TY - JOUR
T1 - Wnt-5a-induced phosphorylation of DARPP-32 inhibits breast cancer cell migration in a CREB-dependent manner
AU - Hansen, Christian
AU - Howlin, Jillian
AU - Tengholm, Anders
AU - Dyachok, Oleg
AU - Vogel, Wolfgang F.
AU - Nairn, Angus C.
AU - Greengrad, Paul
AU - Andersson, Tommy
PY - 2009/10/2
Y1 - 2009/10/2
N2 - Tumorcell migration plays a central role in the process of cancer metastasis.Werecently identified dopamine and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) as an antimigratory phosphoprotein in breast cancer cells. Here we link this effect of DARPP-32 to Wnt-5a signaling by demonstrating that recombinant Wnt-5a triggers cAMP elevation at the plasma membrane and Thr34-DARPP-32 phosphorylation in MCF-7 cells. In agreement, both protein kinase A (PKA) inhibitors and siRNA-mediated knockdown of Frizzled-3 receptor or Gαs expression abolished Wnt-5a-induced phosphorylation of DARPP-32. Furthermore, Wnt-5a induced DARPP-32-dependent inhibition of MCF-7 cell migration. Phospho-Thr-34-DARPP-32 interacted with protein phosphatase-1 (PP1) and potentiated the Wnt-5a-mediated phosphorylation of CREB, a well-known PP1 substrate, but had no effect on CREB phosphorylation by itself. Moreover, inhibition of the Wnt-5a/DARPP-32/CREB pathway, by expression of dominant negative CREB (DN-CREB), diminished the antimigratory effect of Wnt-5a-induced phospho- Thr-34-DARPP-32. Phalloidin-staining revealed that that the presence of phospho-Thr-34-DARPP-32 in MCF-7 cells results in reduced filopodia formation. In accordance, the activity of the Rho GTPase Cdc42, known to be crucial for filopodia formation, was reduced in MCF-7 cells expressing phospho-Thr-34-DARPP-32. The effects of DARPP-32 on cell migration and filopodia formation could be reversed in T47D breast cancer cells that were depleted of their endogenous DARPP-32 by siRNA targeting. Consequently, Wnt-5a activates a Frizzled-3/Gα s/cAMP/PKA signaling pathway that triggers a DARPP-32-and CREB-dependent antimigratory response in breast cancer cells, representing a novel mechanism whereby Wnt-5a can inhibit breast cancer cell migration.
AB - Tumorcell migration plays a central role in the process of cancer metastasis.Werecently identified dopamine and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) as an antimigratory phosphoprotein in breast cancer cells. Here we link this effect of DARPP-32 to Wnt-5a signaling by demonstrating that recombinant Wnt-5a triggers cAMP elevation at the plasma membrane and Thr34-DARPP-32 phosphorylation in MCF-7 cells. In agreement, both protein kinase A (PKA) inhibitors and siRNA-mediated knockdown of Frizzled-3 receptor or Gαs expression abolished Wnt-5a-induced phosphorylation of DARPP-32. Furthermore, Wnt-5a induced DARPP-32-dependent inhibition of MCF-7 cell migration. Phospho-Thr-34-DARPP-32 interacted with protein phosphatase-1 (PP1) and potentiated the Wnt-5a-mediated phosphorylation of CREB, a well-known PP1 substrate, but had no effect on CREB phosphorylation by itself. Moreover, inhibition of the Wnt-5a/DARPP-32/CREB pathway, by expression of dominant negative CREB (DN-CREB), diminished the antimigratory effect of Wnt-5a-induced phospho- Thr-34-DARPP-32. Phalloidin-staining revealed that that the presence of phospho-Thr-34-DARPP-32 in MCF-7 cells results in reduced filopodia formation. In accordance, the activity of the Rho GTPase Cdc42, known to be crucial for filopodia formation, was reduced in MCF-7 cells expressing phospho-Thr-34-DARPP-32. The effects of DARPP-32 on cell migration and filopodia formation could be reversed in T47D breast cancer cells that were depleted of their endogenous DARPP-32 by siRNA targeting. Consequently, Wnt-5a activates a Frizzled-3/Gα s/cAMP/PKA signaling pathway that triggers a DARPP-32-and CREB-dependent antimigratory response in breast cancer cells, representing a novel mechanism whereby Wnt-5a can inhibit breast cancer cell migration.
UR - http://www.scopus.com/inward/record.url?scp=70350439474&partnerID=8YFLogxK
U2 - 10.1074/jbc.M109.048884
DO - 10.1074/jbc.M109.048884
M3 - Journal article
C2 - 19651774
AN - SCOPUS:70350439474
SN - 0021-9258
VL - 284
SP - 27533
EP - 27543
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 40
ER -