P121 The anti proliferative effect of Aloin and Aloe emodin on MCF-7 and MDA-MB-231 breast cancer cells

Abstract

chemo-resistance. Therefore, it is necessary to develop CSC targeting therapies. In breast cancer, it has been showed that CD44+/CD24−tumor cells are highly tumorigenic, but the reported frequency of CD44+/CD24− tumor cells are widely ranged because of the differences of their analysis method. The main goal of our study is to develop a semi-quantitative fluorescence immunohistochemical staining method (semi-quantitative FIHC) for evaluating physiological distribution of CD44+/CD24− tumor cells at the level of breast tissue. Methods: Samples were 21 primary breast cancer specimens before and after neoadjuvant chemotherapy (NAC) and 17 sentinel lymph nodes with micro metastasis (sentinel Ly) obtained from Surgery and Oncology, Kyushu University (Fukuoka, Japan) between 2006 and 2008.Collection of only tumor cells from breast cancer tissue applied correspondingly to laser-capture microdissection method. Fluorescence intensity of CD44 and CD24 was evaluated based on that of nuclear staining and then CD44+/CD24− tumor cells were detected individually at single cell level. Results: The ratio of CD44+/CD24− tumor cells to counted total carcinoma cells (%CD44+/CD24−) was significantly higher after NAC than before NAC. %CD44+/CD24− in the sentinel Ly was significantly higher than that in the primary tumors. In both breast cancer tissue and sentinel Ly, the distribution of CD44+/CD24− tumor cells was different between each specimen and its distribution was heterogeneous within the same specimen. In a mouse xenograft model, a hedgehog inhibitor, cyclopamine, suppressed the tumorigenicity of CD44+CD24− cells. Conclusion: Our study suggests that semi-quantitative FIHC is useful and CD44+/CD24− tumor cells are chemo-resistant, metastatic, and tumorigenic. CD44+/CD24− tumor cell may be apossible therapeutic target for patient with breast cancer. Disclosure of Interest: None Declared