Healthy mammary cells may kill cancer cells--study

Scientists form the US Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), and the University of California, Irvine in California, have found the protein interleukin-25(IL-25), amongst six factors secreted by the breast epithelial cells, to be most effective in anti-cancer activity.

"We found that normal breast cells provide an innate defense mechanism against cancer by producing interleukin 25 to actively and specifically kill breast cancer cells," said breast cancer authority and study lead Mina Bissell, of Berkeley Lab's Life Sciences Division.

She added, "This suggests that IL25 receptor signaling may provide a new therapeutic target for the treatment of breast cancer."

Study co-author Saori Furuta, a postdoctoral fellow at Berkeley lab said, "The major function (of IL-25) people have studied so far is its role in inflammatory response."

"It's actually highly expressed in immune cells in response to stress or some diseases or pathogens."

IL-25 is specific to tumor cells
After staining 69 samples of both cancerous and noncancerous breast cells with IL-25 receptor antibodies, researchers observed the cancerous cells remained stained, showing that IL-25 receptors are tumor specific and can be a good marker of cancerous tissue.

In another experiment, 15 breast tumor injected mice showed three times smaller tumor size with no side effects when treated daily with IL-25 compared with saline placebo treatment.

A new tumor killer
Furuta said, "A number of tumor surveillance mechanisms have been described in the past, including the classic molecular tumor suppressors, immune surveillance, and suppression by the extracellular matrix and other micro-environmental factors.

"We are now adding a new type of tumor suppression to this list, IL25 and other proteins secreted by normal breast cells that kill or subdue their mutated neighbors."

"Since IL25 is produced by healthy breast tissue as a natural defense mechanism against cancer during the cell differentiation process, we should be able to utilize IL25/IL25 receptor signaling as an organic approach to breast cancer therapy," Furuta said.

The team is examining five other proteins they found for a more effective breast cancer treatment.

The findings were published online in the journal ‘Science Translational Medicine.’