This book is a printed edition of the Special Issue " Chemically-Induced DNA Damage, Mutagenesis, and Cancer" that was published in IJMS

As chemical exposures and cancer rates increase worldwide, there is a need for students, researchers, public health professionals, and physicians to understand the mechanisms connecting exposure with human cancer risk. This new book is an essential reference, as well as introduction to the field of chemical carcinogenesis, with particular focus on DNA damage as a critical link between exposure and disease, and emphasis on biomarkers associated with cancer risk in humans. In addition to DNA damage, related topics covered include metabolism of selected chemical carcinogens, exposure-induced epigenetic changes, cancer-associated mutations and reduction of DNA damage and cancer risk by chemoprevention. The book is designed to be a comprehensive guide to basic principles, a teaching tool for academics, and a map for the development of protective mechanisms to reduce human cancer risk.

During October 18-30, 1981, the second course of the International School of Pure and Applied Biostructure, a NATO Advanced Study Institute, was held at the Ettore Majorana Center for Scientific Culture in Erice, Italy, co-sponsored by the International Union Against Cancer, the Italian League Against Cancer, the Italian Ministry of Public Education, the Italian Ministry of Scientific and Technological Research, the North Atlantic Treaty Organization, the Italian National Research Council, the Sicilian Regional Government and two pharmaceutical Companies (Zambeletti and Farmitalia). The subject of the course was "Chemical Carcino genesis" with participants selected world-wide from 18 different countries. It is now eminently clear that.the bulk of human cancers are related to one of several types of environmental exposure. Of the environmental hazards, chemicals are among the best characterized carcinogens. However, how chemicals induce cancer is still poorly understood. Because of the magnitude of the problem and the ob vious need for a much more critical scientific analysis of the process by which cancer is induced (carcinogenesis), it was highly desirable to expose a greater number of scientists with varying background to some of the latest thinking in chemical carcino genesis. The course had this as its major objective and the re sulting book does reflect it.

''Useful and timely.'' ---Mutagenesis ''Of considerable value.'' ---Journal of Medical Genetics ''Quite readable....a comprehensive overview....perfectly covers the needs of those researchers who have to decide on the best strategy to identify damage or mutations at the molecular level.'' ---Trends in Cell Biology ''The formats of the presentations are uniform and ample and up-to-date references are provided at the end of each chapter...will be welcomed by postgraduate researchers of all ages and should retain its usefulness for a long time.'' ---Endeavour, 21(4), 1997 This important resource thoroughly reviews a wide range of techniques used in mutagenesis research-ranging from established techniques to recently developed methodologies-based on the polymerase chain reaction. DNA damage analysis, DNA repair assays, and mutation detection are a few of the techniques featured. Chapters present detailed experimental protocols benefiting researchers and students in the fields of toxicology, biotechniques, molecular biology, photobiology, medical genetics, and oncology.

This book originated in numerous Gordon Research Conferences and many other meetings of scientists working in chemistry, biophysics, biochemistry, and biology related to mutagenesis and carcinogenesis. It seemed the appro priate time to sit back and summarize the results of several decades of research in laboratories in different countries. We are very grateful to the Rockefeller Foundation for inviting us to formulate and begin writing the book at the Center for International Studies in Bellagio, Italy, where we were Resident Scholars. We are fortunate to have had the assistance of so many colleagues around the world who cheerfully sent original data, figures, and preprints and lis tened patiently to us as we worked out the various conflicting ideas in this fast-moving. field. The names of these scientists are found within the tables, figures, and references. There is one person whose contributions we especially wish to acknowl edge. Professor Heinz Fraenkel-Conrat was present at the inception of this book and throughout the writing encouraged and criticized in apprOximately equal proportion. Finally, his editing and amalgamation of our two styles gave us great comfort. B.S. D.G.

The free-radical chemistry of DNA had been discussed in some detail in 1987 in my book The Chemical Basis of Radiation Biology. Obviously, the more recent developments and the concomitant higher level of understanding of mechanistic details are missing. Moreover, in the living cell, free-radical DNA damage is not only induced by ionizing radiation, but free-radical-induced DNA damage is a much more general phenomenon. It was, therefore, felt that it is now timely to review our present knowledge of free-radical-induced DNA damage induced by all conceivable free-radical-generating sources. Originally, it had been thought to include also a very important aspect, the repair of DNA damage by the cell’s various repair enzymes. Kevin Prise (Cancer Campaign, Gray Laboratory, L- don) was so kind to agree to write this part. However, an adequate description of this strongly expanding area would have exceeded the allocated space by much, and this section had to be omitted. The directors of the Max-Planck-Institut für Strahlenchemie (now MPI für Bioanorganische Chemie), Karl Wieghardt and Wolfgang Lubitz, kindly allowed me to continue to use its facilities after my retirement in 2001. Notably, our - brarian, Mrs. Jutta Theurich, and her right-hand help, Mrs. Rosemarie Schr- er, were most helpful in getting hold of the literature. I thank them very much. Without their constant help, this would have been very difficult indeed.

This volume will provide a contemporary account of advances in chemical carcinogenesis. It will promote the view that it is chemical alteration of the DNA that is a route cause of many cancers. The multi-stage model of chemical carcinogenesis, exposure to major classes of human carcinogens and their mode-of-action will be a focal point. The balance between metabolic activation to form biological reactive intermediates and their detoxification, ensuing DNA-lesions and their repair will be profiled. It will describe the chemical changes that occur in DNA that result from endogenous insults including epigenetic changes that lead to gene silencing. It will describe major mechanisms of mutagenesis, affects on tumor suppressor genes and proto-oncogenes, and how cell-cycle check points can be by-passed by the "stealth-like" properties of chemical carcinogens. Environmental agents that can promote tumor formation will be discussed. The monograph will have wide appeal as a knowledge base for graduate students, post-doctoral fellows and faculty interested in this aspect of cancer causation and research.