Researchers at IDIVAL and CNIO find the molecular regulation that allows the skin to be continuously exposed to the sun

2 de March de 2020

The Cell Cycle, Determining Stem Cells and Cancer research group of the Valdecilla Health Research Institute (IDIVAL), led by Dr. Alberto Gandarillas, has just published a paper that includes the molecular regulation that makes it possible for epithelial cells such as skin epidermis do not die against continuous carcinogens such as sunlight.

This discovery has allowed us to identify a gene that allows the skin to function despite being exposed to the sun on a daily basis without its cells dying from apoptosis.

Dr. Gandarillas has indicated that the results of this study have direct application in epidermoid cancer, as they provide new prognostic and therapy pathways. This type of cancer, which causes about 12,000 deaths a year in Spain, is the second most frequent neoplasm and one of the leading causes of cancer death, which arises in a variety of tissues such as skin, mouth, throat, esophagus or lung. and that, in general, is usually aggressive and of bad treatment.

 As explained by Alberto Gandarillas, the continuous exposure of the cells of the epidermis to solar radiation causes DNA damage, although externally it is not manifested by a burn or reddening of the skin.

The known response of cells to genetic damage, he pointed out, is apoptosis or programmed cell death. As an example of this phenomenon, “which is widely used in antitumor therapies,” he cited the fact that radiation therapy has always been assumed to eliminate tumor cells by apoptosis.

However, in the case of the epidermis, the cells do not die by apoptosis in response to the daily effects of the sun, since “if that were the case we would not have skin,” he said.

Dr. Gandarillas has stressed that they already had a response to the phenomenon of skin peeling due to the effect of ultraviolet light, “which is not necessarily due to cell death, necrosis or burn, but to an accumulation of genetic damage.” We also knew that this response occurs in cells of the mouth and throat, which are also continually exposed to carcinogens such as tobacco and alcohol.

“But we still didn't understand,” he said, “how or why the cells of these epithelia escape apoptosis and manage to maintain tissue despite the continuous impact on their DNA.”

In this sense, it has indicated that the research work has shown that molecules that control cell division protect the epithelial cells of the skin, mouth and neck from cell death against continued genetic damage. “By eliminating the CDC20 gene, skin cells died.” Genes like this allow the existence of these tissues, their renewal and their function despite being chronically exposed to mutagens, he concluded.

The work, published in the journal 'Cell Death and Differentiation', of the Nature Group, has been carried out in collaboration with the research groups of the National Oncology Research Center (CNIO) led by Mariano Barbacid and Marcos Malumbres.