title: Structure-based discovery of an organic compound that binds Bcl-2 protein and induces apoptosis of tumor cells.
abstract: Bcl-2 and related proteins are key regulators of apoptosis or programmed cell death implicated in human disease including cancer. We recently showed that cell-permeable Bcl-2 binding peptides could induce apoptosis of human myeloid leukemia in vitro and suppress its growth in severe combined immunodeficient mice. Here we report the discovery of HA14-1, a small molecule (molecular weight = 409) and nonpeptidic ligand of a Bcl-2 surface pocket, by using a computer screening strategy based on the predicted structure of Bcl-2 protein. In vitro binding studies demonstrated the interaction of HA14-1 with this Bcl-2 surface pocket that is essential for Bcl-2 biological function. HA14-1 effectively induced apoptosis of human acute myeloid leukemia (HL-60) cells overexpressing Bcl-2 protein that was associated with the decrease in mitochondrial membrane potential and activation of caspase-9 followed by caspase-3. Cytokine response modifier A, a potent inhibitor of Fas-mediated apoptosis, did not block apoptosis induced by HA14-1. Whereas HA14-1 strongly induced the death of NIH 3T3 (Apaf-1(+/+)) cells, it had little apoptotic effect on Apaf-1-deficient (Apaf-1(-/-)) mouse embryonic fibroblast cells. These data are consistent with a mechanism by which HA14-1 induces the activation of Apaf-1 and caspases, possibly by binding to Bcl-2 protein and inhibiting its function. The discovery of this cell-permeable molecule provides a chemical probe to study Bcl-2-regulated apoptotic pathways in vivo and could lead to the development of new therapeutic agents.
authors.affiliation: Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Wang
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Shan
authors.forename: X
authors.initials: X
authors.lastname: Han
authors.forename: S M
authors.initials: SM
authors.lastname: Srinivasula
authors.forename: C M
authors.initials: CM
authors.lastname: Croce
authors.forename: E S
authors.initials: ES
authors.lastname: Alnemri
authors.forename: Z
authors.initials: Z
authors.lastname: Huang
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D003198:Computer Simulation; D015195:Drug Design; D018922:HL-60 Cells; D006801:Humans; D051379:Mice; D009930:Organic Chemicals / Q000737:chemistry* / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D011485:Protein Binding; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D009930:Organic Chemicals; D010455:Peptides; D019253:Proto-Oncogene Proteins c-bcl-2