Abstract: The invention is directed to a method of characterizing a mechanism of action of an agent (e.g., a chemotherapeutic agent, a genotoxic agent). The method comprises contacting a plurality of populations of cells with an agent to be assessed, wherein each population of cells have one gene of interest targeted by a small hairpin RNA (shRNA) and wherein said gene of interest regulates cell death and a plurality of genes that regulate cell death are targeted in the plurality of populations of cells. A responsiveness of each population of cells to the agent is determined, thereby obtaining an shRNA signature of the agent, so as to identify one or more genes that mediate a response to the agent, thereby characterizing the mechanism of action of the agent. The invention is also directed an article of manufacture for characterizing a mechanism of action of a chemotherapeutic or genotoxic agent.

Abstract: In one aspect, the invention is directed to a method of characterizing a mechanism of action of a combination of agents. The method comprises contacting a plurality of populations of cells with a combination of agents to be assessed, wherein each population of cells have one gene of interest targeted by a small hairpin RNA (shRNA) and wherein the gene of interest regulates cell death and a plurality of genes that regulate cell death are targeted in the plurality of populations of cells. A responsiveness of each population of cells to the combination of agents is determined, thereby obtaining an shRNA signature of the combination of agents so as to identify one or more genes that mediate a response to the combination of agents, thereby characterizing the mechanism of action of the combination of agents.

Abstract: In one aspect, the invention is directed to a method of characterizing a mechanism of action of a combination of agents. The method comprises contacting a plurality of populations of cells with a combination of agents to be assessed, wherein each population of cells have one gene of interest targeted by a small hairpin RNA (shRNA) and wherein the gene of interest regulates cell death and a plurality of genes that regulate cell death are targeted in the plurality of populations of cells. A responsiveness of each population of cells to the combination of agents is determined, thereby obtaining an shRNA signature of the combination of agents so as to identify one or more genes that mediate a response to the combination of agents, thereby characterizing the mechanism of action of the combination of agents.

Abstract: The invention is directed to a method of characterizing a mechanism of action of an agent (e.g., a chemotherapeutic agent, a genotoxic agent). The method comprises contacting a plurality of populations of cells with an agent to be assessed, wherein each population of cells have one gene of interest targeted by a small hairpin RNA (shRNA) and wherein said gene of interest regulates cell death and a plurality of genes that regulate cell death are targeted in the plurality of populations of cells. A responsiveness of each population of cells to the agent is determined, thereby obtaining an shRNA signature of the agent, so as to identify one or more genes that mediate a response to the agent, thereby characterizing the mechanism of action of the agent. The invention is also directed an article of manufacture for characterizing a mechanism of action of a chemotherapeutic or genotoxic agent.

Abstract: The present invention describes Photolabile Compounds methods for use of the compounds. The Photolabile Compounds have a photoreleasable ligand, which can be biologically active, and which is photoreleased from the compound upon exposure to light. In some embodiments, the Photolabile Compounds comprise a light antenna, such as a labeling molecule or an active derivative thereof. In one embodiment, the light is visible light, which is not detrimental to the viability of biological samples, such as cells and tissues, in which the released organic molecule is bioactive and can have a therapeutic effect. In another embodiment, the photoreleasable ligand can be a labeling molecule, such as a fluorescent molecule.

Abstract: The invention provides, among other things, methods for performing RNA interference in stem cells and methods for using the stem cells in vivo.

Abstract: The invention provides, among other things, methods for performing RNA interference (RNAi) in stem cells (such as embryonic stem cells) and methods for using such stem cells in vivo. The invention also provides various animal models based on conditional/inducible, reversible, tissue-specific/spacial, and/or developmental stage-specific/temporal RNAi of certain target genes, which animal model may be useful for, e.g., drug target identification and/or validation.

Abstract: This invention features methods of identifying genetic alterations that can modulate cancer cells' sensitivity to an anti-cancer drug. Information on such genetic alterations can be used to predict cancer therapeutic outcomes and to stratify patient populations to maximize therapeutic efficacy.