Data from Identification of the Receptor Tyrosine Kinase c-Met and Its Ligand, Hepatocyte Growth Factor, as Therapeutic Targets in Clear Cell Sarcoma

Abstract

<div>Abstract<p>Clear cell sarcoma (CCS), a childhood tumor of the tendons and aponeuroses, is uniformly fatal once it has metastasized because of its profound therapeutic resistance. CCS is characterized by production of a chimeric transcription factor, EWS-ATF1, which is formed as the result of a disease-specific chromosomal translocation. EWS-ATF1 activates the melanocyte transcription factor MITF, which in turn activates transcription of c-Met, an oncogenic receptor tyrosine kinase recently shown to be activated in CCS. Based on this connection, we hypothesized that c-Met inhibition may offer a strategy to treat CCS, as an indirect tactic to defeat a transforming pathway downstream of EWS-ATF1. Here, we show that primary CCS and CCS-derived cell lines express c-Met, which is activated in an autocrine fashion by its ligand hepatocyte growth factor (HGF)/scatter factor in some CCS cell lines. c-Met expression is critical for CCS invasion, chemotaxis, and survival. Blocking c-Met activity with a small-molecule inhibitor (SU11274) or a neutralizing antibody to its ligand HGF (AMG 102) significantly reduced CCS cell growth in culture. Similarly, AMG 102 significantly suppressed <i>in vivo</i> tumor growth in an autocrine xenograft model of CCS. Collectively, these findings suggest the HGF:c-Met signaling axis as a candidate therapeutic target to improve clinical management of CCS. Cancer Res; 70(2); 639–45</p></div>