IMPACT OF ASTAXANTHIN ON MANIFESTATIONS OF THE DIRECT AND RESCUE TUMOR-INDUCED BYSTANDER EFFECT.

Objective: to investigate the reciprocal impact on the genome of malignant and normal human peripheral bloodlymphocytes under their co-culture and the possibility to modify the effects by astaxanthin.

Methods: Separate and joint/separate culturing of peripheral blood lymphocytes (PBL) of the chronic lymphocyticleukemia (CLL) patients (n = 6) and conditionally healthy individuals (n = 6), Comet assay method, fluorescencemicroscopy with automated software for the analysis of results, statistical methods.

Results: Both direct and rescue tumour-induced bystander effects were observed under the joint/separate culturing of blood lymphocytes of conditionally healthy individuals (the bystander cells) and blood cells from CLL patients(the inducer cells).

ANALYSIS OF DNA METHYLATION CHANGES IN MANIFESTATION OF DIRECT AND RESCUE BYSTANDER EFFECTS.

Objective: to investigate changes in DNA methylation in bystander and inducer cells during the manifestation ofdirect and rescue bystander effects.

Methods: Separate and co-cultivation of peripheral blood lymphocytes (PBL) of 10 conditionally healthy individuals; γ-quantum irradiation (IBL-237C emitter); modified comet electrophoresis method (Comet assay) under neutralconditions using the methylation-sensitive restriction enzyme HpaII; fluorescence microscopy with an automatedcomputer software system for analyzing the results; statistical methods.

Results: The level of DNA methylation in PBL was quantitatively assessed using DNA migration parameters inagarose gel: the length of the comet tail (in μm), the percentage of DNA in the tail part of the comet, and TailMoment (TM), which simultaneously takes into account both the amount of DNA in the tail part of the comet andthe length of the tail.

Chromosomal mutagenesis in human somatic cells: 30-year cytogenetic monitoring after Chornobyl accident.

In the lecture we have generalized and analyzed the data of cytogenetic laboratory of National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine on 30-year selective cytogenetic monitoring among the priority contingents of different ages exposed to radiation after Chornobyl accident in Ukraine. It is highlighted that not only targeted but also untargeted radiation-induced cytogenetic effects should be explored, especially in delayed terms following radiation exposure. The new methodical approaches for studying "bystander effect", individual radiosensitivity, and various forms of radiation-induced chromosomal instability (delayed, hidden, transmissible) have been proposed.

Astaxanthin modifies clastogenic effects of ionizing radiation in vitro in peripheral blood lymphocytes of the persons recovered from acute radiation sickness.

Aim: To assess radioprotective activity of astaxanthin toward radiation-induced in vitro cytogenetic effects in human peripheral blood lymphocytes (PBL).

Materials And Methods: PBL from the cleanup workers exposed to ionizing radiation at high doses in 1986 during accident on Chornobyl nuclear power plant and who were diagnosed with acute radiation sickness of the first and second degrees, were cultured in vitro. Astaxanthin was added into the culture medium at a final concentration of 20.