Synthetic Inhibitors of Ras Palmitoylation: Defining a Novel Class of Drugs Targeting Breast Cancers
Abstract
Members of the Ras family of oncoproteins cause a high percentage of human cancers. Cancer proliferation can result from mutations in ras genes, overexpression of Ras proteins, or the aberrant activation of pathways that impinge on Ras signaling. Ras proteins must be posttranslationally modified with farnesyl and palmitoyl lipids to associate with the plasma membrane and exhibit transforming activity. Consequently, inhibitors of Ras farnesylation halt the growth of breast and other cancers. However, in addition to farnesylation, the palmitoylation of Ras cysteine residues by the enzyme palmitoyl acyltransferase (PAT) contributes to the transforming activity of Ras. Hence, the development of potent and selective inhibitors of PAT could define a novel class of anticancer agents. To identify compounds that affect Ras palmitoylation, we synthesized a novel fluorescent Ras-mimetic substrate. This and a related Src-mimetic substrate were used to investigate a small molecule inhibitor of PAT termed JF081204. To test the hypothesis that this inhibitor may exhibit anticancer activity by blocking palmitoylation of Ras proteins, we evaluated JF081204 as an anticancer agent, synthesized analogues to investigate structure activity relationships, and probed the mechanism of action of these compounds. We demonstrated that JF081204 inhibits PAT activity in platelets but does not inhibit palmitoylation of Ras in cancer cell lines.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2004
- Accession Number
- ADA435054
Entities
People
- Blake R. Peterson
Organizations
- Pennsylvania State University