(Georgia Institute of Technology, 2012-05-07)
Ahmad, Mona
Glioblastoma is an extremely invasive form of brain cancer, causing it to be very deadly even after administering therapy. The cells of glioblastoma invade the tissue surrounding the brain tumor, so that the cancer persists even when the tumor is removed. To address this problem, Imipramine Blue, a novel cancer therapeutic has been developed. The drug has been successful in halting invasion of cancer cells in vitro and in vivo, but its mechanism of action is unclear. From examining the normal mechanism of cell invasion, it seems reasonable to expect that Imipramine Blue binds to actin or one of its upstream regulators. To examine the mechanism of action, actin polymerization assays, immunocytochemistry, nuclear localization, and a magnetic bead binding assay were performed. The data from the actin polymerization assays shows that Imipramine Blue does not affect actin polymerization outside of the cell. The immunocytochemistry data confirms that Imipramine Blue does not affect the actin structures or upstream regulators in healthy cells, but changes the activity of these proteins in cancer cells. Imipramine Blue has been shown to localize to the nucleus in nuclear localization assays. Finally, the magnetic bead binding assay identifies a splice variant of Nox4, an upstream regulator, as the binding protein to the drug. Identifying the mechanism of action of Imipramine Blue ensures that researchers and doctors can confidently apply the drug to other cancers, knowing that it will not interact with healthy cells.