Targeting cancer stem cell pathways for cancer therapy

摘要

Since cancer stem cells (CSCs) were first identified in leukemia in 1994, they have been considered promising therapeutic targets forcancer therapy. These cells have self-renewal capacity and differentiation potential and contribute to multiple tumor malignancies,such as recurrence, metastasis, heterogeneity, multidrug resistance, and radiation resistance. The biological activities of CSCs areregulated by several pluripotent transcription factors, such as OCT4, Sox2, Nanog, KLF4, and MYC. In addition, many intracellularsignaling pathways, such as Wnt, NF-κB (nuclear factor-κB), Notch, Hedgehog, JAK-STAT (Janus kinase/signal transducers andactivators of transcription), PI3K/AKT/mTOR (phosphoinositide 3-kinase/AKT/mammalian target of rapamycin), TGF (transforminggrowth factor)/SMAD, and PPAR (peroxisome proliferator-activated receptor), as well as extracellular factors, such as vascular niches,hypoxia, tumor-associated macrophages, cancer-associated fibroblasts, cancer-associated mesenchymal stem cells, extracellularmatrix, and exosomes, have been shown to be very important regulators of CSCs. Molecules, vaccines, antibodies, and CAR-T(chimeric antigen receptor T cell) cells have been developed to specifically target CSCs, and some of these factors are alreadyundergoing clinical trials. This review summarizes the characterization and identification of CSCs, depicts major factors andpathways that regulate CSC development, and discusses potential targeted therapy for CSCs.