Breast cancer

Protein linked with Down Syndrome may help treat breast cancer

Researchers at the Texas A and M University College of Veterinary Medicine and Biomedical Sciences have found that a protein long suspected to play a role in Down Syndrome might also contribute to treating breast cancer.

Washington, Feb 5 : Researchers at the Texas A and M University College of Veterinary Medicine and Biomedical Sciences have found that a protein long suspected to play a role in Down Syndrome might also contribute to treating breast cancer.

It is already known that Down Syndrome is caused when an individual has an extra copy of the 21st chromosome, giving them a total of three instead of the normal chromosome pair.

And now with advancements in medical care, people with Down Syndrome are living longer and healthier lives.

Along with this improvement came the observation that individuals with Down Syndrome have a significant decrease in risk for several types of tumours.

The most surprising observation is that women with Down Syndrome are 10-25 times less likely to develop breast cancer.

Scientists believe that this effect is due to the presence of one or more 'tumour suppressor' genes on chromosome 21. However, the identity of such genes has not been known, until now.

"Years of research into the genetics of Down Syndrome have helped us to discover a very important gene on chromosome 21," said Dr. Weston Porter, associate professor in the Veterinary Integrative Biosciences Department.

"This gene, called Single-minded 2 or SIM2 is thought to play an important role in Down Syndrome by regulating neuron growth in the developing brain. Based on its developmental role, we hypothesized that SIM2 may also be involved in breast cancer, which is essentially a disease of uncontrolled growth," he added.

For past five years, Porter and his colleagues have been using human breast cells and mouse models to validate this hypothesis, and what they have found they consider it very promising.

SIM2 is lost or suppressed in a majority of human breast tumours, and if the gene is deleted, it triggers rapid tumour growth in mice.

However, the process by which SIM2 suppresses breast cancer is complex and not fully understood.

This same protein, which might hold so much promise for breast cancer treatment, is also thought to contribute to the negative effects of Down Syndrome.

"As we move forward, it will be important for us to understand the circuit of SIM2 and how it is turned on and off. In light of the available data on breast cancer incidence in the Down Syndrome population and our experimental data, knowing how to turn SIM2 expression on and off and identification of down-stream targets should have great therapeutic value," Porter said.

Although the study is in its early stages, it still represents a promising weapon in the fight against breast cancer as it sheds light on a previously unknown target for which to shoot.

The study is published in the journals Molecular and Cellular Biology and Carcinogenesis.

ANI