New Study Proposes Hair Follicles as Origin of Melanoma Development

Overview of Melanoma

Melanoma is recognized as the most lethal form of skin cancer, ranking as the seventh most prevalent cancer in Canada. Over the past three decades, the incidence of newly diagnosed melanoma cases has increased threefold. This type of cancer arises from melanocytes, the cells responsible for producing melanin, which gives color to the skin and hair. While early detection of melanoma can lead to effective treatment, its management becomes challenging once the cancer has metastasized to deeper skin layers and other organs.

Findings of the Study

A recent study published in Nature Communications introduces a groundbreaking model of melanoma development, proposing that this skin cancer originates in hair follicles rather than the epidermis, as previously believed. Researchers engineered mice to allow genetic modifications in the stem cells that develop into melanocytes within hair follicles. This manipulation facilitated the introduction of genetic mutations that resulted in melanoma formation from these stem cells.

The study indicates that melanoma initiates in the melanocyte stem cells and subsequently migrates out of the hair follicles to the epidermis. The researchers monitored how the mutated cells proliferated in the epidermis, leading to melanoma development and eventual spread to the dermis, the layer beneath the epidermis.

Role of Signaling Proteins

The researchers discovered that the melanocytes in hair follicles developed melanoma after being stimulated by endothelin (EDN) and WNT, which are signaling proteins that regulate hair growth and encourage melanocyte proliferation in hair follicles. This study marks the first instance where researchers have demonstrated that melanomas originate in hair follicles.

Future Research Directions

According to Qi Sun, one of the researchers, future investigations will aim to conduct more human trials to validate their findings. They propose that certain skin cancers, including melanoma, may develop from both hair follicles and skin layers. Mayumi Ito Suzuki, another author of the study, emphasizes that confirming the role of melanocytes in hair follicles as the source of melanoma will enhance the understanding of the cancer’s biology and foster the development of new therapeutic strategies.

References

– 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