The phosphotyrosine phosphatase SHP2 is a critical mediator of transformation induced by the oncogenic fibroblast growth factor receptor 3

Abstract

Receptor tyrosine kinases (RTKs) such as the fibroblast growth factor receptor (FGFR) and the epidermal growth factor receptor are overexpressed in a variety of cancers. In addition to overexpression, the FGFRs are found mutated in some cancers. The Src homology 2 domaincontaining phosphotyrosine phosphatase (SHP2) is a critical mediator of RTK signaling, but its role in oncogenic RTK-induced cell transformation and cancer development is largely unknown. In the current report, we demonstrate that constitutively activated FGFR3 (K/E-FR3) transforms NIH-3T3 cells, and that SHP2 is a critical mediator of this transformation. Infection of K/E-FR3-transformed 3T3 cells with a retrovirus carrying a dominant-negative mutant of SHP2 (C/S-SHP2) retarded cell growth, reversed the transformation phenotype and inhibited focus-forming ability. Furthermore, treatment of K/E-FR3-transformed NIH-3T3 cells with PD98059 or LY294002, specific inhibitors of MEK and PI3K, respectively, inhibited focus formation. Biochemical analysis showed that K/E-FR3 activates the Ras-ERK and the PI3K signaling pathways, and that the C/S SHP2 mutant suppressed this effect via competitive displacement of interaction of the endogenous SHP2 with FRS2. However, the C/S SHP2 protein did not show any effect on receptor autophosphorylation, FRS2 tyrosine phosphorylation or interaction of Grb2 with K/E-FR3 or FRS2. Together, the results show that K/E-FR3 is transforming and that the Ras-ERK and the PI3K-Akt signaling pathways, which are positively regulated by SHP2, are important for K/E-FR3-induced transformation.

Modulation of α-catenin Tyr phosphorylation by SHP2 positively effects cell transformation induced by the constitutively active FGFR3

“…We have recently demonstrated that SHP2 mediates the transformation of NIH-3T3 cells by K/E-FR3 via positively modulating the Ras-ERK and PI3K-Akt signaling pathways (Agazie et al, 2003). We have further shown that a phosphotyrosyl protein of B100 KDa (p100) coprecipitates with K/E-FR3 in cells expressing R/E-SHP2 suggesting that this protein could be a potential SHP2 substrate (Agazie et al, 2003).…”

“…Experimentally, SHP2 has been shown to be required for cell transformation induced by v-Src (Hakak et al, 2000). More recently, we have demonstrated that SHP2 is essential for cell transformation induced by the constitutively active FGFR3 (K650E-FGFR3), hereinafter referred to as K/E-FR3 (Agazie et al, 2003). Expression of dominant-negative SHP2 (R465E-SHP2), hereinafter referred to as R/E-SHP2, reverses cell transformation as evidenced by morphological changes, inability to form foci in culture and reduced growth rate.…”

“…Expression of dominant-negative SHP2 (R465E-SHP2), hereinafter referred to as R/E-SHP2, reverses cell transformation as evidenced by morphological changes, inability to form foci in culture and reduced growth rate. Further biochemical analysis showed that reduction in cell growth and reversion of the transformed phenotype correlates with inhibition of the Ras-ERK and the PI3K-Akt signaling pathways (Agazie et al, 2003). In that study, we had detected a phosphotyrosyl protein of B100 KDa (p100) that coprecipitated with K/E-FR3 in cells expressing R/E-SHP2, but the identity of this protein as well as its relevance in SHP2-meditaed and K/E-FR3-induced cell transformation was not known.…”

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

“…9,12,30 Second, SHP2 promotes cell transformation induced by v-Src and the constitutively active form of FGFR3. [1][2][3] and associated leukemia. 4 And finally, the SHP2 protein is overexpressed in approximately 70% of infiltrating ductal carcinoma of the human breast.…”

“…First, SHP2 is essential for cell transformation induced by v-Src 1 and the constitutively active form of fibroblast growth factor receptor 3 (K650E-FGFR3). 2,3 And second, SHP2 has been implicated in the development of Noonan syndrome and associated leukemia. 4 This was based on the discovery of activating SHP2 mutations, sometimes referred to as leukemogenic SHP2 mutants, in patients with these diseases.…”