Where does cancer begin: physicians traced the development of tumors from a single cell

Doctors from the Boston Children's Hospital were able to observe the development of a cancer , starting with the very first cancer cell. Description of observations will help to better understand the development of this disease and help in combating it.

“One of the mysteries associated with cancer was the following: why some cells in the body, which already have signs of mutations associated with cancer, did not behave like cancer cells, explains Charles Kaufman, the first author of the scientific work. “We found that the cancer development process begins with the activation of an oncogene or with the loss of the anti-oncogene [tumor suppressor gene], and includes changes that return the cell to the stem state.”
')
The process of tumor development was observed using the example of a zebrafish melanoma. Apparently, it is the set of genes responsible for this process that should be made the goal of therapy that suppresses the development of cancer. The fish had a BRAFV600E cancer mutation, and the suppressor p53 gene was turned off.

The fish were genetically modified in such a way that the cells in which the christening gene was activated glowed green in a certain light. This gene is responsible for activating the genetic program of stem cells, which usually turns off after the end of embryo formation.

However, for reasons unknown so far, christening and some other genes related in function are sometimes switched on again. As the co-author of the work explains, Leonard Zon, in the experiment, 100% of the time after scientists noticed a green spot on the fish, it developed into a cancerous tumor.

It turned out that the group of genes, including christening, included at the beginning of the formation of a tumor, completely coincides with the group that is activated during the development of the embryo - specifically for the formation of melanocytes, specialized skin cells that produce the melanin pigment. The same group of genes is included in melanomas in humans.

"It is believed that only one of the hundreds of millions of cells of moles turns into melanoma," says Kaufman. - We specifically bred a lot of fish to be able to catch this moment. The rarity of this process is statistically similar to the process occurring in humans. Most likely, the process of formation of human melanoma is the same. ”

Research will help create new testing technologies to test whether a mole turns into melanoma. In addition, it will be possible to understand exactly what mechanism triggers the inclusion of the mentioned group of genes.

Based on their observations, Kaufman and Zon proposed a new model of the formation of the so-called. " fields of cancer " - extensive areas of tissue affected by cancer. They believe that tissues go to a cancer-prone state when oncogenes are activated in them and suppressor genes are turned off or lost — but the cancer itself does not begin to develop until one of the cells acquires the properties of the stem and begins to divide.