VA has recognized that Agent Orange exposure is associated with development of bladder cancer, chronic B-cell leukemia, Hodgkin’s and non-Hodgkin’s lymphoma, multiple myeloma, prostate cancer, respiratory cancer, and a subset of soft tissue cancers including fibrosarcoma. More recently, burn pit exposure has also been implicated in development of several cancers including fibrosarcoma. Patients with advanced cases of fibrosarcoma have poor long-term survival because of resistance that cancer cells develop to chemo, radiation, and biologic therapies. An effective solution is to target multiple components in an essential cancer growth and metastasis pathway. Hypoxia Inducible Factors (HIF) are transcription factors that are activated by hypoxia and other environmental stresses present in solid tumors. The enzyme acyl-CoA synthetase short chain family member 2 (Acss2) also responds to oxygen or glucose deprivation. Acss2 and HIF-2 are independent components of a signaling axis that is usurped by cancer cells to promote tumor growth and metastasis. Acss2/HIF-2 signaling favors cancer spread, whereas depleting Acss2 or HIF-2 reduces growth and metastasis of fibrosarcoma-derived tumors in mice. Not surprisingly, Acss2 and HIF-2 are over-expressed in cancers including soft tissue tumors. Because of its dual role in cytosolic intermediary metabolism and nuclear signaling, Acss2 is considered a high value therapeutic target. Indeed, reducing Acss2 levels blunts cancer growth in cell and mouse models including fibrosarcoma. Although usually very stable, select mutations in the Acss2 carboxy terminal hinge region dramatically shorten Acss2 half-life, which is due to unmasking of potent protein destabilizing elements (PDE) in Acss2 that are normally hidden within an intra-molecular cage. When these PDE in Acss2 are unmasked, the otherwise stable Acss2 protein is rapidly eliminated. Instability of Acss2 has functional consequences as fibrosarcoma-derived cells expressing unstable Acss2 protein have markedly reduced tumor growth and metastases in mice with flank tumors derived from these cells. Our goal is to develop first-in-class drugs to treat fibrosarcoma and other cancers associated with Agent Orange and burn pit exposure. In this proposal, we will identify small molecules that unmask PDE in Acss2 and induce its elimination from cancer cells. To identify inducers of Acss2 degradation, we will screen a large chemical diversity library in collaboration with the Columbia Genome Center High-Throughput Screening Facility using stable cell lines expressing enzymatic (primary screen) or orthogonal fluorescent (secondary screen) reporters fused with portions of stable or unstable Acss2 proteins. We will use cell-based assays to assess the impact of hits from this screen on Acss2-specific features including protein levels, lipid synthesis, and cancer cell properties. Select candidates will be further developed into compounds that ultimately will be tested for thei...