Most of the tissues in our body contain adult stem cells that in theory could combat many aging phenotypes observed in human. However, these stem cells do not regenerate the tissue during aging. To understand, and in the future govern adult stem cell regenerative capacity we need to study the regulators of human adult stem cells. DPSCs are adult mesenchymal stem cells with powerful regenerative capacity that can easily be isolated from waste product, extracted wisdom teeth. Due to low cost and easy accessibility, dental pulp is a more feasible source for mesenchymal stem cells than bone marrow. DPSCs are thought to have the ability to differentiate into multiple cell lineages, and thus hold great promises in tissue regeneration. However, little is known about the molecular markers, cellular regulators, and differentiation capacity of these cells. The goal of my research project is to generate a large diversity set of DPSC to carry on a careful analysis of true common markers and differentiation capacity of these cells. At the moment I have optimized the procedures and isolated DPSCs from over 50 patients in partnership with UW dental clinic. We have now identified the molecular markers of DPSCs, and evaluated their differentiability to better understand the key criteria in the self-renewal and differentiation capacity of these cells. Western blot and flow cytometry analysis shows that most of our DPSCs have a robust expression of CD29 and CD146, both molecular markers of mesenchymal stem cells, but displaying an unexpected diversity on the levels of these markers among individuals. In differentiation tests, we also observe diversity in cartilage and adipocyte differentiation efficiency. With this unprecedented diversity set of easily accessible adult stem cells we will now identify the key components and metabolites that enhance the stemness and regenerative capacity of these adult stem cells.

Agressive cancers are resistant to apoptosis and stem-like cancer cells may be responsible for re-growth of cancerous tumors. This inspired this search for compounds that could aid in the destruction of cancer cells with stem-like properties. Drosophila germ-line stem cells under radiative or chemotoxic stress are protected by a molecular signal from apoptotic daughter cells via the TIE receptor. Thwarting this protective signal by the introduction of a small molecule may lead to the discovery of compounds that can be effective against stem-like cancer cells. The NCI Diversity Set of 1,596 small molecules was screened by undergraduate research students, in-vivo, to find compounds that can induce apoptosis in germ-line stem cells of Drosophila melanogaster. Four compounds have been found that induce apoptosis in both the male and female germ-line stem cells at a low 5 uM concentration. Future investigations will uncover the mechanism of action and efficacy against stem-like cancer cells.