My laboratory studies the role of ovarian steroid hormones estradiol and progesterone and their cognate receptors in breast cancer. Current work focuses on hormonal regulation of stem cells in both normal breast tissue and in luminal estrogen receptor (ER) positive tumors. Using cell line and in vivo models, we are exploring signaling pathways downstream of steroids that promote or prevent the stem cell phenotype. We are also interested in how these stem cells impact therapy resistance, tumor progression, and metastasis in ER positive breast cancers. Using novel screening assays, we hope to identify unexplored targets specifically in luminal breast tumor stem cells. We are also studying how some ER+ tumors progress to basal ER‒ breast tumors.
Ovarian steroid hormones: what's hot in the stem cell pool?
Cittelly DM, Richer JK, Sartorius CA.
Breast Cancer Res. 2010 Aug 31;12(4):309. [Epub ahead of print]PMID: 20825628 [PubMed - as supplied by publisher]
Cytokeratin 5 positive cells represent a steroid receptor negative and therapy resistant subpopulation in luminal breast cancers.
Kabos P, Haughian JM, Wang X, Dye WW, Finlayson C, Elias A, Horwitz KB, Sartorius CA.
Breast Cancer Res Treat. 2010 Jul 28. [Epub ahead of print]PMID: 20665103 [PubMed - as supplied by publisher]
Progestins in hormone replacement therapies reactivate cancer stem cells in women with preexisting breast cancers: a hypothesis.
Horwitz KB, Sartorius CA.
J Clin Endocrinol Metab. 2008 Sep;93(9):3295-8. Epub 2008 Jul 22.PMID: 18647813 [PubMed - indexed for MEDLINE]
Progesterone receptor action: translating studies in breast cancer models to clinical insights.
Lange CA, Sartorius CA, Abdel-Hafiz H, Spillman MA, Horwitz KB, Jacobsen BM.
Adv Exp Med Biol. 2008;630:94-111. Review.PMID: 18637487 [PubMed - indexed for MEDLINE]
Rare steroid receptor-negative basal-like tumorigenic cells in luminal subtype human breast cancer xenografts.
Horwitz KB, Dye WW, Harrell JC, Kabos P, Sartorius CA.
Proc Natl Acad Sci U S A. 2008 Apr 15;105(15):5774-9. Epub 2008 Apr 7.PMID: 18391223 [PubMed - indexed for MEDLINE]
Estrogen insensitivity in a model of estrogen receptor positive breast cancer lymph node metastasis.
Harrell JC, Dye WW, Harvell DM, Pinto M, Jedlicka P, Sartorius CA, Horwitz KB.
Cancer Res. 2007 Nov 1;67(21):10582-91.PMID: 17975003 [PubMed - indexed for MEDLINE]
Contaminating cells alter gene signatures in whole organ versus laser capture microdissected tumors: a comparison of experimental breast cancers and their lymph node metastases.
Harrell JC, Dye WW, Harvell DM, Sartorius CA, Horwitz KB.
Clin Exp Metastasis. 2008;25(1):81-8. Epub 2007 Oct 12.PMID: 17932773 [PubMed - indexed for MEDLINE]
Estrogen receptor positive breast cancer metastasis: altered hormonal sensitivity and tumor aggressiveness in lymphatic vessels and lymph nodes.
Harrell JC, Dye WW, Allred DC, Jedlicka P, Spoelstra NS, Sartorius CA, Horwitz KB.
Cancer Res. 2006 Sep 15;66(18):9308-15.PMID: 16982776 [PubMed - indexed for MEDLINE]
Progesterone receptors (PR)-B and -A regulate transcription by different mechanisms: AF-3 exerts regulatory control over coactivator binding to PR-B.
Tung L, Abdel-Hafiz H, Shen T, Harvell DM, Nitao LK, Richer JK, Sartorius CA, Takimoto GS, Horwitz KB.
Mol Endocrinol. 2006 Nov;20(11):2656-70. Epub 2006 Jun 8.PMID: 16762974 [PubMed - indexed for MEDLINE]
Progestins initiate a luminal to myoepithelial switch in estrogen-dependent human breast tumors without altering growth.
Sartorius CA, Harvell DM, Shen T, Horwitz KB.
Cancer Res. 2005 Nov 1;65(21):9779-88.PMID: 16266999 [PubMed - indexed for MEDLINE]