My laboratory is focused on two areas: 1) the control of self-renewal of normal stem cells and their malignant counterparts; and 2) the identification and characterization of cancer stem cells.

Cancers arise as a result of a series of genetic mutations. A better understanding of the consequences of these mutations on the underlying biology of the neoplastic cells will help to focus the development of more effective therapies.

Solid tumors such as breast cancers contain heterogeneous populations of neoplastic cells. My group has developed a technique that allows the isolation and characterization of tumorigenic and non-tumorigenic populations of cancer cells present in human breast, colon, and head and neck cancer tumors. Only a small minority of cancer cells had the capacity to form new tumors in a xenograft model. This tumorigenic cell population could be identified prospectively, and consistently had definable and identical phenotype. The tumorigenic cells displayed stem cell-like properties in that they were capable of generating new tumors containing additional stem cells, as well as regenerating the phenotypically mixed populations of non-tumorigenic cells present in the original tumor.

Effective treatment of cancer will require therapeutic strategies that are able to target and eliminate this tumorigenic subset of cells. My laboratory is pursuing the identification of cancer stem cells in other tumors so that they can be studied.

Finally, the laboratory is actively pursuing how cancer stem cells self-renew to maintain themselves and escape the genetic constraints on unlimited self-renewal that regulate normal stem cells. Differences in self-renewal pathways between normal and malignant stem cells could be targeted by new therapeutic agents to eliminate cancer stem cells.