title: Induction of the stem-like cell regulator CD44 by Rho kinase inhibition contributes to the maintenance of colon cancer-initiating cells.
abstract: The difficulty in expanding cancer-initiating cells in vitro is one of major obstacles for their biochemical characterization. We found that Rho kinase (ROCK) inhibitors as well as blebbistatin, a myosin II inhibitor, greatly facilitated the establishment of spheroids from primary colon cancer. The spheroid cells expressed cancer stem cell markers, showed the ability to differentiate, and induced tumors in mice. The spheroids were composed of cells that express various levels of CD44, whereas CD44(high) cells were associated with increased sphere-forming ability, expression of the activating form of β-catenin, and elevated levels of glycolytic genes, CD44(-/low) cells showed increased levels of differentiation markers and apoptotic cells. The spheroid cells expressed variant forms of CD44 including v6, and the induction of the variants was associated with the activating phosphorylation of c-Met. As expected from the predicted hierarchy, CD44(high) cells differentiated into CD44(-/low) cells. Unexpectedly, a fraction of CD44(-/low) cells generated CD44(high) cells, and the ROCK inhibitor or blebbistatin primed the transition by inducing CD44 expression. We propose that the transition from CD44(-/low) to CD44(high) state helps to maintain a CD44(high) fraction and the tumorigenic diversity in colon cancer.
authors.affiliation: Division of Cancer Differentiation, National Cancer Center Research Institute, Tokyo, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Ohata
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ishiguro
authors.forename: Yuki
authors.initials: Y
authors.lastname: Aihara
authors.forename: Ai
authors.initials: A
authors.lastname: Sato
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sakai
authors.forename: Shigeki
authors.initials: S
authors.lastname: Sekine
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Taniguchi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Akasu
authors.forename: Shin
authors.initials: S
authors.lastname: Fujita
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakagama
authors.forename: Koji
authors.initials: K
authors.lastname: Okamoto
mesh_terms: D000577:Amides / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D020869:Gene Expression Profiling; D019073:HT29 Cells; D056945:Hep G2 Cells; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009374:Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D011725:Pyridines / Q000494:pharmacology; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018874:Spheroids, Cellular / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000577:Amides; D004791:Enzyme Inhibitors; D006576:Heterocyclic Compounds, 4 or More Rings; D018960:Hyaluronan Receptors; D011725:Pyridines; C108830:Y 27632; C472645:blebbistatin; D054460:rho-Associated Kinases