New vaccine starves cancer.
A vaccine that restricts the supply of blood to tumors, developed by researchers at Karolinska Institutet in Stockholm, has slowed the growth of breast cancer in tests conducted on rodents.

The concept is based on the fact that, for a cancer tumor to become larger than a few millimeters, it must be able to stimulate the formation of new blood vessels in order to secure its supply of oxygen and nutrients. Drugs that prevent the growth of blood vessels are thus a potential treatment alternative for tumors.


A protein known as 'Delta-like ligand 4' (DLL4) regulates the formation of new blood vessels. When a new blood vessel starts to grow from an existing vessel, this prevents nearby cells from forming new vessels. When DLL4 is blocked in a tumor, there is a large increase in the formation of new, but non-functional, blood vessels, and this leads to the tumor growing more slowly.

"We hope that it will be possible to use this vaccine to prevent recurrence of breast cancer after surgical treatment", says Kristian Pietras, head of the study.

For both cancer and infectious diseases, DNA vaccination entails injection of a gene for the protein against which it is desired to vaccinate. This leads to recognition of the unwanted protein by the immune system. In the studies, the vaccination did not cause any undesired effects and did not affect the animal'' capacity for healing.