ABT-263 is an orally bioavailable small molecule inhibitor of Bcl-2 family proteins. It is a substance being studied in the treatment of lymphomas and other types of cancer. It blocks some of the enzymes that keep cancer cells from dying.
Investigated for use/treatment in lung cancer and lymphoma (unspecified).
Mechanism of action
ABT-263 targets the Bcl-2 family of proteins, the major negative regulators of apoptosis. The Bcl-2 proteins, including Bcl-2, Bcl-xL, and Bcl-w, work by binding to two other groups of proteins-the executioners (Bax, Bak) that actually start the destruction pathway, and the sentinel proteins. Cancer cells frequently overexpress the Bcl-2-like proteins, and thus, when they sustain DNA damage-from radiation, for example-they continue growing. Preventing the Bcl-2-like proteins from binding to the executioners might be able to trigger cell death in the tumor.
Suppresses apoptosis in a variety of cell systems including factor-dependent lymphohematopoietic and neural cells. Regulates cell death by controlling the mitochondrial membrane permeability. Appears to function in a feedback loop system with caspases. Inhibits caspase activity either by preventing the release of cytochrome c from the mitochondria and/or by binding to the apoptosis-activating f...
Promotes cell death. Successfully competes for the binding to Bcl-X(L), Bcl-2 and Bcl-W, thereby affecting the level of heterodimerization of these proteins with BAX. Can reverse the death repressor activity of Bcl-X(L), but not that of Bcl-2 (By similarity). Appears to act as a link between growth factor receptor signaling and the apoptotic pathways.