To wake up cancer stem cells, or to let them sleep, that is the question.
Cancer stem cells (CSCs) generate transient-amplifying cells and thereby contribute to cancer propagation. A fuller understanding of the biological features of CSCs is expected to lead to the development of new anticancer therapies capable of eradicating this life-threatening disease. Cancer stem cells are known to maintain a non-proliferative state and to enter the cell cycle only infrequently. Given that conventional anticancer therapies preferentially target dividing cells, CSCs are resistant to such treatments, with those remaining after elimination of bulk cancer cells potentially giving rise to disease relapse and metastasis as they re-enter the cell cycle after a period of latency. Targeting of the switch between quiescence and proliferation in CSCs is therefore a potential strategy for preventing the reinitiation of malignancy, underscoring the importance of elucidation of the mechanisms by which these cells are maintained in the quiescent state. The fundamental properties of CSCs are thought to be governed cooperatively by internal molecules and cues from the external microenvironment (stem cell niche). Several such intrinsic and extrinsic regulators are responsible for the control of cell cycle progression in CSCs. In this review, we address two opposite approaches to the therapeutic targeting of CSCs - wake-up and hibernation therapies - that either promote or prevent the entry of CSCs into the cell cycle, respectively, and we discuss the potential advantages and risks of each strategy.
Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
Shoichiro
S
Takeishi
Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
Keiichi I
KI
Nakayama
D000818:Animals; D002453:Cell Cycle / Q000187:drug effects*; D018797:Cell Cycle Proteins / Q000378:metabolism; D054377:Chemokine CXCL12 / Q000378:metabolism; D044783:F-Box Proteins / Q000378:metabolism; D000073979:F-Box-WD Repeat-Containing Protein 7; D016179:Granulocyte Colony-Stimulating Factor / Q000378:metabolism; D006801:Humans; D016898:Interferon-alpha / Q000378:metabolism; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000473:pathology*; D047495:PPAR gamma / Q000378:metabolism; D000071156:Promyelocytic Leukemia Protein / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000378:metabolism; D044786:S-Phase Kinase-Associated Proteins / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
C527276:CXCR4 protein, human; D018797:Cell Cycle Proteins; D054377:Chemokine CXCL12; D044783:F-Box Proteins; D000073979:F-Box-WD Repeat-Containing Protein 7; C513273:FBXW7 protein, human; D016898:Interferon-alpha; D047495:PPAR gamma; D000071156:Promyelocytic Leukemia Protein; D019718:Receptors, CXCR4; D044786:S-Phase Kinase-Associated Proteins; D016179:Granulocyte Colony-Stimulating Factor; D044767:Ubiquitin-Protein Ligases
Cancer stem cell; Fbxw7; leukemia stem cell; quiescence; stem cell niche