Senescent Cells as a Cancer Vaccine

Researchers here note the discovery that vaccinating mice with senescent cancer cells ensures that the immune system will more aggressively attack a later introduction of cancerous cells. Since we know that most cancer therapies induce senescence in cancerous cells to a fair degree, one has to think that the effectiveness of this approach will diminish as a cancer progresses to form a solid tumor and co-opts the immune system in various ways. Still, it sounds as though it could be a potentially useful after, for example, surgical resection of a tumor, to help reduce the odds that the cancer will reoccur.

Scientists have studied how inducing senescence in cancer cells improves the effectiveness of the immune response to a greater degree than the dead cancer cells. After vaccinating healthy mice with senescent cancer cells and then stimulating the formation of tumours, the researchers observed that the animals did not develop cancer or that the number that do is significantly reduced. They also analysed the efficacy of vaccination in animals that had already developed tumours. In this setting, although the results were more moderate due to the protective barrier of the tumour, improvements were also observed.

The researchers tested the technique in animal models of melanoma, a type of cancer characterised by high activation of the immune system, and also in pancreatic cancer models, which present strong barriers against immune cells. Prophylactic vaccination therapy with senescent cancer cells was effective against both types of tumors. They also complemented the study with tumour samples from cancer patients and confirmed that human cancer cells also have a greater capacity to activate the immune system when they are previously rendered senescent. The group is now studying the combined efficacy of vaccination with senescent cells and immunotherapy treatments.

Link: https://www.irbbarcelona.org/en/news/scientific/senescent-cells-vaccines-against-cancer