A New Approach to Targeting Metastasis in Cancer
Most cancers kill through metastasis, the spread of cancerous cells throughout the body to seed numerous secondary tumors. Without this process cancer would be much less threatening and more amenable to treatment. Thus numerous research groups are investigating ways to shut down or otherwise interfere with metastasis, and here is a recent example:
[Researchers have] developed a protein therapy that disrupts the process that causes cancer cells to break away from original tumor sites, travel through the blood stream and start aggressive new growths elsewhere in the body. Today doctors try to slow or stop metastasis with chemotherapy, but these treatments are unfortunately not very effective and have severe side effects. [This] team seeks to stop metastasis, without side effects, by preventing two proteins - Axl and Gas6 - from interacting to initiate the spread of cancer.Axl proteins stand like bristles on the surface of cancer cells, poised to receive biochemical signals from Gas6 proteins. When two Gas6 proteins link with two Axls, the signals that are generated enable cancer cells to leave the original tumor site, migrate to other parts of the body and form new cancer nodules. To stop this process [researchers] used protein engineering to create a harmless version of Axl that acts like a decoy. This decoy Axl latches on to Gas6 proteins in the blood stream and prevents them from linking with and activating the Axls present on cancer cells.
The researchers gave intravenous treatments of this bioengineered decoy protein to mice with aggressive breast and ovarian cancers. Mice in the breast cancer treatment group had 78 percent fewer metastatic nodules than untreated mice. Mice with ovarian cancer had a 90 percent reduction in metastatic nodules when treated with the engineered decoy protein. "This is a very promising therapy that appears to be effective and non-toxic in pre-clinical experiments. It could open up a new approach to cancer treatment."
Link: http://www.sciencedaily.com/releases/2014/09/140921145112.htm