title: Cancer stem cells and cell size: A causal link?
abstract: The majority of normal animal cells are 10-20 μm in diameter. Many signaling mechanisms, notably PI3K/Akt/mTOR, Myc, and Hippo pathways, tightly control and coordinate cell growth, cell size, cell division, and cell number during homeostasis. These regulatory mechanisms are frequently deregulated during tumorigenesis resulting in wide variations in cell sizes and increased proliferation in cancer cells. Here, we first review the evidence that primitive stem cells in adult tissues are quiescent and generally smaller than their differentiated progeny, suggesting a correlation between small cell sizes with the stemness. Conversely, increased cell size positively correlates with differentiation phenotypes. We then discuss cancer stem cells (CSCs) and present some evidence that correlates cell sizes with CSC activity. Overall, a causal link between CSCs and cell size is relatively weak and remains to be rigorously assessed. In the future, optimizing methods for isolating cells based on size should help elucidate the connection between cancer cell size and CSC characteristics.
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park, Smithville, TX 78957, USA.
authors.forename: Qiuhui
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park, Smithville, TX 78957, USA.
authors.forename: Kiera
authors.initials: K
authors.lastname: Rycaj
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park, Smithville, TX 78957, USA. Electronic address: xchen7@mdanderson.org.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Epigenetics and Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park, Smithville, TX 78957, USA; Cancer Stem Cell Institute, Research Center for Translational Medicine, East Hospital, Tongji University School of Medicine, Shanghai 200120, China. Electronic address: dtang@mdanderson.org.
authors.forename: Dean G
authors.initials: DG
authors.lastname: Tang
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D048429:Cell Size; D006801:Humans; D009369:Neoplasms / Q000209:etiology / Q000378:metabolism* / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology*; D010641:Phenotype; D015398:Signal Transduction
keywords: Cancer; Cancer stem cells; Cell size; Stem cells