Breast cancer stem cells: a novel therapeutic target.

Breast cancer stem cells (BCSCs), characterized by the CD44(+)/CD24(-/low) marker, are attributed with features that are demonstrated by the disease itself, such as growth of tumor, recurrence, metastases, and multiple drug resistance. This review concerns the emergence and expediency of BCSCs in treating relapse and advanced cases of breast cancer. One of the ideal ways of detecting and eliminating BCSCs would be to tweak certain molecular receptors in the desired pathway, which would require extensive and comprehensive knowledge about these cell signaling pathways. Although hedgehog (Hh), Notch, and Wnt signaling are of prime concern, governing tumorigenesis and cancer stem cell (CSC) renewal, designing chemotherapeutic or molecular targeted therapies is still a tricky arena to venture into, as these pathways play a vital role in normal mammary gland development. Thus selective inhibition of pathway receptors needs to be investigated in the future.