Linked Life Data

11728179

Source:http://linkedlifedata.com/resource/pubmed/id/11728179

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
2001-11-30
pubmed:abstractText
Bcl-2 belongs to a growing family of proteins which regulates programmed cell death (apoptosis). Overexpression of Bcl-2 has been observed in 70% of breast cancer, 30-60% of prostate cancer, 80% of B-cell lymphomas, 90% of colorectal adenocarcinomas, and many other forms of cancer. Thereby, Bcl-2 is an attractive new anti-cancer target. Herein, we describe the discovery of novel classes of small-molecule inhibitors targeted at the BH3 binding pocket in Bcl-2. The three-dimensional (3D) structure of Bcl-2 has been modeled on the basis of a high-resolution NMR solution structure of Bcl-X(L), which shares a high sequence homology with Bcl-2. A structure-based computer screening approach has been employed to search the National Cancer Institute 3D database of 206 876 organic compounds to identify potential Bcl-2 small-molecule inhibitors that bind to the BH3 binding site of Bcl-2. These potential Bcl-2 small-molecule inhibitors were first tested in an in vitro binding assay for their potency in inhibition of the binding of a Bak BH3 peptide to Bcl-2. Thirty-five potential inhibitors were tested in this binding assay, and seven of them were found to have a binding affinity (IC(50) value) from 1.6 to 14.0 microM. The anti-proliferative activity of these seven active compounds has been tested using a human myeloid leukemia cell line, HL-60, which expresses the highest level of Bcl-2 protein among all the cancer cell lines examined. Compound 6 was the most potent compound and had an IC(50) value of 4 microM in inhibition of cell growth using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Five other compounds had moderate activity in inhibition of cell growth. Compound 6 was further evaluated for its ability to induce apoptosis in cancer cells. It was found that 6 induces apoptosis in cancer cells with high Bcl-2 expression and its potency correlates with the Bcl-2 expression level in cancer cells. Furthermore, using NMR methods, we conclusively demonstrated that 6 binds to the BH3 binding site in Bcl-X(L). Our results showed that small-molecule inhibitors of Bcl-2 such as 6 modulate the biological function of Bcl-2, and induce apoptosis in cancer cells with high Bcl-2 expression, while they have little effect on cancer cells with low or undetectable levels of Bcl-2 expression. Therefore, compound 6 can be used as a valuable pharmacological tool to elucidate the function of Bcl-2 and also serves as a novel lead compound for further design and optimization. Our results suggest that the structure-based computer screening strategy employed in the study is effective for identifying novel, structurally diverse, nonpeptide small-molecule inhibitors that target the BH3 binding site of Bcl-2.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4313-24
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:11728179-Amino Acid Sequence, pubmed-meshheading:11728179-Antineoplastic Agents, pubmed-meshheading:11728179-Apoptosis, pubmed-meshheading:11728179-Azocines, pubmed-meshheading:11728179-Cell Division, pubmed-meshheading:11728179-Cell Survival, pubmed-meshheading:11728179-Cyclic N-Oxides, pubmed-meshheading:11728179-Databases, Factual, pubmed-meshheading:11728179-Drug Screening Assays, Antitumor, pubmed-meshheading:11728179-Humans, pubmed-meshheading:11728179-Magnetic Resonance Spectroscopy, pubmed-meshheading:11728179-Models, Molecular, pubmed-meshheading:11728179-Molecular Sequence Data, pubmed-meshheading:11728179-Protein Binding, pubmed-meshheading:11728179-Proto-Oncogene Proteins c-bcl-2, pubmed-meshheading:11728179-Structure-Activity Relationship, pubmed-meshheading:11728179-Tumor Cells, Cultured
pubmed:year
2001
pubmed:articleTitle
Discovery of small-molecule inhibitors of Bcl-2 through structure-based computer screening.
pubmed:affiliation
Structural Biology and Cancer Drug Discovery Program, Lombardi Cancer Center and Department of Oncology, Georgetown University Medical Center, 3970 Reservoir Road, Washington, DC 20007, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't