Cancer stem cells in the mechanism of metal carcinogenesis.

Environmental metal carcinogenesis is a major public health concern. The mechanism underlying metal-induced carcinogenesis remains unclear. The concept of cancer stem cell recently has drawn considerable attention. Various studies indicate that the generation of cancer stem cells might contribute to the overall mechanism of development of metal-induced cancer. It is believed that oxidative stress and abnormal signaling caused by metals lead to the enrichment of cancer stem cells and eventually initiate cancer. In addition, metal-induced angiogenesis may also contribute to the generation of cancer stem cells. Studies using animal models further suggest that metals could induce the production of cancer stem cells and thus cause the development of cancer. This review summarizes recent studies of oxidative stress and cancer stem cells in relation to the mechanism of metal carcinogenesis.