International Symposium Fundación Areces: “Sunlight-triggered DNA Lesions and Skin Cancer”

fundacion_areces1International Symposium Fundación Areces: “Sunlight-triggered DNA Lesions and Skin Cancer”

 

 

 

 

International Symposium Fundación Areces: “Sunlight-triggered DNA Lesions and Skin Cancer”

Date: November 4th, 2015

Place: Valencia, Salón de Actos del Cubo Rojo de la Ciudad Politécnica de la Innovación (CPI) de la Universitat Politècnica de València (UPV) (Edificio 8E, Acceso J, Planta 3) (Valencia)

Organizers: Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia and Fundación Areces

Human exposure to sunlight has important public health implications. The occurrence of skin cancer in humans is steadily growing over the last few decades. The incidence of the highly lethal melanoma has largely increased since 1975, being currently the 5th most commonly diagnosed type of cancer in Europe. It has been unambiguously shown that exposure to solar ultraviolet (UV) radiation is involved in the pathogenesis of most types of skin cancer.

The UVB component of sunlight is directly absorbed by DNA and constitutes the most mutagenic and carcinogenic solar radiation reaching the Earth´s surface. Although the contribution of UVA to sunlight is much higher than that of UVB, it does not result in direct DNA damage; however, UVA can mediate photosensitized reactions mediated by drugs, cosmetics or any other chemicals. This possibility has attracted considerable attention, as it may result in an important extension of the active fraction of the solar spectrum with photocarcinogenic potential. This is aggravated by the widespread use of tanning sunbeds, which in July 2009 have been declared as ‘‘carcinogenic to humans” by the International Agency for Research of Cancer (IARC).

It is generally accepted that the chemical modifications of biomolecules occurring upon irradiation are responsible for the photobiological effects of light. Hence, investigation of the photochemical mechanisms is essential to understand most of the key processes involved in DNA damage and repair.

Oxidative DNA damage has attracted considerable attention. This is a relevant issue, associated with the generation of reactive species (excited states, organic radicals, hydroxyl radical, singlet oxygen, etc.) in biological media. In aerobic media, radical reactions may trigger oxidative lesions, both at the nucleobases and at the deoxyribose units, with purines as the most easily oxidizable DNA building blocks. In the pyrimidine series, the most relevant type of DNA damage is formation of several classes of dimeric photoproducts, which been unambigously associated with mutations. As a protection machinery from the UV-mediated harmful effects, living organisms are equipped with enzymes that can restore lesions to recover their intact forms, thus maintaining genetic integrity.

Light can mediate DNA damage, but it can also be used for repair purposes. Moreover, light can be applied for cancer treatment in the so-called photodynamic therapy (PDT). This clinically approved and minimally invasive therapeutic approach is characterized by selective cytotoxic activity toward malignant cells. The procedure involves administration of a photosensitizing drug followed by irradiation at a wavelength corresponding to its absorption band. In the presence of oxygen, a series of events lead to direct tumor cell death, damage to the microvasculature, and induction of a local inflammatory reaction.

In summary, this one-day symposium offers the audience key lectures on a broad range of topics related to sunlight-mediated DNA damage and repair, induction of skin cancer and its treatment. It encompasses from the fundamental (chemical/biological) to the clinical points of view and comprises seven lectures given by worldleading researchers in the field, namely G. Hofbauer (Switzerland), E. Sage (France), J. Cadet (Canada), C. Crespo (USA), M. A. Miranda (Spain), T. Carell (Germany) and K. Berg (Norway).

 

Information and inscription

 

PROGRAM

Wednesday, November 4th

9:00       Opening ceremony

9:30       Photodamage and skin cancer (Günther Hofbauer,University of Zürich, Switzerland)

10:30     Photogenotoxic stress and cancer (Evelyne Sage, Institut Curie, Paris, France)

11:30     Break

12:00     DNA photolesions in cells (Jean Cadet, University of Sherbrooke, Canada)

13:00    Ultrafast processes in DNA photochemistry (Carlos Crespo Hernández, Case Western Reserve University, Cleveland, USA)

14:00     Break

16:00     Photosensitized DNA damage (Miguel Angel Miranda, Institute of Chemical Technology UPV-CSIC, Spain)

17:00     DNA repair (Thomas Carell, University of Munich, Germany)

18:00     Photodynamic therapy of cancer (Kristian Berg, Radium Hospital and University of Oslo, Norway)

19:00     Concluding remarks