Chemical genetic approaches to probing cell death

Abstract

Chemical genetics has arisen as a tool for the discovery of pathways and proteins in mammalian systems. This approach, comprising small-molecule screening combined with biochemical and genomic target identification methods, enables one to assess which proteins are involved in regulating a particular phenotype. Applied to cell death, this strategy can reveal novel targets and pathways regulating the demise of mammalian cells. Numerous diseases have been linked to the loss of regulation of cell death. Defining the mechanisms governing cell death in these diseases might lead to the discovery of therapeutic agents and targets and provide a richer understanding of the mortality of living systems. Recent advances include the discovery of novel small molecules regulating cell death pathways -- necrostatin and erastin -- as well as the elucidation of the mechanism of death induced in cancer cells by the cytotoxic agent Apratoxin A.

Figure 1

Chemical structures of (a) necrostatin-1 (b) aprotoxin A and (c) erastin.

Figure 2

Statistical analysis of an overexpression screen. A two-dimensional fitting model, LOWESS (locally weighted regression and smoothing scatterplots), was used to analyze an overexpression screen of 27 000 cDNAs in 50nM AprA-treated (treatment) and 25% ethanol-treated (control) U20S cells. This analysis revealed cDNAs that prevent AprA-induced toxicity (rescue, red) and cDNAs that enhance toxicity of AprA (cooperativity, yellow). The blue line represents the fitted curve from LOWESS analysis. Reproduced, with permission, from [29••].