Abstract: A method is disclosed for detecting exposure of organisms to biologically significant or hazardous amounts of ionizing radiation. The method uses nucleic acid microarray hybridization to evaluate biological effects, such as patterns of expression of genes after radiation exposure. Numerous genes are provided which have been found to be responsive to radiation exposure in a variety of cell lines. These genes are incorporated into probe sets, which are exposed to a labeled nucleic acid composition from a test cell, such as cDNA reverse transcribed from mRNA in the test cell, which specifically hybridizes to members of the probe set when the cell has been exposed to a biologically significant amount of ionizing radiation. Whether the nucleic acid composition hybridizes to the nucleic acid molecules representing genes that are differentially expressed is determined.

Abstract: The present invention is directed to novel methods for assaying for modulators of GADD45 polypeptide activity. The invention also provides means to sensitize a proliferating cell to a DNA base-damaging agent by administration of novel inhibitors of GADD45 polypeptide activity. The invention further provides polypeptides which interfere with the ability of Cdc2/cyclin B1 complexes to cause a pause at the G2/M stage of the cell cycle in response to GADD45, and nucleic acids which encode such polypeptides.

Abstract: The present invention is directed to novel methods for assaying for modulators of GADD45 polypeptide activity. The invention also provides means to sensitize a proliferating cell to a DNA base-damaging agent by administration of novel inhibitors of GADD45 polypeptide activity. The invention further provides polypeptides which interfere with the ability of Cdc2/cyclin B1 complexes to cause a pause at the G2/M stage of the cell cycle in response to GADD45, and nucleic acids which encode such polypeptides.

Abstract: Isolated or purified oligonucleotides and isolated or purified morpholino oligomers; a method of detecting cancer or a predisposition to cancer in a mammal, comprising comparing the level of expression of Wip1 in the mammal to a control; a method of treating cancer in a mammal that expresses the same or a higher level of Wip1 as compared to a mammal of the same species that does not have cancer, comprising administering to the mammal a cancer-treating effective amount of a Wip1 inhibitor, a method of screening an oligonucleotide or morpholino oligomer for the ability to inhibit the expression of Wip1; a method of determining the efficacy with which a test oligonucleotide or morpholino oligomer inhibits Wip1 expression; a method of screening a compound for Wip1-inhibiting activity; and a method of determining the efficacy with which a test compound inhibits Wip1.