Objectives： To assess the genotoxic effect of a new antitumor ozone-photodynamic therapy using the improvedmodification of the COMET assay. Methods： Xenograft cancer models on 58 rats were used. The sarcoma RA was t...Objectives： To assess the genotoxic effect of a new antitumor ozone-photodynamic therapy using the improvedmodification of the COMET assay. Methods： Xenograft cancer models on 58 rats were used. The sarcoma RA was transplantedsubcutaneously, and after increasing of tumor volume from 0.5 to 4.2 cm3, rats were divided into the four groups： ＂Intact＂--healthy,＂Control＂--with xenografted tumors and no treatment, ＂PDT＂--the rats treated with the photodynamic therapy, ＂PDT ＋ozone＂--the rats were treated with both photodynamic therapy and injections of ozonated saline solution. The toxicity of treatmentwas assessed by DNA damage in leukocytes using the new modification of the COMET assay. The analysis of the ＂COMETs＂ wasperformed following the percentage of DNA in the tail of the ＂COMET＂ （% TDNA）. Results： A combination of PDT and ozonemakes the strongest negative impact on tumor growth. The tumor growth inhibition is associated with low genotoxic exposure ofozone-photodynamic therapy on whole blood leukocytes of cancer rats. Conclusions： A new modification of the COMET assay canprovide the assessment of the genotoxic effect of the antitumor therapy in experimental neoplasia.展开更多
文摘Objectives： To assess the genotoxic effect of a new antitumor ozone-photodynamic therapy using the improvedmodification of the COMET assay. Methods： Xenograft cancer models on 58 rats were used. The sarcoma RA was transplantedsubcutaneously, and after increasing of tumor volume from 0.5 to 4.2 cm3, rats were divided into the four groups： ＂Intact＂--healthy,＂Control＂--with xenografted tumors and no treatment, ＂PDT＂--the rats treated with the photodynamic therapy, ＂PDT ＋ozone＂--the rats were treated with both photodynamic therapy and injections of ozonated saline solution. The toxicity of treatmentwas assessed by DNA damage in leukocytes using the new modification of the COMET assay. The analysis of the ＂COMETs＂ wasperformed following the percentage of DNA in the tail of the ＂COMET＂ （% TDNA）. Results： A combination of PDT and ozonemakes the strongest negative impact on tumor growth. The tumor growth inhibition is associated with low genotoxic exposure ofozone-photodynamic therapy on whole blood leukocytes of cancer rats. Conclusions： A new modification of the COMET assay canprovide the assessment of the genotoxic effect of the antitumor therapy in experimental neoplasia.
