Successfully tested anti-cancer vaccines on animals

US scientists successfully created the vaccine that could be injected directly into the tumor in mice to kill cancer cells. It works on many different types of cancer, including metastatic cancer spread throughout the body.

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The research team at Stanford University (USA) has developed an anti-cancer vaccine from two immune stimulants that are CpG oligonucleotide and an antibody linked to tumors. This vaccine can completely eliminate cancer in mice, when they are genetically modified to develop a variety of different tumors. The results of the study are published in the journal Science Translational Medicine in January 2018.

'When we used these two agents together, we found effective removal of tumors throughout the body. This approach ignores the need to identify specific tumor targets so that the immune system attacks, does not require activation of the immune system on a large scale, or modifies the immune cells of the disease. "said Ronald Levy, a member of the research team.

Because cancer cells are made by the body, the immune system does not identify them as a threat to invaders like the virus. That is why some treatments focus on training the immune system to recognize cancer cells, as a matter of need to deal with. Treatment with cancer immunotherapy (cancer immunotherapy) is quite effective. It often involves removing the patient's immune cells from the body, modifying their genes and injecting them back into the body. This is an expensive and time-consuming process. The vaccine developed by Stanford University promises to help treat cancer at a cheaper and easier cost.

US scientists successfully tested the anti-cancer vaccine in mice.(Photo: TomoNews).

New vaccines do not work like the vaccines we often see today. Instead of vaccination to prevent disease, scientists use it for mice that have cancer, directly injected into the tumor site.'We use small amounts of two stimuli to promote the activity of immune cells within the tumor. In mice, we see the whole body effect, which means that tumors on the entire animal are removed , "Levy said.

New vaccines exploit the specificity of the immune system. As the tumor grows, immune system cells - including T cells - recognize abnormal proteins of cancer cells. But cancer cells can accumulate mutations to avoid destruction by the immune system and prevent T-cells from attacking. The new vaccine works by reactivating these T cells.

The new vaccine includes two main components. The first is CpG oligonucleotide - a short piece of DNA. It along with other nearby immune cells amplifies the expression of OX40 trigger receptors on T. OX40 cells as members of the superfamily of tumor necrosis factor receptors (tumor necrosis factor receptor). superfamily - TNFRSF). The second agent is an antibody linked to OX40, capable of activating T-cells against cancer cells.

Two CpG oligonucleotide and OX40 agents are injected directly into tumors of small microgram size. This means they only activate T cells inside the tumor, causing them to identify cancer cells as a threat. After that, some T cells leave the original tumor to seek and destroy other similar tumors inside the body.

Test results on mice

To test the effect of vaccines, laboratory mice are either transplanted into lymph nodes in the body or genetically modified to develop breast cancer. Of the 90 mice with lymphoma, 87 individuals have completely recovered. Researchers injected two chemicals inside a tumor and both tumors disappeared. Although three rats later recurred, after the second treatment they were out of the disease.

The new vaccine is also effective on genetically altered mice to develop breast cancer. The treatment of tumors prevents the recurrence of tumors, while increasing the lifespan of animals. The research team then tested mice with two diseases of lymphoma and colon cancer, but they only inject the vaccine into lymphoma. As a result, lymphoma is destroyed, and colon cancer is not. This proves that T cells are specific to each type of tumor. Therefore, the treatment is not without limits.

The trial of a new human vaccine will soon be conducted in 15 patients with low-grade lymphoma . If the results are positive, the vaccine will be used to treat future tumors before surgery to remove the tumor to help prevent metastasis, or even prevent cancer recurrence.

'I don't think there's a limit to the type of tumor we can treat, as long as the vaccine can get into the immune system , ' Levy said.