Novel cancer vaccine plays a dual role of prevention and treatment Cancer vaccines are a novel type of immunotherapy that has gained popularity following CAR-T cell therapy and PD-1/PD-L1 inhibitor therapy. Cancer vaccines are categorized into preventative and therapeutic types based on the mechanism of their anti-cancer effects. Similar to what people think of as conventional vaccines, the HPV vaccine is a well-known preventative vaccine that can greatly lower the incidence and death of cervical cancer. Therapeutic cancer vaccines, such as the DC vaccine used in prostate cancer, can be used to fight cancer. A team of experts from Massachusetts’ Brigham and Women’s Hospital just developed a novel cancer vaccine that goes above and beyond to make “cancer cells destroy cancer cells”, acting as both a preventative and curative vaccine. The most recent findings were published in Science Translational Medicine. The researchers targeted cancer cells with a similar “homing effect” that allows them to seek out and return to the cancerous tissue. Based on this trait, the researchers theorized that if these living cancer cells could be manipulated to release the relevant immune substances, and if it would be feasible to activate the immune system and allow the immune cells to immediately locate and kill the malignant tissue. Researchers created a cancer vaccine based on live cancer cells that may operate as both a tumor killer and an immune stimulant. First, the researchers modified live cancer cells using CRISPR technology to remove particular IFN-sensitive receptors in cancer cells. These cancer cells were then engineered to produce IFN-, which may target cancer cells and release immune-regulating substances. The transformed cancer cells can return to the tumor tissue and destroy tumors while also releasing signals that stimulate T lymphocytes. These modified therapeutic cancer cells are referred to as ThTC by the researchers. The researchers then tested the results in a mouse model, which revealed that in a lethal glioblastoma mouse model, ThTC could effectively target glioblastoma cells for killing, as well as express factors that are easily recognized, labeled, and remembered by the immune system, thereby initiating and activating the immune system to exert a long-lasting anti-tumor effect. In mouse model trials, 100% of treated mice survived for 60 days! In addition, the length of tumor remission was longer than in control mice. How can we assure that those cancer cells do not defect and evolve into lethal malignant tissues again? To address this problem, the researchers designed a two-tier safety switch in ThTC that may be engaged to destroy ThTC if it is found to be malfunctioning in order to assure the treatment’s safety. Dr. Khalid Shah, the paper’s corresponding author, expressed hope that a novel cancer vaccine based on this research can be created to produce a good therapeutic impact in the treatment of a wide variety of solid tumors.