title: Reduction of hyaluronan-CD44-mediated growth, migration, and cisplatin resistance in head and neck cancer due to inhibition of Rho kinase and PI-3 kinase signaling.
abstract: OBJECTIVE
  To investigate whether hyaluronan (HA), a ligand for the transmembrane receptor CD44, and CD44, which acts through multiple signaling pathways to influence cellular behavior, promote Rho kinase- and phosphatidylinositol 3 (PI-3) kinase-mediated oncogenic signaling to alter cisplatin sensitivity and stimulate tumor cell proliferation, migration, and matrix metalloproteinase secretion in head and neck squamous cell carcinoma (HNSCC).
  
  
  METHODS
  Laboratory investigation using the HNSCC cell line HSC-3.
  
  
  METHODS
  University laboratory.
  
  
  METHODS
  Rho kinase and PI-3 kinase activity, myosin phosphatase and AKT phosphorylation, tumor cell growth, migration, and matrix metalloproteinase secretion were measured in the presence or absence of HA, cisplatin, and inhibitors of Rho kinase and PI-3 kinase.
  
  
  RESULTS
  The addition of HA, but not HA plus anti-CD44 antibody, resulted in increased Rho kinase and PI-3 kinase activity. Results of immunoblotting studies demonstrated that HA promotes Rho kinase-mediated myosin phosphatase phosphorylation and PI-3 kinase-mediated AKT phosphorylation. Hyaluronan was shown to promote migration and increased matrix metalloproteinase secretion through Rho kinase-mediated signaling. Hyaluronan treatment promoted increased tumor proliferation and resulted in a 12-fold reduced ability of cisplatin to cause HNSCC cell death. On the other hand, the presence of Y-27632, a Rho kinase inhibitor, and LY-294002, a PI-3 kinase inhibitor, blocked HA-mediated cisplatin resistance by HNSCC.
  
  
  CONCLUSIONS
  Our results suggest that HA and CD44 promote Rho kinase- and PI-3 kinase-mediated oncogenic signaling and cisplatin resistance. Perturbation of HA-CD44-mediated Rho kinase and PI-3 kinase signaling pathways may be a novel strategy to treat HNSCC.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, CA 94121, USA.
authors.forename: Carlos
authors.initials: C
authors.lastname: Torre
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Wang
authors.forename: Weiliang
authors.initials: W
authors.lastname: Xia
authors.forename: Lilly Y W
authors.initials: LY
authors.lastname: Bourguignon
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000201:enzymology; D002465:Cell Movement; D049109:Cell Proliferation; D002945:Cisplatin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000201:enzymology; D006801:Humans; D018960:Hyaluronan Receptors / Q000502:physiology; D006820:Hyaluronic Acid / Q000502:physiology*; D015151:Immunoblotting; D008297:Male; D008875:Middle Aged; D043263:Myosin-Light-Chain Phosphatase / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014407:Tumor Cells, Cultured; D054460:rho-Associated Kinases / Q000378:metabolism
chemical_list: C497483:CD44 protein, human; D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid; D019869:Phosphatidylinositol 3-Kinases; D054460:rho-Associated Kinases; D043263:Myosin-Light-Chain Phosphatase; D002945:Cisplatin