Finding Answers about Large Congenital Melanocytic Nevi
In hospitals around the world, physicians and researchers are pondering how some cells in a developing embryo grow into a large congenital melanocytic nevus (CMN). Most especially, they wonder what they can do about it, when a child is born with one.
Searching for Treatment Possibilities
At the Children’s Hospital of Pittsburgh, University of Pittsburgh Medical Center, Miguel Reyes-Múgica, MD, has established a new research group with full-time PhD scientists and student trainees, dedicated to nevus research. Reyes is Chief of Pathology and Director of Laboratories at Children’s Hospital of Pittsburgh.
While he is approaching this work from several angles, the major question he wants to address is this: Once a patient with a nevus is born, what treatments other than surgery can we develop to improve his or her condition?
Reyes is building on the knowledge that CMN derive from a temporary cell type present in the one- to two-month human embryo, called the neural crest.
“Essentially, we are trying to target the biological processes that control the transformation of one tissue into another. In this case, we are looking at the transformation of neural crest cells into a congenital nevus,” Reyes says.
“This is a very complex process, which includes a phenomenon called epithelial-mesenchymal (EM) transition,” he says. “We have identified a potential target molecule that appears to control not only EM transition, but also another biological process called senescence. Senescence has to do with biological aging and death.
“If neural crest cells are going to transform into a nevus cell, and we can harness this molecule to control the process triggering this change, we may be able to stop it,” he says.
Reyes and his colleagues are working with a model of stem cells similar to neural crest cells and hope to develop studies with laboratory animals. Specifically, Reyes wants to see if stem cells programmed to form melanocytes (pigment producing cells) can be stopped or induced to going into senescence. This is a primary angle of his work.
Looking Toward the Future
“The mainstay of treatment today is surgery. It is still relatively early, but eventually we hope to develop drug therapy by which the transition of primitive cells can be controlled and stopped — or even reversed. It is possible that knowing how satellite (smaller) nevi develop after birth, we could arrest their development,” says Reyes.
“That is our aim. We have high hopes for this, but we are early in the process. Importantly, findings from nevus research will be applicable to cancer as well.”
Reyes is also developing a tissue repository, where excess tissue from patients undergoing surgery for removal of congenital moles — especially giant nevi — can be stored. This tissue can then be provided to researchers carrying out additional studies to further increase our understanding of many different angles in nevus development.