Spred2 inhibits TGF-beta1-induced urokinase type plasminogen activator expression, cell motility and epithelial mesenchymal transition.
TGF-beta1 is a potent inductor of malignance in cancer cells. TGF-beta1 stimulates the expression of extracellular matrix degrading proteases, cell migration and it is also involved in the epithelial-mesenchymal transition (EMT). In the present work, we analyzed the role of Spred2 in the urokinase-type plasminogen activator (uPA) stimulation, EMT and cell migration by TGF-beta1. We found that both the expression of mRNA and the protein level of Spred2 were lower in transformed keratinocytes PDV compared with immortalized keratinocytes MCA-3D. The transient ectopic expression of Spred2 in PDV cells inhibited the TGF-beta1-transactivated SRE-Luc reporter which is related with the ERK1,2 signal. The stable ectopic expression of Spred2 in PDV cells (SP cells) led to the loss of ERK 1,2 activation by TGF-beta1, although Smad2 activation was not affected, and the knockdown of Spred2 enhanced the activation of ERK1,2 signal by TGF-beta1. The increment of uPA expression induced by TGF-beta1 was suppressed in SP cells. In contrast, the stimulus on PAI-1 expression was not affected and comparable to parental PDV cells. SP cells under TGF-beta1 treatment were unable to display the EMT, since the overexpression of Spred2 abolished the TGF-beta1-induced disruption of the E-cadherin cell to cell interactions, reorganization of the actin cytoskeleton and upregulation of the mesenchymal marker vimentin. Finally, SP cells could not respond to the TGF-beta1 stimulus on cell migration. Taken together, the data in the present study suggests that Spred2 is a regulator of TGF-beta1-induced malignance in transformed keratinocytes.
Villar
Victor
V
Cellular Biology Laboratory, Nutrition and Food Technology Institute, INTA, Universidad de Chile, Chile.
Kocić
Jelena
J
Santibanez
Juan F
JF
D001483:Base Sequence; D002465:Cell Movement / Q000502:physiology*; D017931:DNA Primers; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000166:cytology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D055785:Gene Knockdown Techniques; D006801:Humans; D008648:Mesoderm / Q000166:cytology*; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053773:Transforming Growth Factor beta1 / Q000502:physiology*; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism*
D017931:DNA Primers; D012097:Repressor Proteins; C500760:SPRED2 protein, human; D053773:Transforming Growth Factor beta1; D048049:Extracellular Signal-Regulated MAP Kinases; D014568:Urokinase-Type Plasminogen Activator