Lung cancer is the leading cause of death from cancer in the United States and worldwide. This is because most patients are not diagnosed until they have advanced lung cancers and are faced with few or no therapeutic options.
Carla Kim, PhD, a Boston Children’s Hospital stem cell researcher, was the first person to discover a group of stem cells from the adult mouse lung called bronchioalveolar stem cells (BASCs). Kim discovered how to extract these cells from lung tissue to study their growth. She also showed that mutated BASCs are the source of certain lung cancers, such as adenocarcinoma. In humans, adenocarcinoma is an aggressive form of lung cancer that, in later stages, is often resistant to treatment. The discovery of BASCs has provided a new way for scientists to better understand the way stem cells function and how they are controlled in a normal lung or altered in lung diseases.
Recent work in other solid tumors indicates that only some of the cells within a tumor are required for tumor growth. These cancer cells have been named “cancer stem cells.” Cancer stem cells may be part of the cause of lung cancer cell resistance to therapy, but it is not yet known if lung cancers contain cancer stem cells. Kim’s lab has developed a way to determine if lung tumors have cancer stem cells. They can create lung tumors in mice or use lung cancer patient samples, isolate special subgroups of tumor cells, and re-grow the lung tumors in recipient mice. Observing which cell groups can grow tumors will zero in on what helps to sustain lung cancer. The lab has already found a cancer stem cell population in mouse lung tumors, and is now searching for similar cells in human lung cancer tissue samples. In summary, the Kim Lab has developed the only system available to simultaneously study normal lung stem cells, the lung cells that give rise to malignancy, and cancer stem cells in lung cancer. Their work will be important for innovative approaches to studying cancer and diseases that affect lung cells as well as identifying potential means of early detection and therapy.