Abstract 5353: Characterization of breast cancer stem cells (BCSCs) in Egyptian breast cancer patients through genetic profiling using the RT-PCR and quantitative real time microarray

Abstract Background: Stem cells (SC) are cells that can differentiate along distinct lineages through systemic differentiation steps. The concept of self renewal is crucial to understand cancer stem cells (CSC) and the mechanisms by which current therapies might evade the available treatment modalities. The aim of the present study was to characterize breast cancer stem cells (BCSC) by genetic profiling of properly isolated BCSCs at different stages using the recently developed quantitative real time microarray technology to understand the origin and contribution BCSCs to breast cancer development and progression. Material and Methods: 60 cases of BC were subjected to enzymatic digestion to obtain single cell suspension for: 1) flowcytometric characterization of cells, 2) mammosphere culture 3) magnetic separation of different subsets of BCSCs (CD44 and CD24), and 4) RNA extraction for RT-PCR and microarray using the SABiosciences's QC PCR profiler Arrays with SC panel of 84 genes (SC specific markers, SC differentiation markers, and signaling pathway markers for SC). Samples for the QC PCR profiler Arrays were categorized into groups: 1) normal breast tissue, 2) BC cells obtained from tumor samples, 3) cells from mammosphere cultures, 4)CD44+/CD24low/EpCAM- cells, 5) CD44+/ CD24low cells. ER, PR and Her-2 assessment was also performed. Results: Discrete mammospheres of different sizes were obtained from 10 cases and IHC of these samples confirmed the SC lineage. By FCM, cells expressing CD44+/CD24low ranged from 0.1% - 79%. MYC, MYST2, DHH, BTRC AND CXCL12 genes showed over-expression in the studied groups in comparison to normal breast tissue. Comparing all studied groups, we identified 5 candidate genes DVL1 and EP300 (Notch pathway), BTRC (Wnt Pathway), DHH (Chro-Chro Modulation), MYST2 (self Renewal), NCAM1 (Cell Adhesion Molecules) which could be used for characterization and molecular target therapy for breast cancerl. Conclusions: Our QC PCR profiler Arrays showed significant differences between the studied groups shedding light on the nature and helping in proper characterization of BCSCs. Correlation between prognostic factors of BC and the number of BCSCs in tumor biopsies together with the probability of mammoshpere formation in culture denotes the contribution of CSCS to the progression of BC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5353. doi:1538-7445.AM2012-5353