Repnyts'ka O. The structural peculiarities of nucleic acids from irradiated and tumour cells.

The genome damages and modification of the structure of nucleic acids molecules induced by such different stimuli as irradiation, tumour progression, chemicals were studied by FTIR-spectroscopy, SEIRA spectroscopy, UV-spectroscopy. Along vith traditional geometry we proposed to apply of surface enhanced infrared spectroscopy (SEIRA) of nucleic acids on gold substrate in reflectance mode and essentially increased the sensitivity of IR spectroscopy. It is shown that influence of low-doses ionizing radiation lead to damage in secondary structure as redistribution H-bonds net, disordering in structure, weakening of bonds, appearance of potential cites of breaks. The results are in accordance with the investigation of melting curves of DNA with biological-active nucleosides. The first time it was showed the difference between IR-spectra of RNA from normal and tumour tissues as well as the spectral peculiarities of RNA from tumour tissues at different stage of malignancy. It was found the number of bands that could be used as markers of tumour process. SEIRA spectra of RNA from tumour cells showed more sensitivity to the grade of tumour malignancy than the spectra of DNA. We observed a numerous changes in infrared spectra of DNA from sensitive and resistant cells that reflect drastic changes in molecular structure of DNA from tumour cells. The changes induced by anti-cancer drugs in the DNA from resistant and sensitive cancer strains was shown.