Carol A. Sartorius, Ph.D. Assistant Professor of Medicine

Dr. Sartorius received her BS in Molecular and Cellular Biology from the University of Michigan , where she studied with steroid hormone biochemistry pioneer Dr. Anita Payne. She received her PhD from the University of Colorado Denver in Molecular and Cellular Biology, studying with Dr. Kathryn Horwitz. She became an Assistant Professor in the Division of Endocrinology, Metabolism, and Diabetes in 2001.

Breast cancers can be classified into several distinct subtypes. The most common are the “luminal” subtypes, which are marked by expression of steroid receptors for the female hormones estradiol and progesterone (ER, PR), and comprise ~70% of all cases. Luminal tumors have a much more favorable prognosis than the less common “basal” subtype breast cancers. Dr. Sartorius' group recently identified a minor population ( ~ 1%) of “basal-like” cells, marked by expression of the basal subtype marker cytokeratin 5 (CK5), in a model of luminal subtype human breast tumors. They found that the minor subpopulation of basal-like CK5+ cells increases in the presence of progestins (progesterone or synthetic drugs), and co-expresses the recently described cancer stem cell marker CD44. The rare CK5+ cells are more “tumorigenic”, capable of forming new tumors from small numbers of cells, compared to the majority of CK5 ? tumor cells. They hypothesize that the rare CK5+ subpopulation may represent cancer stem cells within luminal breast tumors. Current studies in her laboratory focus on the role of progesterone in the biology of luminal subtype tumors, how hormones affect the rare population of basal/stem-like CK5+ cells, and how hormones affect endocrine- and chemo- therapy. A second project is focused on evaluating how hormones – estrogens and progestins – affect breast cancer metastasis.

Selected Publications:

Horwitz KB and Sartorius CA. COMMENTARY: Progestins in hormone replacement therapies reactivate cancer stem cells in occult breast cancers: a hypothesis. J Clin Endo & Metab , in press, 2008

Horwitz KB, Dye WW, Harrell JC, Kabos P and Sartorius CA . 2008. Rare steroid receptor negative basal-like tumorigenic cells in luminal subtype human breast cancer xenografts. Proc Natl Acad Sci USA , 105(15): 5774-9. PUBMED

Harrell JC, Dye WW, Harvell DM, Pinto M, Jedlicka P, Sartorius CA and Horwitz KB. 2007. Estrogen insensitivity in a model of estrogen receptor positive breast cancer lymph node metastasis. Cancer Res , 67 ( 21 ): 10582-91 . PUBMED

Harrell JC, Dye WW, Allred DC, Jedlicka P, Spoelstra NS, Sartorius CA and Horwitz KB. 2006. Estrogen receptor positive breast cancer metastasis: altered hormonal sensitivity and tumor aggressiveness in lymphatic vessels and lymph nodes. Cancer Res , 66(18): 9308-15. PUBMED

Harvell DME, Richer JK, Allred DC , Sartorius CA and Horwitz KB. 2006. Estradiol regulates different genes in human breast tumor xenografts compared with the identical cells in culture. Endocrinology , 147(2): 700-13. PUBMED

Sartorius CA , Harvell DME, Shen T and Horwitz KB. 2005. Progestins initiate a luminal to myoepithelial switch in estrogen-dependent human breast tumor xenografts without altering growth. Cancer Res 65(21): 9779-88. PUBMED

Sartorius CA , Shen T and Horwitz KB. 2003. Progesterone Receptors A and B Differentially Affect the Growth of Estrogen-Dependent Human Breast Tumor Xenografts. Breast Cancer Res Treat 79(3): 287-299. PUBMED