Most cancer patients do not die from the original tumor on an organ. The tumor only develops in a deadly threat when individual tumor cells separate from the first tumor and form metastases. In the process of metastasis, some cells of the first tumor change in a very specific way.
Therapeutic approach against metastasis?
Most cancer patients do not die from their original tumor on a specific organ. The tumor only becomes a deadly threat when individual tumor cells separate from the first tumor, migrate through the body and settle in the liver, lungs, bones or brain, for example, and destroy the tissue forming metastases. In a process of metastasis, some tumor cells for the first time change in a specific way.
In order to develop long-term therapies for metastasis, medicine needs to understand how the fateful process works. But there are still some puzzles to solve. For example, it is not fully understood as Texture and type of cancer cells influences the dispersion in the body. The malignant cells of most beginner tumors are of "epithelial origin": they multiply strongly and make contact with their neighbors to grow in association.
Can these epithelial tumor cells invade other tissues in the body? Or you have to first called epithelial-mesenchymal transition (EMT) through? Mesenchymal cells break cell-cell contacts and tend to break away from a dressing. Then they gain access to a ship and walk the blood, leave the circulation and colonize another tissue in the body.
Researchers in Munich first transplanted breast cancer cells from certain mice to mice without a tumor. They analyzed the developing tumors and recovered potential cancer cells from the blood and bone marrow. "In doing so," said Olivier Gires, "we have shown that this Blood and bone marrow cells really of the first tumor come over ".
The other results
But these tumor cells of dispersion varied very strongly in their type: some remained more epithelial and formed a corresponding number of contacts with other cells and multiplied. But they also had classical properties of small-scale mesenchymal cells has won. Other isolated tumor cells, on the other hand, were submitted to severe or complete EMT. The latter were barely able to form metastases in the lungs and, if so, only very late. Unlike slightly mesenchymal cells more epithelial. "These epithelial tumor cells with mild mesenchymal drift colonized very strongly the lungs"Gires said.
In cooperation with the University of Shanghai, researchers from Munich Results for patients with confirmed metastatic breast cancer, "We were able to show that EpCAM expression on the epithelial surface of proteins in tumor cells in the blood and bone marrow of patients is a measure of low EMT and metastasis and survival," adds Gires.
And the clinical benefit?
The direct benefit to patients is still limited as it is a basic research. According to Gires, a potential future application could be: "If we isolate EpCAM positive cells from the blood of breast cancer patients and investigate the molecular properties of these cells, for example, the expression of the therapeutically relevant surface molecule HER2, according to the results of our study at least assume that targeted therapy is likely to reach the metastatic cells as well. " However, in order to use it for the benefit of patients, necessary clinical studiesthat support the options described.