August 1, 2012

New Therapeutic Target for Aggressive Breast Cancer

(Ivanhoe Newswire) — A new therapeutic target for advanced breast cancer has shown promising results in mouse models, according to a study performed by Western University.

Lynne-Marie Postovit of Western´s Schulich School of Medicine and Dentistry analyzed a protein called Nodal, which is primarily found in embryonic or stem cells. She discovered high levels of Nodal in aggressive breast cancer tumors. The protein was found to promote vascularization in the tumor, providing nutrients and oxygen to help it grow and spread.

"We have determined that breast cancers, specifically those very aggressive, invasive breast cancers that spread, express an embryonic protein called Nodal and the expression of this protein is correlated with more blood vessels in the tumor. Blood vessels, many studies have shown, help to allow tumors to grow but also to spread throughout the body," Postovit was quoted as saying. "In addition, we have shown that if we can target this embryonic protein, we can cause the blood vessels to collapse within the tumor, leading to decreased oxygen levels and tumor cell death. When tumors lack oxygen and nutrients they become what we call necrotic."

For the study, researchers designed mouse models to develop breast cancer tumors. Next, using a genetic modification, the researchers turned off the expression of Nodal. After doing so, the blood vessels in the tumor appeared to collapse and the tumor became less aggressive. Because Nodal is on the outside of the cell, it can be easily targeted by a number of mechanisms like antibodies. Patients could potentially have better outcomes because Nodal isn´t expressed in normal body tissue, thus making it possible to solely target the cancer.

"Ultimately it would be nice to target Nodal in patients who already have quite advanced, well-vascularized tumors as a new option for therapy," Daniela Quail, first author on the research and a PhD candidate in the Postovit lab, was quoted as saying. "Currently, patients like this don't have many options."

"In Canada, breast cancer continues to be one of the most common forms of cancer in women. Although new treatment methods have improved outcomes, a significant number of women still die from this disease", Dr. Morag Park, Scientific Director of the Canadian Institutes of Health Research, was quoted as saying. "Research advancements, such as Dr. Postovit's, have contributed and will continue to contribute to the improvements around our understanding of cancer progression and treatment. I congratulate Dr. Postovit and the team on this advancement and its significant contribution to this field."

Source: Cancer Research, July 2012