Biomaterial Database

Photosensitization by antitumor agents, 4. Anthrapyrazole-photosensitized formation of single strand-breaks in DNA. 1988

J A Hartley, and K Reszka, and J W Lown

Department of Chemistry, University of Alberta, Edmonton, Canada.

Single-strand breaks can be introduced into PM2 closed-circular DNA upon illumination with blue light, in the presence of the anthrapyrazole antitumor agent, compound 1. Damage is observed already after 1 min of blue light illumination, and is significantly enhanced by the presence of electron donors such as NADH, ascorbic acid or Fe(III)/EDTA complex. The photosensitizing properties were not observed for anthrapyrazole analogues with one or more hydroxyl substituents in the chromophore of the drug. The inhibitory effects of sodium azide, methanol, mannitol, SOD, and catalase suggest an oxygen-dependent mechanism of strand-break production, probably involving hydroxyl radicals. However, a second mechanism involving drug molecules bound to the DNA is also indicated under anoxic conditions in the presence of NADH.

UI	MeSH Term	Description	Entries
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D010083	Oxidants, Photochemical	Compounds that accept electrons in an oxidation-reduction reaction. The reaction is induced by or accelerated by exposure to electromagnetic radiation in the spectrum of visible or ultraviolet light.	Photochemical Oxidants
D011720	Pyrazoles	Azoles of two nitrogens at the 1,2 positions, next to each other, in contrast with IMIDAZOLES in which they are at the 1,3 positions.
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D004277	DNA, Single-Stranded	A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.	Single-Stranded DNA,DNA, Single Stranded,Single Stranded DNA
D004279	DNA, Viral	Deoxyribonucleic acid that makes up the genetic material of viruses.	Viral DNA
D004587	Electrophoresis, Agar Gel	Electrophoresis in which agar or agarose gel is used as the diffusion medium.	Electrophoresis, Agarose Gel,Agar Gel Electrophoresis,Agarose Gel Electrophoresis,Gel Electrophoresis, Agar,Gel Electrophoresis, Agarose
D000880	Anthraquinones	Compounds based on ANTHRACENES which contain two KETONES in any position. Substitutions can be in any position except on the ketone groups.	Anthracenedione,Anthracenediones,Anthranoid,Anthraquinone,Anthraquinone Compound,Anthraquinone Derivative,Dianthraquinones,Dianthrones,Anthranoids,Anthraquinone Compounds,Anthraquinone Derivatives,Compound, Anthraquinone,Derivative, Anthraquinone
D000903	Antibiotics, Antineoplastic	Chemical substances, produced by microorganisms, inhibiting or preventing the proliferation of neoplasms.	Antineoplastic Antibiotics,Cytotoxic Antibiotics,Antibiotics, Cytotoxic
D001435	Bacteriophages	Viruses whose hosts are bacterial cells.	Phages,Bacteriophage,Phage