Breakthrough in understanding tumor immune therapy: Induction of tumor dormancy instead of killing

Until now it is strongly believed that the immune system controls growth of tumors by killing tumor cells. The Tubingen researchers, members of the Comprehensive Cancer Center, now show that immune responses can prevent tumor growth without killing tumor cells.

They used a model of endogenously growing tumors that develop, like many human tumors, because of a defect in normal cell death. The researchers show that the immune system can prevent tumor growth without destroying tumor cells. They show that early treatment of developing tumors arrests tumor development at very early stages through a strictly cytokine mediated mechanism. One of the important players that prevents the outgrowth of malignant tumors is interferon.

The researchers show further a second important aspect: Immune responses can both – either induce tumor dormancy or, unexpectedly, tumor growth. In the absence of either interferon or tumor necrosis factor the immune response converts the from a protective into a tumor promoting immune response.

In conclusion, the paper gives a great hope and new aspects for the development of new tumor vaccines. They show that tumor immune responses can induce tumor dormancy, which means that the immune response arrests tumors at early stages. Yet, these immune responses have to occur early in tumor development and have to provide the correct pattern of cytokines. In the case of an inappropriate cytokine pattern, i.e. missing interferon or missing tumor necrosis factor, the same response may dramatically enhance tumor growth.

Prof. Dr. Martin Röcken, MD
Professor of Dermatology
Chairman
Department of Dermatology
Eberhard Karls University
Liebermeisterstr. 25
72076 Tübingen, Germany
Phone +49-7071-2984556
Fax +49-7071-295
mrocken@med.uni-tuebingen.de