As the level of human science and technology advances, medical methods are constantly advancing and progressing. Among them, most researches on tumors focus on early detection of malignant cells and destruction of them, or prevention of environmental carcinogenic factors from coming into contact with susceptible tissues. Few attempts have been made to find ways to reverse the way cells and cancer-causing factors come into contact with each other and how cells turn into malignant. MaughII reported on the National Institutes of Health (NIH), which established a research group based on the National Cancer Institute (NCI) to study the relationship between vitamin A and tumorigenesis. They believe that one of the effective reversal factors is vitamin A and Its derivatives.
The occurrence and growth of the general tumor is divided into three phases, namely the beginning, the early stage and the formation of the tumor. The precancerous phase is a transition from the initial phase to the formation phase. Generally, it takes 20 years for humans to find out how the cells in the early stage of the tumor change. People do not know much about it, but one thing is clear: cells in the early stage of the tumor will be repaired and Return to normal on your own. The main role of vitamin A is to reverse the altered few cells of the gene.
One of the functions of vitamin A is to differentiate epithelial cells into specific tissues. Because the occurrence of tumor cells is related to the loss of epithelial cell differentiation. Therefore, vitamin A plays an important role in preventing the occurrence of tumors. Many of the scientists in the above group have found that carcinogenic factors are particularly capable of causing tumors in animals that have long been deficient in vitamin A.
NCI's Sporn and Kaufman found that the trachea isolated from vitamin A-deficient mice was more tightly bound to various carcinogenic factors in the culture fluid than in normal healthy voles. The incidence of tumors in animals lacking vitamin A is higher than that in the absence of them. Newberne and Rogers of the Massachusetts Institute of Technology (MIT) discovered that rats lacking vitamin A have a significantly higher incidence of colorectal cancer than controls due to exposure to aflatoxin B1, an oncogenic factor. Although these results are preliminary, they are very important.
In addition, supplementation with vitamin A or its derivatives can prevent tumors. For example, Kaufman found that retinyl acetate can inhibit the binding of carcinogenic factors to DNA in the culture fluid of the trachea of ​​rats, and Chopro discovered that the retinol and derivatives added to the mouse's prostate culture medium can inhibit the effect of carcinogenic factors, and Reversal of carcinogenesis.
Some studies have even demonstrated that vitamin A and its derivatives have a therapeutic effect on already formed tumors. Swarm found that the addition of vitamin A derivatives (1,3-cis-retinol) inhibited the growth of sarcomas after the transplantation of chondrosarcoma in rats. Bollag found that retinol can reduce the volume of mouse-induced papillomas caused by oncogenic factors. Bollag also found that retinoic acid analogues can also regress squamous and basal cell carcinomas in humans.
Little is known about the mechanism by which vitamin A inhibits tumor growth. Some people think that it may inhibit the activation of carcinogenic enzymes in the body. However, Metzler believes that vitamin A compounds stimulate the immune system against tumors. He found that retinyl palmitate produced a 100-fold greater anti-tumor effect than BCG, which is immune to another tumor.
Therefore, some scientists believe that the preventive and therapeutic effects of vitamin A on cancer may be one of the most important findings in the prevention and treatment of cancer. However, taking large doses of vitamin A can cause toxic reactions. Therefore, they suggest that the current important issue is how to synthesize and screen new vitamin A derivatives that have no toxic effects to prevent and treat tumors. Before this issue is resolved, it is not advisable to over-promote the use of vitamin A for the treatment of tumors to avoid excessive doses of vitamin A or poisoning.
HbA1c And Blood Glucose Test Quality Control
A1Cchek Pro,A1Cchek Express,Hba1C Quality Control Reagent,Glycohemoglobin Quality Control
Wuxi BioHermes Bio & Medical Technology Co., Ltd. , https://www.biohermesglobal.com