Src-/- fibroblasts are defective in their ability to disassemble focal adhesions in response to phorbol ester/hyaluronan treatment.
Exogenous hyaluronan promotes a rapid recruitment of Src to lamellae of mutant active H-ras transformed fibroblasts and an Src- and RHAMM (CD168)-dependent increase in random motility. These responses are accompanied by a loss of vinculin-positive lamellae focal adhesions. Nontransformed immortalized wild-type fibroblasts (WT) do not increase random motility in response to hyaluronan alone, but do increase motility in response to a combination of PMA treatment followed by hyaluronan. PMA treatment alone increases the number of lamellae/cell, percentage of cells with lamellae and number of focal adhesions/lamellae. Subsequent addition of hyaluronan does not affect the number of lamellae/cell but reduces both the number of focal adhesion/lamellae and the percentage of cells forming focal adhesion-positive lamellae. These effects are prevented by blocking RHAMM antibodies and mimicked by agonist RHAMM antibodies. Src-/- fibroblasts exhibit a limited response to PMA but do not increase motility or disassemble focal adhesions in response to a subsequent addition of HA. Rescue of Src-/- fibroblasts with either SrcA or c-Src restores response to close to WT levels. These results suggest that Src activity is uniquely required for both PMA and PMA-induced hyaluronan regulation of random motility and focal adhesion turnover.
Depts. Oncology and Biochemistry, The University of Western Ontario and London Regional Cancer Center, London, Ontario, Canada N6A 4L6.
Christine L
CL
Hall
Fu-Sheng
FS
Wang
Eva
E
Turley
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects / Q000235:genetics*; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics*; D005109:Extracellular Matrix / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D022001:Focal Adhesions / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D018960:Hyaluronan Receptors / Q000378:metabolism; D006820:Hyaluronic Acid / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D010703:Phorbol Esters / Q000494:pharmacology; D011554:Pseudopodia / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D016596:Vinculin / Q000187:drug effects / Q000378:metabolism; D019061:src-Family Kinases / Q000172:deficiency* / Q000235:genetics
D000906:Antibodies; D016326:Extracellular Matrix Proteins; D018960:Hyaluronan Receptors; D010703:Phorbol Esters; C098946:hyaluronan-mediated motility receptor; D016596:Vinculin; D006820:Hyaluronic Acid; D019061:src-Family Kinases