Changes in p53 expression in mouse fibroblasts can modify motility and extracellular matrix organization

Effects of p53 expression on cell morphology and motility were studied usin g the derivatives of p53-null 10(1) mouse fibroblasts with tetracycline-reg ulated expression of exogenous human p53, Induction of p53 expression was a ccompanied by significant decrease in extracellular matrix (fibronectin) an d reduction of matrix fibrils, diminution of the number and size of focal c ontacts, decrease of cell areas, establishment of more elongated cell shape and alterations of actin cytoskeleton (actin bundles became thinner, their number and size decreased). Expression of His175 and Gln22/Ser23 p53 mutan ts caused no such effects. To study the influence of p53 expression on cell motility we used wound technique and videomicroscopy observation of single living cells. It was found that induction of p53 expression led to increas e of lamellar activity of cell edge, However, in spite of enhanced lamellar activity p53-expressing cells migrated to shorter distance and filled the narrow wound in longer time as compared with their p53-null counterparts. P ossible mechanisms of the influence of p53 expression on cell morphology an d motility are discussed.