Scientists find new mechanism that causes cancer

Scientists find new mechanism that causes cancer

Washington: Scientists have discovered a key chemical process in the body which sometimes goes wrong and causes cancer, a finding that could lead to the development of new drugs and therapies to treat such disease.

Researchers at Brown University and Rhode Island Hospital in the US found that prolactin receptors -- membranes proteins that play a vital role in cellular communications -- are like cellular wiring and susceptible to short circuits that can cause cancer.

Prolactin receptors, which stimulate the mammary glands in women to produce milk, are also found in other organs including the lung and the colon.

The researchers, who detailed their study in the journal Proceedings of the National Academy of Science, found the chemical reaction inside the cell, called "acetylation", is triggered by the binding of the arrival of the prolactin hormone at the receptor.

This process can draw prolactin receptors together into a structure called a "dimer". Like a pair of chopsticks, this dimer structure is just right to pick up growth factors in the body that can lead to cancerous growth, said Y Eugene Chin of the Warren Alpert Medical School of Brown University.

"Our findings may provide an important clue about how to develop drugs to break down receptor dimers in breast cancer therapy," said Chin, a senior author of the study that also involved researchers from Zhejiang University School of Medicine in China and the University of Rochester in New York.

Normally, a shared positive electrical charge and the resulting mutual repulsion keeps prolactin receptors from coming together.

In their experiments, the team found that when prolactin binds to the receptors outside the cells, the acetylation neutralises that charge on the receptors inside the cells, allowing the receptor molecules to come together, Chin said.

The more prolactin receptors a cell has, the more susceptible it is to this problem occurring, Chin said. Overexpression of prolactin receptors in patients has been linked to cancer in the past.

Chin, who has been investigating the molecular basis of cancer for years, said he was encouraged about uncovering this new step and pointed to drugs, such as Herceptin, that target receptors to combat cancer.

"This will be extremely important for breast cancer and other cancer therapy by targeting receptors," he said.

One possibility, he said, will be developing monoclonal antibodies to target the prolactin receptors directly. But artificial compounds could also be developed to block the receptors from joining as dimers.

source: zeenews