Melanoma from follicles
Scientists from the Langone Medical Center at New York University have found out that some types of skin cancer begin to develop in the stem cells of hair follicles, and not in the layers of the skin, as was previously believed. For example, it has been claimed that ultraviolet radiation is one of the main risk factors for melanoma, but this work shows that triggers are also present in normal follicles.
The study was conducted on mice with a c-Kit-CreER mutation of melanocytes, the results were confirmed in human tissue samples.
Scientists traced the path of melanocyte stem cells and noticed that cancer cells can form from those cells that abnormally migrate from hair follicles to the epidermis, the outer layer of the skin. Before that, in the dermis, cells get rid of structures associated with their follicular origin, presumably in response to local signals.
Knowing where to look for the original event that causes cancer, scientists temporarily eliminated signals in the follicles to see if the processes of malignancy begin in their absence. Thus, the team confirmed that the follicular stem cells of melanocytes, even despite the presence of genetic mutations that cause cancer, do not multiply and do not migrate, causing melanoma, if they are not exposed to endothelin proteins (EDN) and proteins of the WNT signaling pathway. These proteins usually cause an increase in hair length and the proliferation of pigment cells in the follicles.
The results of the study clearly show that as the embryo and fetus develop, stem cells divide and specialize until they become functional cells (for example, nerve cells). Stem cells can become more than one type of cell and can move in any direction. This flexibility is useful during childhood development, but can be dangerous for adults, as melanoma can arise from several types of stem cells, which makes it difficult to treat them and makes it difficult to track their origin.
Article by Sun et al. A novel mouse model demonstrates that oncogenic melanocyte stem cells engender melanoma resembling human disease is published in the journal Nature Communications.
Elena Panasyuk, portal "Eternal youth" http://vechnayamolodost.ru based on NYU Langone Health: Some Skin Cancers May Start in Hair Follicles.