ИСТИНА

Platinum (II) complexes are widely used in the treatment of neoplastic diseases. But unfortunately they have strong side effects. Complexes based on platinum (IV) are promising antitumour compounds, because they have not only high activity, but also due to their structure reduced toxicity. In the course of the work, a new platinum (IV) complex (INC-2) with derivatives of isonicotinic acid as ligands was investigated. The aim of the study is to compare the toxicity of the INC-2 with the active antitumor drug cisplatin and determine the mechanism of its effect. The cytotoxicity of the platinum (IV) complex was determined by the MTT assay after 72 hours of the INC-2 effect on cells A-172 and HepG2 at a dose IC50. Determination of the gene expression was carried out by real-time polymerase chain reaction after 12 hours of the INC-2 effect on cells A-172 at a dose of IC50. Analysis of the cell cycle of cells A-172 affected by the INC-2 was performed using flow cytofluorimetry method by DNA staining with propidium iodide. Apoptotic nuclear morphology was discovered by the method of staining the nuclei of cells A-172 and HepG2 with a DAPI. The effect of the INC-2 on the oxidative stress of cells was also studied by detection of reactive oxygen species in the cells of A-172 and HepG2 affected by the INC-2 using the DCFDA. It was investigated, that platinum (IV) complex is substantially less cytotoxic for A-172 and HepG2 cell cultures than cisplatin. Ligands of the INC-2 did not have a cytotoxic effect. Analysis of the cell cycle indicates the stopping of the cell cycle and the induction of cell death. The obtained data confirm the results of gene expression. It was found that the INC-2 in the A-172 cells causes significant activation of the expression of the cell cycle stopping gene P21 and the pro-apoptotic gene NOXA. Similarly, apoptotic nuclear morphology was investigated in fixed cell nuclei affected by the INC-2. It was found that the INC-2 causes oxidative stress in cells. The increased content of reactive oxygen species in the cell leads to the activation of a programmable cell death - apoptosis. In conclusion, it was shown that the platinum(IV) complex INC-2 is promising for further study of antitumor activity. Understanding the mechanisms of INC-2 action is beneficial to the development of new cancer treatment drugs. The work was carried out in the Molecular biology laboratory of IPCP RAS under supervision of A.A. Balakina.