Cell Death or Cancer Growth: A Question of Cohesion

Activation of CD95, a receptor found on all cancer cells, triggers programmed cell death - or does the opposite, namely stimulates cancer cell growth. Scientists from the German Cancer Research Center (DKFZ) have now shown that the impact of CD95 activation depends on whether there are isolated cancer cells or three-dimensional structures. Individual cells are programmed to die following CD95 activation. In contrast, CD95 activation stimulates growth in clusters of cancer cells, for example in solid tumors. This finding points to new ways of specifically transforming growth-stimulating signals into cell death signals for the cancer cells. The receptor protein CD95 is exposed on the surface of all cancer cells like small antennae. Activation of the receptor by the CD95 ligand (CD95L) triggers apoptosis in the cancer cell - or the exact opposite: "We studied various types of cancer tissue and found that CD95 activation usually stimulates tumor growth under natural conditions," remarked Ana Martin-Villalba, who has been conducting research at DKFZ on the role of CD95 for many years now. She was the first to describe the cancer-promoting effect of CD95 in glioblastomas (malignant brain tumors).