Figure 4

CSC are abundant in primary CD44 ^high /CD24 ^low /Ep-CAM ^high /CD49+ cancer cells. A) Representative dot plots for Ep-CAM/CD49f profile of tumor cells from different breast cancer patients as analyzed by flow cytometry (top) and histogram showing percentage of each Ep-CAM/CD49f population (n = 9 for normal breast and n = 13 for breast cancer samples). Lineage negative (CD45^neg, CD10^neg, CD31^neg) cancer cells were gated followed by exclusion (gating out) of Ep-CAM^neg/CD49f^neg mesenchymal fraction. Numbers in the corners indicate percentage of cells in each quadrant. B) Expression level of each of the studied stem/progenitor cell markers in Ep-CAM^high/CD49f^neg and Ep-CAM^high/CD49f + cell fractions in 16 breast cancer patients gated as in A. C) Percentage of CD44^high/CD24^low/Ep-CAM^high cancer cells (top) and after fractionation into CD49f^neg or CD49f + cells (bottom). Cases were stratified to four subtypes of breast cancers based on their estrogen receptor (ER), progesterone receptor (PR) status, as well as overexpression of Her2 as following: ER = ER+/PR+/Her2^neg, ER/Her2 = ER+/PR+/Her2+, Her2 = ER^neg/PR^neg/Her2+, and basal = ER^neg/PR^neg/Her2^neg, D&E) Mammosphere formation, measured by either number (D) or size (E) of tumor cells sorted for the stem/progenitor markers CD44^high/CD24^low or ALDH^high and expressed within Ep-CAM^high/CD49f^neg or Ep-CAM^high/CD49f + breast cancer cell subpopulations (means ± S.E.M, n = 7). **indicates statistical significance.