There is increasing preclinical and clinical evidence that breast cancer stem cells are relatively resistant to both radiation and chemotherapy thereby contributing to treatment resistance and relapse. This suggests that improved clinical outcomes may require selective targeting of this cells population. One approach to accomplish this involves targeting key elements of stem cell self-renewal pathways. These interacting pathways include Notch, Wnt, and Hedgehog, as well as the PI3K, PTEN, AKT pathway, and the MDM2/p53 pathway. In addition, microenvironmental paricrine regulators of stem cell self-renewal such as IL8 represent promising stem cell therapeutic targets. Clinical trials based on these strategies now in development will indicate whether the selective targeting of breast cancer stem cells improves clinical outcome.
Forum: Therapeutic Targets and Breast Cancer Stem Cells

Monica L. Guzman. Univ. of Rochester, Rochester, NY

Cancer stem cell-mediated immunomodulation in human malignant melanoma; Markus H. Frank. Children's Hospital Boston, Boston, MA,