Related Experiment Video
Updated: Oct 8, 2026

Advanced Confocal Microscopy Techniques to Study Protein-protein Interactions and Kinetics at DNA Lesions
Published on: November 12, 2017
Photodynamic DNA damage mediated by delta-aminolevulinic acid-induced porphyrins
1Institut de Pharmacie, Service de Chimie Bioanalytique, de Toxicologie et de Chimie Physique Appliquée, Université Libre de Bruxelles, CP 205/1, Belgium. pduez@ulb.ac.be
Abstract:
The mutagenic properties of UVA are thought to be predominantly radical-mediated, which supposes endogenous sensitizers. In order to investigate a possible role of porphyrins, their synthesis was induced in a murine leukemia P388D1 cell model by treatment with delta-aminolevulinic acid (delta-ala). Intra-cellular protoporphyrin IX reached a plateau after about 2 h, whereas soluble porphyrins, probably the photostable uro- and/or coproporphyrins, were excreted. Irradiation of treated cells by UVA (tanning lamp) but also by visible light was found to generate in DNA a significant increase of 8-oxo-7,8-dihydro-2'-deoxyguanosine, a mutagenic marker of oxidative damage. The different parameters involved in this photodynamic effect are reported, namely delta-ala concentration and loading time, light dosage and the influence of intracellular and medium-excreted porphyrins. These results point to an implication of porphyrins in solar-induced carcinogenicity but also in possible adverse effects of the medical applications of photodynamic therapy and diagnosis.
More Related Videos
Related Concept Videos
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Spontaneous and Induced Mutations
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Nucleotide Excision Repair
Overview of DNA Repair
Chemically...
Translesion DNA Polymerases
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...

