TY - JOUR
T1 - Hyaluronan stabilizes focal adhesions, filopodia, and the proliferative phenotype in esophageal squamous carcinoma cells
AU - Twarock, Sören
AU - Tammi, Markku I.
AU - Savani, Rashmin C.
AU - Fischer, Jens W.
PY - 2010/7/23
Y1 - 2010/7/23
N2 - Hyaluronan (HA) is a polysaccharide component in the parenchyma and stroma of human esophageal squamous cell carcinoma (ESCC). Clinically, esophageal cancer represents a highly aggressive tumor type with poor prognosis resulting in a 5-year survival rate of 5%. The aim of the present study was the detailed analysis of the role of HA synthesis for ESCC phenotype in vitro using the ESCC cell line OSC1. In OSC1 cells, pericellular HA-matrix surrounding extended actin-dependent filopodia was detected. The small molecule inhibitor of HA synthesis, 4-methylumbelliferone (4-MU, 0.3 mM) caused loss of these filopodia and focal adhesions and inhibited proliferation and migration. In search of the underlying mechanism cleavage of focal adhesion kinase (FAK) was detectedbyimmunoblotting. Inaddition, displacing HA byan HA-binding peptide (Pep-1, 500 μg/ml) and digestion of pericellular HA by hyaluronidase resulted in cleavage of focal adhesions. Furthermore, real-time reverse transcription PCR revealed that HA synthase 3 (HAS3) > HAS2 are the predominant HA-synthases in OSC1. Lentiviral transduction with shHAS3, and to a lesser extent with shHAS2, reduced intact FAK protein and filopodia as well as proliferation and migration. Furthermore, down-regulation by lentiviral shRNA of RHAMM (receptor of HA-mediated motility) but not CD44 induced loss of filopodia and caused FAK cleavage. In contrast, knockdown of both HA receptors inhibited proliferation and migration of OSC1. In conclusion, HA synthesis and, in turn, RHAMM and CD44 signaling promoted an activated phenotype of OSC1. Because RHAMM appears to support both filopodia, FAK, and the proliferative and migratory phenotype, it may be promising to explore RHAMM as a potential therapeutic target in esophageal cancer.
AB - Hyaluronan (HA) is a polysaccharide component in the parenchyma and stroma of human esophageal squamous cell carcinoma (ESCC). Clinically, esophageal cancer represents a highly aggressive tumor type with poor prognosis resulting in a 5-year survival rate of 5%. The aim of the present study was the detailed analysis of the role of HA synthesis for ESCC phenotype in vitro using the ESCC cell line OSC1. In OSC1 cells, pericellular HA-matrix surrounding extended actin-dependent filopodia was detected. The small molecule inhibitor of HA synthesis, 4-methylumbelliferone (4-MU, 0.3 mM) caused loss of these filopodia and focal adhesions and inhibited proliferation and migration. In search of the underlying mechanism cleavage of focal adhesion kinase (FAK) was detectedbyimmunoblotting. Inaddition, displacing HA byan HA-binding peptide (Pep-1, 500 μg/ml) and digestion of pericellular HA by hyaluronidase resulted in cleavage of focal adhesions. Furthermore, real-time reverse transcription PCR revealed that HA synthase 3 (HAS3) > HAS2 are the predominant HA-synthases in OSC1. Lentiviral transduction with shHAS3, and to a lesser extent with shHAS2, reduced intact FAK protein and filopodia as well as proliferation and migration. Furthermore, down-regulation by lentiviral shRNA of RHAMM (receptor of HA-mediated motility) but not CD44 induced loss of filopodia and caused FAK cleavage. In contrast, knockdown of both HA receptors inhibited proliferation and migration of OSC1. In conclusion, HA synthesis and, in turn, RHAMM and CD44 signaling promoted an activated phenotype of OSC1. Because RHAMM appears to support both filopodia, FAK, and the proliferative and migratory phenotype, it may be promising to explore RHAMM as a potential therapeutic target in esophageal cancer.
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U2 - 10.1074/jbc.M109.093146
DO - 10.1074/jbc.M109.093146
M3 - Article
C2 - 20463012
AN - SCOPUS:77954938543
SN - 0021-9258
VL - 285
SP - 23276
EP - 23284
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 30
ER -