Roles for the protein tyrosine phosphatase SHP-2 in cytoskeletal organization, cell adhesion and cell migration revealed by overexpression of a dominant negative mutant

Abstract

SHP-2, a SRC homology 2 domain-containing protein tyrosine phosphatase, mediates activation of Ras and mitogen-activated protein kinase by various mitogens and cell adhesion. Inhibition of endogenous SHP-2 by overexpression of a catalytically inactive (dominant negative) mutant in Chinese hamster ovary cells or Rat-1 ®broblasts has now been shown to induce a marked change in cell morphology (from elongated to less polarized) that is accompanied by substantial increases in the numbers of actin stress ®bers and focal adhesion contacts. Overexpression of the SHP-2 mutant also increased the strength of cell-substratum adhesion and resulted in hyperphosphorylation of SHPS-1, a substrate of SHP-2 that contributes to cell adhesioninduced signaling. Inhibition of SHP-2 also markedly increased the rate of cell attachment to and cell spreading on extracellular matrix proteins such as ®bronectin and vitronectin, eects that were accompanied by enhancement of adhesion-induced tyrosine phosphorylation of paxillin and p130Cas. In addition, cell migration mediated by ®bronectin or vitronectin, but not that induced by insulin, was impaired by overexpression of the SHP-2 mutant. These results suggest that SHP-2 plays an important role in the control of cell shape by contributing to cytoskeletal organization, and that it is an important regulator of integrin-mediated cell adhesion, spreading, and migration as well as of tyrosine phosphorylation of focal adhesion contact-associated proteins. Oncogene (2000) 19, 75 ± 84.

Inhibition of EGFR-mediated phosphoinositide-3-OH kinase (PI3-K) signaling and glioblastoma phenotype by Signal-Regulatory Proteins (SIRPs)

“…Mouse ®broblasts de®cient in functional SHP2 showed defects in cell migration and spreading on ®bronectin (Yu et al, 1998). However, expression of catalytically-inactive SHP2 in Rat-1 ®broblasts and CHO cells increased the rate of cell attachment to and spreading on ®bronectin (Inagaki et al, 2000). Therefore, the mechanism by which SHP2 regulates cell motility is not clear and may require a highly complex coordination of signals that are related to cell context.…”

Inhibition of SHP2 leads to mesenchymal to epithelial transition in breast cancer cells

“…These results are consistent with previous reports that showed that SHP2 plays a positive role in fibroblast motility and migration. [23][24][25][26] Thus, interference with SHP2 function might provide a means to inhibit cancer cell metastasis. Unexpectedly, we discovered that EGF can induce translocation of b-catenin to the nucleus in SHP2-dependent manner.…”

“…Previous work has shown that SHP2 suppresses cell adhesion and enhances motility. [23][24][25][26] We sough to investigate the significance of SHP2 inhibition on breast cancer cells motility and scattering. Initially, this possibility was tested by the monolayer wound-healing assay.…”

Catalytic-dependent and -independent roles of SHP-2 tyrosine phosphatase in interleukin-3 signaling

“…When overexpressed, the SHP-2 C459S (SHP-2 C/S) mutant inhibits endogenous SHP-2 function by dominantnegative inhibition of the catalytic activity of SHP-2 and/or trapping its substrates. This mutant has been widely used to study SHP-2 function in cell signaling (Bennett et al, 1996;Maegawa et al, 1999;Manes et al, 1999;Inagaki et al, 2000). We transduced primary BM cells with SHP-2 C/S.…”