The tumor contains millions of cancer cells, and its growth can occupy more space in the body to cause pressure on the surrounding structure. It includes random development from where it starts. Because large vessels with strong walls and dense tissues such as cartilage are often difficult to grow into tumors, tumors usually grow along the "least resistance path.".
At this time, it means that the tumor has developed into a real cancer, that is, invasive cancer, which means that the cancer cells have been infiltrated from the place where they occur to a deeper place. For infiltrating cancer, the main cause of cancer death is the advantage of cancer cell metastasis. According to statistics, 90% of cancer deaths are caused by metastasis. It is difficult to treat metastatic cancer, and lung is a common tumor metastasis site in clinic.
Research has found that cancer cells tend to be "prepared" for cancer metastasis. For example, before the migration of lung metastasis, some tumor related cytokines were transferred to lung tissue "open territory and expand soil", and the main task was to counter the anti-tumor immune cells of lung.
Chen Gen: from cancer to cancer metastasis, immune cells become friends
In addition, under the influence of tumor, the body will also mobilize the myeloid cells into the lung tissue. For example, hematopoietic stem cells and hematopoietic progenitor cells in the marrow of tumor bearing mice expand, and they enter the lungs before the tumor cells and differentiate into immunosuppressive myeloid cells.
Based on this, the team led by Professor rosandra Kaplan of the National Cancer Institute of the United States (NCI) tried to transform the myeloid cells, and released strong anti-cancer signals to the cancer cell transfer destination by using the characteristics of their easy to collect pre metastasis niche, and thus achieved long-term cancer metastasis inhibition effect.
The researchers started with IL-12, one of the cytokines produced by myeloid cells. In general, when infection and tumor appear, myeloid cells will produce IL-12, activate T cells and natural killer (NK) cells, enhance IFN γ reaction, increase antigen presentation and reduce angiogenesis. That is, myeloid cells could help the body fight cancer, but under the counter-tumor, it inhibited the immune system and further promoted cancer metastasis.
So the researchers decided to forcibly enhance the ability of myeloid cells to secrete IL-12 and restore its anti-cancer ability. During the experiment, the researchers used the characteristics of myeloid cells to gather easily to tumor and metastasis sites, and genetically modified them to overexpression of IL-12. They call the transformed myeloid cells IL 12 gemys.
The results showed that the tumor metastasis was inhibited and the tumor in situ decreased in the tumor bearing mice treated with gemys. In addition, the researchers found that gemys secreted IL-12 in situ and pre metastasis niche, recruited and activated anti-tumor immune cells, and reversed the immunosuppressive microenvironment of pre metastasis niche.
In further studies, the researchers combined gemys with chemotherapy, tumor resection, or T-cell immunotherapy, showing significant antitumor effects. Especially in combination with chemotherapy (cyclophosphamide), tumor growth has been controlled for a long time (the tumor will not recur in more than 100 days after treatment).
Metastasis cancer is the cause of death of most cancer patients. From counterinsurrection to counter counter - scheming, cancer and cancer must experience a long-term game. If the "counter reaction" of cancer metastasis can be realized as soon as possible, it will also bring more possibilities for cancer treatment.
