Hyaluronan activates cell motility of v-Src-transformed cells via Ras-mitogen-activated protein kinase and phosphoinositide 3-kinase-Akt in a tumor-specific manner.
We investigated the production of hyaluronan (HA) and its effect on cell motility in cells expressing the v-src mutants. Transformation of 3Y1 by v-src virtually activated HA secretion, whereas G2A v-src, a nonmyristoylated form of v-src defective in cell transformation, had no effect. In cells expressing the temperature-sensitive mutant of v-Src, HA secretion was temperature dependent. In addition, HA as small as 1 nM, on the other side, activated cell motility in a tumor-specific manner. HA treatment strongly activated the motility of v-Src-transformed 3Y1, whereas it showed no effect on 3Y1- and 3Y1-expressing G2A v-src. HA-dependent cell locomotion was strongly blocked by either expression of dominant-negative Ras or treatment with a Ras farnesyltransferase inhibitor. Similarly, both the MEK1 inhibitor and the kinase inhibitor clearly inhibited HA-dependent cell locomotion. In contrast, cells transformed with an active MEK1 did not respond to the HA. Finally, an anti-CD44-neutralizing antibody could block the activation of cell motility by HA as well as the HA-dependent phosphorylation of mitogen-activated protein kinase and Akt. Taken together, these results suggest that simultaneous activation of the Ras-mitogen-activated protein kinase pathway and the phosphoinositide 3-kinase pathway by the HA-CD44 interaction is required for the activation of HA-dependent cell locomotion in v-Src-transformed cells.
Sohara
Y
Y
Department of Molecular Pathogenesis, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Ishiguro
N
N
Machida
K
K
Kurata
H
H
Thant
A A
AA
Senga
T
T
Matsuda
S
S
Kimata
K
K
Iwata
H
H
Hamaguchi
M
M
D000818:Animals; D002460:Cell Line; D002461:Cell Line, Transformed; D002465:Cell Movement; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018960:Hyaluronan Receptors / Q000096:biosynthesis / Q000378:metabolism; D006820:Hyaluronic Acid / Q000494:pharmacology*; D006923:Hymecromone / Q000494:pharmacology; D015151:Immunoblotting; D007202:Indicators and Reagents / Q000494:pharmacology; D020935:MAP Kinase Signaling System; D051379:Mice; D008807:Mice, Inbred BALB C; D019814:Myristic Acid / Q000378:metabolism; D015688:Oncogene Protein pp60(v-src) / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats; D015398:Signal Transduction; D013696:Temperature; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured; D018631:ras Proteins / Q000378:metabolism*
D004791:Enzyme Inhibitors; D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid; D006923:Hymecromone; D007202:Indicators and Reagents; D019814:Myristic Acid; D015688:Oncogene Protein pp60(v-src); D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D018631:ras Proteins; C494920:Akt1 protein, rat