Loss of the chromatin remodeler, ATRX, promotes aggressive features of osteosarcoma with increased NF-κB signaling and integrin receptor binding

Osteosarcoma (OS) is a lethal disease with few known targeted therapies. Here we show that decreased ATRX expression is associated with more aggressive tumor cell phenotypes, including increased growth, migration, invasion, and metastasis. These phenotypic changes correspond with activation of NF-κB signaling, extracellular matrix remodeling, increased integrin αvβ3 expression, and ETS family transcription factor binding. Here we characterize these changes in vitro , in vivo , and in a dataset of human OS patients. This increased aggression substantially sensitizes ATRX -deficient OS cells to integrin signaling inhibition. Thus, ATRX plays an important tumor suppression role in OS, and loss of function of this gene may underlie new therapeutic vulnerabilities. The relationship between ATRX expression and integrin binding, NF-κB activation, and ETS family transcription factor binding has not been described in previous studies and may impact the pathophysiology of other diseases with ATRX loss, including other cancers and the ATR-X alpha thalassemia mental retardation syndrome.