Abstract 4222: CCN5 deficient MCF-7 side population exhibits stem cell like behavior and formed aggressive tumor in xenograft model

Abstract

Abstract The side population (SP) has been identified in a variety of solid tumor cell lines including human breast cancer cell lines. This population of cells has been considered as cancer stem cells (CSCs). Cancer recurrence is currently thought to be due to non-dividing cancer stem/progenitor cells that are resistant to chemo- and radio-therapies. Different therapeutic approaches need to be considered for the elimination/transformation of the cancer stem cells. To reshape our therapeutic approach to breast cancer, we aimed this study and isolated the SP from MCF-7 breast cancer cell line. SP was confirmed by both positive and negative cell surface molecular markers. These include CD44, CD24, b-catenin, E-cadherin, Keratin 19, Oct-4, Notch-1 and Vimentin. Our studies showed that SP and non-SP exhibit differential expression of CCN5, an anti-invasive gene. CCN5 expression was undetected or barely expressed in SP. The comparative studies showed that the in vitro migratory property of SP was significantly higher as compared to non-SP. Moreover, the introduction of CCN5 in SP may enhance the epithelial properties as evidenced by differential expression of MET (mesenchymal-epithelial transition) molecular markers. SP shows higher tumorigenicity in immunodeficient mice. These findings indicate that CCN5 deficiency could be an essential molecular event for the development of a side population having invasive phenotype. Therefore, CCN5 can be used as a therapeutic reagent for advanced breast cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4222.