PROJECT SUMMARYIron plays a central role in cell proliferation and has been implicated in several aspects of cancer biology.Malignant cells harbor an altered iron metabolism aimed at increasing iron acquisition and retention therebysupporting rapid proliferation rates. Iron scavengers including several clinical chelators for the treatment ofiron overload exhibit antiproliferative properties albeit in the presence of narrow therapeutic windows andsystemic toxicity in several cases. The higher demand for iron of cancer cells is now recognized as animportant area of investigation and a therapeutic opportunity; however currently available chelator systems arenot designed specifically to target intracellular iron in malignant cells. This research program seeks to engineercontemporary approaches to iron chelation particularly to improve our control of intracellular delivery andtumor selectivity as well as our understanding of the parameters correlated to iron deprivation in cellproliferation and malignancy. Under the first specific aim of the project we build on our work on prochelatorsystems that are activated for iron coordination upon cell entry. Parameters affecting intracellular oxidativereactivity and toxicity will be assessed and tuned in several tridentate scaffolds. Within the second aim tumor-targeting units are connected to prochelators designed to increase cancer selectivity. The study of a new classof glycoconjugate constructs takes advantage of the glucose avidity of malignant cells. In addition thereactivity of acquired cysteine residues in oncogenic mutant proteins will be employed to activate prochelatorsin cancer cells carrying a specific mutation. Under the third aim of the project the effects of the chelatorsystems on the cytosolic labile iron pool will be assessed through several spectroscopic methods. Their impacton iron homeostasis will be examined through the post-transcriptional regulation and expression of proteinsinvolved in iron uptake transport and storage. Finally our analyses of cell cycle death and metabolicparameters will contribute to delineate the effective cellular susceptibility to our chelator systems. Breastcolon and pancreatic cancer cell lines were selected for this study because the implication of iron in theirprogression and aggressive phenotypes is documented in cell studies animal models and clinical data. Thisstudy is innovative in its combination of principles of iron coordination chemistry with pro-drug and tumor-targeting approaches for intracellular iron binding. Motivated by the increased iron needs of all cancerphenotypes this research program is poised to produce broadly applicable iron-binding strategies andfundamental information on their impact in cell cycle progression with the long-term goal of identifying newpotential avenues for cancer treatment.