Researchers at the University of Pennsylvania School of Medicine and The National Cancer Institute have generated altered immune cells that were able to shrink mesothelioma tumors in mice.
The immune cells are meant to target mesothelin, a protein that is highly expressed in mesothelioma and several other cancers. Mesothelin is generally limited to the cells that make up the protective lining for cavities in the body and internal organs. In cases where the individual is suffering of mesothelioma or pancreatic cancer the mesothelin is abundantly expressed. Researchers believe that it plays a large role in the growth and metastic spread of cancers.
The trouble researchers feel they could run into with this type of treatment is that tumor cells are derived from normal cells that are in the body. Many molecules that are found on tumor cells can also be found on normal cells. This makes it difficult for the immune system to recognize tumor cells as anything out of the ordinary, and often time results in the immune system not attacking the tumor. However, the protein mesothelin is being viewed as a great candidate for generating tumor targeting T-cells because its expression is limited in normal tissues but high when there are cancers like mesothelioma present.
To study the engineered T-cells effects on tumors, researchers placed human mesothelioma cells underneath the skin of the mice and after six weeks tumors began to form. Researchers then injected the engineered T-cells directly into the tumor and into the veins of the mice. In both situations the tumor shrunk, or even disappeared.
Information from the study indicates that small doses of the engineered T-cells could have great potential in treating patients with tumors. There are clinical trials now in the works to use this approach in treating patients who have mesothelioma and ovarian cancer.