Preliminary data established the requirement for NF-kB signaling in a subset of endometrial cancer cell lines. In collaboration with G.L.Maxwell, we examined a signature of NF-kB activity in the gene expression profiles of endometrial cancers balanced for serous vs endometrioid histology and also distributed equally among African American (AA) and caucasian (C) women. We found that the signature was significantly higher in cancers from AA women, especially those of the serous histology variant. Ongoing projects in our lab, and in collaboration with the Maxwell lab, will continue to address the stated goals. We tested 9 endometrial cancer cell lines for their dependence on NF-kB signaling by treating them with IKKb small molecule inhibitor and quantifying viability in XTT assays. We plan to extend these experiments to additional cell lines, and in additional function assays such as adhesion, invasion and cytokine production. We identified at least 2 endometrial cancer cell lines that are sensitive to IKKb inhibition in vitro. We profiled gene expression changes in these 2 cell lines upon blockade of IKKb signaling using both a small molecule inhibitor and introduction of a mutant form of IkBa that serves as a """"""""super-repressor"""""""" of IKKb-mediated signaling. We will confirm decrease in protein expression of the endometrial cancer-specific NF-kB targets by Western blot. These gene and protein signatures will allow us to specifically interrogate the endometrial cancer samples using gene expression profiles and tissue microarrays that are currently being collected and generated by our collaborator. The overall outcome of these studies will be to design clinical trials with NF-kB targeted agents for women whose endometrial cancers show evidence of pathway activation.