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Albany 2019: 20th Conversation - Abstracts

category image Albany 2019
Conversation 20
June 11-15 2019
Adenine Press (2019)

The influence of CuTOEPyP4 porphyrin on DNA damage induced by high energy electron beam radiation

The study and understanding of the mechanisms of radiation causing damage to DNA is one of the inportant problems in the development of new cancer therapies and effective radiosensitizers. The fast electrons directly ionize the DNA molecule, causing damage. These include single-strand breaks and double-strand breaks, DNA–DNA or DNA–protein cross-links. The usage of the porphyrin-based Photodynamic Therapy (PDT) in conjunction with electron beam radiation therapy can be one of the effective treatment methods for cancer. Porphyrins have attracted the attention of researchers globally for application as photosensitizing agents in medicine. However, studies of the radiation damage at the molecular level in the presence of such PDT agents and anticancer drugs like porphyrins are still necessary. The goal of our investigations was to examine DNA damage in the presence of different amounts of Cu containing water soluble cationic meso-tetra-(4N-oxyethyl¬pyridyl) porphyrin induced by 3-4 MeV electron radiation depending on radiation doses in vitro. The samples with different relative concentrations of porphyrins per base pair were irradiated by the electron beam. After the irradiation of samples, the melting curves (the dependence of percentage of denaturized DNA on temperature) of investigated complexes were obtained. As the melting temperature of DNA is sensitive to double helix stability, it can be used as an indicator of strand breaks of DNA molecules after radiation. Our results indicate that at the radiation dose 1Gy when the relative concentration of porphyrins equals 0.01 and 0.02 per DNA base pair, the radiation effect on the DNA structure is higher than the stabilizing effect of porphyrins. At the higher value of the relative concentration of porphyrins (0.04 and 0.06) the DNA stabilizing effect is more significant than DNA damage produced by an electron beam.

On the contrary at the radiation dose equal to 2Gy the radiation effect exceeds the porphyrins stabilizing effect on DNA at all examined relative concentrations.

The experimental studies were conducted within the framework of RA MES Committee of Science Projects no 18T-1F055.

References

(ol> Y.B.Dalyan S.G.Haroutiunian, G.V.Ananyan, V.I.Vardanyan, D.Yu.Lando, V.N.Madakyan, R.K.Kazaryan, L.Messori, P. Orioli & Benight A.S. (2001). Interaction of meso-tetra-(4-N-oxyethylpyridyl) porphyrin, its 3-N analog and their metallo¬complexes with duplex DNA. Journal of Biomol. Structure & Dynamics, v.18, No.5, 677-687.

G. Ananyan A. Avetisyan, L. Aloyan & Dalyan Y. (2011). The stability of DNA–porphyrin complexes in the presence of Mn(II) ions. Biophysical Chemistry , v. 156, 96–101.

Swiderek, P., Angewandte Chemie International Edition 45, 4056, (2006).

Vrouenraets, M. B., Visser G. W., Snow G. B. and van Dongen G. A. (2003). Anticancer Research 23, (1B) 505.

Wilson B. C. (2002). Canadian Journal of Gastroenterology 16, (6) 393.

O’Connor A. E., Gallagher W. M. and Byrne A. T. (2009). Photochemistry and Photobiology 85,1053.

L.R. Aloyan
Y.B. Dalyan
S.G Haroutiunian

Yerevan State University
Al. Manoogian 1
Yerevan, 0025, Armenia

E-mail: aloyan@ysu.am