One of the reasons that melanoma is the deadliest form of skin cancer is its persistence. The disease often comes back even after seemingly effective treatment, a trait that many researchers attribute to cancer stem cells that continually renew melanoma tumors with fresh cancer cells.
Scientists at Wistar have a new theory that turns the cancer stem cell model on its head: individual melanoma cells are neither mother stem cells nor regular cancer cells – they’re both. They call it “dynamic stemness” and it means that all melanoma cells equally harbor cancer stem cell potential and are capable of inducing new tumors.
Their findings, published in the journal Cell, reveal the unique biology of melanoma, and suggest that the disease requires an entirely new therapeutic approach. The researchers discovered that stem-like cells within melanoma tumors are defined by the presence of a protein called JARID1B. They found that all melanoma cells are capable of producing this protein, essentially making every single melanoma cell a potential stem cell.
“Targeting only the bulk tumor population, as most conventional anticancer therapies do, is pointless in melanoma, in that each cell can act as a seed for the tumors to rebound,” said Meenhard Herlyn, D.V.M., D.Sc., professor and leader of Wistar’s Molecular and Cellular Oncogenesis Program.
A two-pronged therapeutic approach is needed: one to target the bulk of the tumor, while another should specifically target the JARID1B subpopulation, says Herlyn. Herlyn and his colleagues are now exploring ways to create new drugs that specifically target JARID1B cells.