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Mechanisms of induction of DNA lesions by UVA light and its biological effects.

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Teiti Yagura
Total Authors: 1
Document type: Master's Dissertation
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
Defense date:
Examining board members:
Carlos Frederico Martins Menck; Joao Dias de Toledo Arruda Neto; José Freire da Silva Neto
Advisor: Carlos Frederico Martins Menck

DNA samples were irradiated with UVA light in different conditions for studying the possible mechanisms involved in the induction of DNA lesions by this radiation. DNA lesions formed after irradiation were quantified with DNA repair enzymes, which recognize and cleave the sites containing oxidized bases and pyrimidine dimers (CPDs). Complementing these analyses, tests were performed with antibodies and HPLC-ED. NaCl and more concentrated DNA are capable of reducing the induction of CPDs. Damage caused by oxidative stress is inhibited in the presence of sodium azide and metal chelators, indicating the involvement of singlet oxygen and Fenton reactions, in the generation of these lesions. Deuterated water and more concentrated DNA increased the induction of oxidized bases. The bigger the amount of irradiated DNA, the more singlet oxygen is formed, which indicates a possible endogenous photosensitization mechanism. (AU)

FAPESP's process: 09/13374-0 - Mechanisms of Lesion Induction on DNA by UVA Light and its Biological Effects
Grantee:Teiti Yagura
Support Opportunities: Scholarships in Brazil - Master