Photo of Pepper J. Schedin, Ph.D.

Pepper J. Schedin Ph.D.

  • (503) 494-9341
    • Professor of Cell, Developmental and Cancer Biology School of Medicine
    • Co-leader, Cancer Prevention and Control Program OHSU Knight Cancer Institute School of Medicine
    • Cell and Developmental Biology Graduate Program School of Medicine
    • Program in Molecular and Cellular Biosciences School of Medicine
    • Cancer Biology Graduate Program School of Medicine

The focus of the Schedin Lab research program is on understanding how normal breast development contributes to breast cancer risk and patient outcomes. We focus on the unique windows of breast development that occur during puberty, pregnancy and peri-menopause, as these developmental windows associate with high risk for breast cancer development and progression. Because tissue remodeling is the hallmark of these risk windows, our lab focuses on mammary epithelial-stromal interactions and how these interactions are modulated by physiology and life choices. My lab is at the forefront of investigating the normal mammary gland tissue environment and has shown that extracellular matrix proteins and immune cells are highly malleable, remodeling in response to puberty, pregnancy, menopause and even dietary intake. This stromal ‘plasticity’ contributes significantly to breast cancer risk, but also identifies unique developmental windows that can be targeted for the prevention and treatment of breast cancer. Current areas of research focus include understanding how pregnancy or menopause/diet interactions increase risk for breast cancer progression. From a prevention perspective, the strength in this ‘window of risk’ approach lies in the ability to limit duration of treatment, thus reducing treatment-related side effects associated with current breast cancer chemoprevention strategies. From a treatment perspective, our work identifies novel stromal markers, as well as potential drivers of breast cancers diagnosed in specific ‘developmental windows’ such as pregnancy and menopause, which can be exploited for targeted drug development. For our studies we utilize the rat MNU model, breast cancer xenograft, transgenic, and immunocompetent mouse models, 3D multi-cell co-culture systems, and human breast tissue. Our systems approach has yielded promising results for prevention and treatment of pregnancy-associated breast cancer and obesity-induced postmenopausal breast cancer.

Areas of interest

  • young women's breast cancer,
  • breast cancer prevention
  • metastasis
  • tumor micro-environment
  • immune suppression, extracellular matrix, fibrosis, ECM proteomics
  • 3D cell culture modeling


  • Ph.D., University of Colorado, Boulder 1988

Memberships and associations

  • American Association for Cancer Research Women in Cancer Research
  • Metastasis Research Society


  • "Extracellular matrix composition reveals complex and dynamic stromal-epithelial interactions in the mammary gland" Journal of Mammary Gland Biology and Neoplasia September 2010
  • "Benign mammary epithelial cells enhance the transformed phenotype of human breast cancer cells" BMC Cancer July 16 2010
  • "Isolation of mammary-specific extracellular matrix to assess acute cell-ECM interactions in 3D culture" Journal of Mammary Gland Biology and Neoplasia September 2010
  • "Hypothesized role of pregnancy hormones on HER2+ breast tumor development" Breast Cancer Research and Treatment January 2013
  • "Non-steroidal anti-inflammatory drugs target the pro-tumorigenic extracellular matrix of the postpartum mammary gland" International Journal of Developmental Biology  2011
  • "An in-solution ultrasonication-assisted digestion method for improved extracellular matrix proteome coverage" Molecular and Cellular Proteomics  2009
  • "Genomic Signatures of Pregnancy-Associated Breast Cancer Epithelia and Stroma and their Regulation by Estrogens and Progesterone" Hormones and Cancer  2013
  • "Macrophages are crucial for epithelial cell death and adipocyte repopulation during mammary gland involution" Development (Cambridge) January 15 2012
  • "Wound healing-like immune program facilitates postpartum mammary gland involution and tumor progression" International Journal of Cancer April 15 2015
  • "Myoepithelial cell differentiation markers in ductal carcinoma in situ progression" American Journal of Pathology November 1 2015
  • "Autonomy and nonautonomy of sex determination in triploid intersex mosaics of C. elegans" Development (Cambridge) July 1991
  • "Loss of singleminded-2s in the mouse mammary gland induces an epithelial-mesenchymal transition associated with up-regulation of slug and matrix metalloprotease 2" Molecular and Cellular Biology March 2008
  • "Inhibition of breast cancer growth and invasion by single-minded 2s" Carcinogenesis February 2007
  • "Adolescent diet and the risk of breast cancer in adulthood" Nutrition  1997
  • "Treatment with chemopreventive agents, difluoromethylornithine and retinyl acetate, results in altered mammary extracellular matrix" Carcinogenesis August 1995
  • "Important Role of Menarche in Development of Estrogen Receptor-Negative Breast Cancer in African American Women" Journal of the National Cancer Institute September 1 2015
  • "Cyclooxygenase-2-dependent lymphangiogenesis promotes nodal metastasis of postpartum breast cancer" Journal of Clinical Investigation September 2 2014
  • "Quantitative analysis of three-dimensional human mammary epithelial tissue architecture reveals a role for tenascin-C in regulating c-met function" American Journal of Pathology February 2010
  • "Estrous cycle regulation of mammary epithelial cell proliferation, differentiation, and death in the Sprague-Dawley rat" Journal of Mammary Gland Biology and Neoplasia  2000
  • "Preface" Journal of Mammary Gland Biology and Neoplasia  2009
  • "Pregnancy and breast cancer" Journal of Mammary Gland Biology and Neoplasia  2009
  • "A surprising link between the energetics of ovariectomy-induced weight gain and mammary tumor progression in obese rats" Obesity April 2010
  • "Clusterin induces matrix metalloproteinase-9 expression via ERK1/2 and PI3K/Akt/NF-κB pathways in monocytes/macrophages" Journal of Leukocyte Biology October 2011
  • "Postpartum mammary gland involution drives progression of ductal carcinoma in situ through collagen and COX-2" Nature Medicine September 2011
  • "Developmental windows of breast cancer risk provide opportunities for targeted chemoprevention" Experimental Cell Research July 1 2013
  • "Alterations in mast cell frequency and relationship to angiogenesis in the rat mammary gland during windows of physiologic tissue remodeling" Developmental Dynamics May 2012
  • "Molecular phenotype of breast cancer according to time since last pregnancy in a large cohort of young women" Oncologist May 29 2015
  • "ESX induces transformation and functional epithelial to mesenchymal transition in MCF-12A mammary epithelial cells" Oncogene March 4 2004
  • "Whole-food sources of vitamin A more effectively inhibit female rat sexual maturation, mammary gland development, and mammary carcinogenesis than retinyl palmitate" Journal of Nutrition June 2007
  • "Tumor mechanics and metabolic dysfunction" Free Radical Biology and Medicine  2015

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