Radiation Induced And Oxidative Dna Damages

DNA stores and passes the genetic information of almost all living organisms. Its molecular structure and their intramolecular interactions are particularly suitable to maximize stability against oxidative stress and UV-light absorption. Yet the protection and repair strategies are still error-prone: DNA lesions are produced, including the most complex and highly mutagenic ones. An important threat to DNA stability comes from photosensitization, i.e. from the dramatic multiplication of radiation-induced defects mediated by the presence of organic or organometallic dyes compared to the direct exposure to UVA radiation. Moreover, the photo-induced production of singlet oxygen generates an extremely high oxidative stress on DNA that, in vivo, normally results in extended cellular apoptosis. Elucidating the processes leading to DNA damages, from the production of a simple radical entity to deleterious lesions, as well as the opportunities of repair by devoted enzymes, is a cornerstone towards the development of more efficient protection strategies. Sensitization and selective production of DNA lesions can also be exploited to induce the selective apoptosis of cancer cells upon exposition to radiation or to oxidative stress, for instance in the field of photodynamic therapy. The importance and relevance of the field is witnessed by the impressive amount of high-level papers dealing with this complex subject, and notably tackling the structural elucidation of DNA and DNA-drug adducts, the mechanisms of formation of DNA lesions (including the precise detection of the final lesion products), as well as the influence of the lesions on the DNA stability and dynamics and the consequences on the ease of repair. Due to the complexity of the field lying at the frontiers between chemistry, physics and biology, multidisciplinary strategies allying modeling and experience are needed. This topic aims at giving an extended overview of the current research in the domain, with fundamental contribution from the leading groups in the field of DNA reactivity, structural characterization, photo-chemistry and photo-physics, as well as repair mechanism. It will therefore be a fundamental guide for scientists wanting to address the field of DNA lesion and repair, but also more generally for researchers working in rational drug design or in the development of biomarkers and medical imaging techniques

DNA stores and passes the genetic information of almost all living organisms. Its molecular structure and their intramolecular interactions are particularly suitable to maximize stability against oxidative stress and UV-light absorption. Yet the protection and repair strategies are still error-prone: DNA lesions are produced, including the most complex and highly mutagenic ones. An important threat to DNA stability comes from photosensitization, i.e. from the dramatic multiplication of radiation-induced defects mediated by the presence of organic or organometallic dyes compared to the direct exposure to UVA radiation. Moreover, the photo-induced production of singlet oxygen generates an extremely high oxidative stress on DNA that, in vivo, normally results in extended cellular apoptosis. Elucidating the processes leading to DNA damages, from the production of a simple radical entity to deleterious lesions, as well as the opportunities of repair by devoted enzymes, is a cornerstone towards the development of more efficient protection strategies. Sensitization and selective production of DNA lesions can also be exploited to induce the selective apoptosis of cancer cells upon exposition to radiation or to oxidative stress, for instance in the field of photodynamic therapy. The importance and relevance of the field is witnessed by the impressive amount of high-level papers dealing with this complex subject, and notably tackling the structural elucidation of DNA and DNA-drug adducts, the mechanisms of formation of DNA lesions (including the precise detection of the final lesion products), as well as the influence of the lesions on the DNA stability and dynamics and the consequences on the ease of repair. Due to the complexity of the field lying at the frontiers between chemistry, physics and biology, multidisciplinary strategies allying modeling and experience are needed. This topic aims at giving an extended overview of the current research in the domain, with fundamental contribution from the leading groups in the field of DNA reactivity, structural characterization, photo-chemistry and photo-physics, as well as repair mechanism. It will therefore be a fundamental guide for scientists wanting to address the field of DNA lesion and repair, but also more generally for researchers working in rational drug design or in the development of biomarkers and medical imaging techniques.

Holland-Frei Cancer Medicine, Ninth Edition, offers a balanced view of the most current knowledge of cancer science and clinical oncology practice. This all-new edition is the consummate reference source for medical oncologists, radiation oncologists, internists, surgical oncologists, and others who treat cancer patients. A translational perspective throughout, integrating cancer biology with cancer management providing an in depth understanding of the disease An emphasis on multidisciplinary, research-driven patient care to improve outcomes and optimal use of all appropriate therapies Cutting-edge coverage of personalized cancer care, including molecular diagnostics and therapeutics Concise, readable, clinically relevant text with algorithms, guidelines and insight into the use of both conventional and novel drugs Includes free access to the Wiley Digital Edition providing search across the book, the full reference list with web links, illustrations and photographs, and post-publication updates

In recent years the field of DNA repair has flourished due to new findings on DNA repair mechanisms and the molecular basis of cancer. This volume covers the most recent developments in this research field and contains contributions from scientists working in various fields.

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.