Measuring DNA mutations accumulated in individual skin cells predicts melanoma risk

  According to a new study that detects DNA mutations in individual skin cells, researchers at the University of California, the University of San Francisco, and the University of Utah were able to estimate the deadliest skin cancer before discovering a suspicious skull, pointing out that melanoma tumors are dangerous.

  As time goes by, the skin damage continues to accumulate, but it is usually invisible to the naked eye. However, the DNA of skin cells has accumulated damage caused by solar radiation over the years, and this damage can be measured.

  The corresponding author of this article, Dr. A. Hunter Shine, assistant professor of dermatology at the University of California, San Francisco, said that the genomic method for detecting skin damage developed in this study is based on the general population. He said it can be used to estimate the risk of linear melanoma, which is very important for dermatologists. Make recommendations on how often someone should be screened for cancer.

  Shane said: “Many cells in so-called normal skin are full of mutations associated with melanoma, which are caused by exposure to sunlight. Melanoma usually only appears after decades of mutational damage, but. Some people are at a higher risk than others. With the technology we have developed, we can monitor those who have accumulated the most mutations more closely and try to protect ourselves from the sun. It can be done."

  Melanoma is produced by a type of skin cell called melanosome. Melanin produces melanin, which helps protect skin cells rich in keratinocytes from sun damage. however. When DNA damage causes melanocytes to grow out of control, melanocytes face the greatest risk. according to

  According to the American Cancer Society, the incidence of melanoma is rising. By 2020, about 100,000 people in the United States will be diagnosed with melanoma, and about 6,850 people will die from the cancer. The lifetime risk of white melanoma is about 1 in 38, black is about 1 in 1,000, and Hispanic is about 1 in 167. If melanoma is detected early, it can be removed by surgery, but once it spreads, it is difficult to treat. In this study, the authors sequenced the black cell DNA in the skin samples of one skin sample at a time and counted the mutations. These mutations focused on several mutations that promote the appearance and growth of melanoma. The skin samples came from 6 people: the corpses of 2 melanoma survivors and the corpses of 4 people who had never experienced melanoma. Everyone is white. The author analyzed a total of 133 types of melanin metal DNA in the back, head, legs, shoulders, hips and feet. These authors found that compared with people who have never experienced melanoma, the normal skin melanin of precancerous patients has significantly more mutations, including mutations related to melanoma. I found a mutation. Shaun said that people with many pigs still need to be screened, but only 30% of melanomas come from existing black cattle.

  Shane said: "Melanoma may appear in thin air. This study found that normal skin contains a large number of melanocytes, which display cancer-related mutations. Basically, 70% of them are Melanoma. It was discovered that the precursor of melanoma was not produced by the existing bitter gourd."

  Sain has a higher risk of exposure to the sun, but the correlation is very complex, skin color and special. It is said that it is also related to DNA. Maintenance ability is related to other factors. Compared with adult occupational exposure (such as outdoor work), children are at greater risk of tanning. Shine said: "Measuring mutations may be a good way to measure the net effect of all these variables on melanoma risk."

  Strangely, melanoma is long-term. It is more noticeable than areas exposed to sunlight (such as the face). It usually occurs on areas of skin that are intermittently exposed, such as the back and thighs. Following this rule, Shain's research team found that the melanocytes of the back and limbs have more mutations than the skin of the head and neck. Sean said that the single-cell analysis performed in this study can help people focus on the relatively sparse melanocytes on the skin and identify cells with precancerous mutations. To this end, new technologies and new methods need to be combined. together. Compared to a typical biological sample containing many cells, the amount of DNA in a cell is too small, so you need to amplify the DNA to obtain enough DNA. The enzymes used to amplify DNA can cause errors, but Shain’s team used other experimental methods to better distinguish amplification errors from true mutations, and developed computer algorithms to further improve the accuracy of this analysis.

  Shain said: “We hope that simplified and automated versions of these methods will one day be widely used to measure the risk of melanoma and serve as the basis for cancer screening recommendations.”