Cancer is a dangerous disease that is deadly in many cases. For this reason, some new methods are being implemented to find the ideal treatment for this disease. Arginine is an amino acid that has a very active effect on cancerous diseases.
Arginine is an amino acid that enters cells through special receptors and transporters. When present in a cancerous cell, arginine produces nitric oxide. Nitric oxide further affects the further progression of cancer and the division of cancer cells.
Transport of arginine depends on several things, tumor necrosis factor and cytokine. It should be noted that both are produced by tumors and due to inflammation. The more these compounds, the faster the transport of arginine and the higher the production of nitric oxide. Arginine is metabolically derived from the enzyme arginase.
Certain tumor cells need arginine to survive. Healthy cells themselves produce arginine from the enzyme arginase. Tumor cells cannot produce arginine alone. For that reason, there is a tendency to reduce arginine levels in cancer cells.
In one such experiment, the enzyme Arginine deiminase was given to liver cancer patients. This enzyme reduced the level of arginine in cancer cells. This enzyme must be given in high doses as it breaks down very quickly when found in cells. The result was a staggering 2 patients out of 19 were completely cured.
On the other hand, arginine is a modulator of the immune system by promoting an increased concentration of T cells that destroy cancer and also affects the level of cytokines that have inflammatory effects.
During chronic inflammation, large amounts of nitric oxide are produced. Its production can lead to the formation of cancer cells. For example, in ulcerative colitis, a disease of chronic inflammation of the intestines, large amounts of nitric oxide are produced. Patients with ulcerative colitis can develop colon cancer, and this is the golden rule for long-term exposure of cells to nitric oxide.
Other types of cancer predominantly caused by the effects of nitrogenous acid are cholangiocarcinoma (bile cancer), lung cancer, metastatic breast cancer, and stomach cancer with long-term ulceration. Nitric oxide also promotes the development of new blood vessels and, by preventing apoptosis, affects tumor cells’ accelerated growth. Nitric oxide acts on cells’ DNA, damaging it and preventing repair. In this way, nitric oxide helps in the development of cancer.
Nitric oxide has three forms known as iNOS, eNOS, and nNOS. All three forms were found in tumor cells. These forms help the cancer cells to divide and invade other tissues. Metalloproteinase helps tumor cells to invade, and nitric oxide increases its expression. These claims further confirm that inflammatory mediators in breast cancer cells help transport arginine and nitric oxide, which help further spread these cells.
Nitric oxide also mediates programmed cell death, known as apoptosis. Depending on the levels of nitric oxide in cancer cells, cell death can be prolonged or caused. Cytokines cause the production of nitric oxide in cancer cells. For example, in liver cancer cells, nitric oxide does not cause cell death.
High levels of nitric oxide kill cells, and lower levels prevent cell death. Therefore, nitric oxide indicates and prevents cell apoptosis depending on its level and cell type.
Tumor cells need large amounts of blood to survive, and therefore the tumor produces new blood vessels. Research shows that nitric oxide cannot accelerate or stop new blood vessels’ development directly. In general, nitric oxide promotes the formation of new blood vessels by improving the factors that regulate this process.
Nitric oxide causes toxicity in macrophages to cells of the immune system that directly destroy cancer. The cytotoxicity showed by nitric oxide also attacked other immune cells, such as T cells. Loss of immune cells helps cancer to spread unhindered. When cancerous cells produce nitric oxide, it suppresses the natural immune system and accelerated tumor progression.
Nitric oxide also helps cancer cells to bind to platelets, which prevents the immune system from destroying them and allows them to spread to distant places in the body.
Understanding all these processes gives us new solutions for combating certain cancer types. Controlling arginine levels and inducing nitric oxide levels can be included in some new types of therapies. Nitric oxide is effective in increasing the effectiveness of radiation. It should also be noted that high levels of nitric oxide can cause apoptosis.
As seen above, the role of nitric oxide is not fully defined. Although it has increased cancer in several cases and accelerated its development, this agent also affects chemotherapy’s functioning. When using adriamycin, nitric oxide is given before taking chemotherapy to increase this medicine’s effectiveness. Due to these very complex factors, new research should be focused on this agent to find all the directions of its positive and negative impact on cancerous diseases.