Researchers found that one’s immune system can re-engage to destroy tumors after combining chemotherapy and immunotherapy in mice.
Chemotherapy remains the first-line approach for the treatment of solid tumors. It is based on the cytotoxic activity on rapidly dividing cells, but adverse effects are seen on healthy cells that also rapidly divide, such as the intestinal mucosal lining, and hair follicles.
The search for safe and effective therapies to reduce the chemotherapy dose or serve as an alternative to chemotherapy has been ongoing. Immunotherapy is one such approach and involves enhancing one’s own immune system to recognize and destroy tumor cells.
One class of immunotherapy that has shown success in cancer treatment is checkpoint inhibitors. Immune checkpoints prevent the immune system from attacking the body’s own cells; however, many tumor cell types can evade immune system attacks by activating immune checkpoints. With this knowledge, checkpoint inhibitors have been developed as a means to overcome the tumor’s use of checkpoints in order to allow T-cell recognition and attack. The downside is the limited forms of cancer that respond to checkpoint inhibitor immunotherapy, creating a need to determine a means to enhance the effects of checkpoint inhibitors.
A group of scientists at the Massachusetts Institute of Technology discovered a treatment method that can bolster the cancer-killing effect of immune checkpoint inhibitor therapy. They found that living, but DNA-damaged, tumor cells can act as immune activators to enhance T-cell activation, targeting, and destruction of tumor cells. The research in mice involved treating tumor cells ex vivo in a culture with cytotoxic chemotherapeutic agents. The treated, DNA-damaged tumor cells were then injected into the tumors of mice. The injured tumor cells enhanced T-cell activation, and co-treatment with a checkpoint inhibitor immunotherapy such as anti-PD-1 increased antigen-specific CD8+ T cells.
Ultimately, reduced tumor growth and increased survival were observed in the mice treated with the injured tumor cells and checkpoint inhibitors. The tumor reducing and survival effects were not seen when the chemotherapeutic agent was injected directly into the tumors of mice. In a subset of mice, the injured tumor cell/checkpoint inhibitor co-treatment was associated with immune memory allowing complete tumor regression. The results of the study suggest a means to boost checkpoint inhibitor immunotherapy efficacy.
The search for safe and effective therapies to reduce the chemotherapy dose or serve as an alternative to chemotherapy has been ongoing. Immunotherapy involves enhancing one's own immune system to recognize and destroy tumor cells. Massachusetts Institute of Technology researchers have found a treatment that can bolster the cancer-killing effect of checkpoint inhibitor therapy. If you want to learn more about how to advance medical research with immunotherapy, contact HemaCare today.
New cancer treatment may reawaken the immune system. (2021). Retrieved 10 December 2021, from https://news.mit.edu/2021/new-cancer-treatment-may-reawaken-immune-system-1019