Localization and Molecular Characterization of human Breast Cancer Initiating Cells from heterogeneous population of Breast Cancer Mesenchymal Stem cells by Immunofluorescence Microscopy

Breast Cancer (BC) is a heterogeneous disease and arises from breast cancer initiating stem cell population in the tumor and these cells are resistant to cancer therapies. Thus identifying this cell type within the tumor clone is an important area of research to understand the mechanism of breast cancer development. Recently, our laboratory has isolated and characterized Human breast cancer mesenchymal stem cells (hBCMSCs) from human breast cancer and showed the heterogeneity of these cells existing in the tumor. Therefore, our present objective is to use this model system to identify, localize and define specific breast cancer initiating cells (BCICs) from the heterogeneous population of hBCMSCs cell line developed in our laboratory. Localization of specific cell types can be done by using specific cancer marker antibodies using Immunofluorescence microscopy. In this study we have used FITC labeled specific cancer antibodies i.e. p53, Rb1, Hras, Ki67, EGFR, GST, ETS1 and ATF2 to localize BCICs in this population of cells. Our results have demonstrated that few cells among many of the BC cells gave fluorescence with specific cancer antibody indicating that these cell types are BCICs that may be responsible for supporting the growth of other cell type to form tumors. The Phase Contrast Microscopy clearly showed giant cells with enlarged nucleus and scanty cytoplasm associated with many cytoplasmic granules. It also indicates that these cells are mainly responsible for supporting proliferation of surrounding cells that form a part of the BC tumor. We have further hypothesized that molecular profiling of these tumor cells will open a new avenue of molecular targeted therapies for Breast Cancer patients even at an advanced stage of disease.