Constitutive Activation of Neuregulin/ERBB3 Signaling Pathway in Clear Cell Sarcoma of Soft Tissue

Abstract

Clear cell sarcoma of soft tissue (CCSST) represents a highly malignant tumor of the musculoskeletal system that is characterized by the chromosomal translocation t(12;22)(q13;q12) of the Ewing sarcoma gene (EWSR1) and activating transcription factor 1 (ATF1). In a former microarray expression study, we identified ERBB3, a member of the epidermal growth factor receptor (EGFR) family, as a promising new diagnostic marker in the differential diagnosis of CCSST. Here we show that, besides ErbB3, all CCSST cell lines (n = 8) also express the ErbB2 receptor or the ErbB4 receptor, representing an adequate coreceptor of ErbB3. The phosphorylation status of ErbB3 revealed these receptor pairs to be either constitutively activated in CCSST cells with high neuregulin-1 (NRG1) expression (n = 4) or activatable by exogenic NRG1 in cells showing low amounts of NRG1 mRNA (n = 4). Exogenous NRG1 stimulated the growth of a subset of CCSST cells but did not affect the kinetics of another subset. This difference was not strictly dependent on endogenous NRG1 expression; however, the growth-inhibiting effect of the pan-ErbB tyrosine kinase inhibitor CI-1033 or PD158780 clearly correlated with NRG1 expression indicating an autocrine growth stimulation loop which may constitute an interesting target of new therapeutic strategies in this tumor entity.

Receptor tyrosine kinase pathway analysis sheds light on similarities between clear‐cell sarcoma and metastatic melanoma

“…We further investigated PDGFRB and RON, by means of immunohistochemistry, IP/WB, FISH, mutational analyses, and the respective cognate ligands by real-time PCR. MET and HER3 were analyzed in the same way, because it has been previously reported that these receptors are activated in the two tumor types (Segal et al, 2003;Schaefer et al, 2004Schaefer et al, , 2006Puri et al, 2007;Reschke et al, 2008;Davis et al, 2010;Mascarenhas et al, 2010). Because EGFR was the most weakly activated receptor, it had not previously been reported to be associated with CCS (Schaefer et al, 2006), and there was insufficient material for IP/WB analyses, we only investigated the presence of its ligands.…”

“…We used IP/WB to confirm the activation of EGFR and PDGFRB receptors that the exploratory phospho-RTK array analyses had shown activated in CCS and MM and to further investigate the activation profiles of the HER3 and MET receptors previously reported to be involved in CCS and MM (Segal et al, 2003;Schaefer et al, 2004Schaefer et al, , 2006Puri et al, 2007;Reschke et al, 2008;Davis et al, 2010;Mascarenhas et al, 2010) extending the study to RON. Furthermore, we explored downstream signalling and interrogated the downstream effectors for mutations.…”

“…It has been reported that HER3 mRNA expression distinguishes CCS from other soft tissue sarcomas (Segal et al, 2003), and HER3 mRNA and protein overexpression (the latter sustained by an autocrine loop involving neuregulin 1 and HER2/ HER3) have been described in cell lines (Schaefer et al, 2004(Schaefer et al, , 2006. Preclinical investigations have shown that the EWSR1/ATF1 chimeric fusion protein interacts with the MITF promoter and, upon binding to MITF, leads to MET overexpression and the activation of the downstream PI3K/AKT and ERK pathways (Davis et al, 2006;Tsuda et al, 2007).…”

The ERBB3 receptor in cancer and cancer gene therapy

“…309,310 Cell lines derived from these tumors expressed ERBB3 protein and either ERBB2 or ERBB4; in half of the lines ERBB3 was constitutively activated by NRG1 expression; the others were responsive to added NRG1. 319 Gastrointestine (Table 7) Expression and function in normal gastrointestinal tissues-ERBB3 protein was detected by immunohisto-chemistry in epithelial cells throughout the gastrointestinal tract, including squamous epithelium of the oropharynx and esophagus, parietal cells of the stomach and surface enterocytes of small and large bowel. 320,321 NRG1 on the other hand was detected in mesenchymal but not epithelial cells of gastric mucosa.…”

Abstract 5726: Human epidermal growth factor 3 (HER3) blockade with U3-1287/AMG888 modulates radiosensitivity in the lung and head and neck carcinomas

“…Thus, aggressive tumors often express HER3, including tumors of the breast (Bobrow et al , 1997), non-small cell lung (NSCLC) (Yi et al , 1997), metastatic colon (mCRC) (Kapitanovic et al , 2000), head and neck (HNSCC) (Takikita et al , 2011), pancreas (Lemoine et al , 1992), ovary (Rajkumar et al , 1993; Tanner et al , 2006), clear cell sarcomas (Schaefer et al , 2006), stomach (Rajkumar et al , 1993), and skin (Buac et al , 2009). In HNSCC and NSCLC, HER3 expression has been observed in approximately 77% of HNSCC and 30% of NSCLC tumor samples, where it was correlated with worse overall survival (Ocana et al , 2013; Takikita et al , 2011; Yi et al , 1997).…”