Figure 1.

Cancer stem cell-related antibody targeting. Tumors are proposed to contain a CSC niche which supports the small number of CSCs through cell-matrix interactions. These CSCs, bearing receptors for adhesion and self-renewal give rise to the bulk tumor cells which also have tumor-associated antigens as well as daughter CSCs. Metastatic CSCs may arise when receptors involved in invasion and homing are expressed. Growth factors are expressed which stimulate tumor angiogenesis, migration to metastatic sites and promote proliferation and protection within existing niches. Chemotherapy drugs have poor access to the tumor. Factors which could be modulated by antibody intervention are shown as well as the use of stem-cell renewal-specific drugs for a combinatorial approach to CSC therapy. Refer to the key for the types and examples of receptors and CSC-factors.