title: Role of receptor for hyaluronic acid-mediated motility (RHAMM) in low molecular weight hyaluronan (LMWHA)-mediated fibrosarcoma cell adhesion.
abstract: Hyaluronan (HA) modulates key cancer cell functions through interaction with its CD44 and receptor for hyaluronic acid-mediated motility (RHAMM) receptors. HA was recently found to regulate the migration of fibrosarcoma cells in a manner specifically dependent on its size. Here, we investigated the effect of HA/RHAMM signaling on the ability of HT1080 fibrosarcoma cells to adhere onto fibronectin. Low molecular weight HA (LMWHA) significantly increased (p ≤ 0.01) the adhesion capacity of HT1080 cells, which high molecular weight HA inhibited. The ability of HT1080 RHAMM-deficient cells, but not of CD44-deficient ones, to adhere was significantly decreased (p ≤ 0.001) as compared with control cells. Importantly, the effect of LMWHA on HT1080 cell adhesion was completely attenuated in RHAMM-deficient cells. In contrast, adhesion of RHAMM-deficient cells was not sensitive to high molecular weight HA treatment, which identifies RHAMM as a specific conduit of the LMWHA effect. Western blot and real time-PCR analyses indicated that LMWHA significantly increased RHAMM transcript (p ≤ 0.05) and protein isoform levels (53%, 95 kDa; 37%, 73 kDa) in fibrosarcoma cells. Moreover, Western blot analyses showed that LMWHA in a RHAMM-dependent manner enhanced basal and adhesion-dependent ERK1/2 and focal adhesion kinase (FAK) phosphorylation in HT1080 cells. Utilization of a specific ERK1/2 inhibitor completely inhibited (p ≤ 0.001) LMWHA-dependent adhesion, suggesting that ERK1/2 is a downstream effector of LMWHA/RHAMM signaling. Likewise, the utilization of the specific ERK1 inhibitor resulted in a strong down-regulation of FAK activation in HT1080 cells, which identifies ERK1/2 as a FAK upstream activator. In conclusion, our results suggest that RHAMM/HA interaction regulates fibrosarcoma cell adhesion via the activation of FAK and ERK1/2 signaling pathways.
authors.affiliation: Department of Histology-Embryology, University of Crete, Heraklion 71003, Greece.
authors.forename: Katerina
authors.initials: K
authors.lastname: Kouvidi
authors.affiliation: Department of Histology-Embryology, University of Crete, Heraklion 71003, Greece.
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Berdiaki
authors.affiliation: Department of Histology-Embryology, University of Crete, Heraklion 71003, Greece.
authors.forename: Dragana
authors.initials: D
authors.lastname: Nikitovic
authors.affiliation: Department of Orthopaedics, Medical School, University of Crete, Heraklion 71003, Greece.
authors.forename: Pavlos
authors.initials: P
authors.lastname: Katonis
authors.affiliation: Laboratory of Biochemistry, Department of Chemistry, University of Patras, Patras 26110, Greece.
authors.forename: Nikos
authors.initials: N
authors.lastname: Afratis
authors.affiliation: Cleveland Clinic, Biomedical Engineering ND-20, Cleveland, Ohio 44195.
authors.forename: Vincent C
authors.initials: VC
authors.lastname: Hascall
authors.affiliation: Laboratory of Biochemistry, Department of Chemistry, University of Patras, Patras 26110, Greece.
authors.forename: Nikos K
authors.initials: NK
authors.lastname: Karamanos
authors.affiliation: Department of Histology-Embryology, University of Crete, Heraklion 71003, Greece. Electronic address: tzanakak@med.uoc.gr.
authors.forename: George N
authors.initials: GN
authors.lastname: Tzanakakis
mesh_terms: D002448:Cell Adhesion; D045744:Cell Line, Tumor; D016326:Extracellular Matrix Proteins / Q000737:chemistry*; D005354:Fibrosarcoma / Q000378:metabolism; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D018960:Hyaluronan Receptors / Q000737:chemistry*; D006820:Hyaluronic Acid / Q000737:chemistry*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D008970:Molecular Weight; D009844:Oligosaccharides / Q000737:chemistry; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D016326:Extracellular Matrix Proteins; D018960:Hyaluronan Receptors; D009844:Oligosaccharides; D034741:RNA, Small Interfering; C098946:hyaluronan-mediated motility receptor; D006820:Hyaluronic Acid; D051416:Focal Adhesion Protein-Tyrosine Kinases; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3