In a new study, researchers propose a novel model of melanoma development, suggesting some skin cancers originate in hair follicles.
Melanoma is the deadliest form of skin cancer. It is considered the seventh most common type of cancer in Canada with the number of newly diagnosed cases having tripled in the last thirty years. Melanoma develops from melanocytes, which are the cells that produce the pigment called melanin that provide the skin and hair with their colour. Melanoma is curable when it is detected early but is difficult to treat after the cancer has spread deeper into the skin and to other organs.
In a new study, published in Nature Communications, researchers developed a model that suggests melanoma begins in hair follicles and not in the epidermis as proposed by past research models. In the study, mice were genetically engineered to enable the researchers to edit genes in the stem cells that mature into melanocytes in the hair follicles. The researchers were able to introduce genetic mutations that led to the formation of melanoma in these stem cells.
The findings of the study suggest that melanoma begins in the melanocyte stem cells and migrates up and out of the hair follicles to the epidermis. The researchers tracked the cells that were carrying the genetic mutation as they multiplied in the epidermis to form melanoma and then spread to the dermis (the layer located below the epidermis). The researchers reported that the melanocytes in the follicles developed melanomas after they were triggered by endothelin (EDN) and WNT. Endothelin and WNT are signalling proteins that are responsible for regulating hair growth and causing melanocytes to multiply in the hair follicles.
The researchers were the first research team to demonstrate that melanomas begin the hair follicles. According to one of the researchers, Qi Sun, future studies will involve conducting more human testing to confirm their findings and suggests that some skin cancers such as melanoma can originate in both the hair follicles and skin layers. Mayumi Ito Suzuki, one of the study authors, writes that the confirmation of melanocytes in the hair follicles as the source of melanoma will enable researchers to obtain a better understanding of the skin cancer’s biology and develop new ideas to counter it.
Written by Ranjani Sabarinathan, MSc
Sun Q, Lee W, Mohri Y, et al. (2019). A novel mouse model demonstrates that oncogenic melanocyte stem cells engender melanoma resembling human disease. Nature Communications. doi: 10.1038/s41467-019-12733-1
Some skin cancers may start in hair follicles. (2019, November 4). Retrieved from https://www.eurekalert.org/pub_releases/2019-11/nlh-ssc110119.php
Melanoma Network fact sheet: What is Melanoma? Available at: https://www.melanomanetwork.ca/melanoma/
Image by Dirk (Beeki®) Schumacher from Pixabay