of the gene changes they found may have no role in prostate cancer, the report lays the groundwork for determining which players and processes may have a role, he said.

"One question is what are the pathways turning on some of these genes in response to signals from the cancer cells," he said. "This description is the start," said Ittmann. "Now we can work on the mechanisms."

"We know that of all men who get prostate cancer, only about 10 percent would die of it," he said. "Of those who have disease localized to the prostate gland, only 5 percent would die from the disease. How do we differentiate those who really need treatment from those who might not? Can we identify the biomarkers that differentiate those? There is probably more than one marker and some may be stromal-based."

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