Brown University and Rhode Island Hospital researchers discovered a process by which cellular receptors involved in signaling breast milk production in women may be linked to cancer. The team of researchers published their findings in the Proceedings of the National Academy of Science journal, according to a press release.
According to Eugene Chin, associate professor of surgery at Alpert Medical School and lab director, these cells are equipped with receptors for prolactin, a hormone secreted by the pituitary gland. Prolactin is responsible for triggering the production of milk in the mammary gland.
While prolactin receptors are essential for the secretion of milk, having too many of them can be dangerous, Chin said. Normally, these receptors are repelled by each other's like charges. But when prolactin binds to the receptor site, it initiates a chemical process in the cell called "acetylation," which can neutralize the receptors' charge, allowing them to bind into "dimers."
"How they form the dimer is what we study," Chin said.
"When the prolactin receptor is over-expressed, that can cause cancer," said Chin. When two receptors bind to form a dimer, they work in a way that Chin compared to chopsticks. Together, they pick up and over-express cancerous cell growths.
From their findings, the research team is continuing to explore relations between prolactin receptors and therapeutic cancer treatment.
"It can be valued in breast cancer," said Li Ma, a post-doctoral researcher in the lab and principal author of the paper. "It has clinical significance" and possibly therapeutic significance, she said.
"It is very important to the whole world," she added.
"Right now we are trying to develop an antibody to therapeutically use for breast cancer patients, especially those who have over-expressed prolactin receptors," said Chin.
Ma also said the process of acetylation is not linked solely to prolactin receptors. "This is not a single phenomenon — it is a common phenomenon. We are now looking at other receptors."
Members of the research team said they think they can link this process in other cell receptors to other forms of cancer. Zhe Zhang, co-author of the paper, said, "The mechanism can be applied to other receptors, not just prolactin receptors. This mechanism may be used for clinical therapy."
