Tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) binds to death receptors 4/5 and selectively induces caspase-dependent apoptosis. The RNA interference screening approach has led to the discovery and characterization of several TRAIL pathway components in human cells. Here, libraries of synthetic small interfering RNA (siRNA) and microRNAs (miRNA) were used to probe the TRAIL pathway. In addition to known genes, siRNAs targeting CDK4, PTGS1, ALG2, CLCN3, IRAK4, and MAP3K8 altered TRAIL-induced caspase-3 activation responses. Introduction of the miRNAs let-7c, mir-10a, mir-144, mir-150, mir-155, and mir-193 also affected the activation of the caspase cascade. Putative targets of these endogenous miRNAs included genes encoding death receptors, caspases, and other apoptosis-related genes. Among the novel genes revealed in the screen, CDK4 was selected for further characterization. CDK4 was the only member of the cyclin-dependent kinase gene family that bore a unique function in apoptotic signal transduction. [Cancer Res 2007;67(22):10782–8]
- Gene Expression, Chromatin Regulation, and Oncogenomics
- Cell Death and Senescence
- CELLULAR, MOLECULAR, AND TUMOR BIOLOGY
- Cell Growth/Signaling Pathways
- Silencing and reactivation of gene expression
Note: Supplementary data for this article are available at Cancer Research Online (http://cancerres.aacrjournals.org/).
- Received April 24, 2007.
- Revision received August 15, 2007.
- Accepted September 21, 2007.
- ©2007 American Association for Cancer Research.