By combining chemotherapy, tumor lesions and immunotherapy, American scientists at MIT managed to reactivate the immune system in mice and thus destroy cancerous tumours.
- Immunotherapy fights tumor cells by directing the immune system against them
- The track studied aims to damage the DNA of certain tumor cells in order to destroy all the tumor cells at the same time
A method considered revolutionary in the treatment of cancer, immunotherapy aims to improve the ability of the immune system to fight tumor cells. American researchers from Massachusetts Institute of Technology (MIT) used this technique to remove tumor cells from the body, then treat them with chemotherapy drugs and finally put them back into the tumour. A process which in scientific jargon responds to the name “immunogenic cell death”.
Stimulate damaged tumor cells to react
The interest of this new approach lies in the fact of administering at the same time drugs which seem to act as a signal of distress by inciting the damaged tumor cells to react. “When you create cells that have damaged DNA but are not killed, under certain conditions these living and injured cells can send a signal that wakes up the immune system“, explains Michael Yaffe, director of the MIT Center for Precision Cancer Medicine and member of the Koch Institute for Integrative Cancer Research at MIT, who co-directed this study published in Science Signaling.
The class of drugs used in this work is that of “checkpoint inhibitors” which may prove effective in fighting tumor cells, but only in a restricted case of specific cancers. The authors of this work therefore sought to improve the efficacy of these treatments by combining them with cytotoxic chemotherapies.
Tumors completely eliminated in almost 50% of cases
The MIT scientists started by treating the cancer cells with several different chemotherapy drugs, at different doses. According to the results of their experiment carried out on mice, the treatment was able to completely eliminate the tumors in almost half of the rodents.
The researchers found, however, that the tumor cells that stimulated the immune system were not killed, but injured by the chemotherapy. “This describes a new concept of immunogenic cell injury rather than immunogenic cell death for the treatment of cancer.“, calculates Michael Yaffe.
The drugs that seem to work best with this approach are those that cause DNA damage. Researchers have in fact discovered that when DNA is damaged in tumor cells, it activates cellular pathways that respond to stress. These pathways send distress signals that prompt T cells to spring into action and destroy not only damaged cells, but also any nearby tumor cells.
“Our findings fit squarely with the concept that “danger signals” inside cells can talk to the immune system, a theory pioneered by Polly Matzinger at the NIH in the 1990s, but not yet universally accepted. accepted“, concludes Mr. Yaffe.
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