Cells were cultured in 37?C in a water\saturated 5% CO2 atmosphere. 2.2. gefitinib and stimulated or not with 25?ng/ml of HGF. (B) Serum starved GTL16 cells were treated 6?h with 0.4?M PHA\665752 and stimulated or not with 25?ng/ml EGF. (A, B) ETV1, ETV4 and ETV5 mRNA levels were determined by RT\qPCR (n?=?3; SD). MOL2-9-1852-s001.docx (18K) GUID:?46820452-6F2C-4391-87B5-42E57A49A181 Supplementary data MOL2-9-1852-s002.pptx (100K) GUID:?0CE1759E-71C6-454C-8E4E-C3573CF36046 Abstract Various solid tumors including lung or gastric carcinomas display aberrant activation of the Met receptor which correlates with aggressive phenotypes and poor prognosis. Although downstream signaling of Met is usually well described, its integration at the transcriptional level is usually poorly comprehended. We demonstrate here that in malignancy cells harboring met gene amplification, inhibition of Met activity with tyrosine kinase inhibitors or specific siRNA drastically decreased expression of ETV1, ETV4 and ETV5, three transcription factors constituting the PEA3 subgroup of the ETS family, while expression of the other members of the family were less or not affected. SIB 1893 Similar link between Met activity and PEA3 factors expression was found in lung malignancy cells displaying resistance to EGFR targeted therapy including met gene amplification. Using silencing experiments, we demonstrate that this PEA3 factors are required for efficient migration and invasion mediated by Met, while other biological responses such as proliferation or unanchored growth remain unaffected. PEA3 overexpression or silencing revealed that they participated in the regulation of the MMP2 target gene involved in extracellular matrix remodeling. Our results exhibited that PEA3\subgroup transcription factors are key players of the Met signaling integration involved in regulation of migration and invasiveness. gene copy number through chromosome 7 polysomy and amplification, which are found in about 5C20% of the gastric and lung cancers (Lee et?al., 2012; Tsuta et?al., 2012). This gene amplification can trigger high level of Met expression leading to spontaneous dimerization and subsequent Met tyrosine kinase activation (Ponzetto et?al., 1991). Malignancy cell lines harboring gene amplification and subsequent ligand\impartial activation displayed addiction to Met signaling, since inhibition of Met expression or activity prospects to decreased cell growth and survival (Corso SIB 1893 et?al., 2008). Interestingly, in non\small cells lung carcinoma, resistance to inhibitors targeting mutated Epidermal Growth Factor Receptor (EGFR) entails amplification of the gene observed in 5C20% of the patients (Engelman et?al., 2007). This prospects to strong Met overexpression and its ligand\impartial activation, which shortcuts inhibition of EGFR activity through activation of comparable downstream signaling pathway including RASCERK and PI3KCAKT pathways (Bertotti et?al., 2009; Wagner et?al., 2013). Comparable mechanism of resistance has been recently revealed in colorectal cancers treated with anti\EGFR antibody (Bardelli et?al., 2013). Even though intracellular signaling network downstream of Met is usually well described, the integration of the transmission at the transcriptional level is still poorly comprehended. Nevertheless, Met signaling is able to regulate activity or expression of several transcription factors including STAT3, ETS1, NFB or p53 (Boccaccio et?al., 1998; Fan et?al., 2005; Furlan et?al., 2012; Paumelle et?al., 2002). In oral squamous carcinoma, HGF/SF activation is also able to trigger expression of the ETV4 (Pea3) transcription factor (Hanzawa SIB 1893 et?al., 2000). Interestingly, we have previously shown that Met and ETV4 display similar pattern of expression during branching morphogenesis of epithelial organs such as lung, kidney and mammary gland (Andermarcher et?al., 1996; Chotteau\Lelievre et?al., 1997; Sonnenberg et?al., 1993). In addition, we showed that overexpression of ETV4 and ETV5 (Erm) in mammary epithelial cells promote branching morphogenesis in matrix, much like those induced by HGF/SF (Chotteau\Lelievre et?al., 2003). In spinal cord, expansion of the ETV4 positive pool of motor neurons is usually in part dependent on Met signaling induced by HGF/SF (Caruso et?al., 2014; Helmbacher et?al., 2003). The PEA3 group of transcription factors is composed by three users, ETV4 (Pea3), ETV5 (Erm) and ETV1 (ER81), which display high sequence homology and comparable subdomain business. The three PEA3 users belong to the larger ETS family of transcription factors, all homologous on their Rabbit polyclonal to Cannabinoid R2 DNA binding domain name (ETS binding domain name) (de Launoit et?al., 2006). The 27 users of the ETS family are divided in 5 or 12 subgroups according to their preferential DNA SIB 1893 binding sequence or their homology in their DNA binding domain name (Laudet et?al., 1999; Wei et?al., 2010). Expression of.