Research Interests:

(i) The molecular regulation of stem and progenitor cell functions.
Our laboratory has established protocols to isolate stem and progenitor cells from the normal human mammary gland at very high purities (~50%). The ability to isolate these rare cells at high purities has enabled us to establish a requirement for NOTCH signaling in the commitment of the primitive, bipotential progenitors to more differentiated luminal-restricted progenitors (Figure 1). This project aims to further our understanding of the mechanism by which NOTCH receptors and other signal molecules control cell-fate determination, self renewal and differentiation of the stem and progenitors by utilizing gain of function (using mutated, constitutively active signaling molecules) and loss of function studies (using shRNA and siRNA) (Figure 1 & Figure 2).

(ii) Identification of signaling molecules whose perturbed function can confer a cancer stem cell phenotype on primitive cells.
The cancer stem cell concept suggests that tumour cells contain a rare cell population with proliferative and differentiation potential giving rise to the heterogenous population cells observed in tumours. Previously, it was demonstrated that Cd24lowCD44+ subpopulation of human mammary tumours contained cells with the ability to form tumours that recapitulated the phenotype of the original tumour while the CD24+CD44- cells did not. Thus, it could be argued that breast stem cells already exists and that understanding their biological properties would lead to the development of more effective breast cancer therapeutics. However, the frequency of cancer stem cells in this population is very low (0.1%) and the relationship between this subpopulation and the normal mammary stem and progenitor cells has not been explored. This project aims to find new marker genes whose expression make possible to purify sub populations of breast tumour cells that are highly enriched for cancer stem cell activity. This will be accomplished through utilizing multi-colour Fluorescent Activated Cell Sorting or FACS, transcriptome profiling, and in vivo and in vitro breast cancer model systems (Figure 2). 


(iii) Explore the unique biological properties of the breast cancer stem and progenitor cells to develop new therapeutics.
The concept that human breast tumour cells are maintained by a rare population of cancer stem cells provides the framework to hypothesize that the induction of long-lasting clinical responses requires targeting these cancer stem cells. To accomplish the goals of this project, breast cancer stem cell-specific genes and their association to breast cancer subtypes will be determined in collaboration with the Manitoba Breast Tumour Bank and genes whose expression associate with poor prognosis and high incidence of recurrence will be identified. The hypothesis is that cancer stem cell-specific markers would associate with malignant and metastasizing tumours and can be used for diagnostic purposes. In vivo and in vitro model systems will be utilized to evaluate the role of these genes in maintaining the cancer stem cell phenotype and thus their potential use to develop new therapeutic modalities. Additionally, the application of cancer immunotherapy concept to eliminating cancer stem cells will be examined as there is now overwhelming evidence supporting the notion that both human and mouse immune systems have the ability to not only recognize but also to constrain tumour growth. However, tumour cells might escape or attenuate this immune pressure, similar to the way in which these cells evade classic mechanisms of tumour suppression. This project aims to use tumour stem cell-specific antigens to sensitize host’s immune system to detect these cells and their progeny in order to achieve curative, less invasive therapies to fight cancer.

Select Publications:
1. Afshin Raouf, Yun Zhao, Karen To, John Stingl, Allen Delaney, Mary Barbara, Norman Iscove, Steven Jones, Steven McKinney, Joanne Emerman, Samuel Aparicio, Marco Marra & Connie Eaves, Transcriptome analysis of the normal human mammary cell commitment and differentiation process. Cell Stem Cell, 2008; 3:109-18.
2. Peter Eirew, John Stingl, Afshin Raouf, Joanne T Emerman, and Connie Eaves, A method for quantifying normal human mammary epithelial stem cells. Nature Medicine, 2008; 14(12):1384-89.
3. Afshin Raouf, Lindsay Brown, Nikoleta Vrcelj, Karen To, Winnie Kwok, David Huntsman, and Connie Eaves, Genomic instability of human mammary epithelial cells overexpressing a truncated form of EMSY. J Natl Cancer Inst. 2005; 97(17):1302-6.
4. Yun Zhao, Afshin Raouf, David Kent, Jaswinder Khattra, Allen Delaney, Angelique Schnerch, Jennifer Asano, Helen MacDonald, Christina Chan, Steven Jones, Marco A. Marra, Connie J. Eaves, Use of a Novel PCR-LongSAGE Protocol to Profile the Transcriptome of Human Bone Marrow CD34+ Stem/Progenitor Cells. Stem Cells, 2007; 25(7):1681-9.
5. John Stingl, Afshin Raouf, Peter Eirew, and Connie J Eaves, Deciphering the mammary epithelial cell hierarchy. Cell Cycle, 2006; 5(14):519-22.
6. Stingl J, Raouf A, Emerman JT, and Eaves CJ, Epithelial progenitors in the normal human mammary gland. J Mammary Gland Biol Neoplasia. 2005 Jan; 10(1):49-59.

PubMed Listed Publication

Positions Available:
Currently we have positions available for graduate students (M.Sc. and Ph.D.) as well as clinical and postdoctoral fellows. Undergraduate students will also be considered.

Lab Members: