The Free Radical Cancer Biology Program (FRCBP) is unique to the HCCC and focuses on studying the biology of inherent differences in reductive and oxidative (redox) metabolism between cancer vs. normal cells. Research in the program is determining the role that redox reactions play in cancer phenotypic changes relevant to cell growth, differentiation, signal transduction, metastasis, functional molecular imaging, and therapy. A unifying goal of the program is to utilize a comprehensive basic science understanding of redox biology to develop novel biochemical rationales for improving cancer therapy. Three overlapping themes exist within the program. Theme 1: Understanding the role of redox biochemistry in regulation of genetic and epigenetic gene expression pathways relevant to cancer biology. Within this theme are research areas of focus exploring redox fluctuations and gene expression globally, as well as gene expression changes related of key redox sensitive molecules such as glutathione, thioredoxin, SOD, and AP2. Ttieme 2: Understanding the role of redox regulation in cell biology. Within this theme are research areas exploring the effects of redox on the cell cycle as well as invasion and metastasis. Ttieme 3: Exploring the role of oxidative stress in therapy outcomes. Within this theme are research areas exploring the role of manipulating oxidative stress to improve therapy as well as using imaging of oxidative metabolism as an approach to monitor and guide therapy. Major accomplishments of the FRCBP over the past funding period include findings that (a) cancer cells (relative to normal cells) produce increased steady-state levels of 02*' and H2O2 from mitochondrial metabolism that significantly contribute to differential susceptibility to clonogenic cell killing induced by glucose deprivation; (b) extracellular superoxide dismutase (EcSOD) inhibits invasion and metastasis; (c) expression of MnSOD governs the late production of reactive oxygen species, cell cycle check points, and transformation following radiation exposure; (d) that inhibitors of glucose and hydroperoxide metabolism can be used to enhance responses to radio-chemo-therapy by enhancing metabolic oxidative stress. The FRCBP consists of 18 members from 1 basic science department and 6 clinical departments and 2 colleges. Peer-reviewed, research funding for this program totals $3.9 million with over $2.0 million total costs from NCI. FRCBP members co-authored 237 publications. Of these publications, 20% were intraprogrammatic, 24% were interprogrammatic and 10% were both intra and interprogrammatic, for a total of 54% collaborative publications.