Senescent cells can act as a cancer vaccine and promote anti-tumor immune response after inoculation

Senescence is a delayed state reached by damaged or aging cells, in which cells neither proliferate nor die. Senescent cells send informational signals to their surroundings to warn of their presence, stimulating inflammatory responses and tissue regeneration.

A recent study shows that in the context of cancer, due to the characteristics of senescent cells (activated dendritic cells and antigen-specific CD8 T cells), they become good candidates for activating the immune system and enhancing the immune system's anti-tumor response.

Recently, researchers from the Barcelona Institute of Biomedical Research and Karolinska Institutet published a research paper in the journal Cancer Discovery entitled "Cellular senescence is immunogenic and promotes anti-tumor immunity". This study shows that cells that have permanently stopped proliferating, known as senescent cells, are immunogenic and can promote anti-tumor immune responses. Vaccination with senescent cancer cells as a vaccine significantly reduced melanoma and pancreatic cancer tumor formation in mice.

In this study, the team found that inoculating healthy mice with senescent cancer cells, after which they were attacked by melanoma and pancreatic cancer cells, prevented or delayed the formation of tumors. In mice that had already grown tumors, inoculation with senescent cancer cells also had a significantly improved effect, albeit less effective, probably because after forming tumors, the cancer cells had created a tumor microenvironment that protected the tumor cells from immune system attack.

To test the validity of these findings in human cancer cells, the team collected tumor samples from cancer patients and observed a similar mechanism in a laboratory setting—inducing senescence in human primary cancer cells enhances their ability to activate autoantigen-specific tumor-infiltrating CD8 T lymphocytes, which activates the immune system to attack tumor cells.

The results of this study suggest that senescent cells may serve as a primary option when it comes to stimulating the immune system to fight cancer.

These findings open exciting avenues for the design of anti-cancer therapies based on a combination of senescence inducers and immunotherapy. However, the process of cellular senescence is very complex, and more research on the potential side effects of senescent cell-based therapies is needed before we can apply this research to the clinic.

The research team says it is currently trying to conduct related studies in animal models of lung cancer in the hope of developing alternative vaccination methods that do not use live senescent cells.