Arsenic Trioxide

**Semantic type:** Inorganic Chemical|Pharmacologic Substance

**Definition:** A small-molecule arsenic compound with antineoplastic activity. The mechanism of action of arsenic trioxide is not completely understood. This agent causes damage to or degradation of the promyelocytic leukemia protein/retinoic acid receptor-alpha (PML/RARa) fusion protein; induces apoptosis in acute promyelocytic leukemia (APL) cells and in many other tumor cell types; promotes cell differentiation and suppresses cell proliferation in many different tumor cell types; and is pro-angiogenic. (NCI04)

**Synonyms:** - ARSENIC TRIOXIDE - ATO - Arsenic (III) Oxide - Arsenic Sesquioxide - Arsenic trioxide - Arsenous Acid - Arsenous Acid Anhydride - Arsenous Oxide - Trisenox - Trisenox - White Arsenic - arsenic trioxide