Cancer Stem Cells and Somatic Stem Cells as Potential New Drug Targets, Prognosis Markers, and Therapy Efficacy Predictors in Breast Cancer Treatment

New drug targets, markers of disease prognosis, and more efficient treatment options are an unmet clinical need in breast cancer (BC). We have conducted a pilot study including patients with luminal B stage IIA–IIIB. The presence frequency various populations stem cells (CSC) somatic were assessed the blood, tumor tissue, normal tissue. Our results suggest that BC can be divided into two distinct groups based on aldehyde dehydrogenase positive (ALDH1+ cells) blood (ALDH1hi ALDH1low). In ALDH1hi group, is dominated by epithelial CD44+CD24low, CD326+CD44+CD24?, CD326?CD49f+, while ALDH1low CSCs mesenchymal origin (CD227+CD44+CD24? CD44+CD24?CD49f+) predominant. vitro group expressing CD326 showed high resistance to cytostatics, CD227+ sensitive cytostatics. Epithelial precursors healthy mammary gland revealed tissue from both groups. associated effect chemotherapy remission patients. Thus, dynamic control their assessment sensitivity cytostatics improve effectiveness BC.