Where do Squamous Cell Cancers Come From?
Squamous cell carcinoma (SCC) is a type of cancer that occurs in multiple organs. It is a malignant tumor composed of squamous epithelium (squamous-cell differentiation). The cancer can affect many parts of the body including the skin, lung, bladder, and sex organs. A new study from researchers at the University of California in Los Angeles (UCLA) has found that the origin of SCC is hair follicle stem cells. This finding may lead to new strategies to treat or prevent this terrible disease.
Prior studies found that SCC'’s origin may be from hair follicles, but could not identify the specific type of cell it comes from. The hair follicle stem was found to be the culprit in the new study. Oddly, the progeny of these cells, just a few divisions away from the mother hair follicle stem cell, are not capable of forming squamous cell cancers. In other words, the grandchildren and great grandchildren of the original cancer cell cannot produce further cancer cells.
The UCLA study examined two distinct skin cell types for their ability to develop squamous cell cancers. "It was surprising that the progeny of these stem cells, which are developmentally more restricted, could not develop cancers when the mother stem cells could," said William Lowry, assistant professor of molecular, cell, and developmental biology and senior author of the study. "There is something fundamentally different between the two, and it's important that we figure out why one type of cell was able to develop cancer and the other was not. The insights we gain will tell us how these cancers arise in the first place and could provide us with a wealth of novel targets we could go after to prevent the cancer before it starts."
The study sought to find out if skin stem cells were more likely to develop tumors than non-stem skin cells. According to Andrew White, postdoctoral fellow in Lowry's lab and the first author of the study, "Adult stem cells are long-lived and can acquire mutations that can cause cancer, but they also have intrinsic properties for self-renewal that are similar to cancer that could make them more tumor-prone."
White plans to molecularly profile the hair follicle stem cells going forward in order to map out the biological chain of events which occurs when cancer-causing genes are delivered. The results can lead to therapies which specifically prevent cancer rather than treating the disease once it exists. The study was published in the journal Proceedings of National Academy of Sciences.
Link to published article: http://www.pnas.org/content/early/2011/04/14/1012670108.abstract