Narrator: This is Science Today. New evidence in cancer development has uncovered a molecular dialogue between cells that can trigger the onset of cancer. A team of researchers at the University of California, San Francisco, including urologic oncologist Gary Grossfeld, discovered abnormal epithelial cells from human prostates that were part-way towards becoming cancerous, were finally pushed towards cancer by neighboring cells called carcinoma-associated fibroblasts.

Grossfeld: We found that when the initiated cells were grown with normal fibroblasts that they did not form tumors. But when they were grown with carcinoma-associated fibroblasts, large tumors formed.

Narrator: Current treatment targets epithelial cells, which line the surfaces of many organs besides the prostate, and are the cells from which most cancers - including breast and colon - arise. But these findings suggest therapy may instead be directed towards these carcinoma-associated fibroblasts.

Grossfeld: Our eventual goal is actually to discover how these cells talk to each other. If we can figure out how they talk to each other and what's abnormal, if we can interrupt that, I think that then we can treat patients and I think it's very, very exciting.

Narrator: For Science Today, I'm Larissa Branin.